Hugh Flanagan

Incidence and morbidity of extubation failure in surgical intensive care patients.

The rate of extubation failure (reintubation rate) was determined for 700 consecutive extubations in surgical patients admitted to one of two ICUs. Patients were weaned in a standardized fashion and extubated using a standardized gas exchange and mechanics criteria. Of 400 extubations in the general surgical ICU, there were 22 reintubations in 20 patients. Average age was 65 yr, and the major reason for reintubation was need for positive-pressure ventilation. Morbidity (pulmonary edema and/or pneumonia) was 36%, and the inhospital mortality was 40% in this group. The major cause of death was progressive cardiopulmonary failure. There were 10 failures in eight patients, of 300 extubations in the Burn/Trauma unit, where the mean age was 44 yr. Five failures occurred in patients with smoke inhalation and burns, a 13% incidence in this population. The reason for reintubation was airway maintenance and pulmonary toilet. Four failures occurred in head injury patients, a 5% incidence with the major reason for reintubation being airway protection. Morbidity was 60% (new pulmonary infiltrates), while mortality rate was only 10% in this group. Only one failure was noted in a nonhead-injured trauma patient. In no group studied were any predictors of extubation failure detected. We conclude that the incidence, reasons for, and outcome of reintubations in surgical ICU patients varies dramatically depending on the underlying disease process. Overall failure rate was 4%.

Comparison of bupivacaine- and ropivacaine-induced conduction blockade in the isolated rabbit vagus nerve

Ropivacaine (LEA-103) is a new amino-amide local anesthetic agent the chemical structure and anesthetic properties of which are similar to bupivacaine. Preliminary studies in animals indicate that the CNS toxicities of ropivacaine and bupivacaine are similar, but that ropivacaine may have less arrhythmogenic effects than bupivacaine. The current study was designed to compare the in vitro potency, onset and recovery from block of ropivacaine and bupivacaine using an isolated rabbit vagus nerve model. The effect of varying concentrations of ropivacaine and bupivacaine on the compound action potential of A and C nerve fibers was assessed to determine whether motor and sensory fibers have different sensitivities to the two agents. The results showed that the depressant effect of bupivacaine was 16% greater than that of ropivacaine on motor fibers, but only 3% greater on sensory fibers. An analysis of variance indicated that this was a statistically significant difference (P=0.028). Thus, at the concentrations tested, ropivacaine appears to produce relatively less blockade of motor fibers than does bupivacaine but with similar sensory blockade. The onset of this difference became significant as early as five minutes after the drug exposure was begun. No significant differences in recovery times were observed.

Improvement of intraoperative antibiotic prophylaxis in prolonged cardiac surgery by automated alerts in the operating room.

OBJECTIVE To assess the impact of an automated intraoperative alert to redose prophylactic antibiotics in prolonged cardiac operations. DESIGN Randomized, controlled, evaluator-blinded trial. SETTING University-affiliated hospital. PATIENTS Patients undergoing cardiac surgery that lasted more than 4 hours after the preoperative administration of cefazolin, unless they were receiving therapeutic antibiotics at the time of surgery. INTERVENTION Randomization to an audible and visual reminder on the operating room computer console at 225 minutes after the administration of preoperative antibiotics (reminder group, n = 137) or control (n = 136). After another 30 minutes, the circulating nurse was required to indicate whether a follow-up dose of antibiotics had been administered. RESULTS Intraoperative redosing was significantly more frequent in the reminder group (93 of 137; 68%) than in the control group (55 of 136; 40%) (adjusted odds ratio, 3.31; 95% confidence interval, 1.97 to 5.56; P < .0001). The impact of the reminder was even greater when compared with the 6 months preceding the study period (129 of 480; 27%; P < .001), suggesting some spillover effect on the control group. Redosing was formally declined for 19 of the 44 patients in the reminder group without redosing. The rate of surgical-site infection in the reminder group (5 of 137; 4%) was similar to that in the control group (8 of 136; 6%; P = .42), but significantly lower than that in the pre-study period (48 of 480; 10%; P = .02). CONCLUSION The use of an automatic reminder system in the operating room improved compliance with guidelines on perioperative antibiotic prophylaxis.

Effect of pregnancy on bupivacaine-induced conduction blockade in the isolated rabbit vagus nerve

Bupivacaine-induced conduction blockade of A, B, and C fibers of the isolated vagus nerve was compared in fourteen pregnant and fourteen nonpregnant rabbits. After a control period in HEPES-Liley solution, the isolated nerves were exposed to bupivacaine concentrations of 0.1 mM to 1.0 mM. After 30 min exposure, the nerves were stimulated supramaximally and the percent reduction in amplitude of A, B, and C fiber compound action potentials was recorded. Linear regressions were fitted by the least squares method. The A fiber conduction blockade was consistently greater in the nerves from pregnant rabbits (P less than 0.001). The slope of the C fiber dose-response curves was also significantly greater in nerves from pregnant rabbits (P less than 0.01). The results indicate that the response of isolated nerves from pregnant animals to local anesthetic-induced conduction blockade differs from that of nerves from nonpregnant animals. However, it is not certain whether the difference is related simply to a more rapid diffusion and shorter onset of block or an enhanced sensitivity of the nerve membrane during pregnancy.

Introduction of Anesthesia Resident Trainees to the Operating Room Does Not Lead to Changes in Anesthesia- controlled Times for Efficiency Measures

Background:Operating room efficiency is an important concern in most hospitals today. Little work has been reported to evaluate the contribution of anesthesia residents to changes in anesthesia-controlled time-related efficiencies in the operating room. The goal of this study was to measure the impact of the initiation of new residents to the operating room on anesthesia-related time measures of operating room efficiency. Methods:Using the computerized operating room information systems, specific data regarding anesthesia-controlled times were extracted over three distinct 2-week periods over the course of 1 academic year. These included the first 2 weeks of July, when most of the operating rooms were staffed by attending physicians working alone; 2 weeks in September when new anesthesia residents were working in a 2:1 ratio with staff; and 2 weeks in May. The induction times, emergence times, and room turnover times were compared over these three periods for first-year anesthesia residents. Standard descriptive statistics were computed. Analysis of variance testing was then conducted comparing each of these time periods. Significance was set at P < 0.05. Results:A total of 3,004 surgical procedures were performed during the 2-week study periods in July, September, and May, respectively. For the July, September, and May groups, the mean anesthesia induction times were 17.3, 19.0, and 20.8 min (P = 0.047); the emergence times were 8.7, 9.7, and 10.0 min, (P = 0.024); and the corresponding mean room turnover times were 47.6, 48.5, and 48.6 min (P = 0.907), respectively. Conclusion:Although statistically significant time differences were found, these data strongly suggest that the initiation of anesthesia trainees to the operating room has no clinically or economically meaningful adverse effect on the anesthesia-controlled time component of operating room efficiency.

Chronically Administered Progesterone Decreases Halothane Requirements in Rabbits

The MAC for halothane is 25% lower in pregnant than that in nonpregnant ewes. The reason for this is uncertain, but changes in both steroidal and endogenous opiate have been implicated. This study was undertaken to assess the effect of exogenous progesterone on minimal alveolar concentrations (MAC) of halothane in ovariectomized rabbits. Minimal alveolar concentration of halothane was determined in 84 female rabbits, 37 intact (group A), 20 ovariectomized and injected with inert carrier peanut oil (group B), and 27 ovariectomized and injected with progesterone in peanut oil (group C). Minimal alveolar concentration in group A, 1.68 ± 0.06% (mean ± SEM), did not differ significantly from that in group B rabbits, 1.77 ± 0.06%. However, MAC in progesterone-treated rabbits, 1.48 ± 0.06%, was significantly lower than the MAC of the other two groups (P < 0.01). Plasma progesterone concentrations in group A, B, and C were 5.28 ± 0.62 nglml, 6.83 ± 2.00 nglml, and 37.33 ± 4.25 nglml, respectively. These results suggest that experimental treatment with progesterone can reduce the amount of halothane required to produce anesthesia and may explain the phenomenon of decreased need of inhalation anesthetic in human parturients.

Decreased incidence of tourniquet pain during spinal anesthesia with bupivacaine. A possible explanation.

In a previous report, the incidence of tourniquet pain was found to be 25% with bupivacaine and 60% with tetracaine (P < 0.05) spinal anesthesia. On the other hand, tetracaine is more potent than bupivacaine in abolishing the single-compound action potential in vitro in isolated nerves. These conflicting observations may be reconciled if bupivacaine produced greater frequency-dependent conduction blockade of nerve action potentials. This hypothesis was tested in C fibers of isolated, desheathed rabbit vagus nerves. The nerves were supramaximally stimulated at frequencies of 9 or 15 Hz. After a control period, the nerves were exposed to bupivacaine (0.2 mM) or tetracaine (0.02 mM) for 30 minutes. The local anesthetics were then washed out by continuous constant-rate perfusion. The decline and recovery of the first and last action potential amplitudes of the train were measured. Bupivacaine and tetracaine produced similar depression of the first action potential of the 9-Hz and 15-Hz trains. However, bupivacaine caused a delayed recovery of the last action potential of the 15-Hz train but not of the 9-Hz train. These results show that bupivacaine produces greater frequency-dependent conduction blockade of C fibers than does tetracaine. These findings offer a possible explanation as to why spinal anesthesia with bupivacaine results in a lower incidence of tourniquet pain than tetracaine.

Brachial plexus injury from CT-guided RF ablation under general anesthesia.

Brachial plexus injury in a patient under general anesthesia (GA) is not uncommon, despite careful positioning and, particularly, awareness of the possibility. The mechanism of injury is stretching and compression of the brachial plexus over a prolonged period. Positioning the patient within the computed tomography (CT) gantry for abdominal or chest procedures can simulate a surgical procedure, particularly when GA is used. The potential for brachial plexus injury is increased if the case is prolonged and the patient’s arms are raised above the head to avoid CT image degradation from streak artifacts. We report a case of profound brachial plexus palsy following a CT-guided radiofrequency ablation procedure under GA. Fortunately, the patient recovered completely. We emphasize the mechanism of injury and detail measures to combat this problem, such that radiologists are aware of this potentially serious complication.

Process Redesign to Improve First Case Surgical Starts in an Academic Institution

ABSTRACT Purpose: On time start of the first surgical case improves operating room (OR) utilization, physician, and patient satisfaction and decreases delays in subsequent cases. The goal of our study was to evaluate the effect of a multidisciplinary initiative to improve first patient in the room (FPIR) and first case on time start (FCOTS) metrics in a tertiary care setting. Materials and Methods: A multidisciplinary committee focused on first case start data collection. Reasons for both anesthesia and surgical delays were analyzed. Improvement efforts focused on the timely completion of surgical consent, a requirement of a surgical, anesthesia, and nurse team member presence at the patients bedside by specific time, and parallel processing in the OR. Results: Over 65,100 OR cases were analyzed between 2007 and 2014. There was a statistically significant improvement in FPIR (82.80% versus 69.60%, p < .0001) and FCOTS (66.60% versus 55.90%, p < .0001). Surgical consent completion rate increased from 35% baseline to 68%–100%, depending on the surgical subspecialty. Improvements appeared sustainable several years following process implementation for both FPIR (84.60% versus 69.60%, p < .0001) and FCOTS (67.60% versus 55.90%, p < .0001). Conclusions: Our study demonstrates a successful targeted, multidisciplinary initiative to improve first case surgical starts in an academic setting. Our approach was organizational rather than punitive or rewarding on an individual basis. Strategies included establishing concrete, time-specific goals and posting them visibly, empowering individuals to fulfill them, and ensuring no compromise in patient safety. In the complex environment of academic medicine including research protocols and teaching in the ORs, our organizational approach proved sustainable over several years.

Strategies to maintain operating room functionality following the complete loss of the recovery room due to an internal disaster

The post-anesthesia care unit (PACU) is a major contributor to the operating room (OR) process flow and efficiency. A sudden failure of hospital facility infrastructure due to a burst pipe resulted in the complete loss of a 66-bed combined preoperative and PACU facility of a major academic medical center. The OR suites were undamaged. The clinical and administrative challenges of caring for surgical patients without the usual preoperative and postoperative care areas are discussed. Our strategy for maintaining OR functions and management of patient flow, OR personnel, case prioritization, and equipment needs are detailed from the time of initial crisis until restoration of these clinical care areas. Utilization of the hospital disaster Incident Command Structure and the activation and decision support provided by the hospital Emergency Operations Center (EOC) for the week immediately following the crisis, helped maintain OR functionality.