Abstract
The American Society of Anesthesiologists Committee on Standards and Practice Parameters and the Task Force on Neuraxial Opioids and the American Society of Regional Anesthesia and Pain Medicine present an updated report of the Practice Guidelines for the Prevention, Detection, and Management of Respiratory Depression Associated with Neuraxial Opioid Administration.
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PRACTICE guidelines are systematically developed recommendations that assist the practitioner and patient in making decisions about health care. These recommendations may be adopted, modified, or rejected according to the clinical needs and constraints and are not intended to replace local institutional policies. In addition, practice guidelines developed by the American Society of Anesthesiologists (ASA) are not intended as standards or absolute requirements, and their use cannot guarantee any specific outcome. Practice guidelines are subject to revision as warranted by the evolution of medical knowledge, technology, and practice. They provide basic recommendations that are supported by a synthesis and analysis of the current literature, expert and practitioner opinion, open-forum commentary, and clinical feasibility data.
This document updates the “Guidelines for the Prevention, Detection, and Management of Respiratory Depression Associated with Neuraxial Opioid Administration: An Updated Report by the ASA Task Force on Neuraxial Opioids,” adopted by ASA in 2008 and published in 2009.†
What other guidelines are available on this topic?
These practice guidelines update the “Practice Guidelines for the Prevention, Detection, and Management of Respiratory Depression Associated with Neuraxial Opioid Administration: An Updated Report by the American Society of Anesthesiologists Task Force on Neuraxial Opioids,” adopted by the American Society of Anesthesiologists (ASA) in 2008 and published in 2009.1
Few guidelines on the topic of respiratory depression associated with neuraxial opioids are available, and none have comprehensively identified patients at risk for respiratory depression, or developed strategies for the prevention, detection, and management of respiratory depression associated with neuraxial opioids.
Why was this guideline developed?
In October 2014, the ASA Committee on Standards and Practice Parameters, in collaboration with the American Society of Regional Anesthesia and Pain Medicine, elected to collect new evidence to determine whether recommendations in the existing practice guidelines continue to be supported by current evidence. The resultant guidelines, presented in this issue, incorporate an analysis of current scientific literature and survey results.
How does this statement differ from existing guidelines?
This statement presents new findings from the scientific literature since 2008 and from surveys of both expert consultants and randomly selected ASA members.
These practice guidelines are developed as a collaborative effort between the ASA and the American Society of Regional Anesthesia and Pain Medicine.
These guidelines include specific recommendations in four areas:
1. Identification of patients at increased risk of respiratory depression, with specific recommendations for focused history and physical examination.
2. Strategies for the prevention of respiratory depression after neuraxial opioid depression, including recommendations for drug selection and dose selection.
3. Detection of respiratory depression through monitoring for adequacy of ventilation, oxygenation, and level of consciousness.
4. Management and treatment of respiratory depression with recommendations regarding the administration of supplemental oxygen, reversal agents, and application of noninvasive positive pressure ventilation.
Why does the statement differ from existing guidelines?
Methodology
Definitions of Neuraxial Opioid Analgesia and Respiratory Depression
Neuraxial opioid analgesia refers to the epidural or spinal administration of opioids, including single injection, continuous or intermittent infusion, and patient-controlled analgesia. For these guidelines, respiratory depression may be indicated by (1) reduced respiratory rate (e.g., to less than 10 breaths/min), (2) reduced oxygen saturation (e.g., arterial oxygen saturation less than 90%), or (3) hypercapnia/hypercarbia (e.g., arterial carbon dioxide tension more than 50 mmHg). Other measures of respiratory function (e.g., tidal volume) or clinical signs (e.g., drowsiness, sedation, periodic apnea, cyanosis) may also provide indications of respiratory depression.
Purposes of the Guidelines
The purposes of these updated guidelines are to improve patient safety and enhance the quality of anesthetic care by reducing the incidence and the severity of neuraxial opioid-related respiratory depression or hypoxemia. In addition, these guidelines are intended to reduce the incidence and severity of adverse outcomes related to reduced respiratory rate or oxygen levels (e.g., cardiac arrest, brain damage, death).
Focus
These updated guidelines focus on the management of all patients receiving epidural or spinal opioids in inpatient (e.g., operating rooms, intensive care units, labor and delivery suites, postoperative surgical floors, hospital wards) or ambulatory (e.g., stand-alone outpatient facilities) settings. These guidelines do not apply to patients with chronic or cancer pain (except those with acute postoperative pain), patients with preexisting implantable drug delivery systems, or patients with contraindications to spinal or epidural opioids (e.g., coagulopathy, sepsis).
Application
These updated guidelines are intended for use by anesthesiologists. They also may serve as a resource for other physicians administering neuraxial opioids and other healthcare providers involved in the management of patients receiving neuraxial opioids.
Task Force Members and Consultants
In 2014, the ASA Committee on Standards and Practice Parameters requested that the updated guidelines published in 2009 be reevaluated. This current update consists of a literature evaluation, new surveys, and an update of the evidence-based guideline nomenclature. A summary of recommendations is found in appendix 1.
This update was developed by an ASA-appointed Task Force of 10 members, including anesthesiologists in both private and academic practice from various geographic areas of the United States and consulting methodologists from the ASA Committee on Standards and Practice Parameters.
The Task Force developed these updated guidelines by means of a seven-step process. First, they reached consensus on the criteria for evidence. Second, original published research studies from peer-reviewed journals relevant to neuraxial opioid administration were reviewed and evaluated. Third, expert consultants were asked to (1) participate in opinion surveys on the effectiveness of various neuraxial opioid management strategies and (2) review and comment on a draft of the guidelines developed by the Task Force. Fourth, opinions about the guideline recommendations were solicited from a random sample of active members of the ASA. Fifth, the Task Force held an open forum at a major national meeting‡ to solicit input on its draft recommendations. Sixth, the consultants were surveyed to assess their opinions on the feasibility of implementing the updated guidelines. Seventh, all available information was used to build consensus within the Task Force to finalize the updated guidelines (appendix 1).
Availability and Strength of Evidence
Preparation of these guidelines followed a rigorous methodological process. Evidence was obtained from two principal sources: scientific evidence and opinion-based evidence (appendix 2).
Scientific Evidence.
Scientific evidence used in the development of these updated guidelines is based on the cumulative findings from literature published in peer-reviewed journals. Literature citations are obtained from PubMed and other healthcare databases, direct Internet searches, Task Force members, liaisons with other organizations, and from manual searches of references located in reviewed articles.
Findings from the aggregated literature are reported in the text of the guidelines by evidence category, level, and direction. Evidence categories refer specifically to the strength and quality of the research design of the studies. Category A evidence represents results obtained from randomized-controlled trials (RCTs), and Category B evidence represents observational results obtained from nonrandomized study designs or RCTs without pertinent comparison groups. When available, Category A evidence is given precedence over Category B evidence for any particular outcome. These evidence categories are further divided into evidence levels. Evidence levels refer specifically to the strength and quality of the summarized study findings (i.e., statistical findings, type of data, and the number of studies reporting/replicating the findings within the two evidence categories). In this document, only the highest level of evidence is included in the summary report for each intervention–outcome pair, including a directional designation of benefit, harm, or equivocality for each outcome.
Category A.
RCTs report comparative findings between clinical interventions for specified outcomes. Statistically significant (P < 0.01) outcomes are designated as either beneficial (B) or harmful (H) for the patient; statistically nonsignificant findings are designated as equivocal (E).
Level 1: The literature contains a sufficient number of RCTs to conduct meta-analysis,§ and meta-analytic findings from these aggregated studies are reported as evidence.
Level 2: The literature contains multiple RCTs, but the number of RCTs is not sufficient to conduct a viable meta-analysis for the purpose of these updated guidelines. Findings from these RCTs are reported separately as evidence.
Level 3: The literature contains a single RCT, and findings are reported as evidence.
Category B.
Observational studies or RCTs without pertinent comparison groups may permit inference of beneficial or harmful relationships among clinical interventions and clinical outcomes. Inferred findings are given a directional designation of beneficial (B), harmful (H), or equivocal (E). For studies that report statistical findings, the threshold for significance is P < 0.01.
Level 1: The literature contains observational comparisons (e.g., cohort, case-control research designs) with comparative statistics between clinical interventions for a specified clinical outcome.
Level 2: The literature contains noncomparative observational studies with associative statistics (e.g., relative risk, correlation, sensitivity/specificity).
Level 3: The literature contains noncomparative observational studies with descriptive statistics (e.g., frequencies, percentages).
Level 4: The literature contains case reports.
Insufficient Literature.
The lack of sufficient scientific evidence in the literature may occur when the evidence is either unavailable (i.e., no pertinent studies found) or inadequate. Inadequate literature cannot be used to assess relationships among clinical interventions and outcomes because a clear interpretation of findings is not obtained due to methodological concerns (e.g., confounding of study design or implementation), or the study does not meet the criteria for content as defined in the “Focus” of the guidelines.
Opinion-based Evidence.
All opinion-based evidence (e.g., survey data, open-forum testimony, Internet-based comments, letters, and editorials) relevant to each topic was considered in the development of these updated guidelines. However, only the findings obtained from formal surveys are reported in the current update.
Opinion surveys were developed by the Task Force to address each clinical intervention identified in the document. Identical surveys were distributed to expert consultants and a random sample of ASA members.
Category A: Expert Opinion.
Survey responses from Task Force–appointed expert consultants are reported in a summary form in the text, with a complete listing of consultant survey responses reported in appendix 2.
Category B: Membership Opinion.
Survey responses from active ASA members are reported in a summary form in the text, with a complete listing of ASA member survey responses reported in appendix 2.
Survey responses from expert and membership sources are recorded using a five-point scale and summarized based on the median values.‖
Strongly Agree: Median score of 5 (at least 50% of the responses are 5)
Agree: Median score of 4 (at least 50% of the responses are 4 or 4 and 5)
Equivocal: Median score of 3 (at least 50% of the responses are 3, or no other response category or combination of similar categories contain at least 50% of the responses)
Disagree: Median score of 2 (at least 50% of responses are 2 or 1 and 2)
Strongly Disagree: Median score of 1 (at least 50% of responses are 1)
Category C: Informal Opinion.
Open-forum testimony obtained during development of these guidelines, Internet-based comments, letters, and editorials are all informally evaluated and discussed during the formulation of guideline recommendations. When warranted, the Task Force may add educational information or cautionary notes based on this information.
Guidelines
Identification of Patients at Increased Risk of Respiratory Depression
Identification of patients with risk factors for respiratory depression includes conducting a focused history (e.g., reviewing medical records) and physical examination.
Literature Findings.
Although it is well-accepted clinical practice to review the medical records and conduct a physical examination, comparative studies are insufficient to directly evaluate the impact of these practices. Studies with observational findings and case reports suggest that certain patient or clinical characteristics (e.g., obesity, obstructive sleep apnea, coexisting disease) may be associated with respiratory depression when neuraxial opioids are used (Category B1/B4-H evidence).1–5
Survey Findings.
Both the consultants and the ASA members strongly agree that (1) a focused history and physical examination should be conducted before administering neuraxial opioids, (2) particular attention should be directed toward signs, symptoms, or a history of sleep apnea; co-existing diseases or conditions; current medications; and adverse effects after opioid administration, and (3) a physical examination should include, but is not limited to, baseline vital signs, airway, heart, lung, and cognitive function.
Recommendations for Identification of Patients at Increased Risk of Respiratory Depression
Conduct a focused history and physical examination before administering neuraxial opioids.
Direct particular attention should be directed toward signs, symptoms, or a history of sleep apnea; co-existing diseases or conditions (e.g., diabetes, obesity); current medications (including preoperative opioids); and adverse effects after opioid administration.
A physical examination should include, but is not limited to, baseline vital signs, airway, heart, lung, and cognitive function.
Prevention of Respiratory Depression after Neuraxial Opioid Administration
Prevention of respiratory depression includes consideration of noninvasive positive pressure ventilation and drug selection.
Noninvasive Positive Pressure Ventilation.
Literature Findings:
The literature is insufficient to assess the efficacy of noninvasive positive pressure ventilation when used for the prevention of respiratory depression in patients who have been administered neuraxial opioids.
Survey Findings:
Both the consultants and the ASA members strongly agree that patients with a history of sleep apnea treated with noninvasive positive airway pressure should be encouraged to bring their own equipment to the hospital.
Drug Selection.
Drug selection includes (1) route of administration, (2) type of drug, (i.e., hydrophilic or lipophilic opioids), (3) dose selection, and (4) drug combinations.
Route of Administration:
Routes of administration considered by these guidelines include (1) single-injection neuraxial opioids compared with parenteral opioids, (2) continuous infusion epidural (CIE) opioids compared with parenteral opioids, and (3) extended-release epidural morphine.
Literature Findings for Single-injection Neuraxial Opioids Compared with Parenteral Opioids:
Meta-analysis of RCTs indicates no significant difference in the frequency of respiratory depression (Category A1-E evidence) and less somnolence or sedation (Category A1-B evidence) for single-injection epidural opioids compared with intramuscular opioids.6–13 Additional RCTs comparing single-injection epidural opioids with intravenous opioids report inconsistent findings regarding respiratory depression, respiratory failure, somnolence, or sedation (Category A2-E evidence).14–19 RCTs comparing patient-controlled epidural opioids (PCEAs) with intravenous patient-controlled analgesia opioids are equivocal regarding respiratory depression and hypoxemia (Category A2-E evidence).20–23 An RCT comparing intrathecal sufentanil with intravenous sufentanil reports equivocal findings for respiratory depression and hypoxemia (Category A1-E evidence).24
Insufficient literature was found comparing single-injection neuraxial opioids with other systemic routes of administration (e.g., oral, transdermal, rectal, nasal).
Literature Findings for Continuous Infusion Epidural Opioids Compared with Parenteral Opioids:
Meta-analysis of RCTs indicate less respiratory depression when continuous infusion of epidural opioids are compared with intravenous infusion of opioids (Category A1-B evidence).25–29 RCTs evaluating differences in hypercarbia are equivocal (Category A2-E evidence).28–31 Meta-analysis findings from RCTs evaluating differences in somnolence or sedation are equivocal (Category A1-E evidence).25,32–35
Literature Findings for Extended-release Epidural Morphine:
A single RCT reports no significant difference in the frequency of respiratory depression when extended-release epidural morphine is compared with intravenous patient-controlled analgesia morphine (Category C2-E evidence).36 In addition, RCTs report no significant differences in respiratory depression, hypoxia, and sedation or somnolence when extended-release epidural morphine is compared with conventional (i.e., immediate-release) epidural morphine (Category C2-E evidence).37–39
Survey Findings for Route of Administration:
The consultants agree and the ASA members neither agree nor disagree that single-injection neuraxial opioids may be safely used in place of parenteral opioids without altering the risk of respiratory depression. Both the consultants and the ASA members neither agree nor disagree that single-injection neuraxial fentanyl or sufentanil may be safe alternatives to single-injection neuraxial morphine. Both the consultants and the ASA members agree that, when clinically suitable, extended-release epidural morphine may be used in place of intravenous or conventional (i.e., immediate-release) epidural morphine, although extended monitoring may be required. Both the consultants and the ASA members neither agree nor disagree that continuous epidural opioids are preferred to parenteral opioids for anesthesia and analgesia for reducing the risk of respiratory depression.
Type of Drug (i.e., Hydrophilic or Lipophilic Opioids):
Hydrophilic or lipophilic opioids considered by these guidelines include (1) single-injection epidural hydrophilic versus lipophilic opioids, (2) single-injection intrathecal hydrophilic versus lipophilic opioids, and (3) CIE hydrophilic versus lipophilic opioids.
Literature Findings:
RCTs report no differences in the frequency of respiratory depression, ventilatory response to carbon dioxide, somnolence or sedation when single-injection morphine is compared with single-injection fentanyl or sufentanil, administered by either an epidural or an intrathecal route (Category A2-E evidence).40–44 RCT findings for respiratory depression are inconsistent when comparing continuous epidural administration of morphine with fentanyl or sufentanil (Category A2-E evidence)45–48 ; RCT findings for hypoxemia and hypercarbia are equivocal (Category A2-E evidence).47,49 In addition, RCT findings for sedation or somnolence are equivocal (Category A2-E evidence).45–47,50,51
Survey Findings for Type of Drug:
Both the consultants and the ASA members agree that, when clinically suitable, appropriate doses of continuous epidural infusion of fentanyl or sufentanil may be used in place of continuous infusion of morphine or hydromorphone without increasing the risk of respiratory depression. The ASA members agree and the consultants strongly agree that, given the unique pharmacokinetic effect of the various neuraxially administered opioids, appropriate duration of monitoring should be matched with the drug. Both the consultants and the ASA members strongly agree that, based on the duration of action of hydrophilic opioids, neuraxial morphine or hydromorphone should not be administered to outpatient surgical patients.
Dose Selection (i.e., Low-dose Compared with High-dose Neuraxial Opioids):
Literature Findings:
Meta-analysis of RCTs indicates that the frequency of respiratory depression is reduced when lower doses of single-injection epidural morphine or sufentanil are compared with higher doses (Category A1-B evidence).37,52–55 RCTs are equivocal regarding respiratory depression, frequency of hypoxemia, hypercarbia, and sedation or somnolence when lower doses of single-injection intrathecal opioids are compared with higher doses (Category A1-E evidence).56–62 An RCT reports equivocal findings for respiratory depression, and another RCT reports equivocal findings for sedation when higher doses of continuous infusion of epidural fentanyl are compared with lower doses (Category A3-E evidence).63,64
Survey Findings for Dose Selection:
Both the consultants and the ASA members strongly agree that the lowest efficacious dose of neuraxial opioids should be administered to minimize the risk of respiratory depression.
Drug Combinations:
Neuraxial Opioids Combined with Parenteral Opioids or Hypnotics:
Literature Findings:
The literature is insufficient to assess whether the addition of parenteral opioids, hypnotics, or dissociative anesthetics (e.g., ketamine) to neuraxial opioids is associated with increased occurrence of respiratory depression or hypoxemia.
Survey Findings for Drug Combinations:
Both the consultants and the ASA members strongly agree that (1) parenteral opioids or hypnotics should be administered cautiously in the presence of neuraxial opioids and (2) the concomitant administration of neuraxial opioids and parenteral opioids, sedatives, hypnotics, or magnesium requires increased monitoring (e.g., intensity, duration, or additional methods of monitoring).
Recommendations for Prevention of Respiratory Depression
Noninvasive Positive Pressure Ventilation.
Encourage patients with a history of sleep apnea treated with noninvasive positive airway pressure to bring their own equipment to the hospital.
Route of Administration.
Single-injection neuraxial opioids may be safely used in place of parenteral opioids without altering the risk of respiratory depression or hypoxemia.
Single-injection neuraxial fentanyl or sufentanil may be safe alternatives to single-injection neuraxial morphine.
When clinically suitable, extended-release epidural morphine may be used in place of intravenous or conventional (i.e., immediate-release) epidural morphine, although extended monitoring may be required.
Continuous epidural opioids are preferred to parenteral opioids for anesthesia and analgesia for reducing the risk of respiratory depression.
Type of Drug.
When clinically suitable, appropriate doses of continuous epidural infusion of fentanyl or sufentanil may be used in place of continuous infusion of morphine or hydromorphone without increasing the risk of respiratory depression.
Given the unique pharmacokinetic effect of the various neuraxially administered opioids, match the appropriate duration of monitoring with the drug.
Based on the duration of action of hydrophilic opioids, do not administer neuraxial morphine or hydromorphone to outpatient surgical patients.
Dose Selection.
Administer the lowest efficacious dose of neuraxial opioids to minimize the risk of respiratory depression.
Drug Combinations.
Administer parenteral opioids or hypnotics cautiously in the presence of neuraxial opioids.
The concomitant administration of neuraxial opioids and parenteral opioids, sedatives, hypnotics, or magnesium requires increased monitoring (e.g., intensity, duration, or additional methods of monitoring).
Monitoring for Respiratory Depression
Respiratory depression monitoring includes (1) consideration of techniques to detect respiratory depression and (2) perioperative monitoring for respiratory depression.
Techniques to Detect Respiratory Depression.
Detection of respiratory depression includes measurement of (1) oxygen saturation levels, (2) carbon dioxide levels, and (3) level of sedation.
Literature Findings:
RCTs have shown pulse oximetry to be effective in detecting hypoxemia in patients receiving a variety of anesthetics, including neuraxial techniques.65–69 However, these studies do not provide separate data for neuraxial opioid anesthesia. Although the literature is insufficient to evaluate carbon dioxide monitoring for neuraxial opioids, literature reporting end-tidal carbon dioxide monitoring for parenteral opioids suggest that such monitoring is effective in detecting hypercapnia or hypercarbia.# The literature is insufficient regarding whether monitoring patient level of sedation reduces the risk of respiratory depression. The literature is insufficient regarding whether continuous monitoring with pulse oximetry, electrocardiogram, or ventilation is associated with improved detection of respiratory depression or hypoxemia for patients administered neuraxial opioids.
Survey Findings for Detection of Respiratory Depression:
Both the consultants and the ASA members strongly agree that (1) all patients receiving neuraxial opioids should be monitored for adequacy of ventilation, oxygenation, and level of consciousness and (2) increased monitoring may be warranted in patients at increased risk of respiratory depression.
Perioperative Monitoring for Respiratory Depression.
Perioperative monitoring for respiratory depression includes (1) monitoring after administration of single-injection neuraxial lipophilic opioids, (2) monitoring during or after continuous infusion or PCEA with neuraxial lipophilic opioids, (3) monitoring after administration of single-injection neuraxial hydrophilic opioids, and (4) monitoring during or after continuous infusion or PCEA with neuraxial hydrophilic opioids.
Monitoring after Administration of Single-injection Neuraxial Lipophilic Opioids.
Literature findings:
The literature is insufficient to assess whether any time interval is optimal for detecting respiratory depression or reducing risks associated with respiratory depression.
Survey findings:
Both the consultants and the ASA members agree that (1) monitoring should be performed for a minimum of 2 h after administration, (2) continual (i.e., repeated regularly and frequently in steady rapid succession) monitoring should be performed for the first 20 min after administration, followed by monitoring at least once per hour until 2 h have passed, and (3) after 2 h, frequency of monitoring should be dictated by the patient’s overall clinical condition and concurrent medications.
Monitoring during or after CIE or PCEA with Neuraxial Lipophilic Opioids.
Literature findings:
The literature is insufficient to assess whether any time interval is optimal for detecting respiratory depression or reducing risks associated with respiratory depression.
Survey findings:
Both the consultants and the ASA members strongly agree that monitoring should be performed during the entire time the infusion is in use. They also agree that (1) monitoring should be continual for the first 20 min after initiation, followed by monitoring at least once per hour until 12 h have passed, (2) from 12 to 24 h, monitoring should be performed at least once every 2 h, and after 24 h, monitoring should be performed at least once every 4 h, and (3) after discontinuation of CIE opioids or PCEA with neuraxial lipophilic opioids, the frequency of monitoring should be dictated by the patient’s overall clinical condition and concurrent medications.
Monitoring after Administration of Single-injection Neuraxial Hydrophilic Opioids (not including Sustained or Extended-release Epidural Morphine).
Literature findings:
The literature is insufficient to assess whether any time interval is optimal for detecting respiratory depression or reducing risks associated with respiratory depression.
Survey findings:
Both the consultants and the ASA members agree that (1) monitoring should be performed for a minimum of 24 h after administration and (2) monitoring should be performed at least once per hour for the first 12 h after administration, followed by monitoring at least once every 2 h for the next 12 h (i.e., from 12 to 24 h). The ASA members agree and the consultants strongly agree that after 24 h, the frequency of monitoring should be dictated by the patient’s overall clinical condition and concurrent medications.
Monitoring during or after Continuous Infusion or PCEA with Neuraxial Hydrophilic Opioids.
Literature findings:
The literature is insufficient to assess whether any time interval is optimal for detecting respiratory depression or reducing risks associated with respiratory depression.
Survey findings:
Both the consultants and the ASA members strongly agree that monitoring should be performed during the entire time the infusion is in use. Further, both the consultants and the ASA members agree that (1) monitoring at least once every hour should be performed for the first 12 h after initiation, followed by monitoring at least once every 2 h for the next 12 h and (2) after 24 h, monitoring should be performed at least once every 4 h. The ASA members agree and the consultants strongly agree that after discontinuation of continuous infusion or PCEA, the frequency of monitoring should be dictated by the patient’s overall clinical condition and concurrent medications.
Monitoring after Administration of Sustained or Extended-release Epidural Morphine.
Literature findings:
The literature is insufficient to assess whether any time interval is optimal for detecting respiratory depression or reducing the risks associated with respiratory depression.
Survey findings:
Both the consultants and the ASA members agree that (1) monitoring at least once every hour should be performed during the first 12 h after administration and at least once every 2 h for the next 12 h (i.e., 12 to 24 h) and (2) after 24 h, monitoring should be performed at least once every 4 h for a minimum of 48 h.
Recommendations for Detection and Monitoring for Respiratory Depression
Monitor all patients receiving neuraxial opioids for adequacy of ventilation (e.g., respiratory rate, depth of respiration [assessed without disturbing a sleeping patient]), oxygenation (e.g., pulse oximetry when appropriate), and level of consciousness.**
Increased monitoring (e.g., intensity, duration, or additional methods of monitoring) may be warranted for patients at increased risk of respiratory depression (e.g., unstable medical condition, obesity, obstructive sleep apnea,†† concomitant administration of opioid analgesics or hypnotics by other routes, extremes of age).
Single-injection Neuraxial Lipophilic Opioids (e.g., Fentanyl).
Monitor for a minimum of 2 h after administration.
Monitor continually (i.e., repeated regularly and frequently in steady rapid succession‡‡) for the first 20 min after administration, followed by monitoring at least once per hour until 2 h have passed.§§
After 2 h, frequency of monitoring should be dictated by the patient’s overall clinical condition and concurrent medications.
Continuous Infusion or PCEA with Neuraxial Lipophilic Opioids.
Monitor during the entire time the infusion is in use.
Monitor continually for the first 20 min after initiation, followed by monitoring at least once per hour until 12 h have passed.
From 12 to 24 h, monitor at least once every 2 h, and after 24 h, monitor at least once every 4 h.
After discontinuation of continuous infusion or PCEA with neuraxial lipophilic opioids, frequency of monitoring should be dictated by the patient’s overall clinical condition and concurrent medications.
Single-injection Neuraxial Hydrophilic Opioids (e.g., Morphine, not Including Sustained or Extended-release Epidural Morphine).
Monitor for a minimum of 24 h after administration.
Monitor at least once per hour for the first 12 h after administration, followed by monitoring at least once every 2 h for the next 12 h (i.e., from 12 to 24 h).
After 24 h, frequency of monitoring should be dictated by the patient’s overall clinical condition and concurrent medications.
Continuous Infusion or PCEA with Neuraxial Hydrophilic Opioids.
Monitor during the entire time the infusion is in use.
Monitor at least once every hour for the first 12 h after initiation, followed by monitoring at least once every 2 h for the next 12 h.
After 24 h, monitor at least once every 4 h.
After discontinuation of continuous infusion or PCEA, frequency of monitoring should be dictated by the patient’s overall clinical condition and concurrent medications.
Sustained or Extended-release Epidural Morphine.
Monitor at least once every hour during the first 12 h after administration and at least once every 2 h for the next 12 h (i.e., 12 to 24 h).
After 24 h, monitor at least once every 4 h for a minimum of 48 h.
Management and Treatment of Respiratory Depression
Interventions for management and treatment for respiratory depression considered by these guidelines include (1) supplemental oxygen, (2) reversal agents, and (3) noninvasive positive pressure ventilation.
Supplemental Oxygen.
Literature Findings:
The literature is insufficient to assess whether supplemental oxygen will reduce the frequency or severity of hypoxia or hypoxemia when neuraxial opioids are administered. Other literature supports the use of supplemental oxygen when nonneuraxial anesthetic techniques (e.g., general anesthesia, sedation, and analgesia) are administered.‖‖
Survey Findings:
The consultants agree and ASA members strongly agree that, for patients receiving neuraxial opioids, supplemental oxygen should be available. Both the consultants and the ASA members strongly agree that supplemental oxygen should be administered to patients with altered level of consciousness, respiratory depression, or hypoxemia and continued until the patient is alert and no respiratory depression or hypoxemia is present.
Reversal Agents.
Literature Findings:
Although there are insufficient comparative studies to assess the efficacy of naloxone or naltrexone to treat respiratory depression in patients administered neuraxial opioids, case reports suggest an association between the administration of naloxone and reversal of opioid-induced respiratory depression (Category B3-B evidence).70–79 RCTs comparing naloxone80,81 or naltrexone82–84 with placebo are equivocal regarding preprocedure prophylaxis for respiratory depression, hypoxemia, sedation, or somnolence (Category A2-E evidence). Other literature supports the use of naloxone for respiratory depression when systemic opioids are administered.#
Survey Findings for Reversal Agents:
Both the consultants and the ASA members strongly agree that (1) intravenous access should be maintained if recurring respiratory depression occurs and (2) reversal agents should be available for administration to all patients experiencing significant respiratory depression after neuraxial opioid administration.
Noninvasive Positive Pressure Ventilation.
Literature Findings:
The literature is insufficient to assess the efficacy of noninvasive positive pressure ventilation to manage patients who have been administered neuraxial opioids. Other literature supports the use of noninvasive positive pressure ventilation for patients with respiratory compromise.##
Survey Findings for Noninvasive Positive Pressure Ventilation:
Both the consultants and the ASA members strongly agree that (1) noninvasive positive pressure ventilation may be considered for improving ventilatory status and (2) if frequent or severe airway obstruction or hypoxemia occurs during postoperative monitoring, initiate noninvasive positive pressure ventilation.
Recommendations for Management and Treatment of Respiratory Depression
For patients receiving neuraxial opioids, supplemental oxygen should be available.
Administer supplemental oxygen to patients with altered level of consciousness, respiratory depression, or hypoxemia and continue until the patient is alert and no respiratory depression or hypoxemia is present.***
Maintain intravenous access if recurring respiratory depression occurs.
Reversal agents should be available for administration to all patients experiencing significant respiratory depression after neuraxial opioid administration.
In the presence of severe respiratory depression, initiate appropriate resuscitation.
Noninvasive positive pressure ventilation may be considered for improving ventilatory status.
If frequent or severe airway obstruction or hypoxemia occurs during postoperative monitoring, initiate noninvasive positive pressure ventilation.
Acknowledgments
Support was provided solely from institutional and/or departmental sources.
Competing Interests
The authors declare no competing interests.
Updated by the American Society of Anesthesiologists Committee on Standards and Practice Parameters: Jeffrey L. Apfelbaum, M.D. (Committee Chair), Chicago, Illinois; Terese T. Horlocker, M.D. (Task Force Chair), Rochester, Minnesota; Madhulika Agarkar, M.P.H., Schaumburg, Illinois; Richard T. Connis, Ph.D., Woodinville, Washington; James R. Hebl, M.D., Rochester, Minnesota; David G. Nickinovich, Ph.D., Bellevue, Washington; Craig M. Palmer, M.D., Tucson, Arizona; James P. Rathmell, M.D., Boston, Massachusetts; Richard W. Rosenquist, M.D., Iowa City, Iowa; and Christopher L. Wu, M.D., Clarksville, Maryland.
Practice guidelines for the prevention, detection and management of respiratory depression associated with neuraxial opioid administration: An updated report by the American Society of Anesthesiologists Task Force on Neuraxial Opioids. Anesthesiology 2009; 110:218–30.
American Society of Regional Anesthesia and Pain Medicine, 40th Annual Meeting, Las Vegas, Nevada, May 15, 2015.
All meta-analyses are conducted by the ASA methodology group. Meta-analyses from other sources are reviewed but not included as evidence in this document.
When an equal number of categorically distinct responses are obtained, the median value is determined by calculating the arithmetic mean of the two middle values. Ties are calculated by a predetermined formula.
American Society of Anesthesiologists Task Force on Sedation and Analgesia by Non-Anesthesiologists. Practice guidelines for sedation and analgesia by non-anesthesiologists. Anesthesiology 2002; 96:1004–17.
In cases with other concerning signs, it is acceptable to awaken a sleeping patient to assess level of consciousness.
“Hospitalized patients who are at an increased risk of respiratory compromise from OSA [obstructive sleep apnea] should have continuous pulse oximetry monitoring after discharge from the recovery room. Continuous monitoring may be provided in a critical care or step-down unit, by telemetry on a hospital ward or by a dedicated, appropriately trained professional observer in the patient’s room. Continuous monitoring should be maintained as long as patients remain at an increased risk. Intermittent pulse oximetry or continuous bedside oximetry without continuous observation does not provide the same level of safety.” From: Gross JB, Bachenberg KL, Benumof JL, Caplan RA, Connis RT, Coté CJ, Nickinovich DG, Prachand V, Ward DS, Weaver EM, Ydens L, Yu S; American Society of Anesthesiologists Task Force on Perioperative Management of Obstructive Sleep Apnea. Practice guidelines for the perioperative management of obstructive sleep apnea: A report by the American Society of Anesthesiologists Task Force on Perioperative Management of patients with obstructive sleep apnea. A nesthesiology 2006; 104:1081–93.
American Society of Anesthesiologists: Standards for basic anesthetic monitoring, Standards, Guidelines and Statements. 2010. Effective date July 1, 2011. Available at: http://www.asahq.org/files/public/resources/standards-guidelines/standards-for-basic-anesthetic-monitoring.pdf. Accessed November 24, 2014.
Including during transport to the postanesthesia care unit.
American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Practice guidelines for management of the difficult airway: An updated report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Anesthesiology 2003; 98:1269–77; and American Society of Anesthesiologists Task Force on Sedation and Analgesia by Non-Anesthesiologists. Practice guidelines for sedation and analgesia by non-anesthesiologists. Anesthesiology 2002; 96:1004–17.
Gross JB, Bachenberg KL, Benumof JL, Caplan RA, Connis RT, Coté CJ, Nickinovich DG, Prachand V, Ward DS, Weaver EM, Ydens L, Yu S; American Society of Anesthesiologists Task Force on Perioperative Management of Obstructive Sleep Apnea. Practice guidelines for the perioperative management of obstructive sleep apnea: A report by the American Society of Anesthesiologists Task Force on Perioperative Management of patients with obstructive sleep apnea. Anesthesiology 2006; 104:1081–93.
The Task Force cautions that routine use of supplemental oxygen may increase the duration of apneic episodes and may hinder detection of atelectasis, transient apnea, and hypoventilation.
In cases with other concerning signs, it is acceptable to awaken a sleeping patient to assess level of consciousness.
Unless otherwise specified, outcomes for the listed interventions refer to the reduction or detection of respiratory depression or hypoxemia.
References
Appendix 1: Summary of Recommendations
Identification of Patients at Increased Risk of Respiratory Depression
Conduct a focused history and physical examination before administering neuraxial opioids.
Direct particular attention toward signs, symptoms, or a history of sleep apnea, co-existing diseases or conditions (e.g., diabetes, obesity), current medications (including preoperative opioids), and adverse effects after opioid administration.
A physical examination should include, but is not limited to, baseline vital signs, airway, heart, lung, and cognitive function.
Prevention of Respiratory Depression after Neuraxial Opioid Administration
Noninvasive Positive Pressure Ventilation
Encourage patients with a history of sleep apnea treated with noninvasive positive airway pressure to bring their own equipment to the hospital.
Route of Administration
Single-injection neuraxial opioids may be safely used in place of parenteral opioids without altering the risk of respiratory depression or hypoxemia.
Single-injection neuraxial fentanyl or sufentanil may be safe alternatives to single-injection neuraxial morphine.
When clinically suitable, extended-release epidural morphine may be used in place of intravenous or conventional (i.e., immediate-release) epidural morphine, although extended monitoring may be required.
Continuous epidural opioids are preferred to parenteral opioids for anesthesia and analgesia for reducing the risk of respiratory depression.
Type of Drug
When clinically suitable, appropriate doses of continuous epidural infusion of fentanyl or sufentanil may be used in place of continuous infusion of morphine or hydromorphone without increasing the risk of respiratory depression.
Given the unique pharmacokinetic effect of the various neuraxially administered opioids, match the appropriate duration of monitoring with the drug.
Based on the duration of action of hydrophilic opioids, do not administer neuraxial morphine or hydromorphone to outpatient surgical patients.
Dose Selection
Administer the lowest efficacious dose of neuraxial opioids to minimize the risk of respiratory depression.
Drug Combinations
Administer parenteral opioids or hypnotics cautiously in the presence of neuraxial opioids.
The concomitant administration of neuraxial opioids and parenteral opioids, sedatives, hypnotics, or magnesium requires increased monitoring (e.g., intensity, duration, or additional methods of monitoring).
Monitoring for Respiratory Depression
Monitor all patients receiving neuraxial opioids for adequacy of ventilation (e.g., respiratory rate, depth of respiration [assessed without disturbing a sleeping patient]), oxygenation (e.g., pulse oximetry when appropriate), and level of consciousness.†††
Increased monitoring (e.g., intensity, duration, or additional methods of monitoring) may be warranted for patients at increased risk of respiratory depression (e.g., unstable medical condition, obesity, obstructive sleep apnea,†† concomitant administration of opioid analgesics or hypnotics by other routes, extremes of age).
Single-injection Neuraxial Lipophilic Opioids (e.g., Fentanyl)
Monitor for a minimum of 2 h after administration.
Monitor continually (i.e., repeated regularly and frequently in steady rapid succession‡‡) for the first 20 min after administration, followed by monitoring at least once per hour until 2 h have passed.
After 2 h, frequency of monitoring should be dictated by the patient’s overall clinical condition and concurrent medications.
Continuous Infusion or Patient-controlled Epidural Analgesia with Neuraxial Lipophilic Opioids
Monitor during the entire time the infusion is in use.
Monitor continually for the first 20 min after initiation, followed by monitoring at least once per hour until 12 h have passed.
From 12 to 24 h, monitor at least once every 2 h, and after 24 h, monitor at least once every 4 h.
After discontinuation of continuous infusion or patient-controlled epidural opioid (PCEA) with neuraxial lipophilic opioids, frequency of monitoring should be dictated by the patient’s overall clinical condition and concurrent medications.
Single-injection Neuraxial Hydrophilic Opioids (e.g., Morphine, not Including Sustained or Extended-release Epidural Morphine)
Monitor for a minimum of 24 h after administration.
Monitor at least once per hour for the first 12 h after administration, followed by monitoring at least once every 2 h for the next 12 h (i.e., from 12 to 24 h).
After 24 h, frequency of monitoring should be dictated by the patient’s overall clinical condition and concurrent medications.
Continuous Infusion or PCEA with Neuraxial Hydrophilic Opioids
Monitor during the entire time the infusion is in use.
Monitor at least once every hour for the first 12 h after initiation, followed by monitoring at least once every 2 h for the next 12 h.
After 24 h, monitor at least once every 4 h.
After discontinuation of continuous infusion or PCEA, frequency of monitoring should be dictated by the patient’s overall clinical condition and concurrent medications.
Sustained or Extended-release Epidural Morphine
Monitor at least once every hour during the first 12 h after administration and at least once every 2 h for the next 12 h (i.e., 12 to 24 h).
After 24 h, monitor at least once every 4 h for a minimum of 48 h.
Management and Treatment of Respiratory Depression
For patients receiving neuraxial opioids, supplemental oxygen should be available.
Administer supplemental oxygen to patients with altered level of consciousness, respiratory depression, or hypoxemia and continue until the patient is alert and no respiratory depression or hypoxemia is present.***
Maintain intravenous access if recurring respiratory depression occurs.
Reversal agents should be available for administration to all patients experiencing significant respiratory depression after neuraxial opioid administration.
In the presence of severe respiratory depression, initiate appropriate resuscitation.
Noninvasive positive pressure ventilation may be considered for improving ventilatory status.
If frequent or severe airway obstruction or hypoxemia occurs during postoperative monitoring, initiate noninvasive positive pressure ventilation.
Appendix 2: Methods and Analyses
For these updated guidelines, a review of studies used in the development of the previous update was combined with studies published subsequent to approval of the update in 2008. The scientific assessment of these guidelines was based on the evidence linkages or statements regarding potential relationships between clinical interventions and outcomes. The interventions listed below were examined to assess their impact on a variety of outcomes related to respiratory depression related to neuraxial opioid anesthesia and analgesia.‡‡‡
Identification of Patients at Increased Risk of Respiratory Depression
Medical records review (focused history)
Physical examination
Prevention of Respiratory Depression
Positive pressure ventilation
Drug selection
Route of administration
Single-injection neuraxial opioids versus parenteral opioids
Extended-release epidural morphine versus parenteral morphine
Extended-release epidural morphine versus immediate-release epidural morphine
Continuous infusion epidural (CIE) opioids versus parenteral opioids
Type of drug
Single-injection epidural hydrophilic opioids (e.g., morphine, hydromorphone) versus lipophilic opioids (e.g., fentanyl/sufentanil).
Single-injection intrathecal hydrophilic opioids versus lipophilic opioids
CIE hydrophilic opioids versus lipophilic opioids
Dose selection
High versus low doses of single-injection/single-dose epidural opioids (i.e., morphine, hydromorphone, fentanyl, or sufentanil)
High versus low doses of single-injection/single-dose intrathecal opioids
High versus low doses of CIE opioids
Single-injection/single-dose epidural morphine versus extended-release epidural morphine
Dose reduction versus cessation of opioids
Drug combinations
Neuraxial opioids with versus without parenteral opioids or hypnotics
Monitoring for Respiratory Depression
Detection of respiratory depression
Pulse oximetry monitoring
End-tidal carbon dioxide monitoring
Monitoring level of sedation
Timing and duration of monitoring
Continuous versus intermittent monitoring
Management of Respiratory Depression
Supplemental oxygen
Reversal drugs
Naloxone versus no naloxone
Naltrexone versus no naltrexone
Positive pressure ventilation
State of the Literature
For the literature review, potentially relevant clinical studies were identified through electronic and manual searches of the literature. The updated searches covered an 8-yr period from January 1, 2008 through July 31, 2015. New citations were reviewed and combined with pre-2008 articles used in the previous update, resulting in a total of 590 articles reviewed; 167 were found to contain direct linkage-related evidence. Search terms consisted of the interventions indicated above guided by the appropriate inclusion/exclusion criteria as stated in the “Focus” section of these Guidelines. Only studies containing original findings from peer-review journals were acceptable. Editorials, letters, and other articles without data were excluded. A complete bibliography used to develop these guidelines, organized by section, is available as Supplemental Digital Content 2, https://links.lww.com/ALN/B236.
Each pertinent outcome reported in a study was classified by evidence category and level, and designated as either beneficial, harmful, or equivocal. Findings were then summarized for each evidence linkage. Literature pertaining to three evidence linkages contained enough studies with well-defined experimental designs and statistical information sufficient to conduct meta-analyses (table 1). These linkages were as follows: (1) single-injection epidural opioids versus intramuscular opioids, (2) CIE opioids versus intravenous opioid infusion, and (3) low versus high doses of single-injection epidural opioids.
General variance-based effect-size estimates or combined probability tests were obtained for continuous outcome measures, and Mantel–Haenszel odds ratios were obtained for dichotomous outcome measures. Two combined probability tests were employed as follows: (1) the Fisher combined test, producing chi-square values based on the logarithmic transformations of the reported P values from the independent studies and (2) the Stouffer combined test, providing weighted representation of the studies by weighting each of the standard normal deviates by the size of the sample. An odds ratio procedure based on the Mantel–Haenszel method for combining study results using 2 × 2 tables was used with outcome frequency information. An acceptable significance level was set at P < 0.01 (one tailed). Tests for heterogeneity of the independent studies were conducted to assure consistency among the study results. DerSimonian–Laird random-effects odds ratios were obtained when significant heterogeneity was found (P < 0.01). To control for potential publishing bias, a “fail-safe n” value was calculated. No search for unpublished studies was conducted, and no reliability tests for locating research results were done. To be accepted as significant findings, Mantel–Haenszel odds ratios must agree with combined test results whenever both types of data are assessed. In the absence of Mantel–Haenszel odds ratios, findings from both the Fisher and weighted Stouffer combined tests must agree with each other to be acceptable as significant.
For the previous update, interobserver agreement among Task Force members and two methodologists was established by interrater reliability testing. Agreement levels using a κ statistic for two-rater agreement pairs were as follows: (1) type of study design, κ = 0.78 to 0.90; (2) type of analysis, κ = 0.74 to 1.00; (3) evidence linkage assignment, κ = 0.79 to 1.00; and (4) literature inclusion for database, κ = 0.70 to 1.00. Three-rater chance-corrected agreement values were as follows: (1) study design, Sav = 0.86, Var (Sav) = 0.009; (2) type of analysis, Sav = 0.82, Var (Sav) = 0.017; (3) linkage assignment, Sav = 0.85, Var (Sav) = 0.004; (4) literature database inclusion, Sav = 0.79, Var (Sav) = 0.310. These values represent moderate to high levels of agreement.
Consensus-based Evidence
Consensus was obtained from multiple sources, including (1) survey opinion from consultants who were selected based on their knowledge or expertise in neuraxial opioid administration, (2) survey opinions solicited from active members of the American Society of Anesthesiologists (ASA), (3) testimony from attendees of publicly held open forums at a national anesthesia meeting, (4) Internet commentary, and (5) Task Force opinion and interpretation. A survey was sent to the consultants and ASA members in May 2015 covering all evidence linkages. The rate of return among consultants was 35% (n = 48 of 138), and 135 surveys were received from active ASA members. Survey results are reported in Tables 2 and 3 and summarized in the text of the guidelines.
For the previous update, the consultants were asked to indicate which, if any, of the evidence linkages would change their clinical practices if the guidelines were instituted. The rate of return was 14% (n = 17 of 123). The percent of responding consultants expecting no change associated with each linkage was as follows: (1) history and physical examination = 94%, (2) single-injection neuraxial opioid administration = 88%, (3) continuous epidural opioid administration = 88%, (4) extended-release epidural opioid administration = 71%, (5) monitoring for adequacy of ventilation, oxygenation, and level of consciousness = 59%, (6) supplemental oxygen administration = 88%, and (7) use of noninvasive positive pressure ventilation = 100%. Fifty-nine percent of the respondents indicated that the guidelines would have no effect on the amount of time spent on a typical case, and 41% indicated that there would be an increase of the amount of time spent on a typical case with the implementation of these guidelines.
