Fentanyl-induced cough is a risk factor for postoperative nausea and vomiting.

BACKGROUND: Postoperative nausea and vomiting (PONV) and fentanyl-induced cough (FIC) are two common anaesthesia-related events, which seem to have common risk factors. In this prospective cohort study, we investigate whether patients who have FIC during induction of anaesthesia have an increased incidence of PONV. METHODS: We studied adult non-smoking gynaecological surgical patients enrolled between July 1, 2011 and July 30, 2012. The presence of FIC during induction and the occurrence of PONV were recorded. Fentanyl-induced cough and other perioperative variables were subjected to multivariate analysis to determine the association between FIC and PONV. RESULTS: All 502 patients enrolled in this study had at least two risk factors for PONV, and 154 (31%) developed FIC. The incidence of PONV in the FIC group was higher than in the non-FIC group (56.5 vs 38.2%; P<0.0001). Multivariate logistic regression analysis found FIC to be a predictive risk factor for the development of PONV (adjusted odds ratio 2.08, 95% confidence interval 1.41-3.07). CONCLUSIONS: Non-smoking women undergoing gynaecological surgery who develop FIC during induction of anaesthesia have a higher incidence of PONV.

Human opioid µ-receptor A118G polymorphism may protect against central pruritus by epidural morphine for post-cesarean analgesia.

BACKGROUND: Intrathecal or epidural morphine used for post-operative analgesia frequently induces central type pruritus. The purpose of this study was to investigate the association between the severity of central type pruritus induced by epidural morphine for post-cesarean analgesia and the A118G polymorphism of the human µ-opioid receptor gene (OPRM1). METHODS: Pregnant women (212) received pure epidural morphine (2 mg) twice per day for post-cesarean analgesia. Blood samples were collected and sequenced with high-resolution melting analysis to detect three different genotypes of OPRM1 (AA, AG and GG). We interviewed all candidates 24 h post-operatively to record the clinical phenotype with subjective complaints and objective observations. RESULTS: The genotyping revealed that 99 women (46.7%) were AA, 88 (41.5%) were AG and 25 (11.8%) were GG. Sixty-two of 212 women suffered from significant pruritus (29.2%), and 150 of 212 women had non-significant pruritus (70.8%). In genotype AA, 33 patients (53.2%) experienced significant pruritus, 26 (41.9%) in genotype AG and 3 (4.8%) in genotype GG. The G allele was a statistically independent protective factor for individuals developing pruritus, and the multivariate-adjusted odds ratio was 0.27. There was a trend for progressively decreasing severity scores among the three groups, with the lowest severity score (0.72) for pruritus in the GG group. CONCLUSIONS: The incidence of significant pruritus in the recessive type (GG) was significantly lower compared with the dominant types (AA+AG). The recessive G allele in the A118G polymorphism may have protective effects against significant pruritus after epidural morphine for post-cesarean analgesia.

Effect of combining dexmedetomidine and morphine for intravenous patient-controlled analgesia.

BACKGROUND: Perioperative use of dexmedetomidine is associated with reduction in postoperative analgesic requirements. This study examined whether dexmedetomidine added to i.v. patient-controlled analgesia (PCA) morphine could improve analgesia while reducing opioid-related side-effects. METHODS: In this double-blinded, randomized, controlled study, 100 women undergoing abdominal total hysterectomy were allocated to receive either morphine 1 mg ml(-1) alone (Group M) or morphine 1 mg ml(-1) plus dexmedetomidine 5 microg ml(-1) (Group D) for postoperative i.v. PCA, which was programmed to deliver 1 ml per demand with a 5 min lockout interval and no background infusion. Cumulative PCA requirements, pain intensities, cardiovascular and respiratory variables, and PCA-related adverse events were recorded for 24 h after operation. RESULTS: Compared with Group M, patients in Group D required 29% less morphine during the 0-24 h postoperative period and reported significantly lower pain levels from the second postoperative hour onwards and throughout the study. Whereas levels of sedation were similar between the groups at each observational time point, decreases in heart rate and mean blood pressure from presurgery baseline at 1, 2, and 4 h after operation were significantly greater in Group D (by a range of 5-7 beats min(-1) and 10-13%, respectively). The 4-24 h incidence of nausea was significantly lower in Group D (34% vs 56.3%, P<0.05). There was no bradycardia, hypotension, oversedation, or respiratory depression. CONCLUSIONS: The addition of dexmedetomidine to i.v. PCA morphine resulted in superior analgesia, significant morphine sparing, less morphine-induced nausea, and was devoid of additional sedation and untoward haemodynamic changes.

An evaluation of the contributions by fresh gas flow rate, carbon dioxide concentration and desflurane partial pressure to carbon monoxide concentration during low fresh gas flows to a circle anaesthetic breathing system.

BACKGROUND AND OBJECTIVE: Numerous in vitro studies have shown that volatile anaesthetics react with desiccated carbon dioxide (CO2) absorbents to produce carbon monoxide (CO). The effects of anaesthetic concentration, fresh gas flow rate, and the hydration of absorbent or the excretion of CO2 by patients on CO production have also been investigated. This work aims to identify the most significant one of these factors on CO concentration in a low-flow anaesthesia system, without control of the hydration of the absorbents. METHODS: A simulated clinical circle anaesthetic breathing system was used to study the CO concentration under various conditions. Desflurane was used at three different concentrations. Two CO2 flow rates and three fresh gas flow rates were used. The absorbent temperatures and hydration were measured simultaneously. RESULTS: Desflurane degraded to produce CO in the breathing tube, when the CO2 absorbents were not dried beforehand. In this imitation clinical low-flow setting, fresh gas flow affected the CO production more than the CO2 did (31.7% vs. 9.5%). The actual desflurane partial pressure was not a significant factor. The CO2 flow rate explained 18.2% and 54.0% of the variation of the absorbent hydration changes (%) and temperature, respectively. CONCLUSIONS: In clinical practice, the CO2 production varies among patients and is uncontrollable, but markedly affects CO production. The only controllable factor is the fresh gas flow rate if the ultimate goal is to reduce the undesirable exposure of patients to CO from the breathing tube according to this bench model without counting the oxygen consumption.

The effect of 3,3-di-pyridyl-methyl-1-phenyl-2-indolinone on the nerve terminal currents of mouse skeletal muscles.

The effects of 3,3-dipyridyl-methyl-1-phenyl-2-indolinone (DPMPI), a new cognition enhancer, on perineural waveforms were assessed on triangularis sterni nerve-muscle preparations in the mouse. The perineural waveforms were recorded with extracellular electrodes placed in the perineural sheaths of motor nerves. At 64.5 microM, DPMPI decreased the fast potassium current of the nerve terminal. The sodium current, calcium currents and calcium-dependent potassium current of the nerve terminal were not affected. At a greater concentration (215 microM), DPMPI decreased all of the components of the waveforms associated with sodium, potassium and calcium currents. It is concluded that DPMPI affects potassium, as well as sodium currents in the nerve terminal. The effect may contribute to its pharmacological actions on synaptic transmission.

The effect of 3,3-dipyridylmethyl-1-phenyl-2-indolinone on the neuromuscular transmission in the rodent skeletal muscles.

The effects of a cognition enhancer, 3,3-dipyridylmethyl-1-phenyl-2-indolinone (DPMPI) (21.5-645 microM), on neuromuscular transmission were studied electrophysiologically on diaphragms of mouse and rat and the soleus muscle of rat. The drug DPMPI (21.5-645 microM) increased both direct and indirect twitch tension of mouse diaphragm. It also increased (a) the frequency of miniature endplate potentials and (b) the quantal content of endplate potential. However, DPMPI (64.5 microM) affected neither the amplitude of the directly elicited action potential of soleus muscle in the rat nor the magnitude of the resting membrane potential of mouse diaphragm, although DPMPI (215 microM) decreased the amplitude of the compound action potential of phrenic nerve. Based on these results, it is concluded that DPMPI had several effects on neuromuscular transmission, i.e. it (a) facilitated the transmitter releasing process of the motor nerve terminal, (b) decreased the conduction in the phrenic nerve and (c) increased the directly elicited twitch tension.

Change of blood pressure and urine flow rate during cardiopulmonary bypass and its relation to postoperative renal function.

The relationship between the perfusion flow, the mean arterial pressure (MAP) and the urine flow rate during cardiopulmonary bypass (CPB) and the effect of oliguria developed during CPB on the postoperative renal dysfunction were studied prospectively in 69 open heart surgery patients. The MAP, the perfusion flow and the urine flow rate were monitored every five minutes during the first 45 minutes after the commencement of CPB and after the removal of the aortic cross clamp (AX). The serum creatinine (Cr), creatinine clearance (CCr) and blood urea nitrogen were measured before operation, as well as on the first, second and third postoperative days. The dosage of catecholamines and diuretics used and the duration of intubation and hospitalization in the intensive care unit were also recorded. The urine flow rate correlated with MAP much better than the perfusion flow during CPB (r = 0.4768, p < 0.0001). The urine flow rate and MAP decreased significantly after the initiation of CPB and after the release of the AX; however, oliguria developed only during the first 30 minutes of CPB. There were no differences in postoperative Cr, postoperative CCr, doses of catecholamines or diuretics, and the duration of intubation between patients with or without development of oliguria during CPB. Parameters measured during CPB could not predict CCr during the first three postoperative days. We conclude that it is MAP rather than perfusion flow which correlates with the urine flow rate during CPB. Periods of oliguria during CPB did not correlate with or help in the prediction of the development of postoperative renal dysfunction.

Can cancer pain attenuate the physical dependence on chronic long-term morphine treatment?

This prospective and comparative study was designed to determine the role of cancer pain and attitudes towards morphine in attenuating the intensity and duration of physical dependence following chronic morphine treatment. Morphine was administered via a stepwise ladder approach in order of oral, spinal and intravenous routes depending on the adequacy of analgesia. On-demand titration of a dose, either upward or downward, was liberal and unlimited. Withdrawal strategy was evaluated and initiated either by patients (PI group) or their families (FI group). The manifestation of physical dependence on morphine was compared between patients who successfully withdrew (total withdrawal), and patients who failed to withdraw (episodic withdrawal), from morphine for a period of more than two weeks. Eighty-eight out of 627 patients (14.1%) were excluded from our protocol; 75% of these exclusions were due to objections toward morphine as the major form of analgesic. Drop-out due to poorly tolerated side effects was relatively rare (18.2%). Fifty-four (10.0%) achieved total withdrawal and 212 (39.3%) experienced episodic withdrawal. Non-pain-related abstinence symptoms were highly prevalent but were tolerable for both groups. Pain-related symptoms were more exaggerated during episodic withdrawal. Intolerable pain, rather than physical dependence, contributed to the failure to withdraw from morphine. Among a total of 539, addiction was found in only one patient (0.18%) who began drug use long before entering our protocol. Attitudes towards morphine affect the acceptance of treatment and hasten the withdrawal strategy. Families were more anxious about morphine than the patients themselves which led to more aggressive, but less tolerable, withdrawal.(ABSTRACT TRUNCATED AT 250 WORDS)

[Analysis of 805 children with Salmonellae infection].

We analyzed 805 children with Salmonellae infection admitted during 1981-1991. 353 of them had typhoid fever. Most of the children were over 3 years old and came from rural area. One child died. Those under 3 years of age had non-typhoid Salmonellae infection, manifesting as enteritis pattern; most sepsis patterns were seen in neonates. S. typhimurium was often seen Salmonellae infection, S. agona came next, and S. derby the third. Salmonellae infection varied, including 7 serum groups and 25 serum types. S. typhimurium and S. agona were drug resistant, with severe carrier status. Infants and young children are very liable the infection, therefore, will be the main subjects of prevention.

Heart rate variability--a useful non-invasive tool in anesthesia.

Fluctuations in heart rate (HR) and arterial blood pressure occurring at respiratory and lower frequencies have long been recognized. However, their significance remained obscure until the monitoring of fetal heart-rate variability (HRV) was appreciated. Recent studies suggest that HRV may reflect the sympatho-vagal interactions that modulate cardiovascular function. Analysis of HRV can provide a noninvasive measure of central autonomic outflow and autonomic reflex functions. A mathematical and signal-processing technique called power spectral analysis (PSA) has been used extensively to quantify HRV. Several frequencies of HR oscillations can be quantified: the low-frequency peak (LFP 0-0.04 Hz), the mid-frequency peak (MFP 0.05-0.15 Hz) and the high-frequency peak (HFP 0.15-0.4 Hz). In this review article, the physiological origins of these HR fluctuations are described and the changes of HRV by different pathophysiological states are also discussed. In conclusion, spectral analysis of HRV may provide important insights regarding the influence of anesthesia on cardiovascular neural control and anesthetic depth and the monitoring may be developed as a very useful non-invasive tool for modern anesthesia in the near future.

Intravenous infusion of low dose propofol for conscious sedation in cesarean section before spinal anesthesia.

BACKGROUND: Conscious sedation, not affecting the safety of both mother and fetus, is especially favorable in anxious patients undergoing Cesarean delivery. However, when sedation is started before performing intrathecal anesthesia, the infusion time before delivery will be prolonged. In this study, the incidence of maternal and fetal complications under propofol infusion were evaluated as well as the blood concentrations of propofol during delivery at different time of sedation. METHODS: Maternal and fetal effects of pre-spinal sedation with low dose propofol infusion technique (3 mg/mg/h following 0.3 mg/kg bolus) in 37 Cesarean parturients were evaluated, compared with another 33 parturients under spinal anesthesia without any sedatives. RESULTS: The induction to delivery time was 32.6 +/- 7.7 min. Satisfactory, airway-maintaining conscious sedation was shown without increasing the incidence of post-spinal hypotension and hypoxemia compared with non-sedative group. The plasma propofol concentrations in the mean time of delivery in maternal vein and umbilical vein were 0.86 +/- 0.29 and 0.33 +/- 0.11 microgram/ml, respectively. Umbilical venous concentration neither correlated with infusion time nor exceeded the maternal venous concentration. The 1-min and 5-min Apgar scores as well as umbilical venous blood gas analyses did not differ significantly between two groups. CONCLUSIONS: Conscious sedation by low dose propofol infusion is safe for both mother and fetus in spite of longer infusion time.

Conscious sedation by low dose propofol infusion during spinal anesthesia for cesarean section.

BACKGROUND: A simple sedative technique without inducing oversedation or amnesia for birth experience would be necessary for patients undergoing Cesarean section receiving regional anesthesia. Clinical effects and dose requirement of intravenous propofol infusion were evaluated for this purpose. METHODS: Forty-five parturients under adequate spinal anesthesia were randomly assigned to three groups and propofol was given after the clamping of the umbilical cord. The loading doses and initial infusion rates for group A, B, C were 0.3, 0.4, 0.5 mg/kg and 3, 4, 5 mg/kg/h, respectively. RESULTS: Oversedation was not found and verbal contact was maintained in patients of group A and B. Two patients in group C were oversedated. Cardiovascular and respiratory function remained stable in all three groups. The incidences of complete amnesia for the experience of baby shown and intraoperative nausea/ vomiting were low. Most patients were satisfied with the sedation technique. CONCLUSIONS: Intravenous infusion of propofol with a rate of 3-4 mg/kg/h after 0.3-0.4 mg/kg bolus injection is a sale, simple and satisfactory intraoperative postdelivery sedation technique in elective patients undergoing Cesarean section under spinal anesthesia.

Long-term propofol infusion and airway management in a patient with Goldenhar's syndrome.

A 2-year-old patient of Goldenhar's syndrome received an operation for corneal transplantation. Difficult endotracheal intubation from the congenital anomaly was treated with laryngeal mask airway and pediatric fiberoptic laryngoscope. Long-term propofol infusion (> 10 h) for anaesthetic maintenance in this small child was used with rapid and smooth recovery.

Effects of ondansetron on postoperative emesis in Chinese children.

BACKGROUND: Postoperative nausea together with vomiting (PONV) is a common adverse effect of general anesthesia. Ondansetron, a new serotonin (5-hydroxytryptamine) receptor antagonist of the subtype 3 is shown to be effective and safe in the prophylaxis and treatment of PONV. However, the clinical experiences of using ondansetron for prevention of PONV is lacking in Taiwan. The purpose of this study is to evaluate the efficacy and safety of ondansetron for prevention of PONV in Chinese children. METHODS: Eighty pediatric patients aged from 2 to 12 years undergoing herinorrhaphy were prospectively randomized to receive either ondansetron 0.1 mg/kg or saline placebo. All patients received general anesthesia with tracheal intubation. The parents of patients were educated how to record the episodes of postoperative emesis and other complications and answer questions in the form of questionnaire. The observation period lasted for 24 h postoperatively. RESULTS: The incidence of postoperative emesis was 55% and 10% in placebo and ondansetron group respectively. As to the severity of emetic symptoms it was milder in the ondansetron group. There was no difference in the incidence of other complications between the two groups. CONCLUSIONS: The intravenous administration of ondansetron 0.1 mg/kg is safe and effective in reducing postoperative emesis in Chinese children undergoing herinorrhaphy surgery.

Comparison of neuromuscular action of rocuronium, a new steroidal non-depolarizing agent, with vecuronium.

BACKGROUND: Rocuronium is a new nondepolarizing muscle relaxant. It features a rapid onset and lack of histamine release: It has an intermediate onset of action as vecuronium. The purpose of this study was to compare the neuromuscular action and condition of intubation after a bolus dose of rocuronium or vecuronium (2 x ED90). We also compared the duration of relaxation after intubation and maintenance doses of each drug. METHODS: Sixty male or female patients, age 18-65, scheduled for elective surgery under general anesthesia were divided randomly into two groups (rocuronium and vecuronium group). All patients were ASA class I-II and pre-operative laboratory data were normal. Anesthesia was performed with fentanyl, isoflurane and O2. Rocuronium 0.6 mg/kg (2 x ED90) or vecuronium 0.1 mg/kg (2 x ED90) was given during induction of anesthesia. The response of adductor pollicis was measured with acceleromyography. Neuromuscular block was maintained by bolus injection of rocuronium 0.15 mg/kg or vecuronium 0.025 mg/kg when T1 reached 25% of control. Onset time, duration, recovery indices, intubation condition and T4/T1 ratio to 70% were recorded. Side effects were recorded during the study. RESULTS: The onset time was significantly longer in vecuronium group than that of rocuronium group (102.8 +/- 26.9 s vs. 54.9 +/- 10.9 s, p < 0.05). The clinical durations of action were respectively 44.2 +/- 13.2 min in rocuronium group and 42.5 +/- 9.1 min in vecuronium group (T1 to 25%). The duration of the maintenance were respectively 28.8 +/- 9.5 min in rocuronium group and 26.1 +/- 6.8 min in vecuronium group (T1 to 25%). No adverse effect occurred with either drug. The intubation condition was similar in both groups. CONCLUSIONS: We conclude that rocuronium provides a more rapid onset of action than that of vecuronium. Rocuronium is an intermediate-acting muscle relaxant as vecuronium with good to excellent intubation condition. It may be an useful alternative to vecuronium for rapid tracheal intubation.

Effect of ropivacaine on endothelium-dependent phenylephrine-induced contraction in guinea pig aorta.

BACKGROUND: Previous studies have shown that ropivacaine has biphasic vascular effects, causing vasoconstriction at low concentrations and vasorelaxation at high concentrations. This study was designed to examine the role of the endothelium during accidental intravascular absorption of ropivacaine, and to elucidate the mechanisms responsible. METHODS: Isolated guinea pig aortic rings were suspended for isometric tension recording. The effects of ropivacaine on endothelium-intact and endothelium-denuded aortic rings were assessed. Endothelium-intact aortic rings were pre-contracted with phenylephrine before being exposed to ropivacaine and acetylcholine, in order to generate and compare concentration-response curves. In the absence and presence of yohimbine, propranolol, atropine, indometacin, N(G)-nitro-l-arginine methyl ester (l-NAME), 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) or methylene blue, the contractile response induced by ropivacaine was assessed on endothelium-intact aortic rings pre-contracted with phenylephrine. RESULTS: Ropivacaine (3 x 10(-4) to 10(-2) mol/l) produced vasoconstriction in endothelium-denuded aortic rings, whereas no such response was observed in aortic rings with intact endothelium. In phenylephrine pre-contracted intact aortic rings, ropivacaine induced a greater degree of vasorelaxation than did acetylcholine. Yohimbine, propranolol and atropine all failed to affect the relaxation responses induced by ropivacaine. However, pre-treatment with indometacin (cyclo-oxygenase inhibitor), l-NAME (nitric oxide synthase inhibitor), methylene blue (soluble guanylyl cyclase inhibitor) or ODQ (soluble guanylyl cyclase inhibitor), significantly decreased the ropivacaine-induced relaxation of endothelium-intact aortic rings (3 x 10(-4) to 10(-2) mol/l). CONCLUSIONS: Ropivacaine elicits an endothelium-dependent vasorelaxation in phenylephrine pre-contracted aortic rings via the nitric oxide-cyclic guanosine 3',5'-monophosphate pathway and the prostaglandin system.

Management of achalasia with transabdominal esophagocardiomyotomy and partial posterior fundoplication.

In this article we present our experience in the management of achalasia. From May 1988 through August 2005, 71 patients with achalasia underwent transabdominal esophagocardiomyotomy and partial posterior fundoplication. Barium swallow, manometry, and 24-h pH studies were performed in all patients preoperatively. Manometry and 24-h pH monitoring were only carried out in 58 patients at the third post-operative week and in 43 patients during follow-up, even though 52 patients were included in the follow-up. There were no operative deaths or complications. All the 71 patients were able to eat semifluid or solid food without dysphagia and heartburn at discharge. Esophageal barium studies showed that the maximum esophageal diameter decreased 2.2 cm and the minimum gastroesophageal junction diameter increased 8.4 mm after operation. Manometry examination in 58 patients revealed that the lower esophageal sphincter resting pressure decreased 15.0 mmHg in the wake of the procedure. Twenty-four hour pH monitoring demonstrated that reflux events were within the normal post-operative range. Fifty-five of the 58 patients had normal DeMeester scores. Among the patients with a mean 90-month follow-up, 49 patients had normal intake of food without reflux, the remaining three had mild dysphagia without requiring treatment. All the patients resumed their preoperative work and social activities. The manometry and 24-h pH studies in the 43 patients showed there were no significant changes between the third post-operative week and during follow-up. Transabdominal esophagocardiomyotomy and posterior partial fundoplication are able to relieve the functional outflow obstruction of the lower esophageal sphincter, obviate the rehealing of the myotomy edge and prevent gastroesophageal reflux in patients who have undergone myotomy alone.

Caesarean section in a patient with protein S deficiency.

Protein S is a nonenzymatic and vitamin K-dependent cofactor of activated protein C. Without protein S, the anticoagulant function of protein C is almost depleted and thrombotic events occur. We report a parturient with hereditary protein S deficiency in whom the risk of thromboembolism was further complicated by pregnancy and who required emergency Caesarean section for fetal distress.

Smoking status and body size increase carbon monoxide concentrations in the breathing circuit during low-flow anesthesia.

The major sources for intraoperative carbon monoxide (CO) in the breathing circuit are related to patient's hemoglobin catabolism, smoking and the degradation between absorbent and anesthetics. We performed this study to evaluate their combined effects on CO production during low-flow anesthesia. We used a direct-measurement instrument to measure real-time CO concentrations in the breathing circuit during different anesthetic conditions for patients who received desflurane or isoflurane. By applying multiple linear regression models, we determined the significant factors related to CO concentrations in the circuit. We identified patients' smoking status, preoperative smoking and body weight as well as gas flow rates as important factors for affecting peak and time-weighted CO levels. These four factors predicted approximately 44.1% and 42.7% of peak and mean inspiratory CO concentrations respectively. We found that chronic and preoperative smokers and patients with larger body weights are associated with increased CO concentrations, whereas increase in gas flow rates could decrease CO concentrations. After controlling these four important factors, we found that inspiratory CO concentrations were not significantly associated with the choice of anesthetic and its concentration during low-flow anesthesia.

Neuromuscular blockade of the fetus with pancuronium or pipecuronium for intra-uterine procedures.

Fetal movement during intra-uterine fetal therapy makes these procedures technically more difficult and increases the likelihood of trauma to the fetus. Pancuronium or pipecuronium were used in a randomised study to temporarily arrest movement in 16 fetuses undergoing intra-uterine procedures. Under ultrasound guidance, pancuronium or pipecuronium 0.2 mg.kg-1 was injected into the fetal gluteal region. Fetal movements ceased within 4.6 +/- 2.3 min in the pancuronium group and 4.5 +/- 2.8 min in the pipecuronium group and returned by 115 +/- 26 min in the pancuronium group and 121 +/- 32 min in the pipecuronium group. No adverse effects of the relaxant were observed in the mothers. There was no evidence of soft tissue, nerve or muscle damage at the fetal injection site after delivery. Both muscle relaxants provided a safer method for diagnostic and therapeutic procedures. However, four cases in the pancuronium group (50%) developed a fetal tachycardia, and two cases in the same group showed loss of beat-to-beat variability. Pipecuronium appeared to be more suitable for intra-uterine procedures.