Perioperative Medicine

Propofol is a popular sedative for endoscopic procedures because of its rapid onset of action and short duration of effect. The safe use of gastroenterologist-administered propofol is supported for advanced endoscopic procedures (e.g. , endoscopic retrograde cholangiopancreatography and endoscopic ultrasound). However, there are limited data on the administration of propofol by nurses and their ability to perform possible airway interventions required if patient rescue is necessary.

This single-institution prospective study evaluated the frequency of sedation-related complications associated with propofol use by three certified registered nurse anesthetists, under the direction of one anesthesiologist, in patients undergoing advanced endoscopic procedures including endoscopic retrograde cholangiopancreatography, endoscopic ultrasound, single-balloon or spiral overtube-assisted small-bowel enteroscopy, and enteral stenting. Sedation-related complications that were assessed included airway modifications (e.g. , chin lifts, modified face mask ventilation, and nasal airway), hypoxemia (Sao²<90%), hypotension requiring vasopressors, and early procedure termination.

Of 799 patients enrolled, endoscopic ultrasound and endoscopic retrograde cholangiopancreatography were the most common procedures performed (52.9 vs.  42.1%), and 61% of patients had an American Society of Anesthesiologists class of 3 or higher. The majority of patients showed no response to intubation (87.2%). Hypoxemia, hypotension, and premature termination occurred in 12.8%, 0.5%, and 0.6% of patients, respectively. No patients required bag-mask ventilation or tracheal intubation. One hundred fifty-four airway modifications were performed in 14.4% of patients, including chin lift (12.1%), modified face mask ventilation (3.6%), and nasal airway (3.5%). Male patients, patients with a higher body mass index, or patients with an American Society of Anesthesiologists class 3 or higher were most likely to need one or more airway modifications.

Propofol is useful for sedation for procedures such as endoscopy. In this study, where experienced certified registered nurse anesthetists performed sedation for advanced endoscopic procedures, 12.1% of patients needed a chin left and 12.8% experienced hypoxemia. Consistent with other studies, male sex, body mass index, and American Society of Anesthesiologists class 3 or higher were independent predictors of airway modifications. It is not clear if the findings would be similar if individuals not as experienced as certified registered nurse anesthetists administered sedation.

Suggested by: Mark Warner, M.D.

Improved overall health, including remission of diabetes, improved cardiovascular disease, and reduced risk of death, has been demonstrated in patients who underwent bariatric surgery. However, safety concerns have increased with increasing frequencies of bariatric surgeries performed. The Longitudinal Assessment of Bariatric Surgery consortium conducts a prospective, multicenter, observational cohort study (Longitudinal Assessment of Bariatric Surgery-1) in consecutive patients undergoing bariatric surgery.

This study reports the incidence of and factors associated with 30-day safety outcomes in adult patients (N = 4,776) enrolled in Longitudinal Assessment of Bariatric Surgery-1 who underwent an initial bariatric surgical procedure. Roux-en-Y gastric bypass was the most common procedure performed in 3,412 patients, 87.2% of which were laparoscopic. Most patients (82.1%) had at least one coexisting condition (e.g. , hypertension, 55.1%; obstructive sleep apnea, 48.9%; diabetes, 33.2%; and asthma, 23.1%). Patients undergoing open Roux-en-Y gastric bypass generally had higher body mass index and more coexisting conditions (P < 0.001) compared with laparoscopic techniques.

Within 30 days of surgery, 0.3% of patients died, and the composite end point of death, deep vein thrombosis (DVT), reintervention, or failure to be discharged by 30 days occurred in 4.1% of patients. Death and the composite end point occurred most frequently in patients who underwent open Roux-en-Y gastric bypass. Abdominal reoperation and endoscopic intervention (2.6% and 1.1%, respectively) were the most common components of the composite end point. The risk of the composite end point was lowest among patients who did not have a history of DVT, venous thromboembolism, obstructive sleep apnea, and who were in the middle range of body mass index. Patients who underwent gastric bypass had a higher risk of adverse events regardless of preexisting characteristics (e.g. , high body mass index or DVT) compared with patients who underwent adjustable banding. Only 13.5% of procedures and 12.2% of events occurred in patients who had a body mass index less than 40 kg/m².

Bariatric surgery is an effective and safe procedure. Adverse events that included death, DVT, venous thromboembolism, reintervention, or failure to be discharged by 30 days after surgery were low. Risk increased for those with a history of DVT, pulmonary embolus, obstructive sleep apnea, or impaired functional status. Patients undergoing gastric bypass experienced more adverse events compared with those who underwent adjustable banding.

Suggested by: J. Lance Lichtor, M.D.

Antimicrobial prophylaxis (AMP) can reduce the risk of surgical site infections (SSIs). Recent guidelines suggest that the administration of perioperative antibiotics should occur within 1 h (parenteral AMP) or within 2 h (vancomycin or fluoroquinolones) before incision. To further explore the relationship among timing, duration, and intraoperative redosing of surgical AMP and the risk of SSI, a prospective, randomized, multicenter study was conducted. This was an ancillary study to the multisite Trial to Reduce Antimicrobial Prophylaxis Errors study.

Patients (N = 4,472) from 29 hospitals undergoing cardiac, hip/knee arthroplasty, or hysterectomy were randomly selected. Most hospitals (79.3%) were teaching hospitals, and the majority (55.2%) had fewer than 250 beds. The majority of patients (76%) received cephalosporins alone or other antibiotics, whereas 13%, 4.9%, and 5.3% of patients received cephalosporins plus vancomycin, vancomycin only, or fluoroquinolones, respectively. One hundred thirteen infections were detected in 109 patients. The majority of infections (69%) were diagnosed after initial hospital discharge. The association between timing and risk of SSI was statistically significant (P = 0.04). There was also a statistically significant risk (P = 0.02) associated with administration of AMP after incision. When AMP was administered within 30 min before incision, the incidence was 1.6% compared with 2.4% between 31 and 60 min (odds ratio = 1.74; 95% confidence interval = 0.98–3.08). Intraoperative AMP redosing was administered in 21% of 690 surgeries lasting longer than 4 h. Risk of SSI was lower in redosing cases only if the preoperative dose was administered in the recommended time frame. Increased risk was also associated with the lack of postoperative AMP; however, this analysis was confounded by procedure type and hospital.

Antibiotic prophylaxis is most effective when administered less than or equal to 30 min before surgical incision, although the risk only slightly increases when administered 31–120 min before incision. The risk substantially increases when antibiotics are administered after incision. This study reinforces antibiotic timing guidelines. Because elective surgeries have a low risk of SSI, this study may not be adequately powered to address specific details of nonelective surgeries, timing of antibiotic administration, and SSI.

Suggested by: Hervé Dupont, M.D., Ph.D.