Anesthetic management for pediatric strabismus surgery: Continuing professional development

Efficacy of the Subtenon Block in Children Undergoing Strabismus Surgery: A Systematic Review and Meta-Analysis

PURPOSE

To investigate the efficacy of the subtenon block in preventing postoperative complications in children undergoing strabismus surgery.

DESIGN

Systematic review and meta-analysis.

METHODS

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, Scopus, Web of Science, and clinicaltrials.gov. All randomized controlled trials investigating the efficacy of the subtenon block in children undergoing strabismus surgery were included. Outcomes included severity of pain after surgery, number of children requiring postoperative opioid and nonopioid analgesia, and the incidences of postoperative nausea and vomiting, oculocardiac events, and block-related complications. We pooled continuous outcomes using a random-effects model to calculate the mean difference (MD) and/or standardized MD and corresponding 95% confidence intervals (CI). Dichotomous outcomes were pooled using a random-effect model to calculate the relative risk (RR) and corresponding 95% CI. Risk of bias was assessed using the Cochrane Risk of Bias instrument and quality of evidence was assessed using a Grading of Recommendations Assessment, Development, and Evaluation approach.

RESULTS

Nine randomized controlled trials (607 participants) were included. We found evidence for an effect of the subtenon block in reducing pain at 20 to 40 minutes after surgery (MD -1.9, 95% CI -2.2 to -1.5; high-quality evidence) and on admission to PACU (MD -1.8, 95% CI -2.2 to -1.4; moderate-quality evidence); however, there was no difference in pain scores at 6 hours after surgery. In addition, evidence was found that the subtenon block decreased the number of children requiring postoperative opioid (RR 0.59, 95% CI 0.37-0.92; high-quality evidence) and nonopioid (RR 0.52, 95% CI 0.27-0.98; moderate-quality evidence) analgesia, and the incidences of postoperative vomiting (RR 0.31, 95% CI 0.12-0.7; high-quality evidence) and intraoperative oculocardiac events (RR 0.40, 95% CI 0.26-0.60; high-quality evidence). Other secondary outcomes had low or moderate-quality evidence. Risk of bias was low in six trials and high in three. There were no reports of block-related complications.

CONCLUSIONS

Our findings suggest that the subtenon block reduces the severity of early postoperative pain and the incidences of postoperative vomiting and intraoperative oculocardiac events compared with controls in children undergoing strabismus surgery.

REVIEW REGISTRATION

PROSPERO (CRD42015025443).

Post-operative vomiting after pediatric strabismus surgery: A comparison of propofol versus sevoflurane anaesthesia

Background and Aims

Squint surgery is a risk factor for postoperative vomiting (POV) in children. This study was designed to compare the incidence of POV in children undergoing strabismus surgery under balanced anesthesia with sevoflurane versus intravenous anesthesia with propofol.

Material and Methods

In this prospective randomized controlled study conducted in a tertiary care ophthalmology hospital, 70 ASA I-II children aged 1-12 years undergoing strabismus surgery were randomized to two groups -Group S (sevoflurane-based anesthesia) and Group P (propofol-based anesthesia) for maintenance. The surgical details, intraoperative hemodynamic parameters, recovery characteristics, and emergence delirium were recorded. Any episode of postoperative vomiting in the 0-2 hours, 2-6 hours, and 6-24 hours period was noted. Rescue antiemetic was administered if there was more than one episode of vomiting.

Results

Both the groups were similar with respect to demographic and surgical details. The average duration of surgery was 118.2 ± 41.88 min in group S and 137.32 ± 39.09 min in group P (P = .05). Four children in group S (11.4%) and one child in group P (2.9%) had POV in the first 24 hours but this was not statistically significant (P = .36). The median time to discharge from post anesthesia care unit was significantly less (P = .02) in the P group (50 min) than in the S group (60 min).

Conclusion

Propofol-based anesthesia does not offer advantage over sevoflurane, in reducing POV after squint surgery, when dual prophylaxis with dexamethasone and ondansetron is administered. It, however, reduces the duration of stay in the post anesthesia care unit.

Efficacy of tetracaine eye drops in strabismus surgery: a systematic review and meta-analysis of randomized controlled trials

AIM

To comprehensively evaluate the efficacy and safety profile of tetracaine eye drops as a local anesthetic agent among pediatric patients undergoing for strabismus surgery.

METHODS

We systemically searched four electronic databases (PubMed, Scopus, Web of Science, and Cochrane Library) from inception until April 2023. We included randomized controlled trials (RCTs) comparing tetracaine and placebo or no intervention for intraoperative and postoperative outcomes in strabismus surgery patients. We used the Cochrane risk of bias-2 tool for the risk of bias assessment. Continuous variables were pooled as mean difference (MD) or standardized mean difference (SMD), and categorical variables were pooled as risk ratio (RR) with a 95% confidence interval (CI).

RESULTS

Six RCTs were included in the meta-analysis, with a total of 326 patients. There was no significant difference between the tetracaine and the control groups regarding the mean operative time (MD = -0.10 minutes, 95% CI [-3.79, 3.59], p = .96), the mean time to first analgesia (MD = -0.87 minutes, 95% CI [-11.15, 9.40], P = .87), the mean behavior score (SMD = -S0.48, 95% CI [-1.24, 0.28], p = .22), the rate of postoperative vomiting (RR = 1.27, 95% CI [0.62, 2.61], p = .52), or the number of additional analgesia (RR = 0.55, 95% CI [0.27, 1.13], p = .10).

CONCLUSION

Our systematic review and meta-analysis found no significant differences in the safety and efficacy of tetracaine eye drops for strabismus surgery when compared to placebo or no intervention. Further investigation is needed to establish the best local anesthetic for strabismus surgery.

Effect of Ice Slush on Reducing the Oculocardiac Reflex During Strabismus Surgery

BACKGROUND

The aim of this study was to explore whether ice slush (IS) causing local hypothermia can effectively inhibit the oculocardiac reflex (OCR) during strabismus surgery.

METHODS

This prospective, randomized, double-blind study included 58 patients with concomitant strabismus scheduled for lateral rectus (LR) recession under general anesthesia. Patients were randomly allocated to receive IS (IS group) or standard treatment (control group) with sterile saline at room temperature before surgery. OCR was defined as a sudden decrease in heart rate (HR) of >15% from baseline. If one incidence of the OCR was found in 1 patient in any stage (0/I/II/III), the patient was defined as an OCR responder, and the incidence of overall OCR was the incidence of OCR responders. The primary outcome was the incidence of overall OCR during all stages of the surgery, which was analyzed by the Z test and computed based on the absolute risk difference with 2-sided 95% confidence intervals (CIs) using the Newcombe method.

RESULTS

The overall OCR occurred in 19 of 29 patients (62.5% [95% CI, 45.7-82.1]) in the IS group and 28 of 29 patients (96.6% [95% CI, 82.2-99.9]) in the control group (absolute risk difference, -31.0% [95% CI, -49.4 to -11.0]; Z test, P < .001), which demonstrated that the incidence of overall OCR in IS group was significantly lower than that in the control group.

CONCLUSIONS

IS on the ocular surface causing local hypothermia is a promising and easily accessible method to reduce the overall OCR, which can improve the safety of strabismus surgery.

Hydroxyzine Dihydrochloride Premedication Is a Necessity for Pediatric Patients Undergoing Strabismus Surgery: An Observational Prospective Clinical Trial

Objective

In this single-blind, observational prospective clinical trial, we aimed to determine and compare the effects of premedication with hydroxyzine plus midazolam and midazolam alone on the incidence of oculocardiac reflex (OCR).

Methods

Forty-five patients were divided into three groups. Group M received 0.5 mg/kg midazolam alone, Group H received 0.5 mg/kg hydroxyzine plus 0.5 mg/kg midazolam, and Group HM received 1 mg/kg hydroxyzine plus 0.5 mg/kg midazolam. The Ramsay Sedation Scale (RSS), the heart rates (HR1: after induction of anesthesia; HR2: before retraction of orbital muscle; and HR3: right after retraction of orbital muscle), the muscles with OCR, and the incidence of OCR (20% decrease of the HR right after the traction) were recorded and compared between the three groups.

Results

The mean HR1, HR2, and HR3 values were significantly increased (p=0.002, p < 0.001, p < 0.001) and the incidence of OCR (p=0.004) was significantly decreased in Group H and in Group HM (for all, p < 0.01) compared to Group M. The most common orbital muscle in which OCR occurred was the rectus medialis.

Conclusion

Premedication with a combination of 0.5 or 1 mg hydroxyzine with 0.5 mg midazolam significantly reduced the incidence of OCR compared to premedication with midazolam alone. This study was registered on https://clinicaltrials.gov/ with number NCT03806270.

The association between surgical technique and oculocardiac reflex in pediatric strabismus surgery: an observational study

Background and objectives

The most common cause of oculocardiac reflex (OCR) is traction of the extraocular muscles. Therefore, strabismus surgery is highly risk for the development of this complication. This study aimed to investigate whether an association exists between the occurrence of OCR and the type of extraocular muscle manipulated during strabismus in a pediatric population.

Methods

A total of 53 pediatric patients who were operated for strabismus under sevoflurane anesthesia were enrolled in this prospective study. The association between surgical techniques and the occurrence of OCR was investigated.

Results

This study included 30 (56.6%) males and 23 (43.4%) females, with a mean age of 8.4 years. Overall, 83 eyes with 93 extraocular muscles were operated. Surgery was performed most frequently on the medial (44.6%) and lateral (36.1%) recti. OCR occurred in 33 (62.3%) patients. OCR was found to be significantly higher in the first operated muscle compared with the second muscle, regardless of muscle type, as identified in the statistical analysis based on the sequence of the operated muscles.

Conclusions

The manipulation of the first extraocular muscle has a higher risk of OCR in the pediatric population undergoing two-muscle surgery for strabismus.

Penehyclidine mitigates postoperative nausea and vomiting and intraoperative oculocardiac reflex in patients undergoing strabismus surgery: a prospective, randomized, double-blind comparison

Background

Postoperative nausea and vomiting (PONV) is one of the most frequent complications following strabismus surgery. Penehyclidine, an anticholinergic agent, is widely used as premedication. This study investigated the effect of preoperative penehyclidine on PONV in patients undergoing strabismus surgery.

Methods

In this prospective, randomized, double-blind study, patients scheduled for strabismus surgery under general anesthesia were randomly assigned to either penehyclidine (n = 114) or normal saline (n = 104) group. Penehyclidine was administrated immediately after anesthesia induction, and normal saline was substituted as control. PONV was investigated from 0 to 48 h after surgery. Intraoperative oculocardiac reflex (OCR) was also recorded.

Results

Compared with normal saline, penehyclidine significantly reduced PONV incidence (30.7% vs. 54.8%, P < 0.01) and mitigated PONV severity as indicated by severity scoring (P < 0.01). Compared with normal saline, penehyclidine also significantly reduced OCR incidence (57.9% vs. 77.9%, P < 0.01) and mitigated OCR severity, as indicated by the requirement for atropine rescue (77.3% vs. 90.1%, P < 0.05) and the maximum decrease of heart rate during OCR (23.1 ± 9.4 bpm vs. 27.3 ± 12.4 bpm, P < 0.05). The recovery course did not differ between groups.

Conclusions

Penehyclidine administrated after anesthesia induction significantly reduced the incidence of PONV and alleviated intraoperative OCR in patients undergoing strabismus surgery.

Trial registration

ClinicalTrials.gov (NCT04054479). Retrospectively registered August 13, 2019.

Comparison of endotracheal intubation, laryngeal mask airway, and I-gel in children undergoing strabismus surgery

Background

Insertion of the advanced airway during induction of general anesthesia can cause undesirable sympathetic stimulation such as increased intraocular pressure (IOP) and hemodynamic parameters. In this study, we compared insertion of three different advanced airway devices; endotracheal tube (ETT), laryngeal mask airway (LMA) and I-gel in terms of IOP, hemodynamic changes and postoperative nausea and vomiting (PONV) following induction of general anesthesia with propofol and remifentanil in children undergoing strabismus surgery.

Materials and Methods

A total of 90 children (5.68 ± 1.49 years old) were randomly assigned to one of the three groups, ETT, LMA, or I-gel insertion as advanced airway devices IOP and also hemodynamic variables were measured before (T0 and T1) and immediately after (T2) the insertion of these airway devices, although 2 min (T3) and 5 min (T4) after it. PONV was assessed about 2 h after the completion of surgery in the recovery room.

Results

The mean arterial pressure (MAP), IOP, and systolic and diastolic blood pressures were significantly different between the three groups immediately (T2), 2 min (T3), and 5 min (T4) after the insertion of airway devices. The heart rate (HR) was significantly different between the three groups in all measurement times except of T0. Within-group comparisons showed that the three groups had significant changes in MAP, IOP, HR, systolic and diastolic pressure before and after airway insertion (T1 and T2). The trend in the LMA and ETT groups was descending-ascending-descending, whereas in the I-gel group, it was quite descending. There was no significant difference among the three groups in terms of PONV.

Conclusion

As a result, our study showed that, compared with LMA and ETT, the I-gel had less impact on undesirable stress responses and seems to be superior to LMA and ETT in children undergoing strabismus surgery.

Desflurane anesthesia compared with total intravenous anesthesia on anesthesia-controlled operating room time in ambulatory surgery following strabotomy: a randomized controlled study

BACKGROUND

Ophthalmic ambulatory surgery is preferred to be performed under general anesthesia either by total intravenous anesthesia (TIVA) or by inhalational anesthesia to increase the patient comfort. However, anesthesia-controlled time (ACT) can cause increased non-operative operating room (OR) time which may adversely affect the ORs efficiency. This study was aimed to compare the ACT of desflurane with that of propofol-remifentanil in strabismus ambulatory surgery.

METHODS

From November 2016 to December 2017, a total of 200 strabismus patients (aged 18-60 years old, and scheduled for elective ambulatory surgery at Zhongshan Ophthalmic Center) were randomly assigned to receive either propofol-based TIVA (group TIVA) or desflurane anesthesia (group DES) for maintenance of anesthesia. The primary outcome was the extubation time. Secondary outcomes included surgical time, anesthetic time, OR exit time, and Phase I and II recovery time. The intraoperative incidences of hypotension, bradycardia and oculocardiac reflex (OCR), and the incidences of any post-operative complications were recorded. Mann-Whitney U test and Chi-square or Fisher exact tests were used to compare the two groups.

RESULTS

We found that the extubation time (5.5 [3.9-7.0] vs. 9.7 [8.5-11.4] min, P < 0.001) and the incidence of prolonged time to extubation (0 vs. 6%, P = 0.029) in the DES group were significantly decreased compared with those in the TIVA group. The patients in the DES group displayed shorter OR exit time as compared with that in the TIVA group (7.3 [5.5-8.7] vs. 10.8 [9.3-12.3] min, P < 0.001). The patients using desflurane exhibited more stable hemodynamics during surgery than the patients using propofol-based TIVA, as demonstrated by lower incidences of hypotension (1% vs. 22%, P < 0.001), bradycardia (2% vs. 13%, P = 0.002), and OCR (17% vs. 44%, P < 0.001).

CONCLUSION

DES enhanced the ophthalmic OR efficiency by reducing the extubation time and OR exit time, and provided more stable hemodynamics intra-operatively than TIVA in patients undergoing strabismus ambulatory surgery.

TRIAL REGISTRATION

ClinicalTrials.gov, No. NCT02922660; https://clinicaltrials.gov/ct2/show/NCT02922660?id=NCT02922660&draw=2&rank=1.

Postoperative Nausea and Vomiting in Pediatric Patients

Postoperative nausea and vomiting (PONV), postoperative vomiting (POV), post-discharge nausea and vomiting (PDNV), and opioid-induced nausea and vomiting (OINV) continue to be causes of pediatric morbidity, delay in discharge, and unplanned hospital admission. Research on the pathophysiology, risk assessment, and therapy for PDNV, OINV and pain therapy options in children has received increased attention. Multimodal pain management with the use of perioperative regional and opioid-sparing analgesia has helped decrease nausea and vomiting. Two common emetogenic surgical procedures in children are adenotonsillectomy and strabismus repair. Although PONV risk factors differ between adults and children, the approach to decrease baseline risk is similar. As PONV and POV are frequent in children, antiemetic prophylaxis should be considered for those at risk. A multimodal approach for antiemetic and pain therapy involves preoperative risk evaluation and stratification, antiemetic prophylaxis, and pain management with opioid-sparing medications and regional anesthesia. Useful antiemetics include dexamethasone and serotonin 5-hydroxytryptamine-3 (5-HT3) receptor antagonists such as ondansetron. Multimodal combination prophylactic therapy using two or three antiemetics from different drug classes and propofol total intravenous anesthesia should be considered for children at high PONV risk. "Enhanced recovery after surgery" protocols include a multimodal approach with preoperative preparation, adequate intravenous fluid hydration, opioid-sparing analgesia, and prophylactic antiemetics. PONV guidelines and management algorithms help provide effective postoperative care for pediatric patients.

Peribulbar anesthesia for strabismus surgery in adult patients

PURPOSE

To evaluate the efficacy and safety of peribulbar anesthesia during strabismus surgery.

METHODS

Medical records of patients undergoing strabismus surgery and peribulbar anesthesia were reviewed. The overall efficacy of peribulbar anesthesia was evaluated as requirement of supplemental peribulbar anesthesia, impossibility to perform eye muscles surgery due to inadequate efficacy of the block and peribulbar block complications that occurred up to 6 weeks postoperatively. Presence of oculocardiac reflex (OCR) and presence of decreased visual acuity and afferent pupillary defect postoperatively were reported.

RESULTS

A total of 510 patients comprised our study group. The total amount of peribulbar injections was 717. Four patients (0.7%) required supplemental injection in the superonasal quadrant. Five of 510 (0.9%) required an anesthesiologic intervention with intravenous atropine. Eighty patients of 510 (15.6%) complained about transitory complete ptosis and/or amaurosis postoperatively. No complications were observed up to 6 weeks postoperatively.

CONCLUSION

Peribulbar anesthesia was an effective and safe option during strabismus surgery in adult patients.

Use of neuromuscular blocking drugs in strabismus surgery: systematic review and ophthalmology survey study

OBJECTIVE

Nondepolarizing neuromuscular blocking drugs have been advocated for accurate forced duction testing (FDT) during strabismus surgery. The purpose of this study was to evaluate the literature on use of muscle relaxants (MRs) in strabismus surgery and to evaluate the current practice of pediatric ophthalmologists.

DESIGN

Systematic review and survey study.

PARTICIPANTS

Seventy-seven pediatric ophthalmologists.

METHODS

MEDLINE, EMBASE, CENTRAL, Web of Science, and OpenGrey were searched to August 2019. Reporting followed the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines. Primary studies on depolarizing or nondepolarizing MRs in patients undergoing strabismus surgery were included. Primary outcomes included indications and prevalence of use. A 23-question survey was emailed to pediatric ophthalmologists worldwide to collect practice pattern information involving MRs in strabismus surgery.

RESULTS

Three studies were included in the systematic review. MRs were used in 34%-45% of patients undergoing strabismus surgery in one 1999 study for FDT. No evidence exists to support the use of MRs for facilitating FDT. Seven of 77 (9.1%) pediatric ophthalmologists requested MRs for FDT. Those who use MRs were more likely to be practicing outside the United States (p < 0.05) and in academic hospitals or private centres rather than in community settings. Drawbacks appeared to outweigh benefits, with the biggest drawback identified as increased turnover time between surgical cases (44%).

CONCLUSIONS

Inadequate evidence exists in the literature to support the use of nondepolarizing MRs to maintain paralysis of extraocular muscles during strabismus surgery, and this is an uncommon practice among pediatric ophthalmologists.

Prevalence of and covariates associated with the oculocardiac reflex occurring in dogs during enucleation

OBJECTIVE

To determine the prevalence of and covariates associated with the oculocardiac reflex (OCR) occurring in dogs during enucleations.

SAMPLE

145 dogs that underwent enucleation at 2 veterinary teaching hospitals between January 2010 and June 2015.

PROCEDURES

Information was collected from the medical records of included dogs regarding age and body weight at hospital admission, breed (for classification of brachycephalic status), and whether they had received anticholinergic drugs or a retrobulbar nerve block (RNB) prior to enucleation. An OCR was considered to have occurred if there was a sudden decrease of ≥ 30% in heart rate from the baseline value (mean heart rate prior to the sudden decrease) during surgery in the absence of intraoperative administration of opioids or α₂-adrenoceptor agonists. Associations were explored between the collected data and the prevalence of OCR by means of binomial logistic regression.

RESULTS

4.8% (7/145) of dogs had an OCR noted during enucleation. Dogs that received a preoperative RNB (n = 82) had significantly lower odds of an OCR being observed than dogs that received no preoperative RNB (OR, 0.12). No association with OCR was identified for age or brachycephalic conformation or for preoperative administration of anticholinergic drugs.

CONCLUSIONS AND CLINICAL RELEVANCE

These findings suggested that preoperative administration of an RNB, but not preoperative administration of anticholinergic drugs, was associated with a lower prevalence of OCR in dogs during enucleations.

Comparison of Ondansetron and Granisetron Effects for Prevention of Nausea and Vomiting Following Strabismus Surgery

BACKGROUND

Postoperative nausea and vomiting (PONV) is a common complaint after strabismus surgery that leads to unpleasantness, increased hospitalisation time and increased costs. In severe cases, it can lead to dehydration, electrolyte disturbances, aspiration, pneumonia, and even sutures opening.

AIM

This study was conducted to compare the effects of both ondansetron and granisetron on the reduction of PONV after strabismus surgery.

METHODS

This randomised, and the double-blind clinical study was conducted on patients with ASA I and II undergoing strabismus surgery with age over 3 years old in Shafa Hospital, Kerman University of Medical Sciences during 2017 under general anaesthesia. Patients with inclusion criteria were randomly assigned to one of three groups including Ondansetron (A), Granisetron (B) and control group (C). Matching cases and controls on drugs were fully completed. Furthermore, 100 μg/kg of Ondansetron was intravenously injected, followed by injection of 40 μg/kg Granisetron for another intervention group. All patients underwent the same anaesthetic procedure and intravenous injection of drugs during anaesthesia induction. The severity of nausea and vomiting in recovery, 6 and 18 hours after the operation were verified according to the Verbal Rating Scale (VRS). Our data were analysed by Chi-square, ANOVA and TUKEY tests via SPSS version 18.

RESULTS

There was no significant difference between the three groups in terms of age and sex. The incidence of postoperative nausea in recovery among three groups of A, B and C was determined to be 15, 7.5 and 37.5%, respectively. No significant difference was found between the two groups A and B (P = 0.68), although there was a significant difference between these two groups and group C (P < 0.05). The incidence of nausea at 6 hours after surgery in groups A, B and C was recorded as 40, 15 and 65% respectively, indicating that the incidence of nausea in group B was significantly lower than the other two groups, while showed a significant difference with group A (P = 0.039) and group C (P < 0.05). Also, the incident of nausea between groups was not statistically significant 18 hours after surgery (P < 0.05). Additionally, no significant difference was found in different groups in terms of vomiting incidence in recovery, 6 and 18 hours after surgery (P < 0.05).

CONCLUSION

Our study suggests that Granisetron is more effective in preventing PONV during 6 hours after the surgery in comparison with Ondansetron which makes it a favourable alternative for preventing PONV.

Anesthesia for pediatric ophthalmologic surgery

This review presents updated recommendations, based on existing clinical research, for anesthetic management of strabismus surgery in children. In children, unlike adults, eye surgery nearly always requires general anesthesia, even for brief procedures. Recommendations for preoperative anxiolysis, fasting guidelines, and management of upper respiratory infections are discussed. Airway considerations and the oculocardiac reflex are highlighted. The prevention of postoperative complications, including those related to opioid prescription therapy, is also addressed. Finally, given the 2016 warning from the Food and Drug Administration about anesthesia neurotoxicity in children, we discuss recent studies on anesthetic neurotoxicity in children undergoing general anesthesia.

Reduction of oculocardiac reflex with Tetracaine eye drop in strabismus surgery

INTRODUCTION

Recently, to reduce the incidence of oculocardiac reflex (OCR) in strabismus surgery, retrobulbar block and anticholinergic drugs or local anesthesia are also used. The present study evaluated the effects of Tetracaine eye drop as a topical nerve blocker on OCR during strabismus surgery.

METHODS AND MATERIALS

In this randomized trial, 70 strabismus surgery candidates were randomly divided into placebo or synthetic teardrop (E) and Tetracaine eye drop (T) groups, so 3 drops of each solution were dropped in four directions of patients' eye immediately after applying anesthesia and before surgery. The incidence and severity of OCR during the stages of muscle release and incision (cutting), hemodynamic changes, the required time for OCR recovery and atropine dose were assessed.

RESULTS

OCR was more seen in release phase compared to cutting phase. There were no significant differences between two group regarding the incidence and severity of OCR in the release phase (p > 0.05), but the incidence and severity of OCR in the cutting phase was more in group E than group T (p = 0.02, for both). The duration of OCR improvement (p-value = 0.74) and Atropine consumption (p-value = 0.92) did not differ between the groups.

CONCLUSION

Tetracaine eye drop only reduces the incidence and severity of OCR during the incision stage of strabismus surgery.

Sedated suture adjustment in children undergoing adjustable suture strabismus surgery

PURPOSE

To study methods and adverse events of postoperative, sedated suture adjustment after strabismus surgery in the post-anesthesia care unit (PACU).

METHODS

We reviewed the postoperative experience of all children ≤18 years of age undergoing adjustable suture strabismus surgery at Boston Children's Hospital over a 3-year period. Time in the hospital, adverse events, and surgical outcomes were reviewed to evaluate safety and healthcare resource utilization.

RESULTS

Of 356 patients, 113 required suture adjustment in the PACU, including 24 adjusted while awake and 89 adjusted under sedation. For sedation, sequential boluses of propofol were administered until adjustment was complete. Complete data from the sedated adjustment was available in 76 patients. The median initial bolus was 30 mg; the median total propofol rate was 273 mcg/kg/min. Twelve patients (16%) required only a single bolus of propofol. Of remaining 64 patients, median time from initial to final propofol dose was 7 minutes. Median anesthesiologist time in the PACU was 13 minutes. In the sedated adjustment group, there were no clinically significant adverse events, and the pain score never exceeded 6 (of a possible 10). Median duration of PACU stay was shortest in the group not requiring adjustment.

CONCLUSIONS

Sedated suture adjustment allows for fine-tuning of postoperative binocular alignment in children and uncooperative adults. No adverse events were observed in our study group, but the procedure does increase the time patients spend in the hospital. This work will inform disclosure of risks and benefits of sedated adjustment while allowing for more accurate assessment of the cost and quality of adjustable sutures in children.

[PONV after strabismus surgery : Risk adapted prophylaxis?]

BACKGROUND

Following strabismus surgery, patients frequently develop variable degrees of postoperative nausea and vomiting (PONV). These symptoms cause discomfort and result in serious complications such as intramuscular bleeding and subconjunctival hemorrhage. In children long lasting PONV can lead to and electrolyte imbalance and dehydration. A prolonged course of recovery is the consequence. For the hospital, PONV can also involve negative economic impacts because of a damaged public reputation of the institution. There is still an ongoing debate on wether prophylaxis of PONV is necessary and how the prophylaxis of PONV should be performed. On one hand, there are proponents of a liberal prophylaxis. These intend to treat almost all patients regardless of their individual risk for PONV. On the other hand, opponents point out that every medication has to be indicated individually. In their view, risk scores should be the base of a risk-adapted approach.

OBJECTIVES

The aim of the study was to reduce the frequency of PONV by using an anesthetic technique adapted to the individual risk for PONV. Until now, all trials studying the efficiency of a score-based antiemetic prophylaxis were performed on adult patients. In this study, a risk-adapted approach was evaluated on children for the first time.

PATIENTS AND METHODS

In 92 patients, the incidence of PONV was analyzed after strabismus surgery. Before surgery we evaluated the risk factors for PONV according to the POVOC score in children (n = 45, 49 %) and the Apfel's score in adults (n = 47, 51 %). Patients with 0-2 risk factors received a balanced anesthesia (n = 47, 51 %). Those with 3-4 risk factors were operated in total IV anesthesia (TIVA) with propofol (n = 45, 49 %). In addition, as an antiemetic prophylaxis, 0.15 mg/kg dexamethason and 0.1 mg/kg ondansetron were applied in the latter patients. we documented the symptoms and severity of PONV 2, 6 and 24 h after surgery by means of a standardized questionnaire for PONV (Wengritzky-Score).

RESULTS

The incidence of PONV was 17 % (n = 16) in all of the patients. The incidence in low-risk patients receiving a BA without prophylaxis were 21 % in adults and 38 % in children. Of the patients at high risk for PONV receiving the multimodal antiemetic approach 8 % (adults) and 9 % (children) suffered from PONV. The combination of TIVA and antiemetics could reduce the incidence of PONV compared to the predicted values in a clinically relevant manner (OR = 0.26, KI: 0.76-0.87).

CONCLUSION

The overall incidence could be reduced to a level below 20 %. Particularly in patients with a high risk of PONV, TIVA could clearly reduce the incidence. However, the incidence in patients with 2 risk factors is still high (30-39 %). Therefore, it is important to reconsider the effort involved with risk screening and individually adapting anesthesia. Risk stratification means a pre- and perioperative effort. Therefore, we advocate a more liberal approach for PONV prophylaxis.

Granisetron versus Granisetron-Dexamethasone for Prevention of Postoperative Nausea and Vomiting in Pediatric Strabismus Surgery: A Randomized Double-Blind Trial

Aim. Efficacy of granisetron and combination of granisetron and dexamethasone was evaluated for prevention of postoperative nausea and vomiting (PONV) in children undergoing elective strabismus surgery. Methods. A total of 136 children (1–15 years) were included. Children received either granisetron (40 mcg/kg) [group G] or combination of granisetron (40 mcg/kg) and dexamethasone (150 mcg/kg) [group GD]. Intraoperative fentanyl requirement and incidence and severity of oculocardiac reflex were assessed. PONV severity was assessed for first 24 hours and if score was >2, it was treated with metoclopramide. Postoperative analgesia was administered with intravenous fentanyl and ibuprofen. Results. The demographic profile, muscles operated, and fentanyl requirement were comparable. Complete response to PONV in first 24 hours was observed in 75% (51/68) of children in group G and 76.9% (50/65) of children in group GD, which was comparable statistically (p = 0.96, Fisher exact test; OR 1.11, 95% CI 0.50, 2.46). Incidence of PONV between 0 and 24 hours was comparable. One child in group G required rescue antiemetic in first 24 hours and none of the children had severe PONV in group GD. There was no significant difference in incidence or severity of oculocardiac reflex. Conclusion. Dexamethasone did not increase efficacy of granisetron for prevention of PONV in elective pediatric strabismus surgery. Registration number of clinical trial was CTRI/2009/091/001000.

The effect of anesthesia depth on the oculocardiac reflex in strabismus surgery

The aim of this study was to investigate the effect of the bispectral index (BIS) guided depth of anesthesia to inhibition of the oculocardiac reflex (OCR) during pediatric strabismus surgery. Patients between the ages of 3 and 16 years who were scheduled for elective strabismus surgery were randomly assigned to two groups. In Group 1 (n: 32), the BIS values of the patients were maintained at <50; in Group 2 (n: 28), the BIS values of the patients were maintained at levels greater than or equal to 50 with 4-7 % desflurane in a 50 % O₂-air mixture by titrating the concentration during the surgery. The heart rates, presence of dysrhythmia, anticholinergic drug usage and the type of the operated extra ocular muscle were recorded. The incidence of OCR was 25 % in Groups 1 and 64.3 % in Group 2, (p < 0.05). Moreover, the incidence of OCR in group 2 was higher in medial rectus (MR) traction (78.9 %) than in lateral rectus (LR) traction (33.3 %) (p = 0.035), with no significant difference in Group 1 between MR (21.1 %) and LR (26.7 %) tractions (p = 0.83). We found that the lower BIS values are associated with the lower incidence of OCR in pediatric patients undergoing strabismus surgery. And our findings confirmed that the deeper anesthesia has a protective effect against the OCR.

Sub-Tenon block does not provide superior postoperative analgesia vs intravenous fentanyl in pediatric squint surgery

PURPOSE

We evaluated the efficacy of sub-Tenon block in decreasing perioperative pain, incidence of intraoperative oculocardiac reflex (OCR), and postoperative nausea and vomiting (PONV) in pediatric squint surgery.

METHODS

A total of 67 children age 2-12 years, American Society of Anesthesiologists Physical Status 1 and 2, were randomized to receive either sub-Tenon block (ST) in the operative eye or 2 mcg/kg of intravenous fentanyl (F) for squint surgery after induction of general anesthesia in this double-blind study. Postoperative pain was measured by either modified Children's Hospital of Eastern Ontario Pain Scale (CHEOPS) or Visual Analogue Scale (VAS). Pain in the postoperative period (up to 2 hours) was measured as the primary endpoint. Other parameters measured in the groups were intraoperative hemodynamics, postoperative modified CHEOPS or VAS at shifting, 1, 2, 6, 12, and 24 hours after surgery, incidence of intraoperative OCR, and PONV at shifting, 30 minutes, 1, 2, 6, 12, and 24 hours after surgery.

RESULTS

There was no statistical difference in the postoperative pain scores in the recovery room up to 2 hours after surgery. The VAS and CHEOPS scores were not different in the groups up to 24 hours after surgery. The incidence of OCR was significantly higher in group F than group ST. The incidence of PONV was significantly higher in group F than group ST at 30 minutes and 1 hour after the surgery (41%, 47% vs 19%, 9%, respectively, p<0.05). However, there was no statistically significant difference in intraoperative hemodynamics and PONV scores after 2 hours in the postanesthesia care unit.

CONCLUSIONS

Use of sub-Tenon block does not decrease the incidence of postoperative pain significantly in children undergoing squint surgery. However, it leads to a statistically significant decrease in the incidence of intraoperative OCR and PONV in the early recovery period in these patients.

Autonomic cardio-respiratory reflex reactions and superselective ophthalmic arterial chemotherapy for retinoblastoma

OBJECTIVE

To describe our experience with superselective ophthalmic artery chemotherapy (SOAC) in retinoblastoma and to report the serious adverse cardio-respiratory reactions we have observed.

METHODS

SOAC was performed using a standardized protocol for general anesthesia, ophthalmic artery catheterization, and pulsed infusion of melphalan. Adverse reactions were defined as those in which the patient required active treatment to maintain cardio-respiratory stability.

RESULTS

Between December 2008 and May 2012, 54 eyes in 52 patients were treated. 143 catheterization procedures were performed, with a technical success rate of 93% (n = 133). There were no deaths or major complications. Adverse cardio-respiratory reactions developed during 35 procedures (24%; 95% CI, 18-32%). All reactions occurred during second or subsequent catheterization procedures (39%; 95% CI, .29-49%) and were characterized by hypoxia, reduced lung compliance, systemic hypotension and bradycardia. Adverse events were successfully treated in all patients. One procedure was abandoned due to prolonged hemodynamic instability.

CONCLUSION

Adverse cardio-respiratory reactions are commonly observed in SOAC for retinoblastoma. We believe that the adverse clinical signs represent an autonomic reflex response, akin to the trigemino-cardiac or oculo-respiratory reflexes, and all patients should be considered at-risk. Reactions occur only during second or subsequent procedures and can be life-threatening. The routine use of intravenous atropine does not seem to have altered the incidence or severity of these reactions. Anesthetists and interventional neuroradiologists involved in SOAC must be vigilant to ensure adverse reactions, when they develop, are treated quickly and effectively.

Effect of ketamine and midazolam on oculocardiac reflex in pediatric strabismus surgery

Background

The oculocardiac reflex (OCR) can be elicited during manipulation of the orbital structures in the strabismus correction surgery. A sinus bradycardia is the most common manifestation of OCR; and cardiac dysrhythmia and asystole may also occur. Various efforts to reduce OCR have been attempted, but without coherent outcome results.

Methods

Sixty one children, undergoing elective strabismus surgery, were randomly allocated into 2 groups: Group K received ketamine 1.0 mg/kg; and Group M received midazolam 0.15 mg/kg for induction of anesthesia. Anesthesia was maintained with 1-1.3 MAC of sevoflurane with 50% N₂O in O₂. Heart rate and blood pressure were measured 30 seconds before extraocular muscle (EOM) traction and immediately after traction. The OCR was defined as a decrease in heart rate more than 20% of the baseline heart rate, following manipulating EOM. Postoperative nausea and vomiting (PONV) and emergence agitation (EA) were assessed in postanesthetic care unit (PACU).

Results

Blood pressure before tightening EOM in Group K was higher than that in Group M (P < 0.05). However Δ HR (2.7 ± 15% vs. - 0.9 ± 16%) and incidence of OCR (10.0% vs. 19.4%) after traction an EOM were not different between the two groups. The occurrence of PONV (6.7 vs. 9.7%) and EA (30.0% vs. 22.6%) were similar.

Conclusions

Ketamine does not reduce the incidence of OCR compared with midazolam in pediatric strabismus surgery. In addition, ketamine does not increase the incidence of PONV and EA. In conclusion, it is reliable to use ketamine in pediatric strabismus surgery.