Randomized comparison of isoflurane and sevoflurane for laparoscopic gastric banding in morbidly obese patients.

STUDY OBJECTIVE: To compare the efficacy and recovery profile of sevoflurane and isoflurane as the main anesthetics for morbidly obese patients. DESIGN: Randomized, blinded study. SETTING: Inpatients. PATIENTS: 30 ASA physical status II and III obese patients [body mass index (BMI) > 35 kg/m(2)] undergoing laparoscopic gastric banding for morbid obesity. INTERVENTIONS: After standard intravenous induction of general anesthesia and tracheal intubation, anesthesia was maintained with either sevoflurane or isoflurane as the main anesthetics. The end-tidal concentrations of the volatile drugs were adjusted to maintain systolic arterial blood pressure within +/-20% from baseline values. When the surgeon started the skin suture, the end-tidal concentration of the inhalational drug was reduced to 0.5 minimum alveolar concentration in both groups. At the last skin suture, the inhalational drug was discontinued and the vaporizator was removed to allow blinded evaluation of the emergence times. MEASUREMENTS AND MAIN RESULTS: No differences in anesthetic exposure, hemodynamic parameters, incidence of untoward events, or postoperative pain relief were reported between the two groups. Extubation, emergence, and response times were shorter after sevoflurane [6 min (3-15 min), 8 min (5-18 min), and 12 (6-25 min)] than isoflurane [10 min (6-26 min), 14 min (6-21 min), and 21 min (14-41 min)] (p = 0.001, p = 0.03, and p = 0.0005, respectively). The median time for postanesthesia care unit discharge was 15 minutes (25th-75th percentiles: 10-18 min) after sevoflurane and 27 minutes (25th-75th percentiles: 20-30 min) after isoflurane (p = 0.0005). CONCLUSIONS: Sevoflurane provides a safe and effective intraoperative control of cardiovascular homeostasis in morbidly obese patients undergoing laparoscopic gastric banding, with the advantage of a faster recovery and earlier discharge from the postanesthesia care unit than isoflurane.

Effects of pneumoperitoneum and reverse Trendelenburg position on cardiopulmonary function in morbidly obese patients receiving laparoscopic gastric banding.

We prospectively evaluated the effects of pneumoperitoneum and reverse Trendelenburg position on cardiopulmonary function in 20 ASA physical status II-III morbidly obese patients (body mass index > 35 kg m(-2)) undergoing laparoscopic gastric banding. After general anaesthesia was induced, patients' lungs were ventilated using intermittent positive pressure ventilation (at measurement times, the following parameters were used: tidal volume 12 mL kg(-1) ideal body weight, respiratory rate of 12 bpm, an inspiratory to expiratory time ratio of 1:2). Haemodynamic variables, blood gas parameters, and lung/chest compliance were recorded: in the supine position, after induction of general anaesthesia (T0, baseline) and induction of pneumoperitoneum (T1); after placing the patient in a 25 degree reverse Trendelenburg position (T2); during the surgical time (T3); before deflating the abdomen (T4); after pneumoperitoneum resolution (T5), and before the end of anaesthesia, with the patient supine (T6). The PaO2, PaO2/FiO2 ratio, and lung/chest compliance decreased during the study. After the pneumoperitoneum had been resolved, lung/chest compliance but not oxygenation parameters returned to baseline values. The arterial to end-tidal CO2 tension difference progressively increased from 0.38+/-0.3 kPa (2.85+/-2.25 mmHg) (T0) to 0.63+/-0.3 kPa (4.73+/-2.25 mmHg) (T6). In morbidly obese patients, undergoing laparoscopic gastric banding, a CO2 pneumoperitoneum markedly affected gas exchange and lung/chest compliance, while positioning the patient in a 25 degree reverse Trendelenburg position had no beneficial effects.

0.2% ropivacaine with or without fentanyl for patient-controlled epidural analgesia after major abdominal surgery: a double-blind study.

STUDY OBJECTIVE: To evaluate the effects of adding low concentration of fentanyl to 0.2% ropivacaine when providing patient-controlled epidural analgesia (PCEA) outside the Post-Anesthesia Care Unit. DESIGN: Prospective, randomized, double-blind study. SETTING: Inpatients at a University Department of Anesthesia. PATIENTS: 32 ASA physical status I, II, and III patients, who were scheduled for elective major abdominal surgery, including bowel resection, hepatic resection, and pancreaticoduodenectomy. INTERVENTIONS: Patients received standard general/epidural anesthesia. After surgery patients were randomly allocated in a double-blind fashion to receive PCEA with either 0.2% ropivacaine (n = 16) or 0.2% ropivacaine/2 microg/mL fentanyl (n = 16) [background infusion ranging between 4 and 6 mL/hr, with 1.5-mL incremental doses and a 20-min lock-out time]. Dynamic pain during coughing, sedation, pulse oxymetry, hemodynamic variables, and motor block were evaluated at 1, 6, 12, 24, and 48 hours after the end of surgery by a blinded observer. Occurrence of untoward events, including nausea, vomiting, pruritus, need for supplemental oxygen (for SpO(2) < 90%), and respiratory complications, as well as total consumption of PCEA solution and incremental doses given to the patient were also recorded. MEASUREMENTS AND MAIN RESULTS: No differences in pain relief, motor block, degree of sedation, recovery of gastrointestinal motility, and other side effects were observed between the two groups. Patients receiving 0.2% ropivacaine alone requested far more incremental doses (23 doses [0-60] vs. 5 doses [0-25]) (p = 0.006) and needed far more analgesic solution (230 mL [140-282] vs. 204 [130-228]) (p = 0.003) than patients receiving the ropivacaine/fentanyl mixture. Peripheral oxygen saturation was lower at 12, 24, and 48 hours during ropivacaine/fentanyl infusion than in patients receiving ropivacaine alone (12 h: 91% +/- 2% vs. 95% +/- 2%, p < 0.006; 24 h: 93% +/- 1% vs. 96% +/- 2%, p = 0.003; 48 h: 92% +/- 1.8% vs. 96% +/- 1%, p = 0.004). CONCLUSIONS: A thoracic epidural infusion of 0.2% ropivacaine, with or without fentanyl, provided effective pain relief in most patients with a very low degree of motor blockade. Adding 2 microg/ml fentanyl to 0.2% ropivacaine reduced total consumption of local anesthetic solution and need for incremental doses, but did not provide clinically relevant advantages in quality of pain relief and incidence of motor block, leading to a significant decrease in peripheral SpO(2), lasting up to 48 hours after surgery.

[Comparison of the diagnostic efficacy of various in vitro tests for the study of thyroid performance (author's transl)]. / Valutazione comparativa della efficacia diagnostica di alcuni test in vitro per lo studio della funzionalità tiroidea

Discriminating analysis was employed in an evaluation of the diagnostic efficacy of individual in vitro tests of thyroid performance (T3 resin uptake, T4, FTI, ETR) and PB131I determination, and their combinations, when used for the differentiation of euthyroid, Basedow hyperthyroid, hyperfunctioning autonomous adenoma, and hypothyroid cases. The results are discussed with reference to optimization of the data: radiation dose ratio.