Science, Medicine, and the Anesthesiologist

Acute kidney injury (AKI) is a common complication following surgery and is associated with poor outcomes and high health care costs. This ancillary study was derived from the recently published Perioperative Ischemic Evaluation 2 (POISE-2) trial that included ~20,000 patients undergoing major noncardiac surgery and aimed to determine whether aspirin and clonidine when compared with their respective placebos alters the risk of perioperative AKI. AKI was defined as an increase in serum creatinine concentration from the preoperative concentration of 0.3 mg/dl or greater (26.5 μmol/l) within 48 h of surgery or 50% or greater within 7 days of surgery. Neither aspirin nor clonidine was found to reduce the perioperative risk of AKI in this patient population.

Most large trials have established that hydroxyethyl starch increases the risk of death, acute kidney injury, and bleeding in septic intensive care unit patients. The debate has been ongoing since an EMA review last year permitted continued use in some patients, overturning an earlier decision to withdraw the product completely. The risk/benefit balance of using limited amounts of hydroxyethyl starch solutions for correction of intraoperative hypovolemia remains unresolved. In this review, the authors effectively discuss the evidence and call on clinicians to avoid using starch formulations.

The clinical evidence base demonstrating bariatric surgery’s health benefits is much larger than it was when the National Institutes of Health last held a consensus panel, in 1991. The current symposium reported in this article aimed to summarize the present state of knowledge surrounding bariatric surgery and review research findings on the long-term outcomes of bariatric surgery, while establishing priorities for future research directions. Sound evidence supports the benefit of bariatric surgery on greater weight loss and the remission of type 2 diabetes in obese patients compared with nonsurgical techniques. However, more information is needed regarding complications after bariatric procedures and the long-term durability of comorbidity control. This evidence will likely come in the form of additional carefully designed observational studies.

Although β-blockers reduce mortality in heart failure with preserved ejection fraction (HFPEF, also called diastolic heart failure), the hypothesis that β-blockers are associated with reduced all-cause mortality in HFPEF has not been established. In this study, propensity scores for β-blocker use in 41,976 patients were derived from 52 baseline clinical and socioeconomic variables obtained from a nationwide registry based in Sweden. In patients with HFPEF, use of β-blockers was associated with lower all-cause mortality but not with combined all-cause mortality or hospitalization for heart failure. There remains need for a randomized controlled trial to assess the impact of β-blockers on mortality in this patient population.

While mild therapeutic hypothermia is recommended after out-of-hospital cardiac arrest, its feasibility and impact on long-term outcomes has recently been challenged. In a two center retrospective study of patients admitted to the intensive care unit for in- or out-of-hospital cardiac arrest and treated with targeted temperature management, favorable Cerebral Performance Category at hospital discharge predicted better survival and long-term outcomes of those survivors. The second study is a prospective observational European–U.S. study derived from the Hypothermia Network and the International Cardiac Arrest Registries that included 663 in-hospital cardiac arrest patients treated with mild induced hypothermia. Positive outcomes were reported in 41% of patients (defined as a Cerebral Performance Category of 1 or 2) at hospital discharge and 34% at 6-month follow-up. Mortality was primarily due to cardiac causes while the most frequent complications were infection (43%) and bleeding requiring transfusion (11%). These new studies suggest that inducing mild hypothermia is feasible after cardiac arrest and that adverse events are manageable in this population.

Fibromyalgia is a prevalent chronic pain syndrome that is difficult to treat and associated with patient suffering and significant rates of disability. Use of N-methyl-d-aspartate (NMDA) receptor antagonists as analgesics has been examined for many forms of pain, but they have not gained widespread acceptance. This is a 6-month randomized, placebo-controlled trial of the NMDA receptor antagonist memantine for the treatment of fibromyalgia. Significant reductions in both overall pain and on the ischemia-induced pain were seen in those receiving memantine. Improvements in depression and quality of life were also seen. The number needed to treat for 50% pain reduction was 6.2, and only minor adverse events were reported. This trial suggests that NMDA receptor antagonists may provide a new avenue of treatment for pain and other symptoms related to fibromyalgia.

Cardiopulmonary resuscitation (CPR) has matured to a point where evidence-based protocols provide patients with effective care, often resulting in the return of spontaneous circulation. Is there more room for improvement in CPR? Burden and her anesthesiology colleagues recently answered with a “Yes.” They evaluated whether simulation education improved the crisis resource management (CRM) aspect of CPR. One group of residents received lecture-based education on communication and leadership during CPR; a second group received simulation-based education with practice on the same areas of communication and leadership. Both groups performed CPR during simulated scenarios after lecture or simulation CRM education and then again 6 months later. Residents that experienced simulated CRM education communicated and managed CPR teams better than those provided lecture-based CRM training. The clear inference is that simulation-based training may well have advantages for all trainees.