A pilot study of dexmedetomidine sedation and caudal anesthesia for inguinal hernia repair in infants

Scoping review finds insufficient evidence on potential risks of procedural sedation with dexmedetomidine in children

AIM

Dexmedetomidine is commonly used in hospitals for sedation during procedurals. It has been considered safe even though studies have shown that it may cause bradycardia and hypotension. The aim of this study was to map the current evidence regarding potential risks of sedation of children with dexmedetomidine.

METHODS

Two database searches were conducted to gather all articles published through 30 January 2024 that matched the inclusion criteria. PubMed and Embase were chosen for the initial search. Search terms were chosen to create a broad systematic search that would include articles reporting adverse events during procedural sedation on children. From the included articles, data on type of sedation, administration, patient characteristics, endpoints and number of adverse events were collected.

RESULTS

After the initial search, 357 individual papers were screened and 41 papers were included. The most common adverse event reported was bradycardia. In almost 40% of the articles that measured oxygen saturation, one or more incidents of desaturation occurred. 27% reported that interventions to prevent further harm were preformed, most of the interventions were to improve oxygenation.

CONCLUSION

There is a need for further investigation regarding adverse events, especially respiratory adverse events during sedation with dexmedetomidine.

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.

Anesthetic management of inguinal hernia in an ex-premature infant with subglottic stenosis: a case report

BACKGROUND

We report the anesthetic management of inguinal hernia repair for an infant with subglottic stenosis. A previously scheduled operation had been cancelled due to unexpected airway trouble during the induction.

CASE PRESENTATION

A boy was born at 24 weeks of gestation and his trachea was intubated for 45 days. At 16 months old, surgery for inguinal hernia was planned, but cancelled due to unexpected narrow airway, and subglottic stenosis was first suspected. At 17 months old, he was transferred to us for inguinal hernia surgery. After careful discussion between the surgical team and the anesthesiologists, a strategy to manage this patient was developed. He underwent open hernia surgery under spinal anesthesia and diagnostic rigid bronchoscopy under tubeless general anesthesia separately, which revealed low-grade stenosis and some subglottic cysts. The postoperative course was uneventful.

CONCLUSION

Interdepartmental discussion weighing risks and benefits may deduce the safest and most appropriate anesthesia method.

Dexmedetomidine - An emerging option for sedation in neonatal patients

Dexmedetomidine is a sedative agent with limited dosing, safety, and efficacy information in the neonatal population. This comprehensive review describes the available evidence summarizing the use of dexmedetomidine in various neonatal populations. We identified 21 studies and 1 case report supporting the efficacy and short-term safety of DEX in neonates. Reported dosing ranges from 0.5-1.5 mcg/kg/h with or without loading doses. Clinically relevant adverse effects include bradycardia and hypotension. Future studies are needed to determine long-term safety and facilitate clinical applicability.

Spinal anesthesia for muscle biopsy in an infant with a suspected neuromuscular disorder: a case report

Background

Neuromuscular disorders (NMDs) occur in different forms and are generally diagnosed using muscle biopsy. Among the available anesthetic management options for infants with a suspected NMD are general anesthesia (GA) and regional anesthesia (RA), including spinal anesthesia (SA). Anesthesia selection is often challenging from the point of potential airway risks and anesthetic drug-related complications.

Case presentation

A 6-month-old male infant repeatedly underwent endotracheal intubation and extubation after birth because of respiratory muscle weakness and copious secretions. He was suspected of having NMD and was scheduled for muscle biopsy. His generalized hypotonia and decreased respiratory function presented a potentially difficult airway and complicated the selection of an appropriate anesthetic method. We selected SA and dexmedetomidine, which are safe for infants.

Conclusion

We report the successful and effective anesthetic management of SA and dexmedetomidine in an infant with a suspected NMD.

Research progress and treatment strategies for anesthetic neurotoxicity

Every year, a large number of infants and young children worldwide are administered general anesthesia. Whether general anesthesia adversely affects the intellectual development and cognitive function of children at a later date remains controversial. Many animal experiments have shown that general anesthetics can cause nerve damage during development, affect synaptic plasticity, and induce apoptosis, and finally affect learning and memory function in adulthood. The neurotoxicity of pediatric anesthetics (PAN) has received extensive attention in the field of anesthesia, which has been listed as a potential problem affecting public health by NFDA of the United States. Previous studies on rodents and non-human primates indicate that inhalation of anesthetics early after birth can induce long-term and sustained impairment of learning and memory function, as well as changes in brain function. Many anti-oxidant drugs, dexmedetomidine, as well as a rich living environment and exercise have been proven to reduce the neurotoxicity of anesthetics. In this paper, we summarize the research progress, molecular mechanisms and current intervention measures of anesthetic neurotoxicity.

Postoperative emergence agitation and intraoperative sevoflurane sedation under caudal block in children: a randomized comparison of two sevoflurane doses

BACKGROUND

Sub-umbilical surgery under caudal block in conjunction with sevoflurane sedation may be safe in terms of maintaining spontaneous breathing and avoiding complications associated with general anesthesia. However, sevoflurane-induced emergence agitation (EA) continues to be a clinically important phenomenon in children. To compare the incidence of EA in children undergoing sub-umbilical surgery under caudal block with two different doses of sevoflurane.

METHODS

Forty children (aged 1-5 years) scheduled to undergo inguinal hernia repair under caudal block with sevoflurane sedation via a face mask were randomized into either the low-dose (1.0%) end-tidal sevoflurane concentration group (Group LS) or the high-dose (2.5%) end-tidal sevoflurane concentration group (Group HS). We monitored EA episodes at 5 and 30 min in the post-anesthetic care unit (PACU) by using the fourpoint agitation scale and the Pediatric Anesthesia Emergence Delirium (PAED) scale.

RESULTS

The four-point agitation scale scores and PAED scores were not different between the groups at 5 min. However, the agitation score was higher in Group HS than in Group LS at 30 min after arriving in the PACU. The time required to recover from sedation was longer in Group HS than in Group LS.

CONCLUSIONS

Face-mask sedation with 1.0% sevoflurane in conjunction with caudal block may be more effective than that with 2.5% sevoflurane in preventing EA.

Effects of adding dexmedetomidine to local infiltration of bupivacaine on postoperative pain in pediatric herniorrhaphy: a randomized clinical trial

Background

Postoperative pain is a major problem, especially in children, as their tolerance level is lower and several drugs are contraindicated in childhood. This study aimed to compare the effect of dexmedetomidine added to local infiltration of bupivacaine for postoperative pain relief in children undergoing inguinal herniorrhaphy.

Methods

This double-blind, randomized clinical trial included 60 children aged 6–72 months undergoing unilateral herniorrhaphy at selected hospitals in Shiraz, Iran, randomly allocated into two groups, 30 in each group. One group received 1 µg/kg dexmedetomidine plus local infiltration of 0.2 ml/kg bupivacaine 0.5% at the incision site before surgery (BD), and the other group received bupivacaine and normal saline (BO). Analgesic requirements, emergence time, and nausea/vomiting, postoperative pain and sedation scores were assessed for 4 h after the operation. Heart rate (HR), systolic blood pressure (SBP), and oxygen saturation (SaO₂) were recorded at baseline, and at 10 and 20 min after injection.

Results

Eighty percent were boy in each group; mean age was 22.75 ± 18.63 months. SaO₂ and SBP were not different between the groups, while HR was significantly lower in the Group BD at 10 and 20 min after injection (P < 0.05). Group BD had a lower pain score at 1 and 2 h after the operation, a higher sedation score at the first three time intervals, and longer emergence time than Group BO (all P < 0.001). Group BD had a lower pain score at 1 and 2 h after the operation (P < 0.001, P < 0.047 respectively).

Conclusions

Addition of dexmedetomidine to local infiltration of bupivacaine in children undergoing herniorrhaphy significantly reduced postoperative pain and increased sedation.

Practicalities of Total Intravenous Anesthesia and Target-controlled Infusion in Children

Propofol administered in conjunction with an opioid such as remifentanil is used to provide total intravenous anesthesia for children. Drugs can be given as infusion controlled manually by the physician or as automated target-controlled infusion that targets plasma or effect site. Smart pumps programmed with pharmacokinetic parameter estimates administer drugs to a preset plasma concentration. A linking rate constant parameter (keo) allows estimation of effect site concentration. There are two parameter sets, named after the first author describing them, that are commonly used in pediatric target-controlled infusion for propofol (Absalom and Kataria) and one for remifentanil (Minto). Propofol validation studies suggest that these parameter estimates are satisfactory for the majority of children. Recommended target concentrations for both propofol and remifentanil depend on the type of surgery, the degree of surgical stimulation, the use of local anesthetic blocks, and the ventilatory status of the patient. The use of processed electroencephalographic monitoring is helpful in pediatric total intravenous anesthesia and target-controlled infusion anesthesia, particularly in the presence of neuromuscular blockade.

Randomised controlled trial of dexmedetomidine sedation vs general anaesthesia for inguinal hernia surgery on perioperative outcomes in infants

BACKGROUND

Neonates and infants undergoing general anaesthesia for hernia surgery are at risk of perioperative cardiorespiratory adverse events. The use of regional anaesthesia with dexmedetomidine preserves airway tone and may potentially avoid these complications. This study compares the perioperative conditions and adverse events between dexmedetomidine sedation with caudal block and general anaesthesia with caudal block for inguinal hernia surgery in infants.

METHODS

A randomised controlled trial was conducted in a tertiary hospital in Singapore involving 104 infants younger than 3 months, who were randomised to receive either dexmedetomidine sedation (DEX) with caudal block or general sevoflurane anaesthesia with tracheal intubation and caudal block (GA) for inguinal hernia surgery. Perioperative conditions, haemodynamics and adverse events were compared between groups.

RESULTS

Fifty-one infants received DEX and 48 infants received GA. In the DEX group, 46 infants (90.2%) had their operations completed solely under this technique, two (3.9%) were converted to general anaesthesia with intubation, and three (5.9%) required brief administration of nitrous oxide or low-dose sevoflurane. Overall, 96.1% of infants in the DEX group did not require intubation. Perioperative conditions were similar in both groups. The DEX group had significantly lower heart rates and higher mean arterial pressures intraoperatively. Two infants in the DEX group (3.9%) required postoperative intensive care admission compared with six infants (12.5%) in the GA group.

CONCLUSIONS

Dexmedetomidine sedation with caudal block provides a feasible alternative to general anaesthesia in infants undergoing hernia surgery. This technique avoids the need for tracheal intubation, which may be beneficial in neonates.

CLINICAL TRIAL REGISTRATION

NCT02559102.

Neurotoxicity of anesthetic drugs: an update

PURPOSE OF REVIEW

This article reviews the most recently published evidence that investigated anesthesia-induced neurotoxicity in both animals and humans, especially as it pertains to the perinatal period.

RECENT FINDINGS

Several recent studies have focused on better understanding the complex mechanisms that underlie intravenous and volatile anesthesia-induced neurotoxicity in animals. Adjuvant agents that target these pathways have been investigated for their effectiveness in attenuating the neuroapoptosis and neurocognitive deficits that result from anesthesia exposure, including dexmedetomidine, rutin, vitamin C, tumor necrosis factor α, lithium, apocynin, carreic acid phenethyl ester. Five clinical studies, including one randomized control trial, provided inconsistent evidence on anesthesia-induced neurotoxicity in humans.

SUMMARY

Despite a growing body of preclinical studies that have demonstrated anesthesia-induced neurotoxic effects in the developing and aging brain, their effects on the human brain remains to be determined. The performance of large-scale human studies is limited by several important factors, and noninvasive biomarkers and neuroimaging modalities should be employed to define the injury phenotypes that reflect anesthesia-induced neurotoxicity. Ultimately, the use of these modalities may provide new insights into whether the concerns of anesthetics are justified in humans.

Effects of dexmedetomidine versus midazolam for premedication in paediatric anaesthesia with sevoflurane: A meta-analysis

Background Dexmedetomidine (DEX), an α₂-adrenergic receptor agonist, produces ideal sedation and early postoperative recovery for premedication in paediatric surgery, reducing preoperative anxiety and facilitating smooth induction of anaesthesia. We performed a meta-analysis to compare the effects of DEX and midazolam (MDZ) in paediatric anaesthesia with sevoflurane. Methods PubMed, Ovid, Web of Science, and Public Health Management Corporation were searched through December 2016 for randomized controlled trials (RCTs) that compared DEX and MDZ in children undergoing sevoflurane anaesthesia. The risk ratio (RR) with 95% incidence interval (95%CI) was used for dichotomous variables. Results Twelve RCTs involving 422 patients in the DEX group and 448 patients in the MDZ group were included. Patients in the DEX group had a significantly lower incidence of unsatisfactory sedation (RR [95%CI] = 0.71 [0.57-0.89]), unsatisfactory parental separation (RR [95%CI] = 0.56 [0.35-0.87]), and rescue analgesia (RR [95%CI] = 0.52 [0.35-0.77]) than patients in the MDZ group. However, both groups had a similar incidence of unsatisfactory mask acceptance, emergence agitation, and postoperative nausea and vomiting. Conclusion Compared with MDZ, DEX is beneficial in paediatric anaesthesia with sevoflurane because of its lower incidence of unsatisfactory sedation, parental separation, and rescue analgesia.