Continuous wound infusion with ropivacaine fails to provide adequate analgesia after caesarean section.

BACKGROUND: Continuous wound infusion with local anaesthetic has been used in post-caesarean pain management with conflicting results. We carried out a study comparing three groups: continuous ropivacaine wound infusion, intrathecal morphine with saline wound infusion and saline wound infusion only. METHODS: Sixty-six women undergoing elective caesarean section under combined spinal-epidural anaesthesia were randomly allocated to receive intrathecal morphine with saline wound infusion or 48 h continuous wound infusion with either ropivacaine or saline. All parturients received oral ketoprofen and intravenous oxycodone patient-controlled analgesia. Consumption of oxycodone, visual analogue scale pain scores (0-10 cm), patient satisfaction, side effects and recovery parameters were recorded for 48 h in a double-blind manner. RESULTS: Continuous wound infusion with ropivacaine failed to reduce oxycodone consumption or pain scores compared with saline control. In the first 24 h intrathecal morphine reduced mean oxycodone consumption compared to the ropivacaine wound infusion group (26 mg vs. 48 mg, P=0.007) and saline wound infusion group (26 mg vs. 45 mg, P=0.021). The first 24-h mean pain score was also lower in the intrathecal morphine group vs. the saline wound infusion group (1.3 vs. 2.2, P=0.021). Pain scores were not significantly different between intrathecal morphine and ropivacaine wound infusion groups. Pruritus was more common with intrathecal morphine. CONCLUSION: Compared to saline control, continuous wound infusion with ropivacaine failed to reduce the use of intravenous oxycodone patient-controlled analgesia or pain scores. Intrathecal morphine decreased oxycodone consumption by 46% in the first 24 h after surgery when compared to continuous ropivacaine wound infusion.

Persistent pain after caesarean section and vaginal birth: a cohort study.

BACKGROUND: Although persistent pain has been described to occur after various types of surgery, little is known about this entity following caesarean section or vaginal birth. We sought to examine the association between mode of delivery and development of persistent pain, as well as the nature and intensity of the pain. METHODS: A questionnaire was sent to 600 consecutive Finnish-speaking women within one year of their giving birth. The survey recorded the women's health history, obstetric history, previous pain, details of the caesarean section or vaginal birth, and a description of their pain, if present. RESULTS: Persistent pain one year after delivery was significantly more common after caesarean section (42/229, 18%) than after vaginal birth (20/209, 10%: P=0.011, OR 2.1 with 95% CI 1.2-3.7). The persistent pain was mild in 55% of the patients in both groups, and intense or unbearable for four caesarean sections and six vaginal births. Persistent pain was significantly more common in women with previous pain (P=0.013), previous back pain (P=0.016), and any chronic disease (P=0.016). The women with persistent pain recalled significantly more pain on the day after caesarean section (P=0.004) and vaginal birth (P=0.001) than those who did not report persistent pain. CONCLUSION: Persistent pain is more common one year after a caesarean section than after vaginal birth. A history of previous pain and pain on the day after delivery correlated with persistent pain.

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.

Propofol versus alfentanil to prevent movement responses during uterine curettage.

BACKGROUND: Propofol anaesthesia is frequently associated with movement responses in non-paralysed patients. Opioids decrease the probability of movement during noxious stimulation. Heart rate variability and frontal electromyography (EMG), which are related to subcortical functions, may be more closely related than surface electroencephalography (EEG) to movement responses to noxious stimulation. METHODS: Eighty-two patients scheduled for uterine dilatation and curettage were randomized to receive at the first intra-operative movement either a supplemental alfentanil bolus, 0.5 mg intravenously, or a supplemental propofol bolus, 0.7 mg/kg intravenously. The incidences of recurring movement during the procedure were compared between the two groups. The associations of a measure of heart rate variability (Anemon index), heart rate, EMG and two EEG variables with movement responses were evaluated. RESULTS: The incidences of recurring movement were 73% and 38% in the alfentanil and propofol groups, respectively [difference, 35%; 95% confidence interval, 9-56%; P= 0.014 between the groups). The Anemon index, heart rate, EMG and surface EEG variables displayed mainly reactive associations with movement responses. CONCLUSION: During uterine curettage under propofol-alfentanil-nitrous oxide anaesthesia, a propofol bolus of 0.7 mg/kg was more effective in preventing the recurrence of movement responses than an alfentanil bolus of 0.5 mg. Several physiological variables may be used to track significant arousal reactions, but not to predict them.

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.

EEG spectral entropy, heart rate, photoplethysmography and motor responses to skin incision during sevoflurane anaesthesia.

BACKGROUND: Analgesia is a part of balanced anaesthesia, but direct indicators of nociception do not exist. We examined the relationship between motor reactions and physiological variables during skin incision in sevoflurane anaesthesia and hypothesized that nociception could be detected and graded by significant changes in these variables. METHODS: Thirty-one women scheduled for abdominal hysterectomy participated in the study. Anaesthesia was induced with fentanyl (1 microg kg(-1)), propofol (1 mg kg(-1)) and sevoflurane. Skin incision was performed 14 min after induction during 1.6% end-tidal sevoflurane anaesthesia without neuromuscular blockade. Electrocardiography (ECG), photoplethysmography (PPG) and electroencephalography (EEG) were registered, and a range of variables was computed from these signals. The postincision values, normalized with respect to their preincision values, of movers vs. non-movers were compared. The variables showing significant differences between movers and non-movers were used to develop a logistic regression equation for the classification of patients into movers or non-movers. RESULTS: Twenty-six patients were eligible for analysis, and 12 (46%) displayed a motor reaction to skin incision (movers). Many ECG, PPG and EEG-related variables showed significant differences between the pre- and postincision periods. The best classification performance, assessed by leave-one-out cross-validation, between movers and non-movers was achieved with the combination of response entropy of EEG, RR-interval and PPG notch amplitude. The corresponding equation yielded 96% correct classification with 90% sensitivity and 100% specificity. The classification performance of any single variable alone was considerably worse. CONCLUSION: Combination of information from different sources may be required for monitoring the adequacy of analgesia during anaesthesia.

Sevoflurane titration using bispectral index decreases postoperative vomiting in phase II recovery after ambulatory surgery.

UNLABELLED: We tested the hypothesis that titration of sevoflurane using bispectral index (BIS) of the electroencephalogram decreases postoperative nausea and vomiting and improves recovery after outpatient gynecologic laparoscopy. After propofol induction, anesthesia was maintained in all patients with sevoflurane in 65% nitrous oxide and oxygen. In the BIS-Titrated group (n = 32), sevoflurane was titrated to maintain the BIS between 50 and 60 during surgery. In the Control group (n = 30), sevoflurane was adjusted to keep hemodynamic variables within 25% of control values. The severity of pain, postoperative nausea and vomiting, and recovery variables were recorded. In the Control group, 30% of the patients had BIS <40 during surgery (versus 0 in the BIS-Titrated group). Orientation and ability to drink were achieved earlier in the BIS group (P < 0.05). At 30 min after cessation of nitrous oxide, patients in the BIS group performed better in the psychomotor recovery test (P < 0.01). In Phase II recovery room, these patients had significantly less vomiting than the patients in the Control group (16% versus 40% of the patients, respectively, P < 0.05). No differences were found in times to achieve home readiness. IMPLICATIONS: In patients undergoing outpatient gynecologic laparoscopy, the monitoring of bispectral index decreases vomiting in Phase II recovery room, but it has no effect on the time to achieve home readiness.

Comparison of 9 mg of intrathecal plain and hyperbaric bupivacaine both with fentanyl for cesarean delivery.

UNLABELLED: We randomized 76 parturients to a double-blinded trial to receive spinal anesthesia with either hyperbaric or plain bupivacaine 9 mg with fentanyl 20 microg for elective cesarean delivery. A combined spinal-epidural technique was used. The onset and duration of anesthesia (absence of pinprick sensation), analgesia (absence of sharp sensation to pinprick), and absence of cold sensation and motor block were measured until recovery from the motor block. No major differences were seen in onset or duration of anesthesia between the groups. Motor block, however, vanished faster when hyperbaric bupivacaine was used (P < 0.05). The level of anesthesia (no pinprick sensation) required for painless operation was at dermatome T5. At this time, the absence of cold sensation ranged from dermatome T1 to C3. The median time for the anesthesia to reach dermatome T5 was 10 min. Cervical spread of pinprick anesthesia was noted in six patients, and five needed supplementary analgesics during surgery (not significant between the groups). Maternal satisfaction was good. Nine milligrams of either plain or hyperbaric bupivacaine with fentanyl intrathecally provided similar onset, depth, and duration of sensory anesthesia for cesarean delivery with good maternal satisfaction. Motor block developed and diminished faster with the hyperbaric solution. IMPLICATIONS: Nine milligrams of either plain or hyperbaric bupivacaine with fentanyl intrathecally provided similar onset, depth, and duration of sensory anesthesia for cesarean delivery with good maternal satisfaction. Motor block developed and diminished faster with the hyperbaric solution.

Transient hyperdynamic response associated with controlled hypocapneic hyperventilation during sevoflurane-nitrous oxide mask induction in adults.

UNLABELLED: We assessed hemodynamic variables during sevoflurane face mask anesthetic induction in female ASA physical status I or II patients. Anesthesia was induced with a single-breath inhalation method with 8% sevoflurane in 50% nitrous oxide in oxygen. Thirty patients were randomized either to breathe spontaneously (SB group, n = 15) or to receive controlled ventilation (CV group, n = 15) for 6 min after the loss of consciousness. Noninvasive blood pressure and heart rate (HR) were recorded at 1-min intervals. Mean +/- SD HR increased from 83+/-18 to 112+/-24 bpm at 4 min in the CV group (P < 0.001 between groups and within group compared with baseline). Mean arterial pressure increased from 97+/-9 to 106+/-26 mm Hg at 4 min in the CV group, which was significantly higher than that in the SB group (P < 0.01). In the SB group, mean arterial pressure decreased significantly, from 96+/-8 to 78+/-13 mmHg, at 6 min (P < 0.001), and HR remained unchanged. Therefore, hyperventilation should be avoided during the induction of sevoflurane anesthesia via a mask. IMPLICATIONS: In this randomized, prospective study, we found that controlled hypocapneic hyperventilation delivered manually during sevoflurane/ N2O/O2 mask induction was associated with a significant transient hyperdynamic response. This kind of hemodynamic arousal can be detrimental to many patients and can be avoided by conducting sevoflurane mask induction with unassisted spontaneous breathing.

Awakening, clinical recovery, and psychomotor effects after desflurane and propofol anesthesia.

We compared postanesthetic and residual recovery of desflurane versus propofol anesthesia. Twenty volunteers were anesthetized for 1 h at 1-wk intervals with either propofol (induction) plus desflurane (1.25 minimum alveolar anesthetic concentration) in O2 (PD), propofol plus desflurane in N2O-O2 (PDN), propofol plus propofol infusion with N2O-O2 (PPN), or desflurane (induction) plus desflurane in O2 (DD). Awakening and clinical recovery were measured. Psychomotor skills (attention, coordination, reactive skills, and memory) were tested before and 1,3,5, and 7 h after anesthesia. Awakening was fastest in Group PDN. At 1 h after anesthesia, the subjects given desflurane for maintenance (PD, PDN, and DD) performed significantly (P < 0.05-0.01) better in several psychomotor tests compared with those whose anesthesia was maintained with propofol (PPN). However, subjects met criteria for home readiness as fast after PPN as after PDN anesthesia (mean times +/- SE until fitness for discharge were 126 +/- 20, 81 +/- 14, 70 +/- 7, and 106 +/- 14 min after PD, PDN, PPN, and DD, respectively). Awakening and early psychomotor recovery for as long as 1 h after anesthesia is faster after desflurane than after propofol, but there was no difference in time to home readiness or in residual effects thereafter between propofol and desflurane with N2O in O2.

Post-anaesthetic psychomotor and cognitive function.

Day surgery has a remarkable overall record of safety. To provide safe anaesthesia and as little post-anaesthetic psychomotor and cognitive impairment as possible after longer and more extensive operations performed in ambulatory surgical facilities, we must carefully assess home readiness and instruct patients in such a way that they receive and understand all relevant information. Policies for safe discharge from the hospital are most important for good outcome and have to be followed. If a patient does not have an escort home, the procedure should be cancelled or the patient should be admitted to the hospital. Recommendations not to drive after anaesthesia or sedation vary between 24 and 48 hours, depending on the duration of anaesthesia. It is hoped that the recently introduced short-acting drugs will further improve outcome of day surgery by providing fast exit and early return to normal daily activities.

Sedation and recovery of psychomotor function after intravenous administration of various doses of midazolam and diazepam.

A placebo-controlled, double-blind, crossover trial in 11 healthy male volunteers compared clinical sedation and psychomotor function after intravenous injection of midazolam (0.05, 0.1, or 0.15 mg/kg), diazepam (0.15 or 0.3 mg/kg), or placebo (saline). The depth of sedation was estimated at 5-10-min intervals during the first hour after injection. A comprehensive battery of psychomotor tests was used to collect objective data of psychomotor performance before drug injection and 1, 3, 5, and 7 h after injection. Midazolam (0.15 mg/kg) produced the highest scores of sedation and most impairment of psychomotor performance. In most tests, the maximal psychomotor effects seen after 0.3 mg/kg of diazepam did not reach those of 0.1 mg/kg of midazolam. Although the strongest psychomotor effects were induced by midazolam, these effects disappeared sooner than those of diazepam. By 5 h after injection, 0.3 mg/kg of diazepam showed the highest scores of psychomotor impairment. The authors conclude that at least four times as much diazepam as midazolam is needed to produce equally severe psychomotor impairment. That the residual effects of midazolam terminate sooner than those of diazepam probably accounts for the occasional underestimation of the potency of midazolam in clinical practice.

Effect of intravenously administered dexmedetomidine on pain after laparoscopic tubal ligation.

Ninety-six women undergoing laparoscopic tubal ligation were randomized to receive intravenously either 0.2 or 0.4 microgram/kg of dexmedetomidine, 60 micrograms/kg of oxycodone, or 250 micrograms/kg of diclofenac for postoperative pain in a double-blind study design. The study drugs were administered in the recovery room for moderate or severe pain and were repeated until pain subsided or disappeared. In the group receiving diclofenac, 83% of the patients required analgesic supplementation with morphine. This contrasted (P less than 0.01) with 33% of the patients receiving either oxycodone or the higher dose of dexmedetomidine. After the first dose of oxycodone was injected, the visual analogue scale for pain (0%-100%) was reduced from 58% to 33%, whereas corresponding pain relief was only achieved after the third injection of 0.4 microgram/kg of dexmedetomidine. Repeated doses of 0.2 microgram/kg of diclofenac or dexmedetomidine did not reduce the visual analogue scale value by more than 17%. More sedation was seen with the higher dose of dexmedetomidine than with either diclofenac or oxycodone (P less than 0.001). Both doses of dexmedetomidine decreased heart rate when compared with diclofenac (P less than 0.001). In the group given 0.4 microgram/kg of dexmedetomidine, 33% of the patients required atropine for bradycardia. The authors conclude that after laparoscopic tubal ligation, intravenously administered dexmedetomidine relieves pain and reduces opioid drug requirement but is attended by sedation and a high incidence of bradycardia.

Evaluation of a new computerized psychomotor test battery: effects of alcohol.

In order to better evaluate the effects of centrally active drugs, a new computer based set of psychomotor tests was developed. Compared to the older apparati, the new set is very flexible and easy to operate allowing the measurement of hand/eye coordination, attention and several types of reaction skills. To evaluate the sensitivity and usefulness of the new tests, the effects of alcohol (oral doses of 0.5 g/kg and 1.0 g/kg) were studied in twelve healthy volunteers. The peak blood alcohol concentration after the larger dose was 0.86 g/l, and the effects were clearly seen with all new tests. The smaller dose of alcohol gave 0.33 g 1 peak blood alcohol concentration and it impaired significantly only coordination at 1 hr after drinking. The results suggest that the new tests are at least as sensitive and reliable as older psychomotor tests detecting the effects of central depressant agents. The advantage of the new tests is that they are easy to operate and easy to modify without any specific programming skills. Because they can be used with a computer which is easy to transport, these tests are suitable for use in clinical areas to conduct studies with patients.

Effects of alfentanil and fentanyl on common bile duct pressure.

The effects of alfentanil (7.5 or 15 micrograms/kg) and fentanyl (1.5 micrograms/kg) on common bile duct pressure were examined by using an indwelling postoperative T-tube in 36 conscious, unpremedicated patients. All opiate doses significantly (P less than 0.001) increased the pressure. There was no significant difference among the groups in the peak pressures nor in the times to peak pressures. Fentanyl had a significantly longer duration of effect on pressure.