Lumbar and thoracic epidural anaesthesia in children

Epidural anaesthetic techniques are an established part of paediatric anaesthesia. Their positive effects on general anaesthetic requirements, stay in the recovery unit, efficient perioperative pain relief and blunting of the perioperative stress response promote the routine use of regional anaesthetic techniques in children.With increasing knowledge of the anatomy and physiology of children, refinements in equipment and increased knowledge of the pharmacology of the agents used, continuous epidural catheter techniques are considered to be safe. There is some evidence that an epidural approach via the caudal and trans-sacral route is a low-risk procedure, even if the catheter is advanced to higher levels. Despite its positive effects the direct puncture at thoracic levels will probably never reach the level of routine practice. Because of its potential risks, the use of thoracic epidural anaesthesia (TEA) should be restricted to experienced paediatric anaesthetists and specialized centres.     

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.     

Effect of desflurane/remifentanil anaesthesia on glucose metabolism during surgery: a comparison with desflurane/epidural anaesthesia

BACKGROUND: The aim of this study was to investigate the effect of general anaesthesia combined with remifentanil or epidural blockade on glucose metabolism during surgery. METHODS: We randomly assigned patients undergoing elective colorectal surgery to receive either desflurane anaesthesia supplemented with intravenous remifentanil (n = 7) or desflurane anaesthesia supplemented with epidural bupivacaine (n = 7). Plasma concentrations of glucose, lactate, free fatty acids (FFA), insulin, glucagon and cortisol were measured before and after 2 h of surgery. Pre- and intraoperative whole body glucose production and glucose clearance, an indicator of glucose uptake, were determined by an isotope dilution technique using [6,6-2H2]glucose. RESULTS: In both groups intraoperative glucose production ( P< 0.05) and uptake ( P< 0.05) decreased. Plasma glucose concentrations ( P< 0.05) increased during surgery but did not exceed the normal range (remifentanil group: 5.7 +/- 0.7 mmol l-1, epidural group: 5.8 +/- 0.4 mmol l-1). The plasma concentrations of lactate, FFA, insulin and glucagon remained unchanged during the operation. The plasma cortisol concentration in both groups increased intraoperatively (P< 0.05). CONCLUSION: Both desflurane/remifentanil and desflurane/epidural anaesthesia decrease the intraoperative rate of whole body glucose production, thereby attenuating the hyperglycaemic response to colorectal surgery.     

Continuous caudal anaesthesia during inguinal hernia repair in an awake, 1440 g infant

The physiological immaturity of respiratory musculature and central respiratory control centres leads to an increased risk of apnoea and respiratory complications following general anaesthesia in the neonate. Regional anaesthetic techniques such as caudal epidural anaesthesia may obviate the need for general anaesthesia and lessen the risks of perioperative morbidity. Although these techniques have been used frequently in neonates, we are unaware of previous reports of continuous caudal anaesthesia in infants less than 2000 g. We present our experience with continuous caudal anaesthesia using 3% chloroprocaine in a 1440 g infant during repair of bilateral inguinal hernias.     

Pulmonary Doppler flow velocity pattern during caudal epidural anaesthesia in children

BACKGROUND: Haemodynamic effects of caudal anaesthesia in children have not been fully investigated. In the present study, we evaluated pulmonary haemodynamics during caudal anaesthesia in otherwise healthy children using Doppler-echocardiography. METHODS: Fifteen children undergoing elective lower abdominal surgery were randomly divided into two groups: nine children received 1.5% lidocaine and six physiological saline in the caudal epidural space. General anaesthesia was slowly induced and maintained using nitrous oxide and sevoflurane in oxygen. An epidural catheter was inserted into the caudal epidural space. Haemodynamic data including those with echocardiography were measured before and after epidural administration of lidocaine or saline. RESULTS: Mean blood pressure, end diastolic diameter of the left ventricle, ejection fraction of the left ventricle and mean velocity circumferential fibre shortening did not change in either group following caudal epidural block. Indices of pulmonary Doppler flow velocity, including peak velocity of pulmonary flow and acceleration-to-ejection time ratio, demonstrated a significant decrease after caudal lidocaine, but not after saline. CONCLUSIONS: Our data suggest that pulmonary Doppler flow velocity changes during caudal epidural anaesthesia, probably due to an increase in the pulmonary arterial resistance.     

Use of ultrasound bladder monitoring in children after caudal anaesthesia

Urinary retention occurring after caudal anaesthesia in children has a low incidence. Most children will void within 12 h of surgery, although the incidence of retention is higher after hypospadias repair. However, overdistention causing bladder atony that is temporary, or may become permanent, is described in adults. Long-term effects of overdistention in children have not been described. Urine volume, used to describe overdistention, is traditionally measured after catheterization. We report two children suffering from urine retention after caudal anaesthesia (bupivacaine 0.25%) was used to supplement a general anaesthetic. Ultrasound bladder monitoring was used to assist with the clinical diagnosis of bladder distension in the postanaesthesia care unit (PACU) and subsequent management. In-out catheterization was required in a 1-year-old-girl with a bladder volume of 12 ml.kg-1 after external manual compression over the bladder was unable express urine. Spontaneous micturation occurred within the subsequent 8 h. A 10-year-old boy suffered distress in PACU with a bladder volume, measured by ultrasound, of 5 ml.kg-1. Catheterization relieved distress and spontaneous micturation returned 18 h after surgery. Measured urine volumes were similar to those estimated by ultrasound. Ultrasound bladder monitoring is a simple, noninvasive technique that can be used to assist with the diagnosis and management of urinary retention in children. It may replace catheterization as the prefered technique to measure urine volume. The correlation between measured bladder volumes and urine volume appears reasonable. A volume of approximately 10 mg.kg-1 may be considered as causing overdistension.     

Intravenous meperidine for control of shivering during Caesarean section under epidural anaesthesia

To determine the efficacy of meperidine in controlling shivering during epidural anaesthesia for Caesarean section, forty-six parturients were studied. After delivery of the infant, shivering patients received either a single dose of intravenous meperidine 50 mg, or saline in a randomized double-blind fashion. Shivering was classified on a scale of 0 to 3 (grade 0 = none, grade 3 = severe shivering that was distressing to the patient and interfered with monitoring). Shivering and other variables were recorded at epidural placement, skin incision, delivery, and 2,5,15,30 and 60 minutes following injection. Administration of meperidine resulted in a significant decrease in both the overall incidence of shivering (87 to 35 per cent, p < 0.0 J) and severity of shivering (grade 3: 57 to 0 per cent, p < 0.01), compared with saline (incidence: 87 to 83 per cent, grade 3:57 per cent, no change). This effect was apparent within two minutes of drug injection and persisted throughout the study period. There were no differences in vital signs, oxygen saturation or temperature between groups. The incidence of nausea was similar, although patients receiving meperidine were more drowsy at two and five minutes following injection (p < 0.01) compared with patients in the saline group. There were no differences in level of consciousness at the later intervals. The mechanism of action of meperidine on shivering remains to be elucidated.     

A randomised controlled trial comparing needle movements during combined spinal‐epidural anaesthesia with and without ultrasound assistance

Ultrasound assistance for neuraxial techniques may improve technical performance; however, it is unclear which populations benefit most. Our study aimed to investigate the efficacy of neuraxial ultrasound in women having caesarean section with combined spinal‐epidural anaesthesia, and to identify factors associated with improved technical performance. Two‐hundred and eighteen women were randomly allocated to ultrasound‐assisted or control groups. All the women had a pre‐procedure ultrasound, but only women in the ultrasound group had this information conveyed to the anaesthetist. Primary outcomes were first‐pass success (a single needle insertion with no redirections) and procedure difficulty. Secondary outcomes were block quality, patient experience and complications. Exploratory sub‐group analysis and regression analysis were used to identify factors associated with success. Data from 215 women were analysed. First‐pass success was achieved in 67 (63.8%) and 42 (38.2%) women in the ultrasound and control groups, respectively (adjusted p = 0.001). Combined spinal‐epidural anaesthesia was ‘difficult’ in 19 (18.1%) and 33 (30.0%) women in the ultrasound and control groups, respectively (adjusted p = 0.09). Secondary outcomes did not differ significantly. Anaesthetists misidentified the intervertebral level by two or more spaces in 23 (10.7%) women. Sub‐group analysis demonstrated a benefit for ultrasound in women with easily palpable spinous processes (adjusted p = 0.027). Regression analysis identified use of ultrasound and easily palpable spinous processes to be associated with first‐pass success.     

Desflurane in paediatric anaesthesia

Summary
Despite the low blood-gas coefficient of desflurane, inhalational induction is delayed by airway complications in paediatric practice. A slow induction technique reduces airway complications in adults. The aim of this study was to examine the use of desflurane for paediatric anaesthesia and to reduce airway complications with a slow induction technique. Sixty children (age range, 1 month to 12 years) were anaesthetized with 3% desflurane, increased by 1% every minute until anaesthesia was adequate for tracheal intubation. Anaesthesia was maintained with oxygen, nitrous oxide, and desflurane delivered by mechanical ventilation. During induction of anaesthesia, the incidence of moderate to severe coughing was 20%, breath-holding 14%, and laryngospasm 31%. Blood pressure fell significantly ( P < 0.05) from baseline after induction of anaesthesia and remained at this level during anaesthesia. Heart rate was stable in children less than six years, but increased significantly in older children. There were no significant airway problems during recovery from anaesthesia. Recovery time was rapid: the time to awakening was 10.2 min and to discharge from the recovery room, 29.2 min. Although desflurane is not an ideal anaesthetic agent for inhalational induction in children, it maintains stable anaesthesia and provides rapid smooth recovery.     

Dose-response in infants receiving caudal anaesthesia with bupivacaine*

Caudal epidural anaesthesia was performed in 25 awake or sedated infants, the sensory levels measured and the dose-response determined (bupivacaine dose [ml kg^?1] v. sensory level). The infants were divided into two groups based on body weight, group 1 (1.9–2.6 kg) and group 2 (3.4–7.0 kg). There was a significant difference between the dose-response when comparing group 1 to group 2 (P < 0.01). Smaller infants require a larger volume (ml kg^?1) of local anaesthetic to achieve mid-thoracic sensory levels than larger infants. In small infants, we recommend increasing the volume of local anaesthetic while still limiting the total bupivacaine dose to 3.25 mg kg^?1 by using 1.6 ml kg^?1 of bupivacaine 0.20% (3.20 mg kg^?1) instead of 1.3 ml kg^?1 of bupivacaine 0.25% (3.25 mg kg^?1).     

The reliability of endtidal CO2 in spontaneously breathing children during anaesthesia with laryngeal mask airway,low flow,sevoflurane and caudal epidural

BACKGROUND: Noninvasive devices for monitoring endtidal CO2 (PECO2) are in common use in paediatric anaesthesia. Questions have been raised concerning the reliability of these devices in spontaneous breathing children during surgery. Our anaesthetic technique for elective infraumbilical surgery consists of spontaneous breathing through a Laryngeal Mask Airway (LMA), low fresh gas flow, sevoflurane and a caudal epidural. We wanted to compare PECO2 and arterial CO2 (PaCO2) during surgery. METHODS: Twenty children, aged 1-6 years, scheduled for infraumbilical surgery, were studied and one arterial sample was taken 45 min after induction of anaesthesia. PECO2, inspiratory PCO2, oxygen saturation, heart rate, respiratory rate, mean arterial blood pressure and expiratory sevoflurane concentration were measured every 5 min. The respiratory and circulatory parameters were stable during surgery. RESULTS: The mean PaCO2 - PECO2 difference was 0.15 (0.16) kPa [1.1 (1.2 mmHg)]. CONCLUSIONS: PECO2 is a good indicator of PaCO2 in our anaesthetic setting.     

Intraspinal haematoma following lumbar epidural anaesthesia in a neonate

A neonate with chromosomal 9 abnormality and omphalocele received a lumbar epidural catheter after laparotomy. Several attempts were needed to establish this catheter. Bleeding occurred from the operative wound after surgery. Using an epidural infusion with ropivacaine 0.1% for 48 h postoperative pain relief was sufficient. Four days after epidural catheter removal, dysfunction of the sacral parasympathetic nerves was noted. Motor and sensor function of the lower limbs were unaffected. Magnetic resonance imaging showed a localized intraspinal haematoma in the lower lumbar region.     

Rocuronium in infants, children and adults during balanced anaesthesia

We studied 20 infants, 20 children and 20 adults during balanced anaesthesia to compare the neuromuscular blocking effects of rocuronium in these age groups. Neuromuscular function was recorded by adductor pollicis emg and a cumulative log-probit dose-response curve of rocuronium was established. Thereafter, full spontaneous recovery of the neuromuscular function was recorded. Onset time of the first dose of rocuronium was shorter in children than in infants or adults. The potency of rocuronium was greatest in infants and least in children; the ED₅₀ doses (mean ± SD) being 149 ± 36 μg˙kg^?1 in infants, 205 ± 52 μg˙kg^?1 in children and 169 ± 47 μg˙kg^?1 in adults (P<0.05 between infants and children) and the ED₉₅ doses being 251 ± 73 μg˙kg^?1, 409 ± 71 μg˙kg^?1 and 350 ± 77 μg˙kg^?1, respectively (P<0.05 between all groups). The emg recovery following an average 94.5 ± 4.8% neuromuscular blockade established by rocuronium was roughly similar in all study groups. Thus, one ED₉₅ dose of rocuronium, unlike vecuronium, acts as an intermediate-acting agent in all age groups.     

Effect of minimizing preoperative fasting on perioperative blood glucose homeostasis in children

Two hundred healthy, unpremedicated children, ages 1–10 years, scheduled for elective outpatient surgery were studied in order to examine the effect of minimizing preoperative fasting on perioperative blood glucose concentrations in paediatric patients. None of the patients ingested solids after midnight. On the day of surgery, the children were assigned to one of two groups. Group A children (n= 113) were not allowed any liquids for at least 6 h prior to surgery (NPO). Children in Group B (n= 87) ingested 10 ml·kg^?1 of apple juice 2–4 h prior to the induction of anaesthesia. All patients received lactated Ringer's solution intraoperatively, unless BG at induction was < 50 mg·dl^?1 (2.8 m·mol·l^?1) in which case dextrose 2.5% in lactated Ringer's solution was administered. None of the patients who received apple juice was hypoglycaemic during induction of anaesthesia. However, two children in the NPO group had blood glucose values ± 50 mg·dl^?1 (2.8 m·mol·l^?1) at the time of induction of anaesthesia. Thirteen (11%) patients in Group A and 6 (7%) patients in Group B showed either no change or a further decrease in their postoperative BG concentration as compared with their induction values. Two of 43 patients in Group A and 2 of 41 patients in Group B had gastric fluid volumes > 0.4 ml/kg. All patients in both groups had gastric pH < 2.5. This study shows that gastric fluid volume and pH following a 2–4 h fast are not different from the values measured in children who were subjected to a traditional fasting period of 6 h or longer. Moreover, apple juice consumed 2–4 h prior to surgery neither buffers gastric pH nor does it modify intraoperative glucose homeostasis in children.     

How to prolong postoperative analgesia after caudal anaesthesia with ropivacaine in children: S-ketamine versus clonidine

BACKGROUND: The aim of the study was to determine whether caudal S-ketamine or clonidine prolonged analgesia together with ropivacaine. METHODS: Sixty-three boys, aged 1-5 years, who were undergoing minor surgery, were allocated in order to receive one of three solutions for caudal anaesthesia. Group R received 2 mg x kg(-1) 0.2% ropivacaine; group C, 2 mg x kg(-1) 0.2% ropivacaine + clonidine 2 microg x kg(-1); and group K, 2 mg x kg(-1) 0.2% ropivacaine + S-ketamine 0.5 mg x kg(-1). RESULTS: Postoperative analgesia assessed by CHEOPS lasted 701 min in group K (P < 0.05) compared with 492 min in group C and 291 min in group R. There were no significant differences between the groups for incidence of haemodynamic and respiratory alterations, motor block or sedation. CONCLUSIONS: This study demonstrates that S-ketamine 0.5 mg x kg(-1) when added to 0.2% caudal ropivacaine provides better postoperative analgesia than clonidine without any clinically significant side-effect.     

Timely bolus insulin for glucose control during cardiopulmonary bypass

Hyperglycemia during cardiopulmonary bypass (CPB) with glucose containing cardioplegia is common; normoglycemia is difficult to maintain and failure to do so may result in worse outcomes. The purpose of this quality improvement initiative was to show that a simple timely insulin bolus is more effective for glucose control during CPB with glucose containing cardioplegia than conventional (not standardized) glucose management in historical case-matched controls. A single bolus of insulin (.2 international units per kilogram; iu/kg) was administered, at the time of aortic cannulation, to 211 consecutive patients undergoing cardiac surgery with CPB and glucose containing cardioplegia. A further .1 iu/kg bolus of insulin was given for blood glucose (BG) measurements greater than 10.0 mmol/L (180 mg/dL) during CPB. The control group of 211 historical case-matched patients had glucose management according to anesthesiologist preference (insulin as a bolus, bolus plus infusion, infusion only, or no insulin). The frequency of hyperglycemia (BG > 11.0 mmol/L; 198 mg/dL) during CPB was significantly less in the study group (22; 10.5%) than in the control group (117; 55.5%) (p < .0001). Hyperglycemia in the first 6 hours in the intensive care unit was also significantly less frequent in the study group (5; 2.4%) than in the control group (14; 6.6%) (p = .03). Severe hypoglycemia (BG < 2.8 mmol/L; 50.4 mg/dL) occurred in one patient (.47%) in the timely bolus insulin group and five patients (2.3%) in the control group (p = .09). The timely bolus insulin method is more efficacious, but equally safe, in preventing hyperglycemia during CPB with glucose containing cardioplegia, compared with conventional (not standardized) insulin treatment in historical case-matched controls.     

Free and total bupivacaine plasma concentrations after continuous epidural anaesthesia in infants and children

We measured free and total venous bupivacaine plasma concentrations in fourteen infants and children aged 6 days (2800 g) to 9 years (27 kg) undergoing epidural anaesthesia. An initial bolus of 0.5 ml·kg^?1 bupivacaine 0.25% was followed by a continuous infusion administered one h after bolus over a period of seven h (first hour 0.25 ml·kg^?1·h^?1 0.25%; then reduced to 0.125%). Although total bupivacaine plasma concentrations were within acceptable limits (<1.5 μg·ml^?1), four of the seven infants showed adverse reactions. Maximum plasma concentrations of free bupivacaine were significantly higher in infants (P<0.05) than in older children. We conclude that toxicity may be underestimated when only measuring total bupivacaine concentrations. In young infants the bupivacaine dose administered for continuous epidural anaesthesia should be further lowered below recommended concentrations and the patients closely observed for possible adverse reactions.     

Evaluation of caudal anaesthesia performed in conscious ex-premature infants for inguinal herniotomies

Ex-premature infants, before 45 weeks postconceptional age, are at high-risk of apnoea after surgery. General anaesthesia increases the risk of apnoea. We evaluated the tolerance and the efficiency of caudal anaesthesia performed in 25 consecutive conscious ex-premature infants for inguinal herniotomies. N2O/O2 and EMLA cream are used to facilitate caudal puncture. Anaesthesia procedure, patient comfort and complications following the 24 postoperative hours were studied. We report good anaesthesia conditions without compromising the baby's comfort and few perioperative complications. Only two infants with a prior history of apnoea or bronchopulmonary dysplasia had apnoea during and after surgery. A total spinal anaesthesia was the major complication in one infant and prolonged surgery requiring general anaesthesia was the main limitation of this technique in another child. The principal advantage of the procedure is to facilitate and simplify the postoperative management of the babies. The anaesthetic technique does not alter surgical conditions. Caudal epidural anaesthesia performed in awake high-risk preterm infants is beneficial for these infants but requires experienced operators.     

Combined spinal and epidural anaesthesia for inguinal hernia repair in babies

We describe combined subarachanoid-epidural anaesthesia for inguinal herniotomy in eight ex-premature babies less than 47 weeks postconception and one full-term baby aged 21 weeks who had Pierre-Robin syndrome. No additional anaesthetic supplements were needed during surgery. Motor block was profound and operating conditions were excellent. One baby had brief self-limiting bradycardias shortly after lumbar puncture. A second baby with severe bronchopulmonary dysplasia had recurrent oxygen desaturations associated with apnoea during surgery. There were no other intra- or postoperative complications. All babies were fed immediately on return to the ward. We conclude that combined subarachnoid-epidural anaesthesia is a satisfactory technique for anaesthesia for inguinal herniotomy in babies at risk of apnoea after surgery.