Hypotension in spinal anesthesia for cesarean section: a comparison of 0.5% hyperbaric bupivacaine and 5% hyperbaric lidocaine.

Hypotension is a common side effect associated with spinal anesthesia. However, there is no previous report comparing the incidence of hypotension between two commonly used local anesthetic agents, bupivacaine and lidocaine. The objective of this study was to compare the incidence of spinal hypotension induced by bupivacaine and lidocaine in parturients undergoing cesarean section. A double blind, randomized controlled trial was conducted in 142 parturients scheduled for cesarean section. The patients were randomized into two groups, 71 each. After receiving 10 ml/kg of normal saline intravenously, patients in the first group were given 2.2 ml of 0.5 per cent hyperbaric bupivacaine plus 0.2 mg of morphine as a spinal anesthetic agent while in the other group, 1.2 ml of 5 per cent hyperbaric lidocaine plus 0.1 mg of epinephrine and 0.2 mg of morphine were administered. Hypotension, defined as 30 per cent less systolic blood pressure than baseline value, was recorded and the patients were treated with 6 mg of ephedrine every 2 minutes until normotension was achieved. There was no statistically significant difference of incidence, onset, duration, and severity of hypotension between the two groups (p > 0.05). The amount of ephedrine used in both groups was also not significantly different. Late onset hypotension occurred after delivery (20-22 minutes after spinal anesthesia was performed) in 17 patients (12%). As such, the rate of hypotension in lidocaine group was comparable to bupivacaine group. Delayed onset hypotension occurring after delivery was noted and these events have never been described. However, the mechanism of late onset hypotension remains unidentified. Thus, bupivacaine and lidocaine can be used interchangeably for spinal anesthesia for elective cesarean section without significant difference in the incidence of hypotension.

Learning manual skills in spinal anesthesia and orotracheal intubation: is there any recommended number of cases for anesthesia residency training program?

Wide variability exists in the number of anesthetic procedures to which anesthesia residents are exposed during their training. The number of attempts at various procedures before a trainee becomes proficient at performing each anesthetic procedure is not known. To determine the learning process of 150 attempts of spinal anesthesia and 100 attempts of orotracheal intubation, the two most frequent anesthetic procedures, we evaluated 9 first-year anesthesia residents according to their rate of success or failure. The learning curves of both procedures revealed an initial rapid improvement of success during the first 20 attempts. Spinal anesthesia was more difficult to learn (p=0.0002) but the learning curves of spinal anesthesia and orotracheal intubation reached a nondifferent high success rate of 82 per cent and 88.9 per cent respectively (p=0.13). According to this study the institutional recommended number of cases for spinal anesthesia and orotracheal intubation were 112 and 27 cases respectively.

Anesthetic management of cerebral aneurysm clipping using the deep hypothermic circulatory arrest technique: a case report.

Deep hypothermic circulatory arrest may prove advantageous during surgery of some technically difficult brain lesions. This technique was first applied in one patient with a large intracavernous aneurysm which had failed standard neurosurgical techniques. For this technique to be successful the cooperation of neurosurgeons, cardiovascular surgeons, anesthesiologists, perfusionists and nurses is essential. Techniques aimed at improving the outcome include a short period of circulatory arrest, the depth of hypothermia, barbiturate administration, coagulation management and well-controlled blood glucose levels. The total time of circulatory arrest and the thiopentone dosage were 61 minutes and 1,700 mg respectively. The lowest core temperature was 13.9 degrees C. The positive outcome supports the use of this technique in selected patients with complex intracranial vascular lesions who may not be operable by standard techniques.

Comparison of ondansetron and placebo for preventing postoperative nausea and emesis in gastrointestinal tract surgery: a multicenter randomized controlled trial.

BACKGROUND: Nausea and emesis are undesirable events that may cause discomfort and suffering in the postoperative period. This study was carried out to evaluate the efficacy and safety of ondansetron for preventing postoperative nausea and vomiting in patients undergoing gastrointestinal tract surgery. METHODS: Using a randomized double-blind study design, 408 surgical patients (163 male and 245 female) receiving general endotracheal anesthesia were studied at five medical centers in Bangkok. Ondansetron (4 mg) or placebo was administered prior to induction of anesthesia. Episodes of nausea and vomiting, adverse events and laboratory tests (complete blood count and liver function test) were evaluated during 24 hours after study drug administration. RESULTS: The incidence of postoperative nausea and vomiting in the placebo group (42.7 and 35.2%) were significantly higher than the ondansetron group (23.9 and 15.4%). However, no significant differences occurred in the incidence of adverse events or changes in laboratory tests in the ondansetron group compared to the placebo group. CONCLUSIONS: Ondansetron 4 mg given intravenously before surgery is safe and effective for preventing postoperative nausea and emesis following gastrointestinal tract surgery.

Cardiovascular and respiratory changes in laparoscopic cholecystectomy.

Although laparoscopic cholecystectomy has several advantages over the traditional open cholecystectomy, it may however cause some adverse cardiovascular and respiratory effects associated with intraperitoneal insufflation of CO2. It is, therefore, recommended that appropriate hemodynamic and respiratory monitorings should be used routinely in order to prevent deleterious complications, especially in high risk patients.