This Month in: Anesthesiology

Three hundred thirty-eight photographs from 1860 to 1970 depicting 610 surgeons and 219 anesthesia providers were reviewed to determine when each of the four basic components of operating room attire (gowns, caps, masks, and gloves) achieved general acceptance and was consistently worn by surgeons and by anesthesia providers. Statistical modeling determined quantitatively when each component of operating room attire became widely accepted and routinely worn by surgeons and by anesthesia providers. The years associated with general acceptance (i.e., when the predicted probability exceeded 50%) for surgeons were 1876 for gowns, 1904 for caps, 1919 for masks, and 1911 for gloves. The years associated with general acceptance for anesthesia providers were 1890 for gowns, 1910 for caps, and 1937 for masks, but gloves were not generally accepted by 1963

The literature on perioperative medication error rates consists largely of either spontaneous self-reports of errors or facilitated incident reporting. Reductions in medication errors in other patient care areas have occurred because error rates were measured, errors were categorized to determine their root causes and potential for harm, and solutions were designed and implemented. In a prospective observational study from November 2013 to June 2014, 124 (44.8%) of 277 operations on 275 patients included one or more medication error and/or adverse drug event. One hundred ninety-three (5.3%) of the 3,671 medication administrations involved a medication error and/or an adverse drug event, 153 (79.3%) of which were preventable. Fifty-one (33.3%) of the 153 medication errors led to an observed adverse drug event and 70 (45.8%) had the potential for harm. See the accompanying Editorial View on page 1.

There has been increasing interest in the effect of the perioperative period on cancer progression because tumor seeding and an impaired immune response may make patients undergoing cancer surgery susceptible to development of metastasis. This retrospective analysis of 7,030 patients undergoing elective cancer surgery between June 2010 and May 2013 evaluated long-term survival in those receiving inhalational anesthesia or total IV anesthesia. After propensity matching 2,607 patients in each group and adjustment for known confounding factors, the hazard ratio for death was 1.46 in patients receiving an inhalational anesthetic compared to those receiving total IV anesthesia. Patients had a worse outcome if they received inhalational anesthesia regardless of their American Society of Anesthesiologists physical status or surgical severity, or whether they had recorded metastasis at the time of surgery.

Use of subjective pain reports as the only outcome measures in early analgesic drug development studies can both miss efficacious target engagement and fail to detect ineffective compounds. The utility of functional magnetic resonance imaging in distinguishing the effects of gabapentin, a first-line therapy for the treatment of neuropathic pain, from those of ibuprofen, an analgesic with doubtful efficacy in neuropathic pain, was assessed in a double-blind randomized, placebo-controlled three-way crossover study in 24 healthy volunteers with capsaicin-induced central sensitization, a mechanism relevant in neuropathic pain. Gabapentin suppressed the neural activity evoked by capsaicin-induced hyperalgesia in an area of the brainstem that contains the nucleus cuneiformis, an area with increased activity in capsaicin-induced central sensitization, whereas ibuprofen failed to suppress this activity.

Data collected by the Pediatric Sedation Research Consortium between September 2007 and November 2011 were used to evaluate possible links between nil per os (NPO) status and aspiration, pulmonary adverse events, and major adverse events (defined as unplanned admission, aspiration, cardiac arrest, or death) that occur during pediatric procedural sedation/anesthesia. Aspiration occurred in 8 of 82,546 (0.0097%) patients who were NPO and in 2 of 25,401 (0.0079%) who were not while major adverse events occurred in 46 of 82,546 (0.056%) patients who were NPO and in 15 of 25,401 (0.059%) who were not. Although there was little association between NPO status and aspiration or major adverse events, the latter were related to other factors, including American Society of Anesthesiologists physical status, age, and specific procedures.

The onset of ventilator-induced lung injury (VILI) is poorly characterized and VILI is almost always superimposed on an underlying primary pulmonary lesion. Serial computed tomography was used to study the propagation of VILI by ventilation with a moderate tidal volume in a rat model of acid aspiration with variable injury trajectory and by large tidal volume ventilation in normal rats and to determine predictors of propagation. When VILI complicated a preexisting lesion, it started at the underlying lesion and was propagated concentrically to the rest of the lung. When VILI was induced as the primary injury in previously healthy lungs, it originated in peripheral lung regions and spread centrally toward the hilum. Lung strain (tidal volume/expiratory lung volume) predicted propagation in both the presence and the absence of a primary underlying lung injury.

There is a lack of evidence-based approaches to airway management in patients with airway trauma because the incidence of such injuries is low. This commentary on the approach to evaluating and managing patients with traumatized airways begins by describing the anatomy of airway trauma for the three compartments into which airway injuries can be divided: maxillofacial, neck, and laryngeal. Factors affecting the choice of prehospital personnel to temporize at the scene of injury or provide definitive airway and other interventions are then presented. This is followed by recommendations for the evaluation of the traumatized airway and adjoining structures and a general approach to management of patients with airway trauma. The commentary concludes with consideration of specific situations, including facial trauma, neck trauma with extrinsic airway compression, and laryngeal-tracheal disruption.

The term “ICU acquired weakness” (ICUAW) refers to the bilateral and symmetrical neuromuscular sequelae of critical illness that occurs during the intensive care unit stay and is unrelated to another specific etiology. The incidence of surgical ICUAW is 25 to 31%. It can be associated with significant and potentially long-term adverse outcomes for patients and substantial costs involved in caring for it and its consequences. The present review begins with an overview of the classification of diseases related to skeletal muscle weakness. The epidemiology of postoperative muscle weakness is then considered as are the etiology and mechanisms of ICUAW. The diagnosis of muscle weakness in the surgical intensive care unit is described next. The review concludes with an extensive discussion of how to prevent ICUAW. See the accompanying Editorial View on page 7.