Lumbar epidural anaesthesia for inguinal hernia repair in low birth weight infants

Regional anesthesia in neonates and infants

Optimal pain management can significantly impact the surgical outcome and length of stay in the neonatal intensive care unit (NICU). Regional anesthesia is an effective alternative that can be used in both term and preterm neonates. A variety of neuraxial and peripheral nerve blocks have been used for specific surgical and NICU procedures. Ultrasound guidance has increased the feasibility of using these techniques in neonates. Education and training staff in the use of continuous epidural infusions are important prerequisites for successful implementation of regional anesthesia in NICU management protocols.

Pro con debate: the use of regional vs systemic analgesia for neonatal surgery

In recent years the inclusion of regional techniques to pediatric anesthesia has transformed practice. Simple procedures such as caudal anesthesia with local anaesthetics can reduce the amounts of general anesthesia required and provide complete analgesia in the postoperative period while avoiding large amounts of opioid analgesia with potential side effects that can impair recovery. However, the application of central blocks (epidural and spinal local anesthesia) via catheters in the younger infant, neonate and even preterm neonate remains more controversial. The potential for such invasive maneuvers themselves to augment risk, can be argued to outweigh the benefits, others would argue that epidural analgesia can reduce the need for postoperative ventilation and that this not only facilitates surgery when intensive care facilities are limited, but also reduces cost in terms of PICU stay and recovery profile. Currently, opinions are divided and strongly held with some major units adopting this approach widely and others maintaining a more conservative stance to anesthesia for major neonatal surgery. In this pro-con debate the evidence base is examined, supplemented with expert opinion to try to provide a balanced overall view.

Effects of intrathecal fentanyl on quality of spinal anesthesia in children undergoing inguinal hernia repair

BACKGROUND

The effect of intrathecal fentanyl on the characteristics of spinal anesthesia has not been investigated in children undergoing inguinal hernia repair. The purpose of this study was to assess whether the incidence and severity of pain during peritoneal sac traction is decreased by addition of fentanyl to bupivacaine in children undergoing inguinal hernia repair with spinal anesthesia.

METHODS

Children (6-14 years) were randomized into two groups. Group F (n = 25): hyperbaric bupivacaine plus 0.2 microg.kg(-1) of fentanyl. Group P (n = 25): hyperbaric bupivacaine plus 0.9% NaCl (placebo). The dose of bupivacaine was 0.4 mg.kg(-1). The primary variable was the incidence and severity of pain during peritoneal sac traction. Spinal block characteristics, duration of spinal anesthesia assessed by recovery of hip flexion and duration of analgesia were the secondary variables measured, and the side effects were noted.

RESULTS

There were significant differences in incidence of pain and pain scores during sac traction with lower incidence and scores in the fentanyl group (P = 0.009). Two groups were similar regarding the level of sensory block during sac traction and duration of spinal anesthesia. Duration of spinal analgesia was prolonged significantly in the fentanyl group (P = 0.025).

CONCLUSION

Intrathecal fentanyl at a dose of 0.2 microg.kg(-1) added to bupivacaine significantly improves the quality of intraoperative analgesia and prolongs postoperative analgesia in children undergoing inguinal hernia repair with spinal anesthesia.

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).

Spinal anaesthesia in full-term infants of 0-6 months: are there any differences regarding age?

BACKGROUND AND OBJECTIVE

The aim of the study was to report our experience concerning the effectiveness, complications and safety of spinal anaesthesia, and to determine whether spinal anaesthesia was effective in full-term infants undergoing elective inguinal hernia repair.

METHODS

Sixty-eight full-term infants aged < 6 months were included in the study. Infants were divided into three groups; Group I (< 1 month, n = 20), Group II (> 1 and < 3 months, n = 26), and Group III (3-6 months, n = 22). All spinal blocks were performed under mask inhalation anaesthesia. A dose of bupivacaine 0.5% 0.5 mg kg(-1) was used for infants under 5kg and 0.4 mg kg(-1) for those over 5 kg. Heart rate, mean arterial pressure, respiratory rate and SPO2 were recorded before and after spinal anaesthesia at 5 min intervals. Time to onset of analgesia, time to start of operation, duration of operation, anaesthesia and hospitalization, postoperative analgesic requirement and complications were recorded.

RESULTS

Adequate spinal anaesthesia without sedation was better, time to obtain maximum cutaneous analgesia was shorter and need for sedation and postoperative analgesic requirement were significantly lower in Group I. Although heart rate, mean arterial pressure and respiratory rate decreased < 20% in all groups following spinal analgesia, the decrease in Group I was lower than the others.

CONCLUSIONS

Spinal anaesthesia is an effective choice in inguinal hernia repair for full-term infants aged < 1 month, providing excellent and reliable surgical conditions. However, this technique is not as useful for infants aged between 1 and 6 months.

Anaesthetic considerations for the management of very low and extremely low birth weight infants

The opportunities for very low birth weight infants (birth weight < 1500 g) and extremely low birth weight infants (birth weight < 1000 g) to undergo surgery are increasing. These infants are prone to prematurity-related morbidities including respiratory distress syndrome, intraventricular haemorrhage, periventricular leukomalacia, retinopathy of prematurity, patent ductus arteriosus and necrotising enterocolitis. Evidence is accumulating that preterm infants are also sensitive to pain and stress. The pharmacokinetics of drugs in preterm infants is not fully understood but smaller doses of anaesthetic drugs are usually required in preterm infants compared to term infants and older children and their effects last longer due to low clearance rates and longer elimination half-lives. Key anaesthetic considerations are (i) inspired oxygen concentration that should be adjusted to avoid hyperoxia, (ii) haemodynamic parameters that should be kept stable and (iii) prevention of hypothermia by using adequate measures to keep the infants warm. These precautions must be continuously taken during the operation and the transport to and from the operating theatre.

Benefit and risks of local anesthetics in infants and children

Regional anesthesia has become a routine part of the practice of anesthesiology in infants and children. Local anesthetic toxicity is extremely rare in infants and children; however, seizures, dysrhythmias, cardiovascular collapse, and transient neuropathic symptoms have been reported. Infants and children may be at increased risk from local anesthetics compared with adults. Larger volumes of local anesthetics are used for epidural anesthesia in infants and children than in adults. Metabolism and elimination of local anesthetics can be delayed in neonates, who also have decreased plasma concentrations of alpha(1)-acid glycoprotein, leading to increased concentrations of unbound bupivacaine. Most regional anesthetic procedures in infants and children are performed with the patient heavily sedated or anesthetized; because of this, and because a test dose is not a particularly sensitive marker of intravenous injection in the anesthetized patient, detection of intravascular local anesthetic injection is extremely difficult. The same local anesthetics used in adult anesthetic practice are also used in infants and children. Because of its extremely short duration of action, chloroprocaine has been used primarily for continuous epidural techniques in infants and children. The use of tetracaine has generally been limited to spinal and topical anesthesia. Lidocaine (lignocaine) has been used extensively in infants and children for topical, regional, plexus, epidural and spinal anesthesia. The association between prilocaine and methemoglobinemia has generally restricted prilocaine use in infants and children to the eutectic mixture of local anesthetics (EMLA). Because of its greater degree of motor block compared with other long-acting local anesthetics, etidocaine has generally been limited to plexus blocks in infants and children. Mepivacaine has been used for both plexus and epidural anesthesia in infants and children. Because postoperative analgesia is often the primary justification for regional anesthesia in infants and children, bupivacaine, a long-acting local anesthetic, is the most commonly reported local anesthetic for pediatric regional anesthesia. Given the lower toxic threshold of bupivacaine compared with other local anesthetics, the risk-benefit ratio of bupivacaine may be greater than that of other local anesthetics. Two new enantiomerically pure local anesthetics, ropivacaine and levobupivacaine, offer clinical profiles comparable to that of bupivacaine but without its lower toxic threshold. The extreme rarity of major toxicity from local anesthetics suggests that widespread replacement of bupivacaine with ropivacaine or levobupivacaine is probably not necessary. However, there are clinical situations, including prolonged local anesthetic infusions, use in neonates, impaired hepatic metabolic function, and anesthetic techniques requiring a large mass of local anesthetic, where replacement of bupivacaine with ropivacaine, levobupivacaine or (for continuous techniques) chloroprocaine appears prudent.

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.

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.

Anesthesia for the micropremie

Providing anesthesia for the micropremie involves many considerations beyond what is needed for the full-term neonate. Immaturity of the airway, lungs, cardiovascular system, liver, kidneys, and central nervous system makes the micropremie susceptible to anesthestic complications. Immature respiratory mechanisms and respiratory control increase the risk of apnea, hypoxemia, and hypercapnia intraoperatively as well as postoperatively. Anesthetic drugs depress myocardial contractility and impair baroreflexes in the micropremie to increase the risk of hypotension during anesthesia. Drug metabolism in the micropremie is slow because of the immature liver and kidneys. The micropremie brain requires less drug to achieve the anesthetized state. As a result, administration of the dose and timing of anesthetic drugs differs in the micropremie compared with the full-term neonate. This article describes anesthetic considerations for a few surgical prodedures common in the micropremie.

Lumbar epidural morphine infusions for children undergoing cardiac surgery

OBJECTIVE

To determine whether outcomes and costs in children undergoing cardiac surgery are affected by the method of postoperative pain management.

DESIGN

Retrospective, case control.

SETTING

Tertiary care children's hospital in a university setting.

PARTICIPANTS

Two groups of children undergoing cardiac surgery for palliation or repair of congenital heart disease oer a 21-month period between January 1993 and September 1994.

INTERVENTIONS

Lumbar epidural morphine infusions (LEM) in one group, and IV opioid (IVO) medication in the other for postoperative pain control.

MEASUREMENTS AND MAIN RESULTS

Hospital courses of 27 LEM patients and 27 IVO patients were analyzed. In LEM patients, epidural catheters were placed following anesthetic induction, but before anticoagulation. A bolus of 50 micrograms/kg of preservative-free morphine sulfate was administered through the catheter, followed by a continuous infusion at 3 to 4 micrograms/kg/h for 22 to 102 (median, 46) hours postoperatively. The IVO patients received 50 micrograms/kg, IV, of fentanyl before incision followed by a continuous infusion at 0.3 microgram/kg/min. The fentanyl infusion rate was decreased to 0.1 microgram/kg/min postoperatively and maintained for 24 hours. Although the LEM group was demographically similar to the IVO group, times to tracheal extubation, transfer from the intensive care unit, and resumption of regular diet were significantly shorter in LEM patients. LEM and IVO patients received similar amounts of fentanyl during surgery (10.4 +/- 19.3 micrograms/kg/h v 13.7 +/- 8.1 micrograms/kg/h, p = 0.4). However, during postoperative recovery, LEM patients who were extubated late received significantly less supplemental opioid medication than IVO patients extubated late during the first 5 postoperative days. No complications related to dural puncture, bleeding into the epidural space, or respiratory depression were encountered. Pruritus and nausea/vomiting were the most commonly reported morbidities in both groups. Fifty-six percent (15/27) of LEM patients and 41% of IVO patients reported pruritus (p = 0.4). There was no significant difference in the incidence of nausea and vomiting between the groups (34% v 30%, respectively).

CONCLUSIONS

Given the present methodologic limitations, the authors found improved outcomes only in LEM patients extubated late compared with IVO patients. Randomized, prospective studies to evaluate this conclusion and to determine the comparative efficacy and safety of LEM infusions are in progress.