This Month in: Anesthesiology

Mass cytometry allows for the simultaneous phenotypic and functional characterization of all major immune cell subsets in peripheral blood at unparalleled single-cell resolution. Single-cell mass cytometry of postsurgical blood samples identified strong immune correlates of surgical recovery in patients undergoing primary hip arthroplasty. The ability of evoked immune responses in presurgical blood samples to predict the speed of recovery from fatigue, pain, and functional impairment was tested in 25 patients undergoing primary hip arthroplasty. Two particularly strong correlates with clinical recovery parameters were the phosphorylated mitogen activated protein kinase–activated protein kinase-2 response to lipopolysaccharide in CD14⁺ monocytes and classical dendritic cells, each of which accounted for almost 50% of the variability associated with the speed at which patients recovered from functional impairment of the operated hip. See the accompanying Editorial View on page 1221.

A large prospective detailed cohort study with complete 90-day follow-up was conducted to assess postoperative outcomes after fast-track total hip arthroplasty and total knee arthroplasty in patients with pharmacologically treated psychiatric disorders. Dispensed prescriptions for psychopharmacological treatment (excluding benzodiazepines) were reported for 1,001 of 8,757 procedures between January 2010 and November 2012 in seven departments using similar standardized perioperative fast-track protocols. Median length of stay for all patients was 2 days, but 16.5% of patients with treated psychiatric disorders had lengths of stay longer than 4 days compared to 7.3% of controls. Thirty- and 90-day surgery-related readmission rates for all patients were 5.9% and 8.3%, respectively, but the respective readmission rates were 9.9% and 12.8% in patients with psychiatric disorders and 5.1% and 7.4% in control patients.

Establishing immediate postoperative range of motion using continuous passive motion equipment helps ensure adequate surgical and functional outcome after major elbow surgery. Continuous brachial plexus analgesia within a multimodal regimen minimizes pain and enhances functional outcome. These interventions usually require inpatient admission for 3 to 4 days. This prospective randomized study of 38 patients undergoing complex arthroscopic elbow surgery found 24 h of hospital admission followed by continuous brachial plexus anesthesia and continuous passive motion at home resulted in arc range of motion 2 weeks after surgery and improvements in functional outcome that were at least similar to those observed with 72-h hospital admission. No significant differences in pain, physical function, and patient satisfaction were observed. Associated hospital costs were 15% lower in the early discharge group. See the accompanying Editorial View on page 1224.

The long-term follow-up of the Evaluation of Nitrous Oxide in the Gas Mixture for Anaesthesia (ENIGMA) trial found that nitrous oxide increased risk of myocardial infarction in noncardiac surgery patients. Because the patients in ENIGMA were not selected on the basis of risk for cardiovascular events and event rates were low, the ENIGMA-II trial was conducted to explore the risks and benefits of nitrous oxide in 7,112 noncardiac surgery patients at risk of perioperative cardiovascular complications, who were randomly assigned to 70% nitrous oxide in 30% oxygen or 70% nitrogen in 30% oxygen. Nitrous oxide administration did not increase the incidence of the primary outcome, a composite of death and cardiovascular events (nonfatal myocardial infarction, cardiac arrest, pulmonary embolism, and stroke), among the 5,844 patients evaluated at 1 yr. See the accompanying Editorial View on page 1229.

Early postoperative mobilization may be hindered by orthostatic hypotension and orthostatic intolerance. The oral α₁-adrenoreceptor agonist midodrine is used to treat recurrent symptomatic orthostatic hypotension and orthostatic intolerance. The hypothesis that preemptive administration of 5 mg midodrine hydrochloride could reduce the prevalence of orthostatic hypotension during mobilization 6 h after total hip arthroplasty under spinal anesthesia was tested in a randomized, double-blind, placebo-controlled study of 114 patients. Orthostatic hypotension during mobilization 6 h after surgery was present in 14/56 (25%) patients in the midodrine group and 23/58 (40%) patients in the placebo group. The prevalence of orthostatic hypotension or orthostatic intolerance during mobilization was not significantly reduced among patients receiving midodrine compared to those receiving placebo at either 6 or 24 h after surgery.

Steroids might reduce the risk or intensity of persistent incisional pain after cardiac surgery by moderating acute pain and reducing ongoing inflammation. The primary hypothesis that patients randomized to receive 500 mg methylprednisolone intraoperatively will have less persistent incisional pain than patients given placebo was tested in 1,043 patients undergoing cardiac surgery via a median sternotomy in this substudy of Steroids in caRdiac Surgery (SIRS) trial. Methylprednisolone did not significantly affect persistent incisional pain at 6 months, which occurred in 78 of 520 patients (15.7%) in the methylprednisolone group and in 88 of 523 patients (17.8%) in the placebo group. Pain at 6 months was significantly related to younger age, female sex, and deep surgical site infections.

In high-value surgical procedures, overall benefits outweigh the risks with enough margin to make the procedure worth doing despite the costs for the patient and society. It is equally important that the patient fully understands risks, benefits, and alternatives, and there should be concordance between patient preferences and values and expected clinical outcomes. A review of methods developed to prevent overuse in surgeries suggests they fall short in completely fulfilling all of these criteria. Institutions and programs exist to address the appropriateness of provider and place, but there is a notable absence of variables related to alignment of patient and provider goals, the extent of patient engagement in decision making, and decisional quality.

Surgical trauma induces a stress response that threatens metabolic and physiologic homeostasis. Whereas an ongoing or exaggerated surgical stress response can have adverse consequences, attenuating it can improve surgical outcome. This review first presents effects of surgery on intermediary metabolism, including hyperglycemia, protein catabolism, and lipid oxidation, as well as the consequences of those effects. Nutrition-focused clinical strategies that can attenuate the metabolic stress response to surgery, including preoperative nutritional assessments, avoiding preoperative fasting, and providing optimal postoperative nutritional care, are then discussed. Anesthetic strategies to facilitate nutritional gains and optimize metabolic functions, including epidural blockade, optimized fluid dynamics, control of nausea and vomiting, and mobilization, are considered next. The review ends with a presentation of emerging concepts aimed at optimizing the preoperative period, including glycemic control and prehabilitation.