Regional anaesthesia for surgical treatment of inguinal hernia in preterm babies

The success rate and complications of awake caudal epidural bupivacaine alone or in combination with intravenous midazolam and ketamine in pre-term infants

BACKGROUND

The aim of the present study is to compare the success rate and complications of caudal epidural bupivacaine alone or in combination with intravenous (IV) midazolam and ketamine in awake infants undergoing lower abdominal surgery.

MATERIALS AND METHODS

In this double-blind, clinical trial study, 90 infants (aged below 3 months and weight below 5 kg) with American Society of Anaesthesiologists I-II, were divided into three groups of each 30: Group 1 received bupivacaine 0.25%, 1 mL/kg for caudal epidural block; Groups 2 and 3 received caudal block with same dose bupivacaine along with IV pre-treatment with midazolam 0.1 mg/kg or IV midazolam 0.1 mg/kg and ketamine 0.3 mg/kg, respectively.

RESULTS

The success rates in Groups 2 and 3 were 93.3% and 93.1%, respectively, compared with a caudal block with bupivacaine alone 80%; P = 0.015). There was no significant difference among the three groups in terms of mean systolic and diastolic blood pressures and mean heart rate at intervals of 0, 20, 40 and 60 min (P < 0.05). There were no significant differences in the pain scores >3 on the Neonatal Infant Pain Scale at three intervals (30, 60 and 120 min) after surgery among the three groups. The complications such as apnoea or desaturation were not found in any of the studied groups.

CONCLUSIONS

Adding IV ketamine and/or midazolam to bupivacaine caudal epidural block in the conscious infants can positively affect block success rate.

Reduction of incarcerated inguinal hernia in infants using caudal epidural anaesthesia

Incarcerated inguinal hernias in infants are commonly encountered. Reduction with intravenous sedation using morphine and related drugs carries risks of apnoea and/or respiratory arrest, especially in small, ex-premature babies who have an increased incidence of incarceration and thus opiate use is best avoided. Caudal epidural anaesthesia is widely used as pre- and post-operative analgesia in elective inguinal herniotomy in infants. In this study we sought to determine if caudal epidural anaesthesia would allow reduction of an incarcerated inguinal hernia in the acute setting, thereby obviating the need for intravenous sedation. A retrospective review of 12 male infants, with irreducible, incarcerated inguinal hernias was done. Each hernia was successfully reduced with the help of caudal epidural anaesthesia. This group of babies was treated at The Royal Belfast Hospital for Sick Children. Twelve male infants were identified with an incarcerated inguinal hernia in whom attempted reduction, without sedation had failed. Using Bupivacaine (1 ml/kg 0.25%), placed into the caudal space, these hernias were successfully reduced non-operatively. Ages at presentation ranged from 2 to 17 weeks with a median gestational age of 36 weeks (range 29-39 weeks). Caudal epidural anaesthesia is a safe, feasible and effective method of achieving reduction of irreducible, incarcerated inguinal hernias. It is especially useful in low-birth weight, premature infants where intravenous opiate sedation is best avoided.

Levobupivacaine spinal anesthesia in neonates: a dose range finding study

BACKGROUND

Our aim was to determine the clinical efficacy of levobupivacaine for awake spinal anesthesia in ex-premature infants having lower abdominal surgery. The secondary aim was to determine the minimum local analgesic dose (MLAD) defined as the median effective local anesthetic dose for spinal anesthesia in neonates.

METHODS

Fifty neonates < 55 weeks postconceptional age having lower abdominal surgery were enrolled. The dose of levobupivacaine was determined by up-down sequential allocation. The first infant received 1.25 mg x kg(-1) 0.5% levobupivacaine with subsequent doses determined by the response of the previous patient. Dose interval was 0.25 mg x kg(-1).

RESULTS

There were no significant adverse effects attributable to levobupivacaine. Success rates for 1.25, 1, 0.75 and 0.5 mg x kg(-1) were 100, 83, 81 and 46%, respectively. Mean duration (95% confidence interval) of lower limb motor blockade was 81.7 min (75.8-87.6 min). Duration of anesthesia far exceeded surgical duration in all but one case. The up-down sequences were analyzed with the Dixon and Massey method. The motor block MLAD (95% confidence interval) was 0.48 mg x kg(-1) (0.42-0.54). Probit analysis was used to compare calculated ED50 and to calculate an ED95 by extrapolation of data into the clinical range. The ED(50) (95% C.I.) was 0.52 mg x kg(-1) (0.30-0.73). The calculated ED95 was 1.14 mg x kg(-1) (0.78-1.50). These values were confirmed by logit analysis.

CONCLUSIONS

Levobupivacaine is an effective agent for spinal anesthesia in neonates at a recommended dose of 1 mg x kg(-1). It appears to be of equivalent potency to racemic bupivacaine for motor blockade in ex-premature infants requiring lower abdominal surgery.