Ondansetron has similar clinical efficacy against both nausea and vomiting.

Ondansetron is widely believed to prevent postoperative vomiting more effectively than nausea. We analysed data from 5161 patients undergoing general anaesthesia who were randomly stratified to receive a combination of six interventions, one of which was 4 mg ondansetron vs placebo. For the purpose of this study a 20% difference in the relative risks for the two outcomes was considered clinically relevant. Nausea was reduced from 38% (969/2585) in the control to 28% (715/2576) in the ondansetron group, corresponding to a relative risk of 0.74, or a relative risk reduction of 26%. Vomiting was reduced from 17% (441/2585) to 11% (293/2576), corresponding to a relative risk of 0.67, or a relative risk reduction of 33%. The relative risks of 0.67 and 0.74 were clinically similar and the difference between them did not reach statistical significance. We thus conclude that ondansetron prevents postoperative nausea and postoperative vomiting equally well.

Effects of cigarette smoking on serum fluoride concentrations and renal function integrity after 1 MAC-h sevoflurane anaesthesia.

BACKGROUND: Tobacco smoke contains various chemicals which may affect drug metabolism. Sevoflurane is metabolized to inorganic fluoride, and elevated serum fluoride concentrations (S-F(-)) may cause deterioration of renal function. Whether smokers develop high S-F(-) and associated disturbances in renal function is not known. METHODS: We investigated sevoflurane metabolism in 25 non-smoking and 25 smoking (> 10 cigarettes/day) generally healthy women, aged 19-68 years, undergoing gynaecological elective surgery under one minimum alveolar concentration-hour (1 MAC-h) standardized sevoflurane anaesthesia. S-F(-) was measured for 24 h. Glomerular and tubular function was assessed by measuring serum and urine tumour-associated trypsin inhibitor (TATI), beta(2)-microglobulin and serum creatinine for 48 h after sevoflurane inhalation. RESULTS: There were no differences between the two study groups with regard to S-F(-). It increased significantly in both groups: in non-smokers, from a baseline between 1.0 and 11 micromol/l (median, 1.6 micromol/l) to a maximum between 8.2 and 40 micromol/l (26 micromol/l) (P < 0.001) and, in smokers, from a baseline between 0.5 and 5.2 micromol/l (1.7 micromol/l) to a maximum between 19 and 71 micromol/l (25 micromol/l) (P < 0.001). In both groups, S-F(-) remained elevated for the entire sampling period (P < 0.001). In all five women (one non-smoker and four smokers) with a maximum S-F(-) of 40 micromol/l or higher and an area under the serum fluoride concentration-time curve (AUC(F0-24)) of 500 micromol/h/l or higher, serum TATI increased above the pathological concentration of 3.0 nmol/l, whereas only six of the 45 patients with S-F(-) below 40 micromol/l had serum TATI above 3.0 nmol/l (P < 0.001). Beta(2)-Microglobulin increased significantly (> 1 mg/l) in two patients with high S-F(-) relative to two of the 45 patients with S-F(-) below 40 micromol/l (P= 0.005). None of the patients developed clinically detectable renal dysfunction. CONCLUSION: Smoking did not affect S-F(-) after sevoflurane anaesthesia. Glomerular dysfunction, seen as increased serum TATI, was noted in five women with S-F(-) above 40 micromol/l. Our results suggest that the renal toxic threshold of S-F(-) seems to be lower than the earlier reported value of 50 micromol/l.

Ondansetron and tropisetron do not prevent intraspinal morphine- and fentanyl-induced pruritus in elective cesarean delivery.

BACKGROUND: Although intraspinal morphine has been shown to be effective in providing analgesia after cesarean delivery, pruritus as a side-effect remains a common cause of dissatisfaction. The role of ondansetron has been studied in preventing pruritus but the results have been contradictory. METHODS: We randomized 98 parturients undergoing elective cesarean section using combined spinal-epidural anesthesia into a double-blinded trial to receive tropisetron 5 mg (T group) or ondansetron 8 mg (O group) or placebo (NaCl group) after delivery, when intrathecal morphine 160 microg and fentanyl 15 microg were used for post-operative pain control. The patients additionally received ketoprofen 300 mg per day. Post-operative itching, nausea and vomiting, sedation and need for rescue analgesics were registered every 3 h up to 24 h, and all patients were interviewed on the first post-operative day. RESULTS: Seventy-six percent of the parturients in the placebo group, 87% in the ondansetron, and 79% in the tropisetron group had itching. The incidence of post-operative nausea and vomiting was 21%, 20% and 11% of the patients in the placebo, ondansetron and tropisetron groups, respectively. Medication for pruritus was needed by 31%, 23% and 39% of the patients in the placebo, ondansetron and tropisetron groups, respectively. In the post-operative questionnaire, the patients reported less post-operative nausea in the tropisetron group than in the placebo group (P < 0.01). CONCLUSION: Neither ondansetron nor tropisetron prevent itching caused by intrathecal morphine with fentanyl. However, tropisetron reduced post-operative nausea.

Patient-controlled epidural technique improves analgesia for labor but increases cesarean delivery rate compared with the intermittent bolus technique.

BACKGROUND: We tested the hypothesis that patient-controlled epidural analgesia for labor (PCEA) provides better analgesia and satisfaction than the intermittent bolus technique (bolus) without affecting the mode of delivery. METHODS: We randomized 187 parturients to receive labor analgesia using either the PCEA or bolus technique. The PCEA group received a starting bolus of 14 mg of bupivacaine and 60 micro g of fentanyl in a 15-ml volume, followed by a background infusion (bupivacaine 0.08% and fentanyl 2 microg ml(-1)) 5 ml h(-1) with a 5-ml bolus and 15-min lock-out interval. The bolus group received boluses of 20 mg of bupivacaine and 75 micro g of fentanyl in a 15-ml volume. RESULTS: Parturients in the PCEA group had significantly (P < 0.05-0.01) less pain during the first and second stages of labor. There was no difference in the spontaneous delivery rate between the groups, but the cesarean delivery rate was significantly (P < 0.05) higher (16.3% vs. 6.7%) in the PCEA group than in the bolus group. Bupivacaine consumption was significantly (P < 0.01) higher (11.2 mg h(-1) vs. 9.6 mg h(-1)) and the second stage of labor was significantly (P < 0.01) longer (70 min vs. 54 min) in the PCEA group than in the bolus group. Patient satisfaction was equally good in both groups. CONCLUSION: The PCEA technique provided better pain relief. This was associated with higher bupivacaine consumption, prolongation of the second stage of labor, and an increased rate of cesarean section.

Fluoride metabolism in smokers and non-smokers following enflurane anaesthesia.

BACKGROUND: Inorganic fluoride is released by the metabolism of enflurane and the increased serum fluoride concentrations may impair renal function. Tobacco smoke consists of numerous reactive compounds that can either induce or inhibit drug metabolism. Studies on the interaction of smoking with anaesthetic drug metabolism and possible toxicity are warranted. METHODS: Sixteen non-smoking and 17 smoking (>10 cigarettes day(-1)) generally healthy women undergoing elective gynaecological surgery were given 1 MAC (minimum alveolar concentration)-hour standardized anaesthesia with enflurane in oxygen-air mixture. The serum inorganic fluoride and renal function markers beta(2)-microglobulin, tumour-associated trypsin inhibitor (TATI) and serum creatinine were measured for 48 h. RESULTS: The greatest inorganic fluoride concentration was between 8.4 and 21.0 (mean 13.8 (SD 3.4)) micromol litre(-1) in the non-smokers and between 8.6 and 38.0 (18.7 (7.0)) micromol litre(-1) in the smokers; the mean difference was 4.9 micromol litre(-1) (95% confidence interval (CI) 1.0-8.8, P<0.05). Serum beta(2)-microglobulin, TATI and creatinine were not increased. Serum inorganic fluoride concentrations were significantly greater in the smokers compared with the non- smokers 1, 2, 3 and 6 h after 1 MAC-hour inhalation with enflurane (P<0.05). Inorganic fluoride concentrations were still increased 24 h after anaesthesia in both groups. Urine beta(2)-microglobulin and TATI creatinine ratio remained at low values during the whole 48-h period in both groups. CONCLUSIONS: Regular smoking is associated with an increase in serum inorganic fluoride concentration after anaesthesia with enflurane, but there are no signs of renal damage.

A double-blinded, randomized comparison of intrathecal and epidural morphine for elective cesarean delivery.

UNLABELLED: We randomized 150 parturients into a double-blinded trial to receive intrathecal (IT) 100 microg (IT 100 group) or 200 microg (IT 200 group) or epidural 3 mg (Epidural group) of morphine for elective cesarean delivery with a combined spinal/epidural technique. The patients additionally received ketoprofen 300 mg/d. Postoperative pain relief and side effects were registered every 3 h up to 24 h, and all patients were interviewed on the first postoperative day. Pain control was equally good, but the parturients in the IT 100 group requested rescue analgesics more often compared with the other groups (P < 0.05). Itching was a common complaint and was reported by 74% of the parturients in the Epidural group and 65% and 91% in the IT 100 and IT 200 groups, respectively (P < 0.01). Medication for itching was requested by 44%, 24%, and 45% of the patients, respectively (P < 0.05). There was no difference in postoperative nausea or vomiting. The pain relief was perceived as good by >90% of the patients in all groups. In conclusion, because of the decreased incidence of and lesser requirements of medication for itching, IT morphine 100 microg with ketoprofen is recommended in cesarean deliveries. Rescue analgesics nevertheless need to be prescribed. IMPLICATIONS: Spinal morphine is an effective analgesic after cesarean delivery, but it has several side effects. The purpose of this study was to compare the prevalence of side effects and the level of analgesia of epidural morphine with two different doses of spinal morphine after elective cesarean delivery. Although rescue analgesics may be required, intrathecal morphine 100 microg is suggested for postoperative analgesia after cesarean delivery.

Neostigmine with glycopyrrolate does not increase the incidence or severity of postoperative nausea and vomiting in outpatients undergoing gynaecological laparoscopy.

We studied 100 healthy women undergoing outpatient gynaecological laparoscopy in a randomized, double-blind and placebo-controlled study to evaluate the effect of neostigmine on postoperative nausea and vomiting (PONV). After induction of anaesthesia with propofol, anaesthesia was maintained with sevoflurane and 66% nitrous oxide in oxygen. Mivacurium was used for neuromuscular block. At the end of anaesthesia, neostigmine 2.0 mg and glycopyrrolate 0.4 mg, or saline, was given i.v. The incidence of PONV was evaluated in the postanaesthesia care unit, on the ward and at home. The severity of nausea and vomiting, worst pain, antiemetic and analgesic use, times to urinary voiding and home readiness were recorded. During the first 24 h after operation, 44% of patients in the neostigmine group and 43% in the saline group did not have PONV. We conclude that neostigmine with glycopyrrolate did not increase the occurrence of PONV in this patient group.

Reversal of neuromuscular blockade with neostigmine has no effect on the incidence or severity of postoperative nausea and vomiting.

UNLABELLED: We performed this randomized, double-blind, placebo-controlled study to determine whether reversal of neuromuscular block with neostigmine increases the incidence and severity of postoperative nausea and vomiting (PONV). We studied 162 women undergoing abdominal hysterectomy and randomly allocated them into two groups. In Group A, neuromuscular block produced with mivacurium was antagonized with neostigmine 2.0 mg and glycopyrrolate 0.4 mg intravenously, whereas Group B received no drugs to facilitate antagonism of blockade. The incidence and severity of PONV was assessed up to 27 h after the operation. There was no difference in PONV between the groups (in Group A 35% had nausea and 33% vomited; in Group B 28% nauseated and 40% vomited) or in the amount of antiemetics given. We had a 75% chance to find a 30% difference in PONV. We conclude that the administration of neostigmine and glycopyrrolate at the end of anesthesia to reverse neuromuscular block does not increase the incidence or severity of PONV. IMPLICATIONS: Neostigmine may increase postoperative nausea and vomiting. In this study, omission of reversal of neuromuscular block with neostigmine failed to decrease the incidence or severity of postoperative nausea and vomiting.

Recovery and outcome after propofol and isoflurane anesthesia in patients undergoing laparoscopic hysterectomy.

BACKGROUND: Laparoscopic hysterectomy (LH) is expected to provide fast and comfortable recovery, plus an early return to normal daily activities. This study was carried out to compare the outcome after LH in patients anesthetized with isoflurane or propofol. METHODS: Sixty-two patients undergoing LH were randomized to receive either isoflurane-N2O or propofol-N2O anesthesia. The times when the patients could drink, void and walk were recorded. Recovery was also evaluated by the Digit Symbol Substitution Test in the postanesthesia care unit (PACU) 60 and 120 min after the operation. The patients were also given a questionnaire on their further recovery (return to daily activities, pain and nausea) to be filled out at home. RESULTS: Early recovery was significantly (P < 0.05) faster in the isoflurane group (eye opening within 3 min, orientation in 6 min) when compared to the propofol group (eye opening within 7 min, orientation in 14 min), but there was no significant difference in the other parameters of recovery. Most of the patients were discharged from the hospital on the first postoperative day in both groups. Twenty-five percent of the patients, however, stayed two nights in hospital, mainly for social reasons. No difference was found regarding the recovery at home: the patients resumed their normal daily activities on about the sixth postoperative day (median). CONCLUSIONS: It is concluded that both isoflurane and propofol are suitable anesthetics for LH. In this study recovery was not fast enough to make the patients suitable for same-day surgery.