Dilip Thakar

Cerebral oxygenation during warming after cardiopulmonary bypass

OBJECTIVES To evaluate jugular venous oxygen saturation (SjVO2), measured with a fiberoptic oximetry catheter, and brain tissue oxygen saturation, measured by near-infrared spectroscopy (NIRSO2), as monitors of cerebral oxygenation during cardiopulmonary bypass surgery. DESIGN Prospective, clinical study. SETTING Operating room of a Veterans Administration Hospital. PATIENTS Nineteen patients undergoing moderate hypothermic cardiopulmonary bypass surgery. INTERVENTIONS SjvO2 and NIRSO2 were monitored in the patients during the surgical procedure. MEASUREMENTS AND MAIN RESULTS Moderate hypothermic cardiopulmonary bypass surgery had two distinct cerebral hemodynamic phases. While the patients were hypothermic, SjvO2 averaged 80 +/- 7% and none of the patients had an increase in cerebral lactate production. During the rewarming period, however, reductions in SjvO2 to < 50% occurred in 16 (84%) patients and increased cerebral anaerobic metabolism developed in 11 (58%) patients. SjvO2 during rewarming was dependent on mean arterial pressure, with 60 mm Hg appearing to be a critical value. Two other factors appeared to also contribute to the jugular desaturation, a low hematocrit and a rapid warming time. The SjvO2 catheter had excellent performance during the surgery. The average difference between paired measurements of SjvO2 by the catheter and in blood samples was -0.4 +/- 4.25%, and the correlation between the two measurements was highly significant (r2 = .93; p < .001). The NIRSO2 trended with the SjvO2 in most patients (r2 = .63; p < .001). CONCLUSIONS The study confirms other studies showing that jugular venous desaturation can occur during rewarming after cardiopulmonary bypass surgery. Presently, SjvO2 appears to be a better monitor of cerebral oxygenation than NIRSO2. However, NIRSO2 has promise as a noninvasive monitor of cerebral oxygenation if future developments allow more quantitative measurements of oxygen saturation.

Effects of postoperative epidural analgesia on recurrence-free and overall survival in patients with nonsmall cell lung cancer ☆

STUDY OBJECTIVE To determine whether postoperative epidural analgesia is associated with better recurrence-free survival and overall survival after lung cancer surgery. DESIGN Retrospective study. SETTING Academic hospital. MEASUREMENTS Data of patients with stage 1, stage 2, and stage 3 nonsmall cell lung cancer, who underwent tumor resection surgery, were studied. Patient data were grouped into three different postoperative pain management interventions: intravenous patient-controlled analgesia, patient-controlled epidural analgesia, and their combination. Univariate and multicovariate Cox proportional hazards models were applied to assess the effects of covariates of interest on overall survival and recurrence-free survival. MAIN RESULTS The type of postoperative analgesia used for patients who underwent surgery for nonsmall cell lung cancer did not affect recurrence-free survival or overall survival. However, certain variables, including age ≥ 65 years, male gender, body mass index ≥ 25 kg/m(2), ASA physical status 4, and the need for preoperative blood transfusions, pneumonectomy, and postoperative radiation, were associated with decreased recurrence-free survival and overall survival. CONCLUSIONS The type of postoperative analgesia used after surgery for nonsmall cell lung cancer is not associated with better 2-year or 5-year recurrence-free survival or overall survival rates.

A Retrospective Evaluation of the Use of Video-Capable Double-Lumen Endotracheal Tubes in Thoracic Surgery

OBJECTIVE The objective of this study was to evaluate whether the use of a video double-lumen tube reduced the need for fiberoptic bronchoscopy for (1) verification of initial tube placement and for (2) reverification of correct placement after repositioning for thoracotomy. DESIGN A single-center retrospective study. SETTING Thoracic surgery in a medical university hospital. PARTICIPANTS & INTERVENTIONS After institutional review board approval, 29 patients who underwent thoracic surgical procedures using video double-lumen tubes were included in the final retrospective analysis. MEASUREMENTS AND MAIN RESULTS For 27 (93.2%) patients, the use of fiberoptic bronchoscopy was not needed either for initial placement or for verification of correct video double-lumen tube placement upon final positioning of the patient. However, for two patients, fiberoptic bronchoscopy was needed: for (1) one patient with severe left mainstem bronchus distortion as a result of a large left upper lobe tumor, and (2) a second patient with secretions that were difficult to clear. CONCLUSION This study demonstrates that the video double-lumen tube requires significantly less (6.8%) fiberoptic use for both initial placement and verification of final position, in stark contrast to standard practice in which bronchoscopy is always used to verify final positioning of the double-lumen tube. As opposed to intermittent bronchoscopy, the continuous visualization offered by an embedded camera may confer an added measure of safety.

A possible association between aprotinin and improved survival after radical surgery for mesothelioma

Aprotinin has been used to decrease blood loss with complicated cardiac surgery but has not been investigated in extrapleural pneumonectomy, an operation that does not use cardiopulmonary bypass. In this prospective, randomized, placebo‐controlled, double‐blind trial, the authors investigated whether aprotinin decreased blood loss in patients who underwent this operation.

Use of deep intravenous sedation with propofol and the laryngeal mask airway during transesophageal echocardiography

OBJECTIVE To describe the use of either deep intravenous sedation with propofol or light sedation with midazolam and topical anesthesia during transesophageal echocardiography (TEE) and to report the incidence of respiratory complications and their management. DESIGN Retrospective study from March 2000 through August 2002. SETTING Single institution, specialized cancer center. PARTICIPANTS All patients undergoing TEE examination in the specified time period (n = 42). MAIN RESULTS Eight patients received light sedation and 34 patients received deep intravenous sedation with propofol. An airway event occurred in one patient in the light sedation group and in six patients in the deep sedation group. The patient in the light sedation group was managed with the use of a face-mask and a manual resuscitation bag. All airway events in the deep sedation group were managed successfully using the laryngeal mask airway (LMA). CONCLUSION Deep sedation with intravenous propofol can provide both excellent patient comfort and optimal conditions for TEE examination, particularly in patients who may require more lengthy procedures or in whom other techniques have failed. Although the incidence of respiratory depression was higher in patients receiving deep sedation with propofol than in patients who were lightly sedated (17.6% versus 12.5%, respectively), all six patients who had respiratory depression while under deep sedation with propofol were successfully ventilated using the LMA trade mark, without the need to remove the TEE probe and without terminating the examination prematurely. In contrast, in the one patient in the light sedation group who had respiratory depression, the TEE probe had to be removed to ventilate the patient via a face mask, and the procedure was cancelled.

Aprotinin significantly decreases transfusion rates in extrapleural pneumonectomy

INTRODUCTION: Aprotinin (TrasylolTM Bayer Corporation, West Haven, CT) is a serine protease inhibitor, which inhibits all serine proteases including plasmin. It has been used to significantly decrease blood loss during repeat cardiac surgery utilizing cardiopulmonary bypass and is currently the only pharmacologic agent approved by the FDA for this purpose. The operation of extrapleural pneumonectomy (EPP), done almost exclusively for mesothelioma, is associated with the potential for significant blood loss due to the large raw surface of the hemithorax left behind after resection of the parietal pleura. We investigated whether aprotinin would decrease blood loss and transfusion requirement in this major operation.