Randomised trial of intranasal nicotine and postoperative pain, nausea and vomiting in non-smoking women.

BACKGROUND: The primary aim of this study is to test the hypothesis that intranasal nicotine reduces postoperative opioid use among non-smoking women. The second aim is to determine the effects of intranasal nicotine on the incidence of postoperative nausea and vomiting (PONV). METHODS: In this double-blind, randomised placebo-controlled trial, non-smoking women undergoing gynaecological procedures received either 3 mg intranasal nicotine (N=90) or placebo spray (N=89) at the conclusion of surgery. Postoperative opioid use (intravenous morphine equivalents) and PONV rates were recorded during the recovery room (postanaesthesia care unit, PACU) stay and first 24 postoperative hours. RESULTS: From an overall analysis, opioid dose administered within the first 24 h was lower in patients receiving nicotine [median (25th, 75th) 38 (17, 62) mg for placebo vs. 25 (13, 46) mg for nicotine; P=0.012]. Inpatients who received intranasal nicotine used less opioid. From an overall analysis, patients in the nicotine group were more likely to experience nausea (71.1 vs. 56.2% P=0.044), receive rescue antiemetics (57.8 vs. 38.2% P=0.011), and report higher Nausea Verbal Descriptive Scores [2 (0, 2; vs. 1 (0, 2), P=0.006] in PACU. Inpatients who received nicotine were more likely to receive antiemetics (P=0.009) and report higher Nausea Verbal Descriptive Scores (P=0.025) in the PACU. CONCLUSION: Intraoperative use of intranasal nicotine has a sustained opioid-sparing effect in non-smoking women undergoing gynaecological procedures and is associated with a higher frequency of PONV.

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.

Alveolar recruitment and arterial desflurane concentration during bariatric surgery.

BACKGROUND: We investigated whether reversal of intraoperative atelectasis with the lung recruitment maneuver (RM) affects desflurane arterial concentrations during bariatric surgery. METHODS: After anesthetic induction and maintenance with propofol, patients were randomized to receive alveolar RM at intervals (RM group) or not (controls). Desflurane 6% was initiated, and rate of increase of alveolar desflurane concentration (ratio of end-expiratory to inspiratory concentrations, F(A)/F(I)) and desflurane blood concentrations were measured in both groups. Blood and end-tidal desflurane concentrations were also measured after the discontinuation of anesthesia. RESULTS: The RM group had higher intraoperative Pao(2)/Fio(2) compared with the control group (both, P < 0.001). During induction, the rate of increase in blood desflurane concentrations was rapid in both groups. At comparable mechanical ventilation settings, median times to achieve 0.5 mM (approximately 3%) were 2.1 and 1.59 min (P = 0.09) in the control and RM group, respectively. The times to achieve 0.7 mM (approximately 4.2%) desflurane were 15.9 and 9.3 min in the control and RM group, respectively (P = 0.08). Desflurane blood concentrations tended to be higher during the first 30 min after induction in the RM group (P = 0.066). During maintenance or emergence, the blood desflurane concentrations were not different between control and RM groups. Consequently, the time to eye opening did not differ between groups. CONCLUSION: Although the RM during bariatric surgery represents an effective method for improving intraoperative oxygenation, it does not significantly affect the desflurane blood concentrations during anesthesia or its elimination during emergence.

A prospective trial of elective extubation in brain injured patients meeting extubation criteria for ventilatory support: a feasibility study.

INTRODUCTION: To assess the safety and feasibility of recruiting mechanically ventilated patients with brain injury who are solely intubated for airway protection and randomising them into early or delayed extubation, and to obtain estimates to refine sample-size calculations for a larger study. The design is a single-blinded block randomised controlled trial. A single large academic medical centre is the setting. METHODS: Sixteen neurologically stable but severely brain injured patients with a Glasgow Coma Score (GCS) of 8 or less were randomised to early or delayed extubation until their neurological examination improved. Eligible patients met standard respiratory criteria for extubation and passed a modified Airway Care Score (ACS) to ensure adequate control of respiratory secretions. The primary outcome measured between groups was the functional status of the patient at hospital discharge as measured by a Modified Rankin Score (MRS) and Functional Independence Measure (FIM). Secondary measurements included the number of nosocomial pneumonias and re-intubations, and intensive care unit (ICU) and hospital length of stay. Standard statistical assessments were employed for analysis. RESULTS: Five female and eleven male patients ranging in age from 30 to 93 years were enrolled. Aetiologies responsible for the neurological injury included six head traumas, three brain tumours, two intracerebral haemorrhages, two subarachnoid haemorrhages and three ischaemic strokes. There were no demographic differences between the groups. There were no unexpected deaths and no significant differences in secondary measures. The difference in means between the MRS and FIM were small (0.25 and 5.62, respectively). These results suggest that between 64 and 110 patients are needed in each treatment arm to detect a treatment effect with 80% power. CONCLUSIONS: Recruitment and randomisation of severely brain injured patients appears to be safe and feasible. A large multicentre trial will be needed to determine if stable, severely brain injured patients who meet respiratory and airway control criteria for extubation need to remain intubated.

Acute Physiology and Chronic Health Evaluation (APACHE) III outcome prediction after major vascular surgery.

OBJECTIVE: To investigate the performance of the Acute Physiology and Chronic Health Evaluation (APACHE) III scoring system in patients admitted to the intensive care unit (ICU) after major vascular surgery. DESIGN: Retrospective cohort study. SETTING: A tertiary referral center. PARTICIPANTS: Three thousand one hundred forty-eight patients who underwent major vascular surgery between October 1994 and March 2006. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Data were abstracted from an institutional APACHE III database. Standardized mortality ratios (SMRs) (with 95% confidence intervals) were calculated. The area under the receiver operating characteristic curve (AUC) and Hosmer-Lemeshow C statistic were used to assess discrimination and calibration, respectively. The mean age of 3,148 patients studied was 70.5 years (+/- standard deviation 9.6). The mean Acute Physiology Score and the APACHE III score on the day of ICU admission were 31.0 (+/- 17.5) and 45.1 (+/- 18.8), respectively. The mean predicted ICU and hospital mortality rates were 3.2% (+/- 7.8%) and 5.0% (+/- 9.5%), respectively. The median (and interquartile range) ICU and hospital lengths of stay were 4.3 (3.6-5.1) and 14 days (11.9-16.8 days), respectively. The observed ICU mortality rate was 2.4% (75/3, 148 patients) and hospital mortality rate was 3.7% (116/3,148). The ICU and hospital SMRs were 0.74 (0.58-0.91) and 0.74 (0.61-0.88), respectively. The AUC of APACHE III-derived prediction of hospital mortality was 0.840 (95% confidence interval, 0.799-0.880), indicating excellent discrimination. The Hosmer-Lemeshow C statistic was 28.492, with a p value <0.01, indicating poor calibration. CONCLUSIONS: The APACHE III scoring system discriminates well between survivors and nonsurvivors after major vascular surgery, but calibration of the model is poor.

Perioperative statin therapy and renal outcomes after major vascular surgery: a propensity-based analysis.

OBJECTIVE: To evaluate how the presence and timing of statin therapy affect perioperative renal outcomes after major vascular surgery. DESIGN: Retrospective cohort study. SETTING: Surgical intensive care unit at a single academic medical center. PARTICIPANTS: Patients undergoing major vascular surgery between July 2004 and October 2005. MEASUREMENTS AND MAIN RESULTS: The presence and timing of perioperative statin administration and the propensity for receiving such therapy were noted. Renal outcomes, lengths of stay, and mortality were reviewed. One hundred fifty-one procedures were performed. Eighty-nine patients (59%) received statin therapy. There was no evidence for renal protection with perioperative statin therapy (Delta creatinine 0.2 mg/dL v 0.2 mg/dL, p = 0.41; acute renal injury/acute renal failure 8% v 6%, p = 1.00; renal replacement therapy 3% v 3%, p = 1.00; all statin v no statin, respectively). With the possible exception of early reinstitution of statin therapy in chronic statin users, subgroup analyses failed to confirm an association between statin timing and prevention of postoperative renal dysfunction. CONCLUSIONS: In the present investigation, neither the presence nor timing of perioperative statin therapy was associated with improved renal outcomes in patients undergoing a range of major vascular procedures. A possible exception is early postoperative reinitiation of statin therapy in chronic statin users. The discrepant results of available literature preclude a definitive statement on the use of statin therapy as a means of preventing postoperative renal dysfunction. An adequately powered prospective trial is needed before advocating the routine use of statin therapy for perioperative renal protection.

The effects of the alveolar recruitment maneuver and positive end-expiratory pressure on arterial oxygenation during laparoscopic bariatric surgery.

Abnormalities in gas exchange that occur during anesthesia are mostly caused by atelectasis, and these alterations are more pronounced in morbidly obese than in normal weight subjects. Sustained lung insufflation is capable of recruiting the collapsed areas and improving oxygenation in healthy patients of normal weight. We tested the effect of this ventilatory strategy on arterial oxygenation (Pao2) in patients undergoing laparoscopic bariatric surgery. After pneumoperitoneum was accomplished, the recruitment group received up to 4 sustained lung inflations with peak inspiratory pressures up to 50 cm H2O, which was followed by ventilation with 12 cm H2O positive end-expiratory pressure (PEEP). The patient's lungs in the control group were ventilated in a standard fashion with PEEP of 4 cm H2O. Variables related to gas exchange, respiratory mechanics, and hemodynamics were compared between recruitment and control groups. We found that alveolar recruitment effectively increased intraoperative Pao2 and temporarily increased respiratory system dynamic compliance (both P < 0.01). The effects of alveolar recruitment on oxygenation lasted as long as the trachea was intubated, and lungs were ventilated with high PEEP, but soon after tracheal extubation, all the beneficial effects on oxygenation disappeared. The mean number of vasopressor treatments given during surgery was larger in the recruitment group compared with the control group (3.0 versus 0.8; P = 0.04). In conclusion, our data suggest that the use of alveolar recruitment may be an effective mode of improving intraoperative oxygenation in morbidly obese patients. Our results showed the effect to be short lived and associated with more frequent intraoperative use of vasopressors.

Intensive care unit readmission prevention checklist: is it worth the effort?

RATIONALE, AIMS AND OBJECTIVES: Checklists have been adopted by various institutions to improve patient outcomes. In particular, readmission prevention checklists may be of potential value to improve patient care and reduce medical costs. As a result, a prior quality improvement study was conducted to create an intensive care unit readmission prevention checklist. The previous pilot demonstrated zero readmissions when the readmission prevention checklist was utilized but yielded low compliance (30%). Thus, a subsequent quality initiative was undertaken to refine the readmission prevention checklist with the primary aim of improved compliance while maintaining a reduced readmission rate that was observed with the original quality improvement study. METHOD: A single-centre, cross-sectional study for assessing baseline data and a prospective observational study to assess the effectiveness of a refined readmission prevention checklist tool in a 20-bed tertiary medical-surgical intensive care unit at an academic medical centre in Rochester, MN was conducted. Medical patients admitted through the emergency department, upon direct transfer from outside facility, and post-operative surgical patients at our institution were included. A refined readmission prevention checklist tool was administered during an 8-week pilot period for medical and post-operative surgical patients. RESULTS: The refined readmission prevention checklist resulted in an even lower compliance (10.5%) from the initial phase likely resulting from utilization of a paper readmission prevention checklist in an electronic medical environment. Moreover, the refined readmission prevention checklist demonstrated a 22% unplanned readmission rate for patients in which the tool was utilized. CONCLUSIONS: In conclusion, the findings of the current quality improvement study may serve to rethink the process of health care delivery that applies paper tools in an electronic medical environment.

Postoperative emergency response team activation at a large tertiary medical center.

OBJECTIVE: To study characteristics and outcomes associated with emergency response team (ERT) activation in postsurgical patients discharged to regular wards after anesthesia. PATIENTS AND METHODS: We identified all ERT activations that occurred within 48 hours after surgery from June 1, 2008, through December 31, 2009, in patients discharged from the postanesthesia care unit to regular wards. For each ERT case, up to 2 controls matched for age (±10 years), sex, and type of procedure were identified. A chart review was performed to identify factors that may be associated with ERT activation. RESULTS: We identified 181 postoperative ERT calls, 113 (62%) of which occurred within 12 hours of discharge from the postanesthesia care unit, for an incidence of 2 per 1000 anesthetic administrations (0.2%). Multiple logistic regression analysis revealed the following factors to be associated with increased odds for postoperative ERT activation: preoperative central nervous system comorbidity (odds ratio [OR], 2.53; 95% confidence interval [CI], 1.20-5.32; P=.01), preoperative opioid use (OR, 2.00; 95% CI, 1.30-3.10; P=.002), intraoperative use of phenylephrine infusion (OR, 3.05; 95% CI, 1.08-8.66; P=.04), and increased intraoperative fluid administration (per 500-mL increase, OR, 1.06; 95% CI, 1.01-1.12; P=.03). ERT patients had longer hospital stays, higher complication rates, and increased 30-day mortality compared with controls. CONCLUSION: Preoperative opioid use, history of central neurologic disease, and intraoperative hemodynamic instability are associated with postoperative decompensation requiring ERT intervention. Patients with these clinical characteristics may benefit from discharge to progressive or intensive care units in the early postoperative period.

The acute physiology and chronic health evaluation III outcome prediction in patients admitted to the intensive care unit after pneumonectomy.

PURPOSE: The Acute Physiology and Chronic Health Evaluation (APACHE) III prognostic system has not been previously validated in patients admitted to the intensive care unit (ICU) after pneumonectomy. The purpose of this study was to determine if the APACHE III predicts hospital mortality after pneumonectomy. METHODS: A retrospective review of all adult patients admitted to a single thoracic surgical intensive care unit after pneumonectomy between October 1994 and December 2004. Patient demographics, ICU admission day APACHE III score, actual and predicted hospital mortality, and length of hospital and ICU stay data were collected. Data on preoperative pulmonary function tests and smoking habits were also collected. Univariate statistical methods and logistic regression were used. The performance of the APACHE III prognostic system was assessed by the Hosmer-Lemeshow statistic for calibration and area under receiver operating characteristic curve (AUC) for discrimination. RESULTS: There were 417 pneumonectomies performed during the study period, of which 281 patients were admitted to the ICU. The mean age was 61.1 years, and 67.2% were men; 88.2% were smokers with a median of 40.0 (interquartile range, 18-62) pack-years of tobacco use. The mean APACHE III score on the day of ICU admission was 37.7 (+/- standard deviation 17.8), and the mean predicted hospital mortality rate was 6.4% (+/-10.4). The median (and interquartile range) lengths of ICU and hospital stay were 1.7 (0.9-3.1) and 9.0 (7.0-17.0) days, respectively. The observed ICU and hospital mortality rates were 4.6% (13/281 patients) and 8.2% (23/281), respectively. The standardized ICU and hospital mortality ratios with their 95% confidence intervals (CIs) were 1.55 (0.71-2.39) and 1.27 (0.75-1.78), respectively. There were significant differences in the mean APACHE III score (p < 0.001) and the predicted mortality rate (p < .001) between survivors and nonsurvivors. In predicting mortality, the AUC of APACHE III prediction was 0.801 (95% CI, 0.711-0.891), and the Hosmer-Lemeshow statistic was 9.898 with a p value of 0.272. Diffusion capacity of the lung for carbon monoxide (DLCO) and percentage predicted DLCO were higher in survivors, but the addition of either of these variables to a logistic regression model did not improve APACHE III mortality prediction. CONCLUSIONS: In patients admitted to the ICU after pneumonectomy, the APACHE III discriminates moderately well between survivors and nonsurvivors. The calibration of the model appears to be good, although the low number of deaths limits the power of the calibration analysis. The use of APACHE III data in outcomes research involving patients who have undergone pneumonectomy is acceptable.

Management plan to reduce risks in perioperative care of patients with presumed obstructive sleep apnea syndrome.

STUDY OBJECTIVES: Obstructive sleep apnea (OSA) has been associated with increased perioperative morbidity and mortality. We initiated a protocol designed to screen patients preoperatively and monitor them postoperatively. The goal was to identify patients who were at risk for oxygen desaturation after discharge from the postanesthesia recovery room (PACU). METHODS: Patients without previously diagnosed OSA presenting to the preoperative evaluation clinic were assessed over a 10.5-month period using a validated prediction rule to identify patients thought to be at high risk of OSA (sleep apnea clinical score, SACS > or = 15). Following surgery, patients were monitored in the PACU for significant respiratory events: apnea, increased FiO2 requirement, pain-sedation mismatch, or episodes of desaturation. Patients were placed in 3 groups based on their SACS and the presence or absence of recurrent PACU respiratory events (group 1: SACS < 15, no recurrent events; group 2: SACS > or =15, no recurrent events; and group 3: SACS > or = 15, recurrent events.) The number of oxygen desaturations > or = 4% per hour, the oxygen desaturation index (ODI), was calculated for each patient for 24 to 48 hours after PACU discharge. An ODI > 10 was the threshold chosen to indicate a high frequency of oxygen desaturation. RESULTS: The percentage of patients with ODI > 10 differed significantly across the 3 study groups (12%, 37%, and 57%, for groups 1-3, p = 0.005). Mean ODI in group 1 was significantly different from groups 2 and 3 (5.8 compared to 10.0 group 2 and 11.4 group 3 with p = 0.001). CONCLUSIONS: We have shown that combining preoperative screening is useful for identifying patients at risk for oxygen desaturation after PACU discharge.

Prolonged coma from refractory status epilepticus.

OBJECTIVE: Status epilepticus is a life-threatening medical condition. In its most severe form, refractory status epilepticus (RSE) seizures may not respond to first and second-line anti-epileptic drugs. RSE is associated with a high mortality and significant medical complications in survivors with prolonged hospitalizations. METHODS: We describe the clinical course of RSE in the setting of new onset lupus in a 31-year-old male who required prolonged barbiturate coma. RESULTS: Seizure stopped on day 64 of treatment. Prior to the resolution of seizures, discussion around withdrawal of care took place between the physicians and patient's family. Medical care was continued because of the patient's age, normal serial MRI studies, and the patient's reversible medical condition. CONCLUSION: Few evidence-based data exist to guide management of RSE. Our case emphasizes the need for continuous aggressive therapy when neuroimaging remains normal.

Evidence-based red cell transfusion in the critically ill: quality improvement using computerized physician order entry.

OBJECTIVE: The implementation of evidence-based practice poses a significant challenge in the intensive care unit. In this quality improvement intervention we assessed the effect of an institutional protocol and computerized decision support for red cell transfusion in the critically ill. DESIGN: We compared processes of care and outcomes during the two 3-month periods before and after the introduction of a multidisciplinary quality improvement intervention. SETTING: Multidisciplinary intensive care units--medical, surgical, and mixed--in a tertiary academic center. PATIENTS: Consecutive critically ill patients with anemia (hemoglobin of <10 g/dL). INTERVENTION: Using the computerized provider order entry, we developed an evidence-based decision algorithm for red cell transfusion in adult intensive care units. MEASUREMENTS AND MAIN RESULTS: We collected information on demographics, diagnosis, severity of illness, transfusion complications, and laboratory values. The main outcome measures were number of transfusions, proportion of patients who were transfused outside evidence-based indications, transfusion complications, and adjusted hospital mortality. The mean number of red cell transfusions per intensive care unit admission decreased from 1.08 +/- 2.3 units before to 0.86 +/- 2.3 units after the protocol (p<.001). We observed a marked decrease in the percentage of patients receiving inappropriate transfusions (17.7% vs. 4.5%, p< .001). The rate of transfusion complications was also lower in the period after the protocol (6.1% vs. 2.7%, p = .015). In the multivariate analysis, protocol introduction was associated with decreased likelihood of red cell transfusion (odds ratio, 0.43; 95% confidence interval, 0.30 to 0.62). Adjusted hospital mortality did not differ before and after protocol implementation (odds ratio, 1.12; 95% confidence interval, 0.69 to 1.8). CONCLUSIONS: The implementation of an institutional protocol and decision support through a computerized provider order entry effectively decreased inappropriate red cell transfusions.

Inhaled anesthetics: an historical overview.

Inhalational agents have played a pivotal role in anesthesia history. The first publicly demonstrated anesthetic of the modern era, diethyl ether, was an inhalational anesthetic. The attributes of a good agent, ability to rapidly induce anesthesia, with limited side effects has led research efforts for over a hundred and fifty years. The explosion hazard was largely conquered with the development of the halogenated agents in the 1950s. Rapid emergence, with limited nausea and vomiting continue to drive discovery efforts, yet the 'modern' agents continue to improve upon those in the past. The future holds promise, but perhaps the most interesting contrast over time is the ability to rapidly introduce new agents into practice. From James Young Simpson's dinner table one evening to the operating suite the next day, modern agents take decades from first synthesis to clinical introduction.