Skip Navigation LinksHome > September 2011 - Volume 115 - Issue 3 > Anesthesia Literature Review
Anesthesiology:
doi: 10.1097/ALN.0b013e31822b4186
Education: Anesthesia Literature Review

Anesthesia Literature Review

Section Editor(s): Brennan, Timothy J. Ph.D., M.D.; Editor

Free Access
Back to Top | Article Outline

Perioperative Medicine

J. Lance Lichtor, M.D., Editor
Back to Top | Article Outline
Statin use associates with a lower incidence of acute kidney injury after major elective surgery. J Am Soc Nephrol 2011; 22:939–46
Figure. No caption a...
Image Tools
Currently there is not effective preventive therapy for perioperative acute kidney injury. This large (n = 213,347), population-based, retrospective cohort study was conducted to assess the effects of statins in patients older than 65 yr who underwent elective surgery between 1995 and 2008. Approximately one-third of patients were taking a statin before surgery. Overall, 1.9% of patients developed acute kidney injury within the first 14 postoperative days and 0.5% required acute dialysis. After adjustments for patient and surgical characteristics, statin use was associated with a reduced risk of acute kidney injury, dialysis, and mortality (see fig. below).
Back to Top | Article Outline
Interpretation
In this large, retrospective study of patients who underwent major elective surgery, statin use in individuals older than 65 yr was associated with improved renal outcomes within 14 days of surgery, and 30-day mortality was reduced. As with all retrospective reviews, there may have been other unidentified factors associated with statin use. Therefore, a prospective study is warranted.
Back to Top | Article Outline
Variability in the measurement of hospital-wide mortality rates. N Engl J Med 2010; 363:2530–9
Various methodologies are used to assess hospital performance and determine incentive payments. One measure of hospital quality of care is hospital mortality rate. The authors in this study used four different methods from different vendors to calculate hospital-wide mortality. Each vendor received identical computerized files of discharges from general acute care hospitals in Massachusetts between 2004 and 2007. The proportion of discharges included within each method ranged from 28% to 95%. This resulted in calculation of in-hospital mortality rates at twice the state average for two methods (4.0% and 5.9% vs. 2.1%). Almost one-half of hospitals (12 of 28) classified with higher-than-expected hospital-wide mortality using one method were also classified with lower-than-expected mortality using a different method.
Back to Top | Article Outline
Interpretation
In this assessment of four methodologies used in Massachusetts to assess quality of care at acute care hospitals, results varied depending on the method. One method produced higher-than-expected hospital-wide mortality, and another method produced lower-than- expected mortality. Differences in inclusion and exclusion criteria and how hospitals abstract data were used may have contributed to the differences observed.
Back to Top | Article Outline
Automated cuff pressure modulation: A novel device to reduce endotracheal tube injury. Arch Otolaryngol Head Neck Surg 2011; 137:30–4
Airway injury after prolonged intubation with a cuffed endotracheal tube can occur. Ten pigs were intubated using a cuffed endotracheal tube to assess whether dynamic modulation of endotracheal tube cuff pressure would reduce the extent of intubation-related laryngotracheal injury during 4 h of hypoxic conditions. Five animals had a constant cuff pressure of 25 cm H2O, and in five animals the cuff pressure was changed from 25 cm H2O during inspiration to 7 cm H2O during expiration. Pigs in the variable-pressure group had significantly less overall laryngotracheal (P < 0.001), subglottic (P < 0.001), and tracheal damage compared with those in the constant pressure group. Glottic and supraglottic damage was similar in the two groups.
Back to Top | Article Outline
Interpretation
This basic science study shows that synchronizing cuff pressure with the ventilator cycle may reduce endotracheal tube-related subglottic injury after only 4 h of mechanical ventilation under hypoxic conditions. If confirmed in large clinical trials, these findings may have important implications for mechanical ventilation of long duration in the operating room and in critically ill patients.
Back to Top | Article Outline
Coronary revascularization trends in the United States, 2001–2008. JAMA 2011; 305:1769–76
Figure. No caption a...
Image Tools
More than 1 million coronary revascularization procedures, including coronary artery bypass graft (CABG) and percutaneous coronary intervention (PCI), are performed annually in the United States. It is not known whether recent technologic advances have changed the volume or type of procedures currently performed. A serial cross-sectional study was performed to determine the annual procedure rates of coronary revascularizations, CABG surgery, and PCI. Overall there was a 15% decrease (P < 0.001) in the annual rate of coronary revascularizations (see fig. below) whereas the number of hospitals performing CABG and PCI increased over this period (by 12% and 26%, respectively). The median CABG surgery caseload per hospital decreased by 28%.
Back to Top | Article Outline
Interpretation
Using a federal dataset of hospital discharge records, the authors found that although all coronary revascularization procedures decreased by 15% between 2001 and 2008, CABG surgery specifically has decreased by one-third. Interestingly, the number of hospitals performing CABG surgery has increased, resulting in a decrease in caseloads per hospital and an increase in the number of hospitals performing fewer than 100 surgical procedures per year.
Back to Top | Article Outline
The transcriptional repressor DEC2 regulates sleep length in mammals. Science 2009; 325: 866–70
Mechanisms for sleep are poorly understood as are responses to sleep deprivation and variability in sleep patterns. It is well known that sleep requirements vary among people, and some of this variability is inherited. A mutation in a transcriptional repressor (hDEC2-P385R) was identified in two individuals with lifelong shorter daily sleep times. These subjects were from a family that were naturally short sleepers; their average sleep time was 6 h and this was a result of early awakening. Mice generated with this mutation also showed less sleep and increased vigilance time, and had alterations in sleep rebound and non rapid eye movement intensity after sleep deprivation.
Back to Top | Article Outline
Interpretation
In this genetic translational study, a mutation was identified in humans who slept for short time periods and this was confirmed in a mouse model. These data may provide inferences to patient differences in sensitivities to sedative drugs and anesthetics. These findings could improve our understanding of responses to sleep deprivation after surgery and prolonged sedation in the intensive care unit (ICU).
Back to Top | Article Outline
Randomized trial of stents versus bypass surgery for left main coronary artery disease. N Engl J Med 2011; 364:1718–27
Figure. No caption a...
Image Tools
It is unclear whether PCI is an acceptable alternative to coronary artery bypass grafting. The Premier of Randomized Comparison of Bypass Surgery versus Angioplasty Using Sirolimus-Eluting Stent in Patients with Left Main Coronary Artery Disease (PRECOMBAT) was a prospective, multicenter open-label, randomized trial. Patients underwent coronary artery bypass grafting (n = 300) or PCI with sirolimus-eluting stents (n = 300), and major adverse cardiac or cerebrovascular events at 1 yr were measured. Overall, the complication rates were low in all patients. Based on the primary composite endpoint, PCI was noninferior to CABG (see fig. below). The absolute risk difference was 2.0 and 4.1% points at 1 and 2 yr, respectively.
Back to Top | Article Outline
Interpretation
In this large, randomized clinical trial of 13 sites in Korea, sirolimus-eluting stents were noninferior to coronary artery bypass grafting in patients with unprotected left main coronary artery stenosis. The overall incidence of major adverse events for all patients was low. However, the noninferiority margin was wide, and therefore additional studies are needed to determine clinical significance.
Back to Top | Article Outline

Critical Care Medicine

Jean Mantz, M.D., Ph.D., Editor
Back to Top | Article Outline
Decompressive craniectomy in diffuse brain traumatic injury. N Engl J Med 2011; 364:1493–502
Severe traumatic brain injury may result in death or severe long-term disability, with an economic burden of more than $60 billion. The functional outcome of decompressive craniectomy for patients with traumatic brain injury and refractory raised intracranial pressure is unknown. Patients (n = 155) with severe diffuse traumatic brain injury and intracranial hypertension refractory to first-tier therapies were randomized to receive bifrontotemporoparietal decompressive craniectomy or standard care. Craniectomy did result in significantly reduced intracranial pressure (P < 0.001), days in the ICU, and days with mechanical ventilation compared with standard care. Extended Glasgow Outcome Scale scores were worse for patients who underwent craniectomy compared with standard care (odds ratio = 1.84). An increased risk of negative outcome (odds ratio = 2.21) was also noted in the craniectomy group. The 6-month death rates were similar between groups (19% and 18% in the craniectomy and standard care groups, respectively).
Back to Top | Article Outline
Interpretation
This randomized controlled trial suggests a lack of benefit of decompressive craniectomy on long-term outcome in traumatic brain injury. Therefore, decompressive craniectomy is probably not beneficial in patients with moderate intracranial hypertension. Whether decompression may be useful within the first 72 h of traumatic brain injury in patients in whom intracranial pressure is difficult to control remains unresolved.
Back to Top | Article Outline
Long term quality of life after surgical intensive care admission. Arch Surg 2011; 146:412–8
Figure. No caption a...
Image Tools
Small previous studies have suggested that prolonged hospital stays in the ICU are associated with reduced health-related quality of life (HRQOL) after discharge. This large (n = 575), single-center, prospective observational cohort study was conducted to quantify the long-term HRQOL of patients admitted to the ICU. Between 6 and 11 yr after ICU stay, approximately one-half of all patients still reported HRQOL problems (see fig. near top of right column). Based on Euro-Qol-6D utility scores, HRQOL was worse by 0.11 compared with that of age- and sex-matched control subjects. Differences existed based on the surgical history, with patients undergoing oncologic surgery having the best outcomes (HRQOL = 0.83) compared with vascular surgery patients, who had the worst outcomes (HRQOL = 0.72).
Back to Top | Article Outline
Interpretation
This single-center cohort study indicates that quality of life 6 yr after admission into a surgical ICU is significantly decreased in comparison with an age- and sex-matched control population. Interestingly, decreased cognitive function represents a major disability. These results offer hypotheses for new therapeutic approaches to reduce long-term disability after surgical ICU admission.
Back to Top | Article Outline
Daily titration of neurally adjusted ventilatory assist using the diaphragm electrical activity. Intensive Care Med 2011; 37:1087–94
Figure. No caption a...
Image Tools
For mechanically ventilated patients, neurally-adjusted ventilator assist (NAVA) may provide improved patient-ventilator synchrony and improved oxygenation. This study was conducted to determine whether the NAVA level could be applied for individual patients based on their individual highest diaphragmatic electrical activity during the daily spontaneous breathing trial (SBT). The median duration of NAVA ventilation in 12 patients was 4.5 days. There was a significant increase in electrical activity, with no changes in tidal volume, carbon dioxide tension, and pH values (see fig. below).
Back to Top | Article Outline
Interpretation
Neurally-adjusted ventilator assist is a new ventilator mode that provides pressure in proportion to the electrical activity of the diaphragm. The current study provides early evidence that NAVA may be useful to facilitate ventilator weaning in some patients.
Back to Top | Article Outline
Beneficial association of β-blocker therapy on recovery from severe acute heart failure treatment: Data from the survival of patients with acute heart failure in need of intravenous inotropic support trial. Crit Care Med 2011; 39:940–4
It is well established that β-blockade improves survival for patients with chronic heart failure. However, the effect of β-blockade on patients with acute heart failure is not known. In this post hoc analysis of the Survival of Patients With Acute Heart Failure in Need of Intravenous Inotropic Support (SURVIVE) study, outcomes of patients (n = 1,104) receiving β-blockers during hospitalization for decompensated heart failure were reviewed. Patients who received β-blockers at study entry and discharge had a significantly greater likelihood of survival than patients who did not (P = 0.0002 at 31 days, and P < 0.001 at 180 days). After adjustment for age and comorbidities, use of β-blockers at entry and discharge improved survival at 31 and 180 days, respectively (odds ratio = 0.297 and 0.540).
Back to Top | Article Outline
Interpretation
This trial addresses a major concern for intensivists, that is, whether β-receptor blockers should be maintained or initiated before discharge from the ICU in patients admitted for acute severe heart failure. In this randomized, multicenter trial, β-blockade markedly decreased long-term mortality in these patients.
Back to Top | Article Outline

Pain Medicine

Timothy J. Brennan, Ph.D., M.D., Editor
Back to Top | Article Outline
Duration of treatment with nonsteroidal antiinflammatory drugs and impact on risk of death and recurrent myocardial infarction in patients with prior myocardial infarction: A nationwide cohort study. Circulation 2011; 123:2226–35
The association between duration of nonsteroidal antiinflammatory drug (NSAID) use and cardiovascular risks are poorly understood in patients with previous myocardial infarctions (MIs). This retrospective study assessed the risk of death and recurrent MI in patients (n = 83,677) admitted with their first MI between 1997 and 2006 and who had subsequent NSAID use. Overall, 42.3% of patients received NSAIDs during follow-up. NSAID treatment was significantly associated with an increased risk of death or recurrent MI (hazard ratio = 1.45) throughout the duration of treatment. Diclofenac had the highest risk (hazard ratio = 3.26), which increased with increasing duration of use. Celecoxib had an increased risk between 14 and 30 days of treatment. Ibuprofen showed an increased risk when taken for more than 1 week, but the risk was lower than that associated with cyclooxygenase-2 selective inhibitors and diclofenac.
Back to Top | Article Outline
Interpretation
This retrospective study of patients with recurrent MI indicated that MI and death were associated with NSAID use. Surprisingly, the risk of recurrent MI was associated with short-term use of NSAIDs. In agreement with previous studies, certain NSAIDs (e.g., naproxen) were not associated with an increased risk, but drugs such as celecoxib and diclofenac were associated with an increased risk.
Back to Top | Article Outline
Long-term effects of routine morphine infusion in mechanically ventilated neonates on children's functioning: Five-year follow-up of a randomized controlled trial. Pain 2011; 152:1391–7
Previous studies have demonstrated mixed results for the use of morphine in neonatal surgical patients. Here the authors provide 5-yr follow-up data from a randomized, placebo-controlled trial of neonates mechanically ventilated who received a 100 μg/kg loading dose of morphine followed by a continuous infusion of 10 μg/kg/h of either morphine (n = 49) or placebo (n = 41). Follow-up tests included intelligence quotient scores, visual motor integration, behavior, chronic pain, and health-related quality of life. After correction for treatment conditions, no differences in outcomes were observed between groups.
Back to Top | Article Outline
Interpretation
Drugs used in the neonatal period are undergoing increased scrutiny. In this 5-yr follow-up of a previous randomized controlled trial, morphine use did not influence intelligence quotient, behavior, or pain status. The authors note that the number of patients treated was small and that many parameters measured were nearly significant. Further follow-up on this patient group at a later time period is warranted, and future studies on greater dosages for longer periods of time could be undertaken.

© 2011 American Society of Anesthesiologists, Inc.

Publication of an advertisement in Anesthesiology Online does not constitute endorsement by the American Society of Anesthesiologists, Inc. or Lippincott Williams & Wilkins, Inc. of the product or service being advertised.
Login

Article Tools

Images

Share