A comparison of the hemodynamic effects of paracervical block and epidural anesthesia for labor analgesia

BACKGROUND: Both paracervical block (PCB) and epidural analgesia are sometimes associated with hemodynamic effects potentially harmful to the well-being of the fetus. Our study was designed to test the hypothesis that PCB would have a more profound effect on maternal and fetal blood flow than epidural analgesia. METHODS: Forty-four healthy primiparous parturients were randomized to receive either PCB (n=21) or epidural analgesia (n= 23) with 25 or 30 mg of bupivacaine, respectively, for labor analgesia. Maternal blood pressure and fetal heart rate were recorded. Blood flow was measured using a color Doppler device. The blood flow measurements consisted of assessment of the pulsatility indices (PI) of the right maternal femoral artery and the main branch of the uterine artery (placental side), the umbilical artery and the fetal middle cerebral artery. The measurements were performed before administration of analgesia and approximately 15-20 min later after the onset of analgesia. RESULTS: Both methods provided in general good analgesia, but rescue medication was required more often after PCB. Epidural analgesia decreased maternal blood pressure more than PCB and the PI of maternal femoral artery decreased after onset of epidural analgesia, indicating epidural-induced vasodilation. The PI of the uterine artery increased after the onset of PCB, indicating vasoconstriction of this artery. No significant adverse effects or differences in the well-being of the newborn were observed, as indicated by similar Apgar scores and pH-status. CONCLUSION: There were small differences in the effects of PCB and epidural analgesia on uteroplacental circulation as well as on maternal hemodynamics. PCB may have a vasoconstrictive effect on the uterine artery. This and the fact that the parturients required rescue analgesia more frequently after PCB than after epidural block speaks for the feasibility of the latter in obstetrics.     

Tropisetron or droperidol in the prevention of postoperative nausea and vomiting

BACKGROUND: Women undergoing laparoscopic cholecystectomy are susceptible to postoperative nausea and vomiting (PONV). This study was undertaken to evaluate the efficacy of tropisetron or droperidol for preventing PONV after laparoscopic cholecystectomy. METHODS: In a prospective, randomised, double-blind trial, 120 female patients received either tropisetron 5 mg or droperidol 1.25 mg intravenously at the beginning of surgery. A standard general anaesthetic technique and postoperative analgesia were used. Nausea, emetic episodes and the need for rescue medication were recorded for 24 h postoperatively. RESULTS: Nausea was experienced by 55% of the patients in the tropisetron group and by 62% in the droperidol group (ns). The incidence of emetic episodes was 20% and 52% (P=0.001) in the two groups, respectively. Rescue antiemetic medication was needed in 42% and 50% (ns) of the patients, respectively. Patients in the droperidol group were more drowsy in comparison with patients in the tropisetron group, mean sedation score being 6.7 vs 5.7, respectively (P=0.023). No difference in other side-effects was observed. CONCLUSION: Tropisetron, when compared with droperidol, had no better efficacy on the prevention of postoperative nausea but resulted in a significantly lower incidence of vomiting after laparoscopic cholecystectomy.     

Marked enhancement of anti-allodynic effect by combined intrathecal administration of the adenosine A1-receptor agonist R-phenylisopropyladenosine and morphine in a rat model of central pain

BACKGROUND: There is often no satisfactory treatment for chronic pain after spinal cord injury. We have previously reported that intrathecal (i.t.) administration of the adenosine A1-receptor agonist R-phenylisopropyl-adenosine (R-PIA) or the opioid morphine has anti-allodynic effects in a model of presumed chronic central pain after photochemically induced spinal cord injury in rats. In the present study, we set out to investigate the possible interaction between i.t. R-PIA and morphine in spinally injured rats. METHODS: Sprague-Dawley rats displaying allodynia-like behaviors to mechanical and cold stimuli after photochemically induced spinal cord injury with minor motor deficits were used. R-PIA and morphine, either alone or in combination, were administered i.t. through an implanted catheter to lumbar spinal cord. RESULTS: Cumulative doses of R-PIA or morphine dose-dependently reduced the mechanical allodynia-like behavior, with a threshold of 1 nmol and 1.5 nmol, respectively. When co-administrated, R-PIA and morphine produced marked suppression of mechanical allodynia at doses of 5 pmol and 7.5 pmol, respectively. The effect of i.t. co-administration of R-PIA and morphine on cold allodynia was comparable to i.t. R-PIA alone. The combination of R-PIA and morphine did not increase adverse effects such as motor deficits in comparison to either drug alone. CONCLUSION: These results demonstrate a supra-additive interaction between the adenosine A1-receptor agonist R-PIA and morphine to reduce mechanical allodynia-like behavior in rats with chronic spinal cord injury. The combination of R-PIA and morphine administered spinally may be superior to R-PIA or morphine alone for treating such pain.     

Cost comparison between three different general anaesthetic techniques for elective arthroscopy of the knee

INTRODUCTION: We compared three anaesthetic techniques for elective knee arthroscopy with special reference to cost-effectiveness. METHOD: Seventy-five ASA I-II patients having elective arthroscopy of the knee joint were randomised to receive an anaesthetic technique based on propofol, fentanyl for induction followed by sevoflurane in oxygen:nitrous oxide (1:2 l/min) for maintenance of one of two intravenous techniques: propofol alfentanil or propofol-remifentanil infusions in combination with oxygen in air. RESULTS: All patients had an uncomplicated course. No differences were seen with regard to emergence, postoperative pain or emesis or time to discharge. The anaesthetic technique based on sevoflurane was associated with the lowest cost US$ 14.7 as compared to US$ 18 for the propfol/alfentanil and US$ 19.9 for the propofol/remifentanil technique, including both cost for wastage as well as premedication and other fixed drug costs. Looking only at the anaesthetic drugs consumed, the cost per minute was US$ 0.56 for sevoflurane/nitrous oxide as compared to US$ 0.68 and 0.63 per minute for the propofol/alfentanil and proprofol/remifentanil, respectively. When the cost for wastage was taken into account, the difference in mean anaesthetic drug cost was more pronounced: the sevoflurane anaesthetic technique US$ 0.58, the propofol/alfentanil US$ 0.74 and the propofol/remifentanil US$ 0.84 per minute respectively. CONCLUSION: From a cost-minimisation point of view, anaesthesia based on sevoflurane in oxygen:nitrous oxide is the technique of choice.     

Comparison of spontaneous with controlled mode of ventilation in tonsillectomy

METHODS: This randomized study compares spontaneous versus controlled ventilation in 60 ASA I and II patients undergoing tonsillectomy as regards haemodynamic stability, recovery characteristics, intra- and immediate postoperative complications and surgical impressions. RESULTS: The patients in the balanced anaesthesia (B) group showed less haemodynamic variability compared to baseline after tracheal intubation, mouth gag application and removal and incision. Two patients had dysrhythmias in the B group compared to six in the spontaneous breathing (S) group. Six patients in the S group had a rise in endtidal carbon dioxide concentration above 7.8 kPa (60 mmHg). Recovery scores were higher in the B group at 10 and 20 min into recovery. The surgical impression of bleeding and jaw relaxation was similar with both groups. The incidence of postoperative nausea and vomiting and agitation was higher in the S group but did not achieve statistical significance. CONCLUSION: Use of balanced anaesthesia offered more haemodynamic stability and a rapid recovery.     

An audit of perioperative management of autistic children

BACKGROUND: Autistic children are very difficult to manage in the hospital setting because they react badly to any change in routine. METHODS: We have developed a unique management program for autistic children admitted for medical and surgical procedures requiring a general anaesthetic. Details of each patient managed according to this program have been prospectively entered into an Autistic Register. RESULTS: An audit of this database shows that we have administered anaesthesia on 87 occasions for 59 autistic children over 4 years. CONCLUSIONS: There is great variation in the severity of autism and hospital needs of these children. The focus is on early communication with the patient's families, flexibility to individualize the admission process and anaesthetic plan with admission and early discharge on the day of surgery whenever possible. Oral midazolam is an effective premedication for the milder cases and oral ketamine is the most reliable for moderate and severe cases. Comparison of oral midazolam and ketamine shows no significant different postoperative recovery and hospital discharge times. Routine intravenous fluids and antiemesis prophylaxis with removal of the i.v. cannula before return to the ward are also seen as important steps to decrease stress and smooth the postoperative phase. This program has also successfully been extended to the management of problem children due to other causes.     

Comparison of transarterial and multiple nerve stimulation techniques for axillary block using a high dose of mepivacaine with adrenaline

BACKGROUND: High-dose transarterial (TA) technique results in high effectiveness of the axillary block. The technique is fast and simple, but does not produce a satisfactory success rate when using the manufacturer's recommended dose of mepivacaine. The multiple nerve stimulation (MNS) technique requires more time and experience. This double-blind study compared effectiveness, safety and the time used to obtain an effective analgesia in 101 patients, having an axillary block by either TA or MNS techniques. METHODS: Mepivacaine with adrenaline (MEPA), 850 mg, was used for the initial block. Five millilitres of 1% solution was injected subcutaneously. In the TA group, 20 mL of 2% solution was injected deep to, and 20 mL superficial to the axillary artery. In the MNS group, four terminal motor nerves were electrolocated in the axilla, and injected with 10 mL each. Analgesia was assessed every 10 min and, when needed, supplemented after 30 min. The block was effective when analgesia was present in all sensory nerve areas distal to the elbow. RESULTS: The MNS group required median 11 min for block performance compared with 8 min for the TA group (P < 0.001). Latency of the initial block was shorter and the frequency of supplemental analgesia lower in the MNS group (median 10 min and 6%) than in the TA group (30 min and 36%, respectively), P < 0.001. All incomplete blocks were successfully supplemented. However, the total time to obtain an effective block was shorter in the MNS group (23 min) than in the TA group (37 min), P < 0.001. Two patients in each group had signs and symptoms of systemic toxicity, the most serious being atrial fibrillation and temporary loss of consciousness in a cardiovascularly medicated patient. The local adverse effects (intravascular injections and haematomas) were fewer in the MNS group, P < 0.001. CONCLUSION: The MNS technique of axillary block by four injections of 10 mL of 2% MEPA produces faster and more extensive block than the TA technique by two injections of 20 mL. Therefore, the MNS technique requires fewer supplementary blocks and results in faster patient readiness for surgery. However, high doses of MEPA may result in dangerous systemic toxic reactions.     

The effects of tramadol on postoperative nausea, vomiting and headache after ENT surgery. A placebo-controlled comparison with equipotent doses of nalbuphine and pethidine

Background: Opioids given as adjuncts to balanced inhalational anaesthesia augment postoperative nausea and vomiting (PONV). Tramadol, equipotent to pethidine, does not depress respiration, but can cause an increase in blood pressure and headache via its monoaminergic actions. Nalbuphine, ten times as potent as pethidine, has a ceiling respiratory depressant and ceiling analgesic effect at >0.3 mg · kg^?1. We compared the effects of equipotent doses of tramadol and nalbuphine (3.0 and 0.3 mg · kg^?1, respectively) given as analgesic with induction of anaesthesia on emesis during recovery from anaesthesia and on PONV and headache until 24 h after ENT surgery, using saline (0.2 ml · kg^?1) and an equipotent dose of pethidine (1.5 mg · kg^?1) as controls. Method: The study population (N=281) comprised 4 comparable subgroubs (N=69 to 71 each). Anaesthetic medications were standardised. Emesis during recovery from anaesthesia and nausea, vomiting, retching, headache and administrations of antiemetic and analgesics until 24 h after surgery were recorded. Results: Emesis and antiemetic requirements during recovery from anaesthesia were similar and infrequent in each group, as were the incidences of nausea alone (3 to 5%), vomiting alone (17 to 31%), and nausea with vomiting (10 to 22%) during the first 24 h after surgery. However, any complaint of PONV was least frequent in the saline and pethidine groups (32% and 37%, respectively) and most frequent in the tramadol and nalbuphine groups (49% and 52%, respectively; P<0.05 versus saline, both comparisons; P=NS versus pethidine, both comparisons). The times to onset and severity of PONV were similar in each group, but patients given nalbuphine most frequently (P<0.025) needed rescue antiemetic to treat PONV. Headache occurred with similar frequency in each group. Conclusion: It is concluded that tramadol, nalbuphine and pethidine have similar emetic effect in the doses and manner used, and that tramadol does not increase the incidence of postoperative headache when used as peroperative analgesic.     

Postoperative pain treatment after cholecystectomy with epidural sufentanil at lumbar or thoracic level

The difference in analgesic activity following lumbar (group I) or thoracic (group II) epidural administration of 50 ug sufentanil was studied after cholecystectomy. Fifteen patients in each group were evaluated for pain relief using a linear analog scale (LAS), heart rate (HR), mean arterial pressure (MAP), respiratory rate (RR), peak expiratory flow (PEF), forced vital capacity (FVC), forced expiratory volume (FEV,) and arterial CO₂ tension (Paco₂). In five additional patients in each group 75 μg sufentanil was injected for determination of serum levels. Pain scores were lower than three in both groups after 10 min, while mean pain scores remained below one from 20 min until 2 h following injection in both groups. Satisfactory pain relief lasted for 4 h. RR was significantly decreased from two until 360 min. in the lumbar group and from five until 120 min in the thoracic group. Paco₂ was raised in both groups only during the first hour. PEF and FVC were significantly improved compared to control 1, 2 and 4 h following injection. Serum sufentanil levels reached a maximum of 0.299 ±0.052 ng.ml^-1 in the lumbar group and 0.377 ± 0.076 ng–ml^-1 in the thoracic group after 5 min. There were no significant differences between the two groups in the variables studied.     

Preoperative oral granisetron for the prevention of vomiting following paediatric surgery

BACKGROUND: We evaluated the efficacy of granisetron, 5-hydroxytryptamine type 3 receptor antagonist, given orally, preoperatively, for the prevention of postoperative vomiting in children undergoing general anaesthesia for surgery (inguinal hernia, phimosis-circumcision). METHODS: In a randomized, double-blinded manner, 100 children, ASA physical status I, aged 4-11 years, received orally placebo or granisetron at three different doses (20 microg x kg(-1), 40 microg x kg(-1), 80 microg x kg(-1)) 60 min before surgery (n=25 of each). The same standard general anaesthetic technique was used. RESULTS: The percentage of patients being emesis-free during 0-6 h after anaesthesia was 56% with placebo, 64% with graniseron 20 microg x kg(-1) (P=0.773), 88% with granisetron 40 microg x kg(-1) (P=0.027) and 92% with granisetron 80 microg x kg(-1) (P=0.01); the corresponding rate during 6-24 h after anaesthesia was 60%, 68% (P=0.768), 92% (P=0.02) and 92% (P=0.02) (P-values versus placebo). No clinically serious adverse events were observed in any of the groups. CONCLUSIONS: In summary, preoperative oral granisetron 40 microg x kg(-1) is effective for the prevention of vomiting following paediatric surgery (inguinal hernia, phimosis-circumcision). Increasing the doses to 80 microg x kg(-1) provides no demonstrable additional benefit.     

Growth of Escherichia coli in propofol, lidocaine, and mixtures of propofol and lidocaine

BACKGROUND: Microorganisms grow rapidly in propofol. Extrinsic contamination of propofol is thought to be a source of postoperative sepsis and wound infection. We studied growth of a strain of Escherichia coli in thiopental, propofol, lidocaine, and mixtures of propofol and lidocaine. METHODS: The pathogen was exposed to 2.5% thiopental; 1.0% propofol; 1.0%, 2.0% and 4.0% preservative-free lidocaine; and propofol solutions containing 0.25%, 0.5%, 1.0%, 2.0%, or 4.0% lidocaine for 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, and 24 h at room temperature, respectively. The inocula from these suspensions were cultured for 48 h at 37 degrees C after the antimicrobial activity of the local anesthetics in the inocula was inactivated by a 1:1000 dilution with distilled water. RESULTS: No organisms grew after exposure to 2.5% thiopental. The exposure of E. coli to propofol increased the colony count to approximately 90 times the control count. The colony counts of E. coli after exposure to 1.0%, 2.0% and 4.0% lidocaine and 0.25%, 0.5%, 1.0%, 2.0% and 4.0% lidocaine in 1.0% propofol were lower than the counts after exposure to 1.0% propofol (P = 0.0048, 0.0027, 0.0003, 0.0503, 0.0188, 0.0080, 0.0044, and 0.0001, respectively). The growth rate of the microorganism was significantly higher in cultures exposed to 1.0% propofol than that in cultures exposed to lidocaine alone or lidocaine-propofol mixtures (P < 0.0001, respectively). CONCLUSION: Lidocaine possesses bacteriostatic activity against E. coli. Addition of lidocaine to propofol confers its bacteriostatic activity to the mixture and may decrease the hazard of infection associated with the extrinsic contamination of propofol.     

Effect of intra-operative magnesium sulphate on pain relief and patient comfort after major lumbar orthopaedic surgery

The effects of intra-operative magnesium sulphate on pain relief after major lumbar surgery were investigated in 24 patients. Patients were randomly allocated to receive either an infusion of 50 mg x kg(-1) magnesium sulphate or an equivalent volume of saline at induction of anaesthesia. Anaesthesia was induced with propofol and remifentanil. Tracheal intubation was facilitated using rocuronium. Maintenance was achieved with remifentanil and sevoflurane in nitrous oxide/ oxygen. Intra-operative monitoring included standard equipment and neuromuscular transmission. During surgery, neuromuscular block recovery was longer in the magnesium group. Postoperative opioid consumption and pain scores were lower in the magnesium group. The first night's sleep and the global satisfaction scores were better in the magnesium group. The results of the study support magnesium sulphate as a useful adjuvant for postoperative analgesia after major lumbar surgery.     

The effect of sufentanil on the cardiovascular responses to tracheal intubation

The effects of sufentanil 0.5 or 1 microgram/kg, given intravenously after induction of anaesthesia, on the cardiovascular responses to tracheal intubation were examined in a controlled, randomised, double-blind investigation. The control group of patients exhibited significant rises in arterial blood pressure and heart rate for 4 minutes after tracheal intubation. Heart rate exceeded 100 beats/minute and systolic pressure increased by over 20% in every patient. All patients moved or breathed within 10 minutes of the administration of suxamethonium. Sufentanil 0.5 microgram/kg prevented increases in the mean values of heart rate and arterial blood pressure, although increases were observed in five patients. Significant falls in the mean values of heart rate and arterial pressure occurred from 4 minutes after intubation until observations ended 15 minutes after induction of anaesthesia. Two patients moved or breathed during this time, although movement in response to nerve stimulation occurred in all patients 10 minutes after administration of suxamethonium. Sufentanil 1 microgram/kg was effective in suppressing a rise in heart rate or arterial pressure in every patient. Significant falls in these variables occurred from 2 minutes after tracheal intubation onwards. No patient moved or breathed for 15 minutes after induction of anaesthesia, although neuromuscular transmission was present 10 minutes after giving suxamethonium in each case.     

Analgesia following paediatric day-surgical orchidopexy and herniotomy

We surveyed 90 boys, aged 1-13 years, who had undergone either orchidopexy or herniotomy, in a cohort study. Their pain and vomiting were assessed using a simple 4-point score in the Recovery Unit by the nursing staff, and at home by the parents. There were no significant differences in pain or vomiting scores between the two groups in the immediate postoperative period. However, children having orchidopexy experienced more pain at home during the first night and the following day than those having herniotomy. Nearly one-third of the former group had moderate to severe pain at home, in contrast to less than one-tenth of children having herniotomy, who are also more likely to be painfree on the next day. We concluded that children having herniotomy can be treated adequately at home with paracetamol alone, whereas children having orchidopexy may require supplementation with stronger analgesics.     

Combination of intra-articular tenoxicam, lidocaine, and pethidine for outpatient knee arthroscopy

BACKGROUND: Studies of intra-articular non-steroidal anti-inflammatory drugs have revealed an analgesic effect equivalent to that of intra-articular local anaesthetic agents and morphine. The aim of this study was to evaluate the analgesic effect of intra-articular lidocaine, pethidine and tenoxicam compared with that of lidocaine and pethidine on postoperative pain after arthroscopy. METHODS: After day-case knee arthroscopy, 60 patients were randomly allocated to one of three groups to receive 20 ml of a solution containing 0.9% saline (group S), 2% lidocaine and 10 mg preservative-free pethidine (group LP) and 2% lidocaine, 10 mg preservative-free pethidine and 20 mg tenoxicam (group LPT). Postoperative pain was assessed using a visual analogue scale and measuring analgesic requirements. RESULTS: Pain scores were significantly lower in the LP group than in the S group at 1 and 2 h after surgery. From 4 h until the end of the first postoperative day, pain scores were significantly lower in the LPT group of patients at rest and on knee flexion than in the other two groups; these patients also used less oral analgesics (P<0.05). CONCLUSION: The combination of 20 ml lidocaine 2%, 10 mg pethidine and 20 mg tenoxicam given intra-articularly provided superior analgesia and reduced oral analgesic requirement during the first day after arthroscopy compared with lidocaine and pethidine alone.     

A comparison of coracoid and axillary approaches to the brachial plexus

BACKGROUND: Brachial plexus block by the coracoid approach does not require arm abduction and may be more effective than the axillary approach because of a more proximal injection of local anaesthetic. However, the clinical usefulness of the coracoid approach has not been tested in prospective controlled trials. The present randomized, observer-blinded study compared success rates, time to obtain a complete block, frequency of adverse effects and block discomfort in two groups of 30 patients, anaesthetized for hand surgery using either the coracoid or the axillary approach to the brachial plexus. METHODS: After subcutaneous infiltration with 5 ml of 1% mepivacaine/adrenaline the brachial plexus was located using a nerve stimulator and an insulated pencil-point needle. Ropivacaine 0.75%, 20-40 ml, depending on body weight, was used for the initial block. In the coracoid (C) group two plexus cords, and in the axillary (A) group four terminal nerves were electrolocated and the volume of ropivacaine was divided equally between them. Spread of analgesia to the arm was assessed every 5 min, by an anaesthetist unaware of the block technique. The block was defined as effective (complete) when analgesia was present in all five sensory nerve areas distal to the elbow. Incomplete blocks were supplemented 30 min after the initial block. RESULTS: In the C group a median 11 min was required for block performance as compared to 12 min in the A group (NS). Onset of block was shorter and the frequency of incomplete blocks lower in the A group (median 17 min and 17%) than in the C group (30 min and 47%, respectively). Lack of analgesia of the ulnar nerve was the main cause of incomplete initial blocks in the C group. All incomplete blocks were successfully supplemented. However, total time to obtain complete block was shorter in the A group than in the C group (29 min vs. 41 min, P<0.05). Accidental arterial puncture occurred in seven patients (five in C and two in A group), which resulted in two haematomas, both in the C group (NS). No permanent sequelae were observed. CONLCUSION: The axillary approach to the brachial plexus using four injections of ropivacaine results in a faster onset of block and a better spread of analgesia than the coracoid approach using two injections.