Paul C. Fitzgerald

Postoperative hypoxemia in morbidly obese patients with and without obstructive sleep apnea undergoing laparoscopic bariatric surgery.

INTRODUCTION: The increased incidence of morbid obesity has resulted in an increase of bariatric surgical procedures. Obstructive sleep apnea (OSA) is a commonly encountered comorbidity in morbidly obese patients. Sedatives, analgesics, and anesthetics alter airway tone, and airway obstruction and death have been reported in patients with OSA after minimal doses of sedatives and anesthetics, yet there is a lack of consensus regarding the care of these patients. In this study, we sought to determine whether obese patients with polysomnography-confirmed diagnosis of OSA were at significantly greater risk for postoperative hypoxemic episodes in the first 24 h after laparoscopic bariatric surgery than morbidly obese patients without a diagnosis of OSA. METHODS: Adult subjects (Body Mass Index, 35–75 kg/m2) scheduled to undergo laparoscopic bariatric surgery were studied. A finger pulse oximetry probe was placed preoperatively and oxygen saturation (Spo2) was recorded continuously. All subjects underwent preoperative polysomnography testing within 4 wk of surgery. Anesthetic management was standardized, using propofol for induction and desflurane and remifentanil for maintenance of anesthesia. Patient-controlled analgesia programmed to deliver morphine, 1 mg. every 10 minutes, was used for pain management postoperatively. Hypoxemic episodes were scored as Spo2 >4% below the polysomnography study baseline and lasting for more than 10 s. RESULTS: Eight men and 32 women were enrolled and 1 subject had incomplete data. Thirty-one of the 40 subjects had polysomnography-confirmed OSA. Eight subjects used home continuous positive airway pressure devices nightly, and six of these used their device postoperatively. Preoperatively, subjects with OSA had lower nadir Spo2 during the polysomnography study and a larger number had an apnea/hypopnea index >10 episodes per hour compared with the non-OSA group. In the first 24 h postoperatively, there was no difference in the median Spo2 with and without oxygen therapy, between OSA and non-OSA groups.The number of episodes of oxygen desaturation >4% below the polysomnography study baseline value and the mean number of desaturation episodes per hour did not differ between the groups. CONCLUSIONS: In morbidly obese subjects, in the first 24 h after laparoscopic bariatric surgery, OSA does not seem to increase the risk of postoperative hypoxemia. Our data confirm that morbidly obese subjects, with or without OSA, experience frequent oxygen desaturation episodes postoperatively, despite supplemental oxygen therapy suggesting that perioperative management strategies in morbidly obese patients undergoing laparoscopic bariatric surgery should include measures to prevent postoperative hypoxemia.

The Pharmacokinetics of Dexmedetomidine in Volunteers with Severe Renal Impairment

Dexmedetomidine, an &agr;2-adrenergic agonist with sedative and analgesic properties, is mainly cleared by hepatic metabolism. Because the pharmacokinetics of dexmedetomidine have not been determined in humans with impaired renal function, we studied them in volunteers with severe renal disease and in control volunteers. Six volunteers with severe renal disease and six matched volunteers with normal renal function received dexmedetomidine, 0.6 &mgr;g/kg, over 10 min. Venous blood samples for the measurement of plasma dexmedetomidine concentrations were drawn before, during, and up to 12 h after the infusion. Two-compartmental pharmacokinetic models were fit to the drug concentration versus time data. We also determined its hemodynamic, respiratory, and sedative effects. There was no difference between Renal Disease and Control groups in either volume of distribution at steady state (1.81 ± 0.55 and 1.54 ± 0.08 L/kg, respectively; mean ± sd) or elimination clearance (12.5 ± 4.6 and 8.9 ± 0.7 mL · min−1 · kg−1, respectively). However, elimination half-life was shortened in the Renal Disease group (113.4 ± 11.3 vs 136.5 ± 13.0 min;P < 0.05). A mild reduction in blood pressure occurred in most volunteers. Although most volunteers were sedated by dexmedetomidine, renal disease volunteers were sedated for a longer period of time.

Intraoperative neuraxial anesthesia but not postoperative neuraxial analgesia is associated with increased relapse-free survival in ovarian cancer patients after primary cytoreductive surgery.

Objectives: Regional anesthesia has been shown to blunt the response to surgical stress and decrease the use of volatile anesthetics and the consumption of opioids, which may reduce immune compromise and potentially delay tumor recurrence. The goal of this study was to find a possible association between intraoperative regional anesthesia and decreased cancer recurrence. Methods: Patients who underwent surgery for ovarian cancer between January 1, 2000, and October 1, 2006, were included. Subjects who had optimal surgical debulking (<1.0 cm of remaining tumor) were evaluated for time to tumor recurrence (carcinoantigen 125 >21 U/mL or computed tomography evidence of disease progression) and/or death. Results: One hundred eighty-two patients were evaluated; 127 did not receive epidural anesthesia/analgesia. Among the 55 who had epidural catheters placed, 26 were used intraoperatively and postoperatively; 29 were used only postoperatively. Cancer recurrence was documented in 121 patients. The median (interquartile range) time to recurrence was 40 (25-52) months. The intraoperative use epidural group had a mean (95% confidence interval) time to recurrence of 73 (56-91) months, which was longer than either the epidural postoperative group 33 (21-45) months (P = 0.002) or the no-epidural group 38 (30-47) months (P = 0.001). The postoperative-only and no-epidural groups were not different (P = 0.92). Intraoperative epidural significantly reduced (hazard ratio, 0.37 [95% confidence interval, 0.19-0.73]) tumor recurrence risk. Conclusions: Intraoperative use of epidural anesthesia was associated with an increased time to tumor recurrence after surgery in ovarian cancer patients. This may be a result of preservation of the immune system function.

The Prevalence of Burnout and Depression and Their Association with Adherence to Safety and Practice Standards: A Survey of United States Anesthesiology Trainees

BACKGROUND:The prevalence of burnout and depression in anesthesiology residents has not been determined. It is also unknown whether anesthesiology resident burnout/depression may affect patient care and safety. The primary objective of this study was to determine the prevalence of burnout and depression in anesthesiology residents in the United States. We hypothesized that residents at high risk of burnout and/or depression would report more medical errors as well as a lower rate of following principles identified as the best practice of anesthesiology. METHODS:A cross-sectional survey was sent to 2773 anesthesiology residents in the United States. The questionnaire was divided into 5 parts examining trainees’ demographic factors, burnout (Maslach Burnout Inventory), depression (Harvard depression scale), 10 questions designed to evaluate best practice of anesthesiology, and 7 questions evaluating self-reported errors. Best practices and self-reported error rates were compared among subjects with a high risk of burnout only, high risk of depression only, high risk of burnout and depression, and low risk of burnout and depression. Pairwise comparisons were considered significant at P < 0.004 and confidence intervals (CIs) reported at 99.6%. RESULTS:There were 1508 (54%) resident responds. High burnout risk was found in 41% (575 of 1417) of respondents. Working >70 hours per week, having >5 drinks per week, and female gender were associated with increased burnout risk. Twenty-two percent (298 of 1384) screened positive for depression. Working >70 hours of work per week, smoking, female gender, and having >5 drinks per week were associated with increased depression risk. Two hundred forty (17%) respondents scored at high risk of burnout and depression, 321 (23%) at high risk of burnout, 58 (4%) at high risk of depression only, and 764 (56%) at low risk of burnout or depression. Median best practice scores (maximum = 30) for residents at high risk of burnout (difference −2; 99.6% CI, −1 to −2; P < 0.001) or high risk of burnout and depression (difference −4; 99.6% CI, −3 to −6; P < 0.001) were lower than scores of residents at low risk for burnout or depression. Thirty-three percent of respondents with high burnout and depression risk reported multiple medication errors in the last year compared with 0.7% of the lower-risk responders (P < 0.001). CONCLUSION:Burnout, depression, and suicidal ideation are very prevalent in anesthesiology residents. In addition to effects on the health of anesthesiology trainees, burnout and depression may also affect patient care and safety.

Effect of dexmedetomidine on the minimum alveolar concentration (MAC) of sevoflurane in adults age 55 to 70 years

STUDY OBJECTIVE To determine the effect of two target dexmedetomidine infusions (0.3 ng/ml and 0.6 ng/ml) on the minimal alveolar concentration (MAC) of sevoflurane in adults age 55 to 70 years. DESIGN Prospective, randomized, placebo-controlled study. SETTING University-affiliated hospital. PATIENTS 45 ASA physical status I and II adults, age 55 to 70 years, undergoing elective surgery with at least a 3 inch skin incision. INTERVENTIONS Patients were given a dexmedetomidine or placebo infusion for at least 15 minutes before anesthetic induction with sevoflurane in oxygen by face mask. After tracheal intubation, a target sevoflurane concentration was maintained for 15 minutes while the dexmedetomidine or placebo infusion continued to run. MEASUREMENTS AND MAIN RESULTS At the time of skin incision, two observers independently determined movement or nonmovement to the incision. Blood samples for dexmedetomidine were taken before the infusion and at the time of skin incision. The dexmedetomidine plasma concentrations were 0 before infusion with all treatment groups. At the time of incision, they were 0 in the placebo group, 0.39 +/- 0.13 ng/ml in the 0.3 ng/ml target group, and 0.7 +/- 0.13 ng/ml in the 0.6 ng/ml target group. The MAC of sevoflurane was 1.83% in the placebo group, 1.78% in the 0.3 ng/ml target dexmedetomidine group, and 1.51% in the 0.6 ng/ml target dexmedetomidine group. CONCLUSIONS Dexmedetomidine 0.7 ng/ml decreased the MAC of sevoflurane by 17%, whereas there was no difference between the placebo and the dexmedetomidine 0.39 ng/ml group.

Systemic Lidocaine to Improve Postoperative Quality of Recovery After Ambulatory Laparoscopic Surgery

BACKGROUND:Perioperative systemic lidocaine has been shown to have beneficial postoperative analgesic effects. The only previous study examining the use of lidocaine in the outpatient setting did not detect an opioid-sparing effect after hospital discharge. More importantly, it is unknown whether systemic lidocaine provides a better postoperative quality of recovery to patients undergoing ambulatory surgery. Our objective in the current study was to examine the effect of systemic lidocaine on postoperative quality of recovery in patients undergoing outpatient laparoscopic surgery. METHODS:The study was a prospective, randomized, double-blind, placebo-controlled clinical trial. Healthy female subjects were randomized to receive lidocaine (1.5 mg/kg bolus followed by a 2 mg/kg/h infusion until the end of the surgical procedure) or the same volume of saline. The primary outcome was the Quality of Recovery-40 questionnaire at 24 hours after surgery. A 10-point difference represents a clinically relevant improvement in quality of recovery based on previously reported values on the mean and range of the Quality of Recovery-40 score in patients after anesthesia and surgery. Other data collected included opioid consumption, pain scores, and time to meet hospital discharge. Data were compared using group t tests and the Wilcoxon exact test. The association between opioid consumption and quality of recovery was evaluated using Spearman &rgr;. P < 0.01 was used to reject the null hypothesis for the primary outcome. RESULTS:Seventy subjects were recruited and 63 completed the study. There were no baseline differences regarding subject and surgical characteristics between the study groups. Patients in the lidocaine group had better global quality of recovery scores compared with the saline group, median difference of 16 (99% confidence interval [CI], 2–28), P = 0.002. Patients in the lidocaine group met hospital discharge criteria faster than the saline group, mean difference of −26 minutes (95% CI, −6 to −46 minutes) (P = 0.03). After hospital discharge, subjects in the lidocaine group required less oral opioids, median difference of −10 (95% CI, 0 to −30) (oral milligrams morphine equivalents), than the saline group (P = 0.01). There was an inverse association between postoperative opioid consumption and quality of recovery (&rgr; = 0.64, P < 0.001). CONCLUSIONS:Systemic lidocaine improves postoperative quality of recovery in patients undergoing outpatient laparoscopy. Patients who received lidocaine had less opioid consumption, which translated to a better quality of recovery. Lidocaine is a safe, inexpensive, effective strategy to improve quality of recovery after ambulatory surgery.

The accuracy of blood loss estimation after simulated vaginal delivery.

BACKGROUND:Visual blood loss estimation often underestimates blood loss. In this study we sought to determine the effect of calibrated drape markings on blood loss estimation in a simulated vaginal delivery. METHODS:Subjects were randomized to estimate simulated blood loss (300, 500, 1000, and 2000 mL) in calibrated or noncalibrated vaginal delivery drapes and then crossover. RESULTS:Visual blood loss estimation with noncalibrated drapes underestimated blood loss, with worsening accuracy at larger volumes (16% error at 300 mL to 41% at 2000 mL). The calibrated drape error was <15% at all volumes. CONCLUSIONS:Calibrated vaginal delivery drapes improve blood loss estimation.

Dose ranging study on the effect of preoperative dexamethasone on postoperative quality of recovery and opioid consumption after ambulatory gynaecological surgery

BACKGROUND Glucocorticoids are commonly administered before ambulatory surgery, although their effects on quality of recovery are not well characterized. The purpose of this study was to evaluate the dose-dependent effects of dexamethasone on patient recovery using the Quality of Recovery 40 questionnaire (QoR-40) after ambulatory surgery. METHODS This prospective, double-blind trial studied 106 female subjects undergoing outpatient gynaecological laparoscopy. Subjects were randomized to receive saline, dexamethasone 0.05 mg kg(-1) or dexamethasone 0.1 mg kg(-1) before induction. The primary outcome was global QoR-40 at 24 h. Postoperative pain, analgesic consumption, side-effects, and discharge time were also evaluated. RESULTS Global median (IQR) QoR-40 after dexamethasone 0.1 mg kg(-1) 193 (192-195) was greater than dexamethasone 0.05 mg kg(-1) 179 (175-185) (P=0.004) or saline, 171 (160-182) (P<0.005). Median (IQR) morphine equivalents administered before discharge were 2.7 (0-6.3) mg after dexamethasone 0.1 mg kg(-1) compared with 5.3 (2.4-8.8) mg and 5.3 (2.7-7.8) mg after dexamethasone 0.05 mg kg(-1) and saline (P=0.02). Time to meet discharge criteria was 30 min shorter after dexamethasone 0.1 mg kg(-1) compared with saline (P=0.005). At 24 h, subjects receiving dexamethasone 0.1 mg kg(-1) had consumed less opioid analgesics, reported less sore throat, muscle pain, confusion, difficulty in falling asleep, and nausea compared with dexamethasone 0.05 mg kg(-1) and saline. CONCLUSIONS Dexamethasone demonstrated dose-dependent effects on quality of recovery. Dexamethasone 0.1 mg kg(-1) reduced opioid consumption compared with dexamethasone 0.05 mg kg(-1), which may be beneficial for improving recovery after ambulatory gynaecological surgery.

A dose-ranging study of the effect of transversus abdominis block on postoperative quality of recovery and analgesia after outpatient laparoscopy.

BACKGROUND: Postoperative pain can delay functional recovery after outpatient surgery. Multimodal analgesia can improve pain and possibly improve quality of recovery. In this study, we evaluated the dose-dependent effects of a preoperative transversus abdominis plane (TAP) block on patient recovery using the Quality of Recovery 40 (QoR-40) questionnaire after ambulatory gynecological laparoscopic surgery. Global QoR-40 scores range from 40 to 200, representing very poor to outstanding quality of recovery, respectively. METHODS: Healthy women undergoing outpatient gynecological laparoscopy were randomly allocated to receive a preoperative TAP block using saline, ropivacaine 0.25%, or ropivacaine 0.5%. Needle placement for the TAP blocks was performed using ultrasound guidance and 15 mL of the study solution was injected bilaterally by a blinded investigator. QoR-40 score and analgesic use were assessed 24 hours postoperatively. The primary outcome was global QoR-40 score at 24 hours after surgery. Data were analyzed using the Kruskal-Wallis test. Post hoc pairwise comparisons were made using the Dunn test with P values and 95% confidence intervals Bonferroni corrected for 6 comparisons. RESULTS: Seventy-five subjects were enrolled and 70 subjects completed the study. The median (range) for the QoR-40 score after the TAP block was 157 (127–193), 173 (133–195), and 172 (130–196) for the saline group and 0.25% and 0.5% ropivacaine groups, respectively. The median difference (99.2% confidence interval) in QoR-40 score for 0.5% bupivacaine (16 [1–30], P = 0.03) and 0.25% bupivacaine (17 [2–31], P = 0.01) was more than saline but not significantly different between ropivacaine groups (−1 [−16 to 12], P = 1.0). Increased global QoR-40 scores correlated with decreased area under the pain score time curve during postanesthesia recovery room stay (&rgr; = −0.56, 99.2% upper confidence limit [UCL] = −0.28), 24-hour opioid consumption (&rgr; = −0.61, 99.2% UCL = −0.34), pain score (0–10 scale) at 24 hours (&rgr; = −0.53, 99.2% UCL = −0.25), and time to discharge readiness (&rgr; = −0.65, 99.2% UCL = −0.42). The aforementioned variables were lower in the TAP block groups receiving ropivacaine compared with saline. CONCLUSIONS: The TAP block is an effective adjunct in a multimodal analgesic strategy for ambulatory laparoscopic procedures. TAP blocks with ropivacaine 0.25% and 0.5% reduced pain, decreased opioid consumption, and provided earlier discharge readiness that was associated with better quality of recovery.

High incidence of burnout in academic chairpersons of anesthesiology: Should we be taking better care of our leaders?

Background: Burnout is a work-related psychologic syndrome characterized by emotional exhaustion, low personal accomplishment, and depersonalization. Methods: By using an instrument that included the MBI-HHS Burnout Inventory, we surveyed academic anesthesiology chairpersons in the United States. Current level of job satisfaction compared with 1 and 5 yr before the survey, likelihood of stepping down as chair in the next 2 yr, and a high risk of burnout were the primary outcomes. Results: Of the 117 chairs surveyed, 102 (87%) responded. Nine surveys had insufficient responses for assessment of burnout. Of 93 chairs, 32 (34%) reported high current job satisfaction, which represented a significant decline compared with that reported for 1 yr (P = 0.009) and 5 yr (P = 0.001) before the survey. Of 93 chairs, 26 (28%) reported extreme likelihood of stepping down as a chair in 1–2 yr. There was no association of age (P = 0.16), sex (P = 0.82), or self-reported effectiveness (P = 0.63) with anticipated likelihood of stepping down, but there was a negative association between the modified efficacy scale sco&rgr;rgr; = −0.303, P = 0.003) and likelihood of stepping down. Of 93 chairs, 26 (28%) met the criteria for high burnout and an additional 29 (31%) met the criteria for moderately high burnout. Decreased current job satisfaction and low self-reported spousal/significant other support were independent predictors of high burnout risk. Conclusion: Fifty-one percent of academic anesthesiology chairs exhibit a high incidence/risk of burnout. Age, sex, time as a chair, hours worked, and perceived effectiveness were not associated with high burnout; however, low job satisfaction and reduced self-reported spousal/significant other support significantly increased the risk.