Effect of lumbar epidural anaesthesia on plasma cortisol levels in children

Comparative efficacy of Micropore™ surgical dressing, Tegaderm™ and Lockit plus® for lumbar epidural catheter fixation in children: a prospective parallel group randomized controlled trial

BACKGROUND

Proper fixation of an epidural catheter is necessary for desired drug effect and to prevent catheter displacement. Different techniques have been used for epidural catheter fixation. The aim of the study was to compare the relative efficacy of Micropore™ surgical dressing, Tegaderm™, and Lockit plus® in preventing lumbar epidural catheter migration in children.

METHODS

We studied 167 patients aged 5-16 years, for up to 48 h. After the elective abdominal or lower limb surgery. Patients were randomly assigned to one of three groups: (1) Micropore™ surgical dressing (group M), (2) Tegaderm™ (group T), or (3) Lockit plus® (group L). Incidence and extent of epidural catheter migration in centimetres (cm); was compared at 24 and 48 h post epidural fixation. Correlation between epidural catheter migration and patient characteristics, and relative incidence of complications in three groups was also analysed.

RESULTS

Incidence of catheter migration was 9.6% at 24 h (group M: 7.1%, group T: 21.1% and group L: 0%) and 45.5% at 48 h (group M: 66.1%, group T: 45.6% and group L: 24.1%). After 48 h, absolute migration (mean migration rounded off to the nearest 0.5 cm) was least in patients in group L: 0.34 cm (1.39) compared to group M 1.22 cm (SD: 1.85) group T: 0.94 cm (1.94) (p = <0.001).

CONCLUSION

Up to 48 h after surgery, the Lockit plus® device demonstrated the less epidural catheter migration when compared to micropore surgical dressing or tegaderm in children undergoing elective abdominal or lower limb surgery.

Thoracic regional anesthesia and the impact on ventilation

Thoracic surgical incisions can be associated with intense pain or discomfort. Postoperative thoracic pain may be multifactorial in origin. Inadequate analgesia causes respiratory dysfunction. Adequate analgesia preserves pulmonary function and may hasten recovery. Intravenous opioids are widely used but sufficient analgesia is seldom achieved in doses that permit safe spontaneous ventilation. Thoracic regional anesthesia provides profound analgesia, is opiate sparing and has minimal depressant effects on ventilation. Thoracic regional anesthesia is both an effective alternative to systemic analgesics or can be used as part of a multimodal analgesic technique.

[Effects of caudal block in pediatric surgical patients: a randomized clinical trial]

BACKGROUND

Surgery generates a neuroendocrine stress response, resulting in undesirable hemodynamic instability, alterations in metabolic response and malfunctioning of the immune system.

OBJECTIVES

The aim of this research was to determine the effectiveness of caudal blocks in intra- and postoperative pain management and in reducing the stress response in children during the same periods.

METHODS

This prospective, randomized clinical trial included 60 patients scheduled for elective herniorrhaphy. One group (n = 30) received general anesthesia and the other (n = 30) received general anesthesia with a caudal block. Hemodynamic parameters, drug consumption and pain intensity were measured. Blood samples for serum glucose and cortisol level were taken before anesthesia induction and after awakening the patient.

RESULTS

Children who received a caudal block had significantly lower serum glucose (p < 0.01), cortisol concentrations (p < 0.01) and pain scores 3 hours (p = 0.002) and 6 hours (p = 0.003) after the operation, greater hemodynamic stability and lower drug consumption. Also, there were no side effects or complications identified in that group.

CONCLUSIONS

The combination of caudal block with general anesthesia is a safe method that leads to less stress, greater hemodynamic stability, lower pain scores and lower consumption of medication.

Effects of caudal block in pediatric surgical patients: a randomized clinical trial

Background

Surgery generates a neuroendocrine stress response, resulting in undesirable hemodynamic instability, alterations in metabolic response and malfunctioning of the immune system.

Objectives

The aim of this research was to determine the effectiveness of caudal blocks in intra- and postoperative pain management and in reducing the stress response in children during the same periods.

Methods

This prospective, randomized clinical trial included 60 patients scheduled for elective herniorrhaphy. One group (n = 30) received general anesthesia and the other (n = 30) received general anesthesia with a caudal block. Hemodynamic parameters, drug consumption and pain intensity were measured. Blood samples for serum glucose and cortisol level were taken before anesthesia induction and after awakening the patient.

Results

Children who received a caudal block had significantly lower serum glucose (p <  0.01), cortisol concentrations (p <  0.01) and pain scores 3 h (p =  0.002) and 6 h (p =  0.003) after the operation, greater hemodynamic stability and lower drug consumption. Also, there were no side effects or complications identified in that group.

Conclusions

The combination of caudal block with general anesthesia is a safe method that leads to less stress, greater hemodynamic stability, lower pain scores and lower consumption of medication.

Epidural local anaesthetics versus opioid-based analgesic regimens for postoperative gastrointestinal paralysis, vomiting and pain after abdominal surgery

BACKGROUND

Gastrointestinal paralysis, nausea and vomiting and pain are major clinical problems following abdominal surgery. Anaesthetic and analgesic techniques that reduce pain and postoperative nausea and vomiting (PONV), while preventing or reducing postoperative ileus, may reduce postoperative morbidity, duration of hospitalization and hospital costs. This review was first published in 2001 and was updated by new review authors in 2016.

OBJECTIVES

To compare effects of postoperative epidural analgesia with local anaesthetics versus postoperative systemic or epidural opioids in terms of return of gastrointestinal transit, postoperative pain control, postoperative vomiting, incidence of anastomotic leak, length of hospital stay and costs after abdominal surgery.

SEARCH METHODS

We identified trials by conducting computerized searches of the Cochrane Central Register of Controlled Trials (CENTRAL) (2014, Issue 12), MEDLINE (from 1950 to December 2014) and EMBASE (from 1974 to December 2014) and by checking the reference lists of trials retained. When we reran the search in February 2016, we added 16 potential new studies of interest to the list of 'Studies awaiting classification' and will incorporate these studies into formal review findings during the next review update.

SELECTION CRITERIA

We included parallel randomized controlled trials comparing effects of postoperative epidural local anaesthetic versus regimens based on systemic or epidural opioids.

DATA COLLECTION AND ANALYSIS

We rated the quality of studies by using the Cochrane 'Risk of bias' tool. Two review authors independently extracted data and judged the quality of evidence according to the GRADE (Grades of Recommendation, Assessment, Development and Evaluation Working Group) scale.

MAIN RESULTS

We included 128 trials with 8754 participants in the review, and 94 trials with 5846 participants in the analysis. Trials included in the review were funded as follows: charity (n = 19), departmental resources (n = 8), governmental sources (n = 15) and industry (in part or in total) (n = 15). The source of funding was not specified for the other studies.Results of 22 trials including 1138 participants show that an epidural containing a local anaesthetic will decrease the time required for return of gastrointestinal transit as measured by time to first flatus after an abdominal surgery (standardized mean difference (SMD) -1.28, 95% confidence interval (CI) -1.71 to -0.86; high quality of evidence; equivalent to 17.5 hours). The effect is proportionate to the concentration of local anaesthetic used. A total of 28 trials including 1559 participants reported a decrease in time to first faeces (stool) (SMD -0.67, 95% CI -0.86 to -0.47; low quality of evidence; equivalent to 22 hours). Thirty-five trials including 2731 participants found that pain on movement at 24 hours after surgery was also reduced (SMD -0.89, 95% CI -1.08 to -0.70; moderate quality of evidence; equivalent to 2.5 on scale from 0 to 10). From findings of 22 trials including 1154 participants we did not find a difference in the incidence of vomiting within 24 hours (risk ratio (RR) 0.84, 95% CI 0.57 to 1.23; low quality of evidence). From investigators in 17 trials including 848 participants we did not find a difference in the incidence of gastrointestinal anastomotic leak (RR 0.74, 95% CI 0.41 to 1.32; low quality of evidence). Researchers in 30 trials including 2598 participants noted that epidural analgesia reduced length of hospital stay for an open surgery (SMD -0.20, 95% CI -0.35 to -0.04; very low quality of evidence; equivalent to one day). Data on costs were very limited.

AUTHORS' CONCLUSIONS

An epidural containing a local anaesthetic, with or without the addition of an opioid, accelerates the return of gastrointestinal transit (high quality of evidence). An epidural containing a local anaesthetic with an opioid decreases pain after abdominal surgery (moderate quality of evidence). We did not find a difference in the incidence of vomiting or anastomotic leak (low quality of evidence). For open surgery, an epidural containing a local anaesthetic would reduce the length of hospital stay (very low quality of evidence).

Efficacy of Caudal Clonidine and Fentanyl on Analgesia, Neuroendocrine Stress Response and Emergence Agitation in Children Undergoing Lower Abdominal Surgeries Under General Anaesthesia with Sevoflurane

INTRODUCTION

Clonidine has proved to be effective drug for postoperative analgesia but it's efficacy to alter neuroendocrine stress response and emergence agitation is unknown. This study was conducted to assess and compare the efficacy of caudal fentanyl vs. clonidine for analgesia, blunting of neuroendocrine stress responses (NESR) and emergence agitation (EA) following sevoflurane anaesthesia.

MATERIALS AND METHODS

This prospective, randomized, double blind study enrolled 60 children undergoing infraumbilical surgery. Three groups of 20 each were assigned to receive caudal block with either bupivacaine 0.25% 1 ml/kg with normal saline (group I) or bupivacaine 0.25% 1 ml/kg and 1 microgram*kg-1fentanyl (group II), or bupivacaine 0.25% 1 ml/kg and 3 μg/kg clonidine [group III]. Postoperative analgesia, sedation, NESR, emergence agitation and side effects were observed.

RESULTS

VAS score at two hours was significantly less in group III (0.60± 0.60) than in group I (1.80± 0.41) and group II (1.25± 0.44), the time to rescue analgesia was also significantly greater in group III (8.03+0.41hours) than groups I and II (4.15± 0.54 hours) and (6.18± 0.5hours) respectively. The EA scores were significantly better in Group III but patients were significantly more sedated postoperatively. Intraoperatively, NESR was blunted in all the groups and the markers of NESR were lowest in group III.

CONCLUSION

Caudal clonidine in a dose of 3 μg/kg prolongs analgesia and decreases emergence agitation as compared to bupivacaine alone or with fentanyl 1μg/kg. Modulation of the neuroendocrine stress response was observed in all the investigated groups though the indicators were lowest in clonidine group.

Migration of pediatric epidural catheters

BACKGROUND

Postoperative pain control in the pediatric population frequently involves epidural catheters placed intraoperatively. A retrospective review of epidural catheter tip position was conducted by evaluation of routine chest anterior-posterior (A-P) X-rays obtained by the surgical and ICU teams.

METHODS

Of the 174 pediatric epidural catheters placed during a 1-year period at Children's Hospital of Wisconsin, 59 pediatric patients with chest X-rays demonstrating epidural catheter tip on at least 2 days were reviewed. The change in epidural catheter position was then calculated. The overall reason for discontinuation of epidural analgesia in the larger population was also compiled.

RESULTS

It was determined that epidural catheters migrated more frequently in patients <10 kg and 10-40 kg, when compared to those >40 kg P < 0.001. The average migration seen on X-ray was 1.1 levels inward in those <40 kg and 0.3 levels inward in those >40 kg. The incidence of catheters discontinued secondary to falling out, or migrating in, was also increased in those patients <40 kg when compared to those >40 kg.

CONCLUSION

Results suggest that epidural catheters move inward more frequently and fall out more frequently in patients <40 kg.

Efficacy of caudal fentanyl and ketamine on post-operative pain and neuroendocrine stress response in children undergoing infraumbilical and perineal surgery: A pilot study

BACKGROUND AND AIMS

It is well-known that neuroendocrine stress response (NESR) occurs in children and it can be modified by caudal block. However, there is paucity of literature comparing caudal fentanyl and ketamine on NESR. The present study was aimed to compare the analgesic efficacy of these caudal adjuvants and their effect on (NESR) in children undergoing infraumbilical and perineal surgery.

MATERIALS AND METHODS

A total of 60 children undergoing infraumbilical surgery were included in this randomized, double-blind study. Three groups of 20 each were assigned to receive caudal block with bupivacaine 0.25% 1 ml/kg along with either 0.9% normal saline (Group I) 1 μg/kg fentanyl (Group II) or 0.5 mg/kg ketamine (Group III). Modified visual analogue scale (VAS) was used for assessment of post-operative pain, and stress response was assessed by blood glucose, serum cortisol and insulin levels at various time intervals.

RESULTS

VAS scores were significantly lower in the ketamine group at all-time intervals upto 4 h (P < 0.05). Patients in ketamine group required rescue analgesia significantly later (8.23 h) when compared to fentanyl (5.95 h) and bupivacaine group (4.10 h). Caudal block led to significant decrease in cortisol and insulin levels within the groups however this significance was not achieved between groups.

CONCLUSION

Caudal ketamine in a dose of 0.5 mg/kg provides prolonged analgesia when compared to fentanyl 1 μg/kg. Blunting of the NESR was observed in all the groups though the indicators of the response were lowest with ketamine.

Continuous lumbar/thoracic epidural analgesia in low-weight paediatric surgical patients: practical aspects and pitfalls

PURPOSE

Continuous epidural anaesthesia attenuates perioperative stress and avoids the need for systemic opioids. In addition, it may prevent the need for postoperative mechanical ventilation. The aim of the study was to prospectively follow the perioperative course of young infants treated with continuous thoracic/lumbar epidural anaesthesia for major surgery.

METHODS

Data were collected prospectively from 44 epidural anaesthetics in 40 infants (18 premature or former premature) weighing 1,400-4,300 g who underwent major abdominal surgery (33 cases), thoracic surgery (5), or both (1), or ano-rectal surgery (5) at our centre.

RESULTS

Epidural placement was achieved easily in all cases, with high quality analgesia for 24-96 h. Tracheal extubation was delayed after 4 anaesthetics due to muscle relaxant overdose (n = 1), surgeon's request (n = 2), and systemic opioid administration before epidural anaesthesia was considered (n = 1). Intraoperative complications included haemodynamic instability (n = 1) and vascular catheter placement (n = 5). Postoperative complications included meningitis (n = 1), insertion site erythema (n = 7), apnoea (n = 6; 4 premature and 2 full-term infants) and tracheal re-intubation (n = 6).

CONCLUSIONS

Continuous epidural analgesia is effective in low-weight infants undergoing major surgery. The trachea may be extubated immediately after surgery. Attention should be paid to the unique anatomical, physiological, and pharmacological aspects. The patients should be monitored carefully for pain, respiratory failure, and meningitis (an extremely rare complication).

Addition of sufentanil to bupivacaine in caudal block effect on stress responses in children

BACKGROUND

The aim of the present randomized study was to determine the effect of adding sufentanil to bupivacaine, compared with bupivacaine alone in caudal block, on the surgical stress response in children.

METHODS

The children were premedicated with midazolam 0.5 mg/kg. All children received induction with nitrous oxide and sevoflurane. Anesthesia was maintained with the same volatile agents in the both groups. The children were randomly allocated to two groups. Group I received bupivacaine alone (n = 17) and group II received bupivacaine + sufentanil (n = 16). Caudal block was performed with 0.25% bupivacaine 2 mg/kg (group I) or 0.25% bupivacaine 2 mg/kg with sufentanil 0.5 microg/kg (group II) after induction of anesthesia. Blood samples were obtained after induction of anesthesia (T(0)) to measure baseline concentrations of cortisol, prolactin, glucose and insulin. Additional samples were obtained 30 min after the start of surgery (T(1)), and 60 min after the end of surgery (T(2)).

RESULTS

All of the basal values (T(0)) were within the normal ranges of the authors' laboratory for children of this age group and there were no differences between the groups (P > 0.05). In both groups, glucose concentration increased at T(1), compared with T(0) and T(2) (P < 0.05). The glucose concentration was unchanged at T(2) compared with T(0) in both group (P > 0.05). In both groups, prolactin concentration increased at T(1), compared with T(0) and decreased at T(2), compared with T(1) (P < 0.05). Cortisol decreased at T(1) and T(2), compared with T(0) in both groups. (P < 0.05). Insulin concentration remained unchanged at T(0) and T(2), but increased slightly at T(1) in both groups (P > 0.05). There were no significant differences in plasma prolactin, cortisol, glucose and insulin levels between the two groups at T(1) and T(2) (P > 0.05).

CONCLUSION

There is no advantage in adding 0.5 microg/kg sufentanil to bupivacaine over bupivacaine alone in the caudal block, with regard to the surgical stress response in children.

Combined spinal-epidural anesthesia in major abdominal surgery in high-risk neonates and infants

BACKGROUND

Combined spinal-epidural anesthesia (CSE-A) is reportedly safe and effective for the pediatric population in infraumbilical surgery. Our main purpose was to describe our experience of this technique in neonates and infants undergoing elective major upper abdominal surgery.

METHODS

Spinal anesthesia was performed in 28 neonates and infants with isobaric bupivacaine 0.5%, 1 mg.kg(-1) followed by placement of a caudal epidural catheter to thoracic spinal segments. The catheter tip position was confirmed radiographically. Respiratory and hemodynamic data were collected before and after the CSE-A and throughout the operation, as a measure of anesthetic effectiveness. Complications related to the anesthesia technique were collected as a measure of the anesthetic technique safety.

RESULTS

Satisfactory surgical anesthesia was achieved in 24 neonates and infants, four patients were converted to general anesthesia. Respiratory and hemodynamic variables did not change significantly during surgery, compared with baseline values: oxygen saturation (P = 0.07), systolic and diastolic blood pressures (P = 0.143, P = 0.198 respectively), heart rate (P = 0.080) and respiratory rate (P = 0.127). However, twenty infants were fussy during the surgical procedures and were calmed with intravenous midazolam; our patients required oxygen supplementation and transient manual ventilation intraoperatively.

CONCLUSIONS

Combined spinal-epidural anesthesia could be considered as an effective anesthetic technique for elective major upper abdominal surgery in awake or sedated neonates and infants, and could be used cautiously by a pediatric anesthesiologist as an alternate to general anesthesia in high-risk neonates and infants undergoing upper gastrointestinal surgery.

The efficacy of caudal morphine or bupivacaine combined with general anesthesia on postoperative pain and neuroendocrine stress response in children

BACKGROUND

The aim of this study was to compare the effectiveness of caudal morphine and bupivacaine usage on surgical stress response in children undergoing abdominal and genitourinary surgery while keeping anesthesia depth constant utilizing the bispectral index analysis (BIS).

METHODS

Following the approval of Institutional Review Board and informed parental consent, 28 children with ages ranging between 4 and 16 years with ASA physical status I and II , undergoing elective lower abdominal and genitourinary surgery were included in this study. Patients were randomized and separated into two subgroups. Before induction of anesthesia, patients were monitored for BIS. Epidural injection of 30 microg.kg(-1) morphine in 1 ml.kg(-1) saline for the first group (group M) and the same volume of (0.25%) bupivacaine for second group (group B) were administered via the sacral hiatus. We analyzed serum cortisol and glucose concentrations for evaluation of the stress response in the patients. Blood samples for cortisol and glucose were withdrawn at the beginning of induction (first samples), 40 min after surgical incision (second samples), and 40 min after end of the surgery (third samples). BIS scores of the patients were kept between 40 and 60 during the surgical procedure.

RESULTS

Group B had significantly lower levels of cortisol than group M in the second samples. There was a significant increase in serum glucose level in group M compared with group B during the intraoperative and postoperative periods.

CONCLUSIONS

We conclude that, caudal administration of bupivacaine is more effective than morphine for attenuating intraoperative and postoperative stress response to surgery in children.

Comparison of the effect of ketamine added to bupivacaine and ropivacaine, on stress hormone levels and the duration of caudal analgesia

BACKGROUND

The aim of this study was to compare bupivacaine 0.25% and ropivacaine 0.2%, singly and in combination with ketamine, for caudal administration in children. Duration of analgesia, the need for other analgesics and the stress response were measured.

METHODS

Eighty children were randomized into four groups of twenty. The bupivacaine group received bupivacaine 0.25% and the ketamine/bupivacaine group received bupivacaine 0.25% plus 0.5 mg/kg ketamine. The ropivacaine group received ropivacaine 0.2%, and the ketamine/ropivacaine group received ropivacaine 0.2% plus 0.5 mg/kg ketamine. The duration of analgesia and analgesic requirements were recorded for each group, as were peri-operative and post-operative concentrations of the stress hormones insulin, glucose and cortisol.

RESULTS

Ketamine, added to either bupivacaine or ropivacaine for caudal analgesia, gave a longer duration of analgesia (P < 0.05) than bupivacaine or ropivacaine alone. In all groups, blood insulin concentration was increased, and cortisol concentration reduced. Glucose concentration was significantly increased in all groups (P < 0.05).

CONCLUSIONS

Ketamine can safely be added to ropivacaine 0.2% or bupivacaine 0.25% for caudal anesthesia in order to prolong duration of analgesia and reduce the need for additional analgesics. Stress hormone levels are partially attenuated.

Comparison of the effects of clonidine and ketamine added to ropivacaine on stress hormone levels and the duration of caudal analgesia

BACKGROUND

The purpose of this study was to compare the analgesic quality and duration of ropivacaine 0.2% with the addition of clonidine (1 microg.kg(-1)) with that of ropivacaine 0.2% and the addition of ketamine (0.5 mg.kg(-1)) to that of ropivacaine 0.2% and also compare the postoperative cortisol, insulin and glucose concentrations, sampled after induction and 1 h later following caudal administration in children.

METHODS

According to the randomization, patients in the ropivacaine group (R; n = 25) received ropivacaine 0.2%, 0.75 ml.kg(-1); those in the clonidine group (RC; n = 25) received ropivacaine 0.2% 0.75 ml.kg(-1) plus clonidine 1 microg.kg(-1) and those in the ketamine/ropivacaine group (RK; n = 25) ropivacaine 0.2% 0.75 ml.kg(-1) plus ketamine 0.5 mg.kg(-1) (10 mg.ml(-1) concentration). Drugs were diluted in 0.9% saline (0.75 ml.kg(-1)) and prepared by a staff anesthesiologist not otherwise involved in the study. In all groups, the duration of analgesia, analgesic requirements, sedation and insulin, glucose, cortisol concentrations were recorded and statistically compared.

RESULTS

There were no significant differences among the three study groups with respect to age, weight or duration of surgery. Caudal administration of clonidine 1 microg.kg(-1) or ketamine 0.5 mg.kg(-1) induced a longer duration of analgesia (P < 0.05) compared with ropivacaine alone. Insulin levels were increased and cortisol reduced in all groups. Glucose concentration was increased in all groups and statistically significant (P < 0.05).

CONCLUSIONS

Addition of ketamine and clonidine to ropivacaine 0.2% 0.75 ml.kg(-1), when administered caudally in children, prolongs the duration of postoperative analgesia. The need for subsequent postoperative analgesic is also reduced. Caudal analgesia attenuates or allows partial changes to postoperative cortisol, insulin or blood glucose responses to surgery.

Effects of ropivacaine infiltration on cortisol and prolactin responses to postoperative pain after inguinal hernioraphy in children

BACKGROUND/PURPOSE

Painful interventions may have a serious adverse psychological impact, particularly in young patients. Inguinal hernia repair is the most common surgical outpatient procedure performed on infants and children. The aim of this study was to compare the effects of pre- and postincisional infiltration of the surgical area with ropivacaine on cortisol (C) and prolactin (PRL) release and postoperative pain in children undergoing inguinal hernia repair.

METHODS

Forty-five school-age children, aged 6 to 10 years, undergoing outpatient inguinal hernia repair under general anesthesia were placed randomly into 3 groups. Preincisional wound infiltration of 3 mg/kg ropivacaine was performed in group I patients before surgery. Postincisional wound infiltration was performed in group II patients after hernia repair but before skin closure, and group III patients (controls) did not received any local anesthetic. In the postanesthesia care unit (PACU), objective pain assessments were performed every 5 minutes using a standardized 10-point objective pain scale.

RESULTS

Plasma C concentrations increased at the end of the operation in all groups but significantly only in the control group (P <.001). There was no significant difference between the pre- and postincisional groups with regard to pre- and postoperative C alterations (P >.05). Although plasma PRL concentrations increased significantly at the end of the operation in the control group (P <.001), no significant difference was found between pre- and postoperative values in the infiltration groups (P >.05). The pre- and postoperative plasma PRL differences were significant between only groups I and III (P <.001).

CONCLUSIONS

The findings of the current study suggest that wound infiltration with ropivacaine decreases the stress response to surgery and the postoperative pain.

Effect of caudal block on stress responses in children

BACKGROUND

The present study was performed during lower abdominal and genitourinary surgery, to assess the effects of caudal block on plasma cortisol, prolactin, insulin and glucose concentrations during and after surgery.

METHODS

Thirty male children aged 3-10 years who were scheduled for elective surgery, were selected for the study. The children were premedicated with oral midazolam 0.5 mg/kg. All children received induction with nitrous oxide in oxygen and sevoflurane. The children were randomly allocated into two groups: Group I, control group (n = 15) and group II, caudal group (n = 15). Anesthesia was maintained by face mask with the same agent in both groups. Caudal block was performed with 0.25% bupivacaine 2 mg/kg after induction of anesthesia in the caudal group. Blood samples were obtained after induction of anesthesia (T(0)) in order to measure baseline concentrations of cortisol, prolactin, glucose and insulin. Additional samples were obtained 30 min after the start of surgery (T(1)), and 60 min after the end of surgery (T(2)).

RESULTS

All of the basal values (T(0)) were within the normal ranges accepted by Meram Medical Faculty of Selcuk University for children of this age group and there were no differences between the groups (P > 0.05). In both groups, glucose concentration increased at T(1), compared with T(0) and T(2) values (P < 0.05). However glucose concentration was lower in the caudal group than in the control group at T(1) (P < 0.05). In both groups, prolactin concentration increased at T(1), compared with T(0) (P < 0.05). The mean plasma prolactin and cortisol concentration were lower in the caudal group than the control group at T(1) and T(2) (P < 0.05). The mean insulin concentration was lower in the caudal group than the control group at T(2) (P < 0.05).

CONCLUSION

These results indicate that caudal anesthesia suppresses the metabolic and endocrine responses to stress associated with lower abdominal and genitourinary surgery in children.

Spinal anaesthesia in a child with hypoplastic left heart syndrome

Hypoplastic left heart syndrome (HLHS), a complex congenital heart disease, is the most common lethal cardiac defect in neonates. Its treatment includes cardiac transplantation and/or surgical palliation. Associated extracardiac congenital abnormalities are exceptional. We report the case of a neonate with HLHS and anorectal atresia who required urgent surgical management to relieve intestinal obstruction. The surgery was successfully performed under spinal anaesthesia.

Effect of ilioinguinal nerve block on the catecholamine plasma levels in orchidopexy: comparison with caudal epidural block

BACKGROUND

Both caudal epidural and ilioinguinal/iliohypogastric nerve blocks have been used to provide effective intra- and postoperative analgesia. Stress response hormone levels can be used as an objective method to assess the analgesic efficacy of the anaesthetic techniques used in infraumbilical surgery in children. In this study, we compared catecholamine blood levels in children undergoing these two different supplementary analgesic/anaesthetic techniques.

METHODS

Thirty male paediatric patients undergoing orchidopexy, ASA I, received inhalation general anaesthesia, and were randomly allocated to one of two groups: a caudal group (n = 15) and an ilioinguinal/iliohypogastric nerve block group (n = 15). Plasma epinephrine and norepinephrine concentrations were measured at the induction time, at the end of surgery, and in the postanaesthesia care unit. Postoperative pain score was also assessed in the postanaesthesia care unit.

RESULTS

In both groups, there was a substantial decrease in the catecholamine blood levels; however, there were significantly higher levels of epinephrine in the ilioinguinal group at the end of surgery (P = 0.008) and in the recovery room (P = 0.02) and a significant higher level of norpinephrine in the recovery room (P = 0.008).

CONCLUSIONS

The result of this study revealed that caudal epidural block was more effective than ilioinguinal block in suppressing the stress response as reflected in epinephrine and norepinephrine blood levels in orchidopexy patients.

Anaesthetic management of a patient with microvillus inclusion disease for intestinal transplantation

We report the anaesthetic management of a 3-year-old-child with microvillus inclusion disease undergoing isolated small bowel transplantation. He required long-term total parenteral nutrition which was complicated with numerous episodes of catheter related sepsis. This resulted in thrombosis of the major blood vessels which critically restricted vascular access available for intravenous nutrition, becoming a life-threatening condition for the patient. Haemodynamic, respiratory parameters and urinary output were well preserved throughout the procedure. Besides a transitory increase in potassium following graft revascularization, biochemical changes were small. Anaesthetic management included comprehensive preoperative assessment, central venous angiography to depict accessibility of central and peripheral veins, assurance of additional vascular access through the intraoperative catheterization of the left renal vein, perioperative epidural analgesia and preservation of splanchnic perfusion to ensure implant viability.

Assessment of autonomic cardiovascular changes associated with recovery from anaesthesia in children: a study using spectral analysis of blood pressure and heart rate variability

Recovery from anaesthesia is associated with large changes in cardiovascular autonomic activity, which are poorly documented in children. This study was undertaken to investigate the cardiovascular autonomic activity in anaesthetized and recovering children, using a noninvasive approach based on spectral analysis of heart rate (HR) and blood pressure (BP) variability. Ten children (aged 5-13 years) undergoing major surgery were studied. Continuous HR and BP were recorded using a noninvasive device during deep anaesthesia and recovery. Spectral analysis was used to determine the main oscillatory components of HR and BP signals. For each power spectrum, the frequency components were identified as follows (i): the low frequency (LF) component (0.04-0.14 Hz) both parasympathetically and sympathetically mediated for HR and corresponding to vasomotor sympathetic modulation for BP; and (ii) the high frequency (HF) component (0.2-0.6 Hz) parasympathetically mediated for HR, and reflecting mechanical influence of ventilation on cardiac output for BP. In addition, the LF : HF ratio for HR, reflecting the cardiac sympathovagal balance, was calculated. Under deep anaesthesia, HR variability and BP variability were very low and mainly due to mechanical influence of intermittent positive pressure ventilation. Conversely, the recovery period was associated with a marked increase of HR and BP overall variability. Compared to anaesthesia, spectral analysis of HR and BP revealed that the LF component of BP and HR spectra increased 40-fold during recovery; the LF : HF ratio of HR was also increased during recovery (0.1 +/- 0.1 versus 1.3 +/- 1.2, P=0.008). The results of this study demonstrate that the recovery period is associated with an increase of cardiovascular sympathetic drive in children after major surgery.

Is epidural analgesia associated with an improved outcome following open Nissen fundoplication?

Postoperative epidural analgesia is increasingly popular in paediatric practice, although evidence of its benefit is scarce. We performed a retrospective analysis of a series of 104 consecutive open Nissen fundoplications, to determine whether mode of analgesia, epidural (n=65) or opioid infusion (n=39), influenced certain outcome measures, including intensive care utilization, duration of hospital stay, morbidity and mortality. The two groups were similar in terms of demographic characteristics and associated pathologies. Overall, morbidity and mortality (2%) rates were low. Mean duration of hospital stay was significantly greater for the opioid group, compared to those receiving epidural analgesia (13 vs. 8 days, P < 0.05). The number of patients who remained in hospital for more than 7 days was also significantly greater in the opioid group. Accepting the limitations of a retrospective study, these data suggest that epidural analgesia might be associated with an improved outcome following Nissen fundoplication and this merits a prospective study.

Pediatric acute pain management

The past decade has brought about an explosion of knowledge about the physiology of nociception and many new techniques for pain relief, new analgesic drugs, and new applications of old analgesic drugs. These techniques include methods of opioid administration by transdermal and transmucosal absorption and the use of neuraxial analgesia for the management of pain in children. Interest in the use of regional anesthesia in children has been rekindled, and analgesic properties and pre-emptive analgesic properties of many agents not typically considered analgesics, such as clonidine and ketamine, have been recognized. Perhaps the greatest advance has been the paradigm shift in the recognition that pain not only exists in infants and children but also is a significant cause of morbidity and even mortality. Given the unprecedented interest in pain management in adults and children, physicians can now look forward to the development of new methods of drug delivery and of receptor-specific drugs that divorce analgesia from the untoward side effects of existing analgesics. Improvement in the quality of life of hospitalized children also will occur.

Does the addition of fentanyl to bupivacaine in caudal epidural block have an effect on the plasma level of catecholamines in children?

We evaluated the effect of adding fentanyl to bupivacaine, compared with bupivacaine alone, on the stress response. The effect was evaluated by determining blood levels of epinephrine (E) and norepinephrine (NE) in pediatric patients receiving caudal epidural blocks. Sixty children, 1-8 yr of age, scheduled for elective herniorrhaphy, were randomly allocated to two groups of 30 patients each. Group A received inhaled anesthesia and caudal epidural block with bupivacaine 0.25% alone, 1.0 mL/kg. Group B received identical anesthesia; however, fentanyl 1 microg/kg was added to the bupivacaine in the caudal block. Blood samples for E and NE plasma levels were drawn at induction time (H(0)), at the end of surgery (H(1)), and in the postanesthesia care unit (H(2)). In both groups, there was a significant decrease in the E and NE plasma levels, when comparing H(1) and H(2) with H(0) within the same group (P < 0.001). There were no significant differences in the E and NE plasma levels between the two groups at H(0), H(1), and H(2) (P = 0.5, P = 0.12, P = 0.5, respectively). Pain scores (modified Children's Hospital of Eastern Ontario Pain Score) were also similar in both groups (P = 0. 19). This study suggests that adding fentanyl 1 microg/kg to bupivacaine in the caudal epidural block in children does not influence plasma levels of E and NE, nor does it improve the analgesic intensity of the caudal block.

Epidural local anaesthetics versus opioid-based analgesic regimens on postoperative gastrointestinal paralysis, PONV and pain after abdominal surgery

BACKGROUND

Gastrointestinal paralysis, nausea and vomiting, and pain, are major clinical problems following abdominal surgery. Anaesthetic and analgesic techniques that reduce pain and postoperative nausea and vomiting (PONV), and prevent or reduce postoperative ileus, may reduce postoperative morbidity, duration of hospitalisation and hospital costs.

OBJECTIVES

To compare effects of postoperative epidural local anaesthetic with regimens based on systemic or epidural opioids, on postoperative gastrointestinal function, postoperative pain, PONV and surgical/anaesthetic complications.

SEARCH STRATEGY

Trials were identified by computerised searches of the Cochrane Controlled Trials Register, MEDLINE, EMBASE and by checking the reference lists of trials and review articles.

SELECTION CRITERIA

Randomised controlled trials comparing the effects of postoperative epidural local anaesthetic with systemic or epidural opioids.

DATA COLLECTION AND ANALYSIS

Collected data included treatment in active (local anaesthetic) and control (opioid based) groups, time to first postoperative stool, time to first postoperative flatus, gastric emptying measured by the paracetamol absorption test, duration of the passage of barium sulphate, pain assessments, use of supplementary analgesics, nausea, vomiting and surgical/anaesthetic complications.

MAIN RESULTS

Most studies in this review involved a small number of patients. Furthermore half of the studies indicated a poor level of methodology in particular regarding blinding and report of withdrawals. Heterogeneity of included studies was substantial. Results consistently showed reduced time to return of gastrointestinal function in the epidural local anaesthetic group compared with groups receiving systemic or epidural opioid (37 hours and 24 hours, respectively). Postoperative pain was comparable. Two studies compared the effect of epidural local anaesthetic with a combination of epidural local anaesthetic and opioid on gastrointestinal function. One study favoured epidural local anaesthetic and one study was indifferent. A meta analysis of five of eight studies comparing the effect of epidural local anaesthetic with a combination of epidural local anaesthetic and opioid on postoperative pain, yielded a reduction in VAS pain scores (0-100 mm) on the first postoperative day of 15 mm, in favour of the combination. No significant differences in PONV were observed between epidural local anaesthetic and opioid based regimens.

REVIEWER'S CONCLUSIONS

Administration of epidural local anaesthetics to patients undergoing laparotomy reduce gastrointestinal paralysis compared with systemic or epidural opioids, with comparable postoperative pain relief. Addition of opioid to epidural local anaesthetic may provide superior postoperative analgesia compared with epidural local anaesthetics alone. The effect of additional epidural opioid on gastrointestinal function is so far unsettled. Randomized, controlled trials comparing the effect of combinations of epidural local anaesthetic and opioid with epidural local anaesthetic alone on postoperative gastrointestinal function and pain are warranted.

Modern concepts of paediatric analgesia

Laboratory data, economic pressures, and the wish for humane treatment have been some of the driving forces behind improvements in paediatric pain management. Within the space of 10 years, there have been dramatic changes in the quality of treatment received by children undergoing surgical operations. Moreover, those receiving medical treatment, for example, sickle cell disease, have also benefited from increased experience in pain management. Children receiving care in specialised centres can now expect to benefit from up-to-date techniques of pain management, such as patient-controlled analgesia, nurse-controlled analgesia, and epidural infusions. They will be managed by ward nurses experienced and trained in paediatric pain relief, they will be attended by nurses whose special interest and training is the management of children's pain, and they will be provided with the techniques of analgesia by competent, trained anaesthetic staff. Improved care, with close attention to pain relief, is not only humane, but improves the patient turnaround by enhancing rapid discharge. Further education is required to spread these benefits to children being managed outside highly specialised centres. Not only education, but investment, is needed also to ensure that all children receive a standard of care second to none.

Combined regional and light general anesthesia: are the risks increased or minimized?

Regional anesthesia during general anesthesia has become increasingly popular in recent years. Most pediatric anesthesiologists are proponents of this practice, and believe that surgical morbidity is reduced, but controversy remains regarding safety. Neuraxial anesthesia during general anesthesia is especially controversial. Unfortunately, outcome studies are lacking but the literature reflects an absence of reported serious morbidity or mortality.

Regional anesthesia and analgesia

Local and regional anesthetic techniques have a significant but limited place in the practice of infant pain control. In certain clinical circumstances, regional anesthetic techniques presumably afford many of the same advantages for the pediatric patient as in the adult patient. However, there are few controlled clinical trials on the advantages and adverse effects compared with conventional analgesic strategies. This article discusses the clinical application, effectiveness, safety, and outcomes of the available local and regional anesthetic techniques for control of postoperative and procedure-related pain in neonates and infants.

[Benefit-risk and monitoring modalities of different techniques and methods of postoperative analgesia]

This review aimed to determine the benefits-risks ratio of postoperative analgesia. The various agents usually used for intravenous postoperative analgesia (paracetamol, NSAID's, opioids), and the techniques for postoperative analgesia (PCA, epidural, perinervous block) are analysed. The rules proposed for the monitoring of postoperative analgesia are considered.

Modifying infant stress responses to major surgery: spinal vs extradural vs opioid analgesia

Twenty-six infants due to undergo major abdominal or thoracic surgery under general anaesthesia were randomized to receive additional analgesia with group A) spinal/epidural analgesia; B) epidural analgesia or C) opioid analgesia with fentanyl. We wished to determine if spinal analgesia followed by epidural analgesia might result in more complete control of cardiovascular or stress responses than the other two treatment groups. Heart rate and blood pressure were recorded at five min intervals throughout surgery. Blood samples were taken for measurement of catecholamines and whole blood sugar on induction, 45 min after skin incision and at the end of surgery. Heart rate rose significantly at the start of surgery in groups B and C but not group A. Systolic blood pressures were higher in group C compared to A and B. The rise in plasma glucose concentrations was significantly different between the groups in the order C > B > A (P < 0.05). A similar trend was seen in the plasma adrenaline and noradrenaline concentrations but this failed to achieve significance due to the limited sample size.

Plasma concentrations of bupivacaine in neonates after continuous epidural infusion

This study reports plasma bupivacaine concentrations in 13 neonates who received lumbar epidural anesthesia during major abdominal surgery. A bolus of 1.8 mg/kg of bupivacaine (2.5 mg/mL) was administered after induction of anesthesia, followed by a continuous infusion of 0.2 mg.kg-1.h-1 (1.25 mg/mL). Plasma concentrations of total and free bupivacaine and alpha 1-acid-glycoprotein (AAG) were determined. Results are presented as mean (+/-SEM). At 48 h, five of nine patients still had increasing total plasma concentrations, and the total bupivacaine concentrations ranged between 0.7 and 3.1 micrograms/mL. The plasma levels of AAG increased significantly between 1 and 24 h (4.3 +/- 2.3 nM and 7.7 +/- 2.3 nM, respectively) (P = 0.018). The free concentrations of bupivacaine were relatively unchanged at 1 and 24 h (84 +/- 20 ng/mL and 58 +/- 15 ng/mL, respectively). No adverse events occurred during the study period. In conclusion, the dose administered in this study appears to be safe. However, a substantial number of patients still had increasing concentrations of total plasma bupivacaine at 48 h. Furthermore, the interindividual variation was considerable. These observations cause concern about the safety of epidural infusions longer than 48 h in the age group studied.

Effects of bupivacaine infiltration on beta-endorphin and cortisol release and postoperative pain following inguinal herniorrhaphy in children

This study was undertaken to investigate the effects of bupivacaine on beta-endorphin (BE) and cortisol (C) release and postoperative pain in children. Thirty children aged 1 month to 2 years undergoing outpatient inguinal hernia under general anesthesia were randomized into three groups. Wound infiltration in group 1 patients (precisional group) was performed with 0.5 ml/ kg 0.25% bupivacaine following anesthesia induction but prior to surgery. Group 2 patients (postincisional group) had wound infiltration with bupivacaine following repair of the hernia but before skin closure. Group 3 patients (control group) did not receive any local anesthetic. In the post-anesthesia care unit (PACU) objective pain assessments were performed every 5 min using a standardized ten-point objective pain scale. Plasma C concentrations increased at the end of the operation in all groups, but this increase was significant only in the control group (P < 0.001). There was no significant difference between the pre- and postincisional groups with regard to pre- and postoperative C alterations (P > 0.05). Although plasma BE concentrations increased significantly at the end of the operation in the control group (P < 0.001), no significant difference was found between pre- and postoperative values in the infiltration groups. There was a more marked difference in BE release between the preincisional and control groups (P < 0.001) than the postincisional group (P < 0.05). Although the objective pain scores were not statistically different upon PACU arrival, the patients in the infiltration groups achieved a pain score of 0 much more quickly than those in the control group (P < 0.05). These findings suggest that wound infiltration with bupivacaine decreases the stress response to surgery and postoperative pain.

Paravertebral vs epidural block in children. Effects on postoperative morphine requirement after renal surgery

Continuous thoracic paravertebral blockade (PVB) has only recently been reported in pediatric patients. The aim of the present study was to compare retrospectively the postoperative analgesic efficacy of PVB vs conventional lumbar epidural blockade (EDA) in children. Thirty-five consecutive pediatric patients undergoing renal surgery, receiving either PVB (n = 15) or EDA (n = 20), were reviewed. The need for supplemental morphine administration during the first 24 postoperative hours was used to assess the postoperative analgesic efficacy of the two different regional techniques. Both the total amount of supplemental morphine and the number of patients with no need for supplemental morphine administration, were compared between the two groups. The need for supplemental morphine administration was significantly lower (P = 0.046) and the number of patients with no need for supplemental morphine administration postoperatively was significantly higher (P = 0.019) in patients treated with PVB vs EDA. The present study indicates that PVB may possess a potential for postoperative analgesia equal to or maybe even superior to conventional lumbar EDA in pediatric patients undergoing renal surgery. Further prospective studies investigating the analgesic efficacy of this novel technique are warranted.

Continuous epidural analgesia in newborn infants undergoing major surgery

Providing safe, effective analgesia for newborn infants undergoing major surgery remains a challenge to pediatric anesthetists and surgeons. Continuous epidural analgesia (CEA) has been shown to provide safe and effective analgesia in infants and children; however, there is little reported use in neonates. We review our experience of CEA in 14 newborn infants (32 to 40 weeks gestation) aged 4 hours to 35 days undergoing major surgery, as well as a further 6 ex-preterm (25 to 29 weeks gestation) infants aged 2 to 5 months at time of surgery. In all cases effective analgesia was achieved for up to 69 hours without complication. All infants were awake and extubated uneventfully at the completion of surgery, which lasted 5 hours in one case. None of the infants developed respiratory depression or prolonged apnea. The technique has been widely accepted by surgeons, neonatal nursing staff, and neonatologists.

[Perioperative perfusion in children: evaluation of a new perfusion solution]

A new intravenous solution (B66) containing 0.9% dextrose in water for infusion therapy in infants and children was assessed. Forty-one children, aged between 6 months and 11 years, scheduled for elective non haemorrhagic surgery, were randomly assigned to two groups: children in group I (n = 22) were given 1% dextrose in lactated Ringer's solution (RLG1), and those in group II (n = 19) the commercially available solution B66 (0.9% dextrose in lactated Ringer's solution). The fluids were administered throughout the study with volumetric infusion pumps (IVAC 541). The infusion rate was adapted to children's weight and age. Blood samples for blood glucose, sodium and protein concentration assessments were obtained at induction (T0), on arrival in the recovery room (T1), than 30 and 60 min later (T2 and T3). Preoperative blood glucose concentrations were within the normal range for all children except for two, who had asymptomatic hypoglycaemia (2.2 and 2.3 mmol.l-1). Postoperative blood glucose concentrations were higher in both groups. This increase was significantly greater in the RLG1 group than in the B66 group. The highest mean figures at T1 were 6.8 +/- 1.5 mmol.l-1 and 5.2 +/- 1.0 mmol.l-1 in the RLG1 and B66 groups respectively. Total protein levels decreased postoperatively significantly in both groups. Preoperative age-related differences in total protein concentrations were also observed postoperatively. Sodium concentrations remained unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of two anesthesia techniques on perioperative insulin response to i.v. glucose infusion in children

Perioperative blood glucose and insulin levels were measured in children (1-9 years of age) randomly assigned to two groups according to anesthesia technique, general anesthesia (group GA) or general anesthesia combined with regional anesthesia (group RA). Children in the GA group (n = 10) received halothane and opioids, while children of the RA group received epidural anesthesia with bupivacaine (0.25%) and adrenaline combined with halothane anesthesia (n = 10). Children in both groups received 2.5% dextrose in 0.4 N saline administered by volumetric infusion pumps throughout the study period, the infusion rate being adapted to the child's age. Blood samples for glucose and insulin determinations were obtained: at induction, at the end of surgery, and 30, 60 and 120 min after surgery. In response to an identical glucose load, blood glucose levels increased significantly in both groups (P < 0.001), while no differences between groups were observed. Insulin levels did not change significantly postoperatively in the GA group (P = 0.058), while a significant increase was observed in the RA group (P < 0.001). Insulin/blood glucose ratio increased significantly only in the RA group (P < 0.05). The higher insulin secretion in response to glucose infusion in the RA group compared to the GA group may indicate an increased peripheral insulin resistance after regional anesthesia or, more likely, this secretion may be beneficial in contributing to improve postoperative nitrogen balance.

“Blended” anaesthesia in urological oncological surgery: Our experience

Some major urological surgery may cause post-operative pain, which is difficult to control, as well as systemic metabolic stress. “Blended” anaesthesia, which is an association of regional anaesthesia and a light general anaesthesia, minimizes the stress on the neuro-vegetative system and reduces drug administration. We treated 39 patients: our data suggest that “blended” anaesthesia is very good for the elderly as well as for younger patients, expecially in Hospitals without a post-operative Intensive Care Unit.

Continuous paravertebral block in children. Initial experience

Continuous paravertebral block has not previously been described for use in children. This study reports the use of this technique in five patients (aged 7 months to 8 years) scheduled for renal surgery or cholecystectomy. The block was not difficult to perform and provided good intra- and postoperative analgesia. Continuous paravertebral block appears to be a promising technique for pain management in children and might prove a valuable addition in the field of paediatric regional anaesthesia.

Metabolic and endocrine responses to surgery during caudal analgesia in children

Plasma concentrations of glucose, lactate, epinephrine, norepinephrine, insulin, cortisol and growth hormone were measured in 28 healthy children, three to six years of age, before, during, and after lower abdominal surgery. The children received premedication with secobarbital, 6 mg.kg-1, pentazocine, 0.5 mg.kg-1, and atropine, 0.01 mg.kg-1 im. Fourteen children received general anaesthesia with nitrous oxide and halothane, and 14 others received caudal analgesia with 1.5% mepivacaine. Plasma glucose, epinephrine and norepinephrine concentrations remained unchanged in the general anaesthesia group, but decreased during and after surgery in the caudal analgesia group (P less than 0.05). During surgery, these concentrations were different between the two groups (P less than 0.05). Plasma insulin and cortisol concentrations increased after surgery (P less than 0.05), and growth hormone concentration increased during and after surgery in the general anaesthesia group (P less than 0.05), but the concentrations of these hormones remained unchanged during and after surgery in the caudal analgesia group. Plasma lactate concentrations were unchanged in both groups. These results indicate that caudal analgesia suppresses the metabolic and endocrine responses to stress associated with lower abdominal surgery in children.

[Hormonal changes induced by etomidate in children during the first 24 postoperative hours]

The hormonal effects of an etomidate infusion were assessed postoperatively in children undergoing hypospadias or clubfoot repair. The study was carried out in 12 children, aged between 9 and 70 months, randomly assigned to two equal groups. The anaesthetic protocol was identical for all the children, consisting in a light general anaesthesia (halothane induction, intubation after 60 to 80 micrograms.kg-1 vecuronium) combined with lumbar epidural anaesthesia (initial dose of 0.75 ml.kg-1 bupivacaine with adrenaline, with repeat injections of half the previous dose when there was a change in the haemodynamic parameters suggesting inadequate analgesia). Anaesthetic maintenance was different in both groups: 1 to 1.5 vol% enflurane in a nitrous oxide-oxygen mixture (1/1 v/v) in the control group, and 16.8 +/- 3.0 mg.kg-1.min-1 etomidate infusion in the etomidate group. Venous blood samples were collected after induction of anesthesia (before starting the epidural anaesthesia and the etomidate infusion), at the end of surgery (H0), at the 3rd (H3), 6th (H6), 12th (H12) and 24th h (H24) following surgery. The following hormonal blood concentrations were measured: cortisol, 11 beta-desoxycortisol, aldosterone, 11 beta-desoxycorticosterone, dehydroepiandrosterone (DHA) and DHA sulphate (DHA-S). In the control group, cortisol and DHA-S concentrations decreased significantly at H0, aldosterone levels also being significantly lower at H24. In the etomidate group, cortisol concentrations remained significantly lower at H0, H3 and H6; aldosterone concentrations were also significantly lower than control values throughout the study period. There was an important prolonged rise in the concentrations of their precursors. DHA and DHA-S concentrations did not change in the etomidate group.(ABSTRACT TRUNCATED AT 250 WORDS)