David J. Plevak

Identification of Patients at Risk for Postoperative Respiratory Complications Using a Preoperative Obstructive Sleep Apnea Screening Tool and Postanesthesia Care Assessment

Background:Patients with obstructive sleep apnea are at risk for perioperative morbidity. The authors used a screening prediction model for obstructive sleep apnea to generate a sleep apnea clinical score (SACS) that identified patients at high or low risk for obstructive sleep apnea. This was combined with postanesthesia care unit (PACU) monitoring with the aim of identifying patients at high risk of postoperative oxygen desaturation and respiratory complications. Methods:In this prospective cohort study, surgical patients with a hospital stay longer than 48 h who consented were enrolled. The SACS (high or low risk) was calculated; all patients were monitored in the PACU for recurrent episodes of bradypnea, apnea, desaturations, and pain–sedation mismatch. All patients underwent pulse oximetry postoperatively; complications were documented. Chi-square, two-sample t test, and logistic regression were used for analysis. The oxygen desaturation index (number of desaturations per hour) was calculated. Oxygen desaturation index and incidence of postoperative cardiorespiratory complications were primary endpoints. Results:Six hundred ninety-three patients were enrolled. From multivariable logistic regression analysis, the likelihood of a postoperative oxygen desaturation index greater than 10 was increased with a high SACS (odds ratio = 1.9, P < 0.001) and recurrent PACU events (odds ratio = 1.5, P = 0.036). Postoperative respiratory events were also associated with a high SACS (odds ratio = 3.5, P < 0.001) and recurrent PACU events (odds ratio = 21.0, P < 0.001). Conclusions:Combination of an obstructive sleep apnea screening tool preoperatively (SACS) and recurrent PACU respiratory events was associated with a higher oxygen desaturation index and postoperative respiratory complications. A two-phase process to identify patients at higher risk for perioperative respiratory desaturations and complications may be useful to stratify and manage surgical patients postoperatively.

Hepatotoxicity after desflurane anesthesia

SEVERAL fluorinated inhalation anesthetics have been associated with hepatotoxicity. Yet to date, desflurane has not been reported to cause liver damage in humans. The following is a report of a patient who experienced hepatitis after receiving a desflurane anesthetic and who may have been sensitized by prior halothane exposure.

Comparison of Analgesic Requirements After Liver Transplantation and Cholecystectomy

In a prospective study of 10 patients who underwent liver transplantation and 10 patients who underwent cholecystectomy, we analyzed the postoperative analgesic requirements and the resultant plasma morphine concentrations. Analgesia was more intense, with less medication, and the plasma morphine concentration was significantly lower in the liver transplant group than in the cholecystectomy group. This finding is most likely attributable to endogenous factors rather than to altered morphine pharmacokinetics.

Skin injury with the use of a water warming device.

HYPOTHERMIA is common during extensive and prolonged surgery such as a liver transplantation (OLT). Hypothermia can cause or exacerbate preexisting coagulation abnormalities and myocardial dysfunction. Efforts to prevent hypothermia during OLT and other major operations have largely employed active warming devices utilizing forced-air warming. A new device, the Allon System with the ThermoWrap garment (MTRE Advanced Technologies Ltd., Centerville, OH), circulates warmed water through a special garment to prevent hypothermia. We report the case of pressure/burn injury secondary to the use of this device.

Critical care issues in liver transplantation.

Critical care medicine will play a more prominent role in orthotopic liver transplantation (OLT) in future years. Until now, the intensive care unit (ICU) has been regarded as a location where patients spent their first few hours after their transplant surgery. However, in the United States patients are spending longer periods of time on the United Network for Organ Sharing transplant list, with consequent progressive worsening of their clinical status. The United Network for Organ Sharing directive of allocating organs to those patients on the list who are most ill has resulted in greater use of ICU resources before and after OLT. Increasing numbers of patients are presenting for liver transplantation with established multiple organ failure. The usual liver transplant patient’s operating room experience may become a mere moment between 2 ICU stays and the role of the ICU may expand to one of rehabilitation and chronic ventilation in patients who are extremely debilitated before and after the transplantation. ICU teams have responded to the challenge of readying these extremely ill patients for transplantation by using improved organ support devices, protocol-driven systemic therapies, and state of the art information systems. The worsening crisis of organ availability has led to an increase in the number of living donors. More ICU resources may be applied to assure successful postoperative management of these individuals. Cadaveric donor management is becoming increasingly more intensive in an effort to improve the yield of donor organs. Donors after cardiac death (DCD) are presenting new medical, ethical, logistical, and personnel management issues. Although many institutions are looking toward forming protocols for DCD, some are suggesting a moratorium. Conflict of interest is a concern and it is essential that the potential DCD and potential transplant recipient receive care from completely different critical care teams, preferably in different ICUs.

Perioperative Outcomes of Robotic-Assisted Hysterectomy Compared With Open Hysterectomy

BACKGROUND: Increasing numbers of robotic hysterectomies (RH) are being performed. To provide ventilation (with pneumoperitoneum and steep Trendelenburg position) for these procedures, utilization of lung protective strategies with limiting airway pressures and tidal volumes is difficult. Little is known about the effects of intraoperative mechanical ventilation and high peak airway pressures on perioperative complications. We performed a retrospective review to determine whether patients undergoing RH had increased pulmonary complications compared to total abdominal hysterectomy (TAH). METHODS: We performed a single center retrospective review comparing the intraoperative, anesthetic, and immediate and 30-day postoperative course of patients undergoing RH to TAH, including intraoperative ventilatory parameters and respiratory complications. Patients undergoing TAH (201) from 2004 to 2006 were compared to RH (251) from 2009 to 2012. It was our hypothesis that patients undergoing RH would have increased incidence of postoperative pulmonary complications. A secondary hypothesis was that morbid obesity predicts pulmonary complications in patients undergoing RH. Complications were compared between groups using Fisher’s exact test. To account for potential confounders, the primary analysis was performed for a subgroup of patients matched on the propensity for RH. RESULTS: A total of 351 RH and 201 TAH procedures are included. Higher inspiratory pressures were required in ventilation of the RH group (median [25th, 75th] 31 [26, 36] cm H2O) than the TAH group (23 [19, 27] cm H2O) (P < .001) at 30 minutes after incision. Peak inspiratory pressures at 30 minutes after incision for RH increased according to increasing body mass index group (P < .001). There were 163 RH and 163 TAH procedures included in the propensity matched analysis. From this analysis, there were no significant differences in cardiopulmonary complications between RH and TAH (0.6% vs 1.2%; odds ratio = 2.0, 95% confidence interval = 0.2–2.4; P = 1.00). Surgical site infection was significantly lower in the RH compared to TAH group (0.6% vs 8.6%; P < .001). Hospital length of stay was longer for those who underwent TAH versus RH (median [25th, 75th] 2 [2, 3] vs 1 [0, 2] days; P < .001). CONCLUSIONS: There was no significant difference in perioperative complications in obese and morbidly obese women compared to nonobese undergoing RH. Patients undergoing RH had shorter hospital stays, fewer infectious complications, and no increase in overall complications compared to TAH. Higher ventilatory airway pressures (RH versus TAH and obese versus nonobese) did not result in an increase in cardiopulmonary or overall complications. We believe that peritoneal insufflation attenuates the effect of high airway pressures by raising intrapleural pressure and reducing the gradient across terminal bronchioles and alveoli. Thus, we propose that lung protective strategies for patients undergoing RH account for the markedly elevated intraperitoneal and intrapleural pressures, whereas transpulmonary airway pressures remain static. This reduced transpulmonary gradient attenuates the strain on lung tissue that would otherwise be imposed by ventilation at high pressures.