Anesthesia and analgesia
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Anesthesia and analgesia · May 2000
Randomized Controlled Trial Comparative Study Clinical TrialIntrathecal fentanyl is superior to intravenous ondansetron for the prevention of perioperative nausea during cesarean delivery with spinal anesthesia.
This study compares intrathecal (IT) fentanyl with IV ondansetron for preventing intraoperative nausea and vomiting during cesarean deliveries performed with spinal anesthesia. Thirty healthy parturients presenting for elective cesarean delivery with standardized bupivacaine spinal anesthesia were randomized to receive 20 microg IT fentanyl (Group F) or 4 mg IV ondansetron (Group O) by using double-blinded methodology. At eight specific intervals during the surgery, a blinded observer questioned the patient about nausea (1 = nausea, 0 = no nausea), observed for the presence of retching or vomiting (1 = vomiting or retching, 0 = no vomiting or retching), and recorded a verbal pain score (0-10, 0 = no pain, 10 = worst pain imaginable). ⋯ The IT fentanyl group had a lower cumulative perioperative pain score than the IV ondansetron group; the median difference in the cumulative pain score was 12 (8, 16) (P = 0.0007). The IT fentanyl group required less supplementary intraoperative analgesia. The median difference in the cumulative fentanyl dose was 100 (75, 100) microg fentanyl, (P = 0.0002).
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Anesthesia and analgesia · May 2000
Randomized Controlled Trial Clinical TrialDetermining minimum effective anesthetic concentration of hyperbaric bupivacaine for spinal anesthesia.
We determined the minimum effective anesthetic concentration (MEAC) of bupivacaine for spinal anesthesia, defined as the median effective concentration at which a spinal anesthetic produces surgically equivalent anesthesia within 20 min of administration in 50% of human subjects. Two doses of spinal bupivacaine (7.5 mg and 10 mg) were administered to 45 volunteers (19-39 yr) in a randomized, double-blinded fashion. Hyperbaric bupivacaine solutions of 0.1% to 0.75% containing 8.25% dextrose were administered intrathecally and MEAC established by using the Dixon's up-and-down method. ⋯ At this dose, a concentration as low as 0.1% could provide complete anesthesia, but consistent blockade was obtained only with the 0.7% solution. The 7.5-mg dose failed to provide complete anesthesia consistently, even in the presence of 0.75% (maximum). The current commercially available 0.75% concentration of hyperbaric bupivacaine seems to be clinically optimal when 10 mg is used if complete bilateral lower extremity blockade is desired.
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Anesthesia and analgesia · May 2000
Randomized Controlled Trial Clinical TrialInhaling nitrous oxide reduces the induction dose requirements of propofol.
Inhaling nitrous oxide (N(2)O) before propofol induction appears to decrease propofol usage. To investigate the efficacy of N(2)O as a component of the drugs used to induce anesthesia, the effect of inhaling a N(2)O:oxygen (O(2)) mixture on the dose of propofol required to induce anesthesia was determined in a double-blinded manner. We randomized 117 unpremedicated patients scheduled for elective surgery into three groups. ⋯ Propofol was infused at 20 mg/min after 1 min of gas mixture inhalation, and the infusion stopped when there was loss of response to verbal command. The mean (SD) propofol dose was 0.75 (0.30), 0.84 (0.26), and 1.33 (0.51) mg/kg, and the induction time 133 (57), 142 (47), and 226 (78) s for Groups FN, PN, and FO, respectively. We conclude that inhalation of 66% N(2)O in O(2) 1 min before the IV induction of anesthesia with propofol at 20 mg/min, reduces the induction dose of propofol by 44% and decreases the time required for the induction of anesthesia (P < 0.001).
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Anesthesia and analgesia · May 2000
Randomized Controlled Trial Clinical TrialA prospective, randomized study of goal-oriented hemodynamic therapy in cardiac surgical patients.
Organ dysfunction and multiple organ failure are the main causes of prolonged hospital stay after cardiac surgery, which increases resource use and health care costs. Increased levels of oxygen delivery and consumption are associated with improved outcome in different groups of postoperative patients. Cardiac surgical patients are at risk of inadequate perioperative oxygen delivery caused by extracorporeal circulation and limited cardiovascular reserves. The purpose of our study was to test whether increasing oxygen delivery immediately after cardiac surgery would shorten hospital and intensive care unit (ICU) stay. Four hundred three elective cardiac surgical patients were enrolled in the study and randomly assigned to either the control or the protocol group. Goals of the protocol group were to maintain SvO(2) >70% and lactate concentration < or =2.0 mmol/L from admission to the ICU and up to 8 h thereafter. Hemodynamics, oxygen transport data, and organ dysfunctions were recorded. The median hospital stay was shorter in the protocol group (6 vs 7 days, P < 0.05), and patients were discharged faster from the hospital than those in the control group (P < 0.05). Discharge from the ICU was similar between groups (P = 0. 8). Morbidity was less frequent at the time of hospital discharge in the protocol group (1.1% vs 6.1%, P < 0.01). Increasing oxygen delivery to achieve normal SvO(2) values and lactate concentration during the immediate postoperative period after cardiac surgery can shorten the length of hospital stay. ⋯ Health care economics has challenged clinicians to reduce costs and improve resource use in cardiac surgery and anesthesia in a patient population increasing in age and in severity of disease. Optimizing cardiovascular function to maintain adequate oxygen delivery during the immediate postoperative period after cardiac surgery can decrease morbidity and reduce length of hospital stay.