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

Awake caudal anesthesia in ex-premature infants undergoing lower abdominal surgery: A narrative review

BACKGROUND AND OBJECTIVES

The aim of this narrative review is to evaluate the literature describing the use of caudal anesthetic-based techniques in premature and ex-premature infants undergoing lower abdominal surgery.

METHODS

All available literature from inception to August 2023 was retrieved according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines from Medline, PubMed, Embase, and the Cochrane Library. Two authors reviewed all references for eligibility, abstracted data, and appraised quality.

RESULTS

Of the 211 articles identified, 45 met our inclusion criteria yielding 1548 cases with awake caudal anesthesia. The review included 558 (36.0%) cases of awake caudal anesthesia, 837 cases (54.1%) of "awake" caudal anesthesia with sedation, and 153 cases (9.9%) of combined spinal caudal epidural anesthesia without sedation. The overall anesthetic failure rate was 7.2% (71.9:1000 caudals). Failure rates were highest for CSEA (13.7%, 7.7-18.4), intermediate for awake caudal (6.6%, 5.26-9.51), and lowest for sedated caudal anesthesia (5.85%, 4.48-7.82). The incidence (range) of perioperative apnea was highest for sedated caudal anesthesia (8.16, 0%-24%), intermediate for awake caudal (7.62%, 0%-60%), and lowest for CSEA (5.53%, 0%-14.3%). High spinal anesthesia occurred in 0.84%, or 8.35:1000 caudals overall. The incidence was highest in awake caudal anesthesia cases (1.97% or 19.7:1000 caudals), intermediate with caudal with sedation (1.07% or 10.7:1000 caudals), and lowest in CSEA (0.7% or 6.6:1000 caudals). Our review was confounded by incomplete data reporting and small sample sizes as most were case reports. There were no high-quality randomized controlled trials, and the eight single-center retrospective data reviews lacked sufficient data to perform meta-analysis.

CONCLUSIONS

There is insufficient evidence to validate or refute the benefits of the use of "awake" caudal anesthesia in premature and ex-premature infants. The high doses of local anesthetics used, the high failure rate, and the increased incidence of high spinal anesthesia would suggest that the techniques offer no real advantages over awake spinal anesthesia or general anesthesia with a regional block.

Ambulatory Pain Management in the Pediatric Patient Population

PURPOSE OF REVIEW

Outpatient surgery in the pediatric population has become increasingly common. However, many patients still experience moderate to severe postoperative pain. A poor understanding of the extent of pain after pediatric ambulatory surgery and the lack of randomized control studies of pain management of the outpatient necessitate this review of scientific evidence and multimodal analgesia.

RECENT FINDINGS

A multimodal approach to pain management should be applied to the ambulatory setting to decrease postoperative pain. These include non-pharmacological techniques, multimodal pharmacologics, and neuraxial and peripheral nerve blocks. Postoperative pain management in pediatric ambulatory surgical patients remains suboptimal at most centers due to limited evidence-based approach to postoperative pain control. Pediatric ambulatory pain management requires a multipronged approach to address this inadequacy.

Inguinal hernia repair in preterm neonates: is there evidence that spinal or general anaesthesia is the better option regarding intraoperative and postoperative complications? A systematic review and meta-analysis

OBJECTIVES

Whether spinal anaesthesia (SA) reduces intraoperative and postoperative complications compared with general anaesthesia (GA) was investigated.

DESIGN

The meta-analysis was structured based on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. Databases (PubMed, MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials and Web of Science) were searched, and four randomised controlled trials (RCTs) and two retrospective cohort studies were included. A random-effects model with pooled risk ratios and mean differences with 95% CIs were used. Statistical heterogeneity was evaluated using the I² statistic. Quality assessment of the studies was performed by assessing the risk of bias according to the Cochrane and GRADE methodology.

SETTING

Publications from January 1990 to November 2018 were included.

PARTICIPANTS AND INTERVENTIONS

Our study selection captured information from studies focusing on neonates born before the 37th gestational week who were scheduled for an inguinal hernia repair operation under either SA or GA.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome measures were apnoea, postoperative ventilation and method failure rates according to predefined eligibility criteria. The duration of surgery, desaturation events <80%, hospital stay duration and postoperative bradycardia were secondary outcomes.

RESULTS

We found significantly fewer events for the outcomes 'any episode of apnoea' and 'mechanical ventilation postoperatively' in the SA group. Bradycardias were significantly less common in the SA group. In total, 7.5% of the SA group were converted to GA. The duration of surgery was significantly shorter in the SA group. No significant differences were found in the outcome measures 'postoperative oxygen supplementation', 'prolonged apnoea', 'postoperative oxygen desaturation <80%' and 'hospital stay'.

CONCLUSIONS

We consider SA a convenient alternative for hernia repair in preterm infants, providing more safety regarding postoperative apnoea. To the best of our knowledge, this is the first meta-analysis to include studies exclusively comparing SA versus GA. More high-quality RCTs are needed.

TRIAL REGISTRATION NUMBER

CRD42016048683.

Effectiveness of caudal epidural block on interaoperative blood loss during hypospadias repair: A randomized clinical trial

BACKGROUND

Intraoperative blood loss is considered to be an important issue in hypospadias surgery. Some studies have demonstrated the utility of caudal epidural block (CEB) in this regard among pediatric patients with hypospadias. Though there is evidence in favor of the use of CEB as the only anesthetic method for pediatric surgeries, it is usually used in combination with general anesthesia. In this form of use, it could have more favorable outcomes for both intra- and postoperative periods. There are few studies regarding the effectiveness of CEB on intraoperative blood loss.

OBJECTIVE

We aimed to evaluate the utility of CEB on blood loss, operation time, and analgesic use during hypospadias repairs of pediatric population referred to our university hospitals.

STUDY DESIGN

In this randomized clinical trial, consecutive patients with hypospadias who were candidate for surgery were enrolled and randomly allocated to one of the two groups: group A received caudal epidural block (CEB) plus general anesthesia (GA) before surgery and group B received only GA. Intraoperative blood loss, operation time, and dose of fentanyl used during the procedure were recorded and compared. All surgeries were performed by a single pediatric urologist in two different university hospitals that was not blinded to the study groups.

RESULTS

In this study, 57 pediatric patients with hypospadias who underwent surgical repair were studied, from which 29 and 28 patients were allocated to receive or not to receive preoperative CEB, respectively. The patients' age, weight, ASA, score and severity of hypospadias were not significantly different between the two groups. The operation time was significantly lower in the CEB before surgery group (p < 0.05). The mean dose of fentanyl and volume of blood loss during procedure were lower in the CEB group, although for fentanyl it approached but did not reach statistical significance.

CONCLUSION

The findings of current study indicated that caudal epidural anesthesia in addition to general anesthesia has a favorable effect on reducing blood loss during operation, operation time, and analgesic use. Our data confirm the findings of previous studies in this field. Further studies are recommended to evaluate the effect of this type of analgesia in other outcomes of hypospadias repair surgery. Our results could be used for revising existing surgical guidelines for better management of hypospadias.

Awake caudal anaesthesia in neonates/young infants for improved patient safety

Caudal epidural block in a conscious infant is a recognised technique that allows the avoidance of general anaesthesia and risks associated with it. It is also technically easier to perform reliably compared with an awake subarachnoid block in skilled hands.1 While local anaesthetic systemic toxicity is a rare complication of caudal anaesthesia, this case illustrates the potential for caudal anaesthesia done awake in enhancing patient safety through early recognition of local anaesthetic systemic toxicity.

Regional block via continuous caudal infusion as sole anesthetic for inguinal hernia repair in conscious neonates

PURPOSE

The use of general anesthesia in young children has come under increasing scrutiny due to its potential long-term neurotoxic effects. Meanwhile, regional anesthesia for surgical procedures in neonates has many advantages, including preservation of respiratory status and faster return to feeding. We describe the successful use of 3% 2-chloroprocaine administered via continuous caudal infusion as the sole anesthetic agent during elective surgical procedures in infants.

METHODS

A retrospective chart review of all patients who underwent elective surgical procedures under continuous caudal regional anesthetic at a single institution was performed. Thirty patients (27 males, three females) were identified: 28 patients underwent inguinal hernia repairs. Caudal anesthesia was established via continuous infusion of 3% 2-chloroprocaine through an indwelling catheter.

RESULTS

Successful analgesia by regional block alone was achieved in all patients for the duration of each surgical procedure without need for rescue anesthesia. Mean operative time was 49 min. Patients were able to return to feeding immediately after surgery and were ready for discharge home within that day.

CONCLUSION

Continuous caudal infusion of chloroprocaine is a safe and effective way to maintain adequate analgesia for elective surgeries in infants. This successful regional approach obviates the use of general anesthetic which reduces post-operative recovery time and avoids concerns for neurotoxicity.

Postoperative analgesia in pediatric herniotomy - Comparison of caudal bupivacaine to bupivacaine infiltration with diclofenac suppository

CONTEXT

Perioperative analgesia in paediatric herniotomies demand safe, effective and less invasive strategies. Local infiltration with Bupivacaine, rectal Diclofenac and caudal Bupivacaine are widely used for pain relief.

AIMS

To compare the analgesic effects of caudal epidural using 1 mlkg(-1) of 0.25% Bupivacaine against a combination of local infiltration 0.25% Bupivacaine 0.5 mlkg(-1) with Diclofenac suppository 2 mgkg(-1) in the management of post-operative pain following paediatric inguinal herniotomy.

SETTINGS AND DESIGN

This is an observational study from a tertiary care teaching hospital.

METHODS AND MATERIAL

A total of 60 children for elective unilateral inguinal herniotomy were assigned to two groups of 30 each. Patients who received caudal block with 1 mlkg(-1) of 0.25% Bupivacaine were allocated to Group A and who received Diclofenac suppository 2 mgkg(-1) and infiltration with 0.25% Bupivacaine 0.5 mlkg(-1) were allocated to Group B. Post operative Pain was assessed using Hannallah's modified objective pain scale. At score ≥3 rescue analgesic oral Paracetamol 15 mgkg(-1) was given. Pain was assessed at 0,15,30,45,60 minutes and half hourly thereafter until 8 hours following surgery or until patient requires rescue analgesic whichever happens first.

STATISTICAL ANALYSIS USED

Employed SPSS software. Data was analysed using sample t test and P-value was calculated.

RESULTS

The demographic profile was comparable between two groups. The mean analgesic duration in group A and group B was 228.5 and 331.0 minutes respectively and is found to be statistically significant (P < 0.05).

CONCLUSIONS

Diclofenac suppository with local infiltration is a less invasive and effective alternative to caudal Bupivacaine for analgesia in paediatric herniotomy.

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.

Recent developments in paediatric neuraxial blocks

Paediatric anaesthesia and paediatric regional anaesthesia are intertwined. Almost all surgeries unless contradicted could be and should be supplemented with a regional block. The main objective of this review is to elaborate on the recent advances of the central neuraxial blocks, such as application of ultrasound guidance and electrical stimulation in the pursuit of safety and an objective end point. This review also takes account of the traditional technique and understand the benefits as well the risk of each as compared with the recent technique. The recent trends in choosing the most appropriate peripheral block for a given surgery thereby sparing the central neuroaxis is considered. A penile block for circumcision or a sciatic block for unilateral foot surgery, rather than caudal epidural would have a better risk benefit equation. Readers will find a special mention on the recent thoughts on continuous epidural analgesia in paediatrics, especially its rise and fall, yet its unique importance. Lastly, the issue of block placements under sedation or general anaesthesia with its implication in this special population is dealt with. We conducted searches in MEDLINE (PubMed) and assessed the relevance of the abstracts of citations identified from literature searches. The search was carried out in English, for last 10 years, with the following key words: Recent advances in paediatric regional anaesthesia; ultrasound guidance for central neuraxial blocks in children; role of electrical stimulation in neuraxial blocks in children; complications in neuraxial block. Full-text articles of potentially relevant abstracts were retrieved for further review.

Caudal blocks

Caudal anesthesia is the single most important pediatric regional anesthetic technique. The technique is relatively easy to learn (1), has a remarkable safety record (2), and can be used for a large variety of procedures. The technique has been reviewed in the English (3) and French (4) literature, as well as in German guidelines (5) and in pediatric anesthesia textbooks (6).

The caudal space in fetuses: an anatomical study

PURPOSE

The caudal epidural space is a popular site for analgesia in pediatrics. High variation in blind needle placement is common during caudal epidurals, increasing the risk of intravascular and intrathecal spread. Knowledge of safe distances and angles for accessing the caudal epidural space in premature infants can improve the safety of caudal epidural blocks.

METHODS

Thirty-nine fetuses with crown-heel length between 33 and 50 cm, corresponding to gestational age of 7-9 months, were included. The dorsal surface of the sacrum from the fourth lumbar vertebra to the tip of the coccyx was dissected, following which measurements were taken on dorsal surface and midsagittal sections. The angle of depression of the needle was measured using a goniometer following the two-step method of needle insertion.

RESULTS

Right and left sacral cornua were palpable in 23 of 39 fetuses (58.97%). Termination of dural sac was at S2 in most of the fetuses (53.84%), whereas the apex of the sacral hiatus was at S3 in most (58.97%). The distance from the apex of the hiatus to the termination of dura ranged from 3 to 13 mm; the anteroposterior distance of the canal at the apex of the hiatus ranged from 1.72 to 4.38 mm. All sacral parameters correlated with crown-heel length except inter-cornual distance, depth of canal at hiatus, and height of sacral hiatus.

CONCLUSION

Distances and angles for accessing the caudal epidural space in fetuses do not provide all parameters for safe performance of caudal epidural blocks in premature and low birth weight infants because the apex of the sacral hiatus and the termination of the dura show wide variation in location.

General anesthesia for repair of omphalocele in a pair of conjoined twins in Enugu, Nigeria

Conjoined twins have been viewed with fascination since antiquity. There are numerous reports in the literature documenting anesthetic management strategies for the separation of conjoined twins. There are also reports in the literature detailing anesthetic approaches for surgical procedures not involving separation. This is the first report of the anesthetic management of a set of omphalagous presenting for palliative repair of omphalocele in Nigeria.

Ultrasound-guided serial ilioinguinal nerve blocks for management of chronic groin pain secondary to ilioinguinal neuralgia in adolescents

We examined the efficacy of serial ilioinguinal nerve blocks using ultrasound guidance for management of chronic inguinal pain secondary to persistent ilioinguinal neuralgia in adolescents. This case series consists of two adolescents who had persistent inguinal pain secondary to ilioinguinal neuralgia who were treated with conventional pain medications that did not relieve the pain. One patient had pain immediately following surgery while the other had pain several months after an injury. Serial ilioinguinal nerve blocks were performed with local anesthetic solution using ultrasound guidance in an outpatient setting. Both the adolescents had complete relief of pain symptoms and were able to resume normal activities. There were no adverse effects associated with the blocks. Performance of serial ilioinguinal nerve blocks using ultrasonography in an outpatient setting in adolescents and adolescents with ilioinguinal neuralgia may reduce pain and allow these adolescents to resume their normal activities.

Experience with remifentanil-sevoflurane balanced anesthesia for abdominal surgery in neonates and children less than 2 years

BACKGROUND

Few data report remifentanil use in the neonatal population. We described here our experience with remifentanil-sevoflurane balanced anesthesia in neonates and children less than 2 years who underwent general anesthesia for abdominal surgery.

METHODS

We retrospectively studied the pattern of remifentanil infusion associated with sevoflurane inhalation in preterm neonates (PTN; n = 18) (born before 37 weeks of gestation and <45 weeks of postmenstrual age), full-term neonates (FTN; n = 21) (born after 37 weeks of gestation and less than 29 days old) and older children up to 2 years (CUT; n = 24). We recorded heart rate (HR), mean arterial pressure (MAP), mean remifentanil dose and sevoflurane concentration before incision and at 5, 10, 20, 30, 45, 60, 90, and 105 min after incision.

RESULTS

We observed that remifentanil doses used during surgery were lower in PTN than in both FTN and CUT and lower in FTN than in CUT. This was because of a progressive decrease in remifentanil dose during anesthesia in PTN and FTN. Conversely, remifentanil doses increased in CUT during anesthesia. Sevoflurane concentrations were higher in CUT group than in PTN and FTN groups. MAP and HR did not vary in the three groups during anesthesia.

CONCLUSIONS

Remifentanil-sevoflurane anesthesia can be used for general anesthesia in neonates. We observed that anesthetists used lower doses of remifantanil and lower concentrations of sevoflurane in neonates compared with the older children.

A simplified technique for giant inguinal hernia repair in infants

Repair of giant inguino-scrotal hernia (GISH) in male infants is a difficult operation, even in experienced hands. It requires an immaculate technique to avoid known complications such as tearing of the sac, injury to delicate testicular vessels and dividing of vas deferens. Moreover, a recurrence rate of 9% is noted in a number of reports. This article describes a new surgical maneuver to simplify the procedure. All GISH repaired by the author, over a 5-year period (October 2001-September 2006), were reviewed retrospectively. In total, 89 infants with 106 GISH underwent uni- or bilateral herniotomies. A standard inguinal incision is made and Scarpa's fascia is sharply opened; the external inguinal ring and the cord is identified. By gentle manipulation and blunt dissection, the spermatic cord together with the testis is exteriorized. The assistant applies gentle traction to the cord, which allows for easy identification of the inguinal sac and its subsequent separation from vas and vessels. Testis is replaced in the scrotum, hernial sac suture ligated at its base and the wound closed in layers. All cases were managed with the above approach. The average length of the procedure was 11 min for unilateral and 19 min for bilateral cases. Except for minimal scrotal swelling post-operatively, no other surgery-related complications were noted during or immediately after the operation. Testicular atrophy or iatrogenic undescended testes were not encountered in the follow-up period. Ipsilateral recurrent hernia was noted in one infant after 6 months which required re-operation with the same technique. In cases of GISH; dislocating the testis into the wound and applying a gentle stretch on the cord allows for a safe dissection of the hernial sac and subsequent herniotomy. This maneuver converts a difficult procedure into a relatively simple one.

Anästhesiologische Aspekte in der Neu- und Frühgeborenenchirurgie

The physiology of the preterm and term neonate is characterized by a high metabolic rate, limited pulmonary, cardiac and thermoregulatory reserve and decreased renal function. Multisystem immaturity creates important developmental differences in drug administration and response when compared to older children. Specific monitoring techniques are required because the neonate is not physically accessible to the anesthetist during the operation. This contribution reviews the specific pathophysiological characteristics of the newborn with relevance to anesthesia and also provides robust guidelines for the anesthetic management of the most frequent non-cardiac procedures which need surgery during the neonatal period. Consideration will also be given to the anesthetic management of very low birth-weight infants with anesthetic key issues such as avoiding hyperoxia, keeping hemodynamic parameters as stable as possible and preventing hypothermia.

Prospective comparison of sevoflurane and desflurane in formerly premature infants undergoing inguinal herniotomy

BACKGROUND

Formerly premature infants having inguinal herniotomy have been at a high risk of postoperative apnoea, newer less soluble anaesthetic agents may reduce this risk.

METHODS

Thirty infants, under 37 weeks gestation and under 47 weeks post-conceptional age, undergoing inguinal herniotomy had an inhalational induction with sevoflurane and were randomly allocated to sevoflurane (group S) or desflurane (group D) for maintenance. All infants received i.v. atracurium 0.5 mg kg(-1), rectal acetaminophen 20 mg kg(-1) and caudal bupivacaine 0.25% 1 ml kg(-1). Infants were monitored for apnoeas (using nasal thermistry and impedance), haemoglobin oxygen desaturations and bradycardias for 12 h before and after operation with an Alice 4 polysomnograph. Emergence timings were recorded.

RESULTS

There was no difference between pre- and postoperative incidence of apnoeas in either group, and no group difference between desflurane and sevoflurane in terms of pre- and postoperative ventilatory events or in the number of apnoeas in the postoperative period (nine patients in group D and five patients in group S had apnoeas). Median times to first movement, tracheal extubation, eye opening and first cry were all faster with group D (group D: 3.0, 10.0, 9.0 and 11.0 min and group S: 7.0, 15.1, 13.5 and 16.1 min, respectively). No infant had problems with airway irritation on emergence and no infant required airway intervention for apnoea.

CONCLUSIONS

Infants wake faster from general anaesthesia when maintained with desflurane as compared with sevoflurane, but no difference in postoperative respiratory events was demonstrated between the groups.

Caudal anesthesia for vascular access procedures in two extremely small premature neonates

With advances in neonatology, there is an increasing need for central vascular access in extremely small (<1,000 g) premature infants. Although the use of peripherally inserted central venous lines have become common practice, surgeons still frequently perform central venous line placements via cut-down in difficult access patients. The advantages of general anesthesia for vascular access procedures are obvious for optimal pain control and ideal operative exposure; however, extremely premature infants are at significant risk for prolonged endotracheal intubation with postoperative apneas. We report two cases where regional caudal anesthesia with bupivacaine and clonidine without intubation was successfully utilized at bedside during central venous line placements in premature infants weighing <600 g. The operative field was ideal with adequate motor and sensory block with caudal anesthesia and both infants received only oxygen by nasal cannula.

Sevoflurane sedation in infants undergoing MRI: a preliminary report

BACKGROUND

Stillness during natural sleep after feeding may not be sufficient for successful magnetic resonance imaging (MRI) in small infants less than 5 kg. Sedation, using an oral agent, is often successful although the timing and depth of sedation is variable. In contrast anesthesia is always effective but is invasive and is associated with postanesthesia apnea and bradycardia in preterm and ex-preterm infants. We are developing an alternative technique involving insufflation of sevoflurane and present our initial experience.

METHODS

Infants presenting for MRI were sedated by nasal insufflation of sevoflurane carried by 2 l.min(-1) oxygen. We recorded the sevoflurane administered, timing of sedation and scanning, conscious level, oxygen saturations, and recovery profile.

RESULTS

Of the 13 infants studied (median postconceptional age: 46 weeks, range: 40-70 weeks; median weight: 4.4 kg, range: 3.3-6.5 kg), sevoflurane caused sleep and enabled successful imaging in 12. Six infants fell asleep within 10 min and the median maximum sevoflurane vaporizer setting for successful sedation was 4% (range: 4-8%). Before scanning, 10 infants remained easily roused by touch and two became unresponsive; one desaturated to 85% and required repositioning of the head to maintain a clear airway. Immediately after scanning all infants were easily roused by touch.

CONCLUSIONS

Sedation by insufflation of sevoflurane in small infants is a simple and practical alternative technique for painless imaging such as MRI; further experience is necessary to determine its limitations.

Patient selection in ambulatory anesthesia — An evidence-based review: part II

PURPOSE

This is the second of two reviews evaluating the management of patients with selected medical conditions undergoing ambulatory anesthesia and surgery. Conditions highlighted in this review include: diabetes mellitus; morbid obesity; the ex-premature infant; the child with an upper respiratory infection; malignant hyperthermia; and the use of monoamine oxidase inhibitors.

SOURCE

Medline search strategies and the framework for the evaluation of clinical evidence are presented in Part I.

PRINCIPAL FINDINGS

Diabetes mellitus has not been linked with adverse events following ambulatory surgery. The morbidly obese patient is at an increased risk for minor respiratory complications in the perioperative period but these events do not increase unanticipated admissions. The ex-premature infant may be considered for ambulatory surgery if post-conceptual age is > 60 weeks and hematocrit is > 30%. The child with a recent upper respiratory tract infection is at an increased risk for perioperative respiratory complications, particularly if endotracheal intubation is required. Patients with malignant hyperthermia may undergo outpatient surgery but require four hours of postoperative temperature monitoring. Sporadic cases of drug interactions have been reported when meperidine and indirect-acting catecholamines are administered in the presence of monamine oxidase inhibitors. Ambulatory anesthesia and surgery is safe if these combinations of drugs are avoided.

CONCLUSION

Ambulatory anesthesia can be performed in, and is being offered to, a variety of patients with significant coexistent disease. In many cases there is little evidence documenting the outcomes expected in such patients. Prospective observational and interventional trials are required to better define perioperative management.

Regional anaesthetic techniques for neonatal surgery: indications and selection of techniques

The goal of neonatal care is to optimise the outcome of term and preterm infants with minimal suffering. Neonates are rare patients for the anaesthetist, therefore personal and even global experiences are limited. This chapter focuses on strategies for dealing with common clinical situations, e.g. heel lancing, obtaining vascular access, circumcision, hernia repair and pyloric stenosis, as well as major neonatal surgery. With the exception of heel lancing, regional techniques are useful in all cases. However, a careful risk-benefit analysis is mandatory, especially when considering more invasive techniques such as epidural catheters.

Awake spinal or caudal anaesthesia in preterms for herniotomies: what is the evidence based benefit compared with general anaesthesia?

PURPOSE OF REVIEW

Postoperative apnoea is known to threaten preterm and ex-preterm infants undergoing surgery for inguinal hernia. Awake regional anaesthesia, initially spinal and later caudal anaesthesia have been suggested as effective techniques to avoid these complications. However, most herniotomies in this group of patients are still performed under general anaesthesia without deleterious consequences. Whereas some experts continue to claim advantages for awake regional over general anaesthesia for preterm infants, others consider awake regional anaesthesia to be an exclusive, technically difficult and unreliable technique of unconfirmed benefit.

RECENT FINDINGS

It is appropriate to weigh the scarce available evidence that has been accumulated since 1984, and put it into perspective with new developments in paediatric general anaesthesia. The actual clinical significance of postoperative apnoea and improvements in neonatal and perioperative care and monitoring must also be reconsidered.

SUMMARY

The available evidence does not allow unequivocal conclusions to be drawn or recommendations to be made. Awake regional anaesthesia for herniotomies in preterm infants has been found to be superior in most studies; however, it requires technical expertise and dedication on the part of the anaesthetist and surgeon. When light general anaesthesia with modern anaesthetic agents such as sevoflurane or desflurane is combined with a caudal block, postoperative apnoea is very rare, and can easily be recognized and managed with good postoperative monitoring and therapy.

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.

Monitoring intraoperative effectiveness of caudal analgesia through skin temperature variation

BACKGROUND/PURPOSE

A reliable noninvasive intraoperative marker of caudal analgesia effectiveness remains elusive. Caudal analgesia causes sympathetic inhibition resulting in vasodilatation, increased blood flow, and a resultant increase in temperature in the affected dermatomes. The authors hypothesize that this change in temperature between the affected and unaffected dermatomes is measurable and may represent a noninvasive method of monitoring effectiveness of caudal analgesia.

METHODS

Children undergoing lower abdominal surgery participated in the caudal or noncaudal (control) analgesia arm of the study. After induction of general anesthesia, 0.25% bupivicaine (1 mL/kg) was infiltrated for a field block in control patients or a caudal block in the experimental group. Temperature was measured at the C4 and L2 dermatomes starting after induction and 5 minutes before the caudal or field block and every 5 minutes after. T(o) is defined as the difference between the C4 and L2. Delta T (DeltaT) is the temperature variation between T(o). A change in the DeltaT is defined by an increase in the L2 temperature.

RESULTS

Forty-six families enrolled (36 experimental, 10 control). The DeltaT for controls was 0.2+/-0.09 degrees C (SEM). Each child in the experimental group had 2 temperature measurements before the caudal with an average DeltaT of 0.3+/-0.07 degrees C (SEM), thus, were internal controls. A marked increase in DeltaT at 5 minutes 0.5+/-0.06 degrees C (SEM) and at 10 minutes 0.6+/-0.07 degrees C (SEM; P <.05) was noted in the experimental group.

CONCLUSION

A significant transient change in temperature is observed after caudal analgesia and maybe a noninvasive marker of effectiveness. Further study may clarify its clinical utility.

Apnoea in a former preterm infant after caudal bupivacaine with clonidine for inguinal herniorrhaphy

Awake regional anaesthesia for inguinal hernia repair in former preterm infants is suggested to avoid life-threatening respiratory complications known to occur after general anaesthesia. Caudal anaesthesia is becoming a more popular technique for this purpose. To prolong duration of anaesthesia and to reduce postoperative need for analgesics in these infants, caudal clonidine has been considered useful. We report a former preterm infant, who had two awake caudal anaesthetics for herniotomy within 3 weeks. The first was uneventful with bupivacaine 0.25% at 35 weeks postconceptional age. At 38 weeks, the baby suffered form intra- and postoperative apnoeas after inadvertent administration of bupivacaine 0.125% plus clonidine.

Caudal block with 4 mg x kg-1 (1.6 ml x kg-1) of bupivacaine 0.25% in children undergoing surgical correction of congenital pyloric stenosis

BACKGROUND

Since 1970, bupivacaine 0.25% in a dose of 4 mg x kg-1 (1.6 ml x kg-1) has been used at the Hospital Infantil de México for caudal block in children undergoing surgical correction of congenital pyloric stenosis (CPS). Although this dose is considered unsafe, in our experience, it has been associated with a high success rate and a low incidence of adverse events. This experience has not been previously documented.

METHODS

A retrospective cohort of patients undergoing surgical correction of CPS was studied. Nineteen patients received general anaesthesia while 223 received caudal block. The latter were then grouped according to the sedation technique. The rate of successful caudal blocks and complications were considered the major outcomes of the study, whereas the postsurgical fasting period and hospital stay were considered secondary outcomes.

RESULTS

The rate of success of caudal block was 96%. Anaesthetic complications related to bupivacaine were present in 1.3%. Mortality occurred in the postoperatory period in one septic patient who also was suffering from gastroschisis that required general anaesthesia. Postoperatory fasting period and hospital stay tended to be higher with general anaesthesia than caudal block. However, of the 19 patients receiving general anaesthesia, five suffered serious comorbidity and nine were failed caudal blocks.

CONCLUSIONS

Caudal block with bupivacaine 0.25% (4 mg x kg-1) was associated with a low rate of anaesthetic complications. Further prospective studies to clarify the risks and benefits are required.

The caudal catheter in neonates: where are the restrictions?

PURPOSE OF REVIEW

In neonates, epidural catheters inserted at the sacral hiatus can easily be advanced to a lumbar or thoracic level. These 'caudal catheters' are popular because they allow the neonate to benefit from epidural analgesia without the concerns of spinal cord injury potentially associated with primary thoracic placement in an asleep neonate. This review looks at use and benefits, and risks and complications of caudal epidural catheters in neonates.

RECENT FINDINGS

Restrictions of neonatal caudal catheters are related to risks associated with placement and advancement of the catheters, infectious risks of caudal catheters, and toxicity risks related to the higher free fraction and lower clearance of bupivacaine in neonates. Caudal catheters in neonates are popular, but evidence that they improve outcome is lacking.

SUMMARY

Epidural anesthesia and analgesia for neonates should be performed and managed by pediatric anesthesiologists. Potential risks and complications must be appreciated and all steps to maximize safety of the technique must be taken. In particular, close postoperative observation and pain service management are indispensable. Future research should investigate the risks of caudal and segmentally placed catheters in neonates, study the role of epidural analgesia in outcome improvement for neonates, and guide us to safer use of local anesthetics suitable for neonates with their pharmacologic immaturity.

Hérnia inguinal na infância

A persistência do conduto peritoniovaginal (CPV) pode se manifestar como hérnia inguinal indireta, hidrocele comunicante, cisto do cordão ou pela combinação de duas ou até três destas formas. A hérnia é muito comum na infância, seu número vem crescendo com a sobrevida cada vez maior de prematuros de baixo peso, e deve ser operada sem demora devido ao risco de encarceramento. Já o cisto e a hidrocele só serão operados após uma certa espera pela sua cura espontânea. São resumidos o quadro clínico e o diagnóstico de cada uma das três formas de apresentação. A irredutibilidade, seja o simples encarceramento ou o estrangulamento, é analisada, lembrando aspectos característicos da criança, como por exemplo o risco que corre o testículo. A técnica operatória na criança é centralizada na ligadura do conduto peritoniovaginal. A conduta a tomar em situações especiais, como o encontro de uma Síndrome de Testículos Feminizantes é descrita, assim como as variantes técnicas a serem empregadas nos casos mais difíceis. Os casos em que a operação não pode ser limitada à simples ligadura do saco são lembrados. A conduta terapêutica na hérnia irredutível é descrita. O problema de explorar ou não a região inguinal oposta, dada a freqüência com que a persistência do CPV é bilateral, é analisado, mostrando os parâmetros que podem nortear a conduta em cada caso, inclusive o uso da videolaparoscopia. Finalmente, são revistas as complicações peculiares à cirurgia da hérnia na criança, lembrando que a recidiva é muito menos freqüente que no adulto.