The association between the oculocardiac reflex and post-operative vomiting in children undergoing strabismus surgery

The role of surgical factors eliciting oculocardiac reflex of patients undergoing orbital tumor surgery: a retrospective study

PURPOSE

Orbital tumors are an interdisciplinary disease, and surgery is one of the main treatment methods. The oculocardiac reflex (OCR) is a condition of surgery for orbital tumors. The aim of this study was to investigate whether there is an association between many surgical factors and the incidence of OCR in orbital tumor surgery.

METHODS

Comparisons were made between patients with and without OCR using the Mann-Whitney test, Fisher's exact test, and Chi-square test. When comparing multiple groups (groups > 2), to explain which two groups had differences, post hoc testing was used for analysis, and the differences between groups were judged according to the adjusted standardized residuals.

RESULTS

The results showed that the incidence of intraoperative OCR was different based on the different exposed operative field locations (p = 0.021). The OCR incidence in those with lesions involving the orbital apex and lesions adhering to extraocular muscles was higher than that of others (p < 0.001 and p = 0.003). In addition, multivariate logistic regression analysis revealed that orbital apex involvement and extraocular muscle adhesion were highly associated with a higher incidence of OCR (p < 0.001 and p = 0.013), while the operative field located in the lateral-superior orbit was highly associated with a lower incidence of OCR (p = 0.029).

CONCLUSION

In orbital tumor surgery under general anesthesia, lesions involving the orbital apex and lesion adhesion to the extraocular muscles were independent risk factors for OCR, and an operative field located in the lateral-superior orbit was a protective factor for OCR.

Acute Closed-Angle Glaucoma-an Ophthalmological Emergency

BACKGROUND

Acute closed-angle glaucoma has an incidence of 2.2-4.1 cases per 100 000 persons per year in Europe. It is an ophthalmological emergency in which markedly elevated intraocular pressure can damage vision permanently. Because the acute symptoms are not always clearly referable to the eyes, patients often present to physicians who are not ophthalmologists.

METHODS

This review is based on pertinent articles retrieved by a selective search in PubMed.

RESULTS

The diverse symptoms of acute closed-angle glaucoma include eye redness, worsening of vision and other visual disturbances, headache, and nausea. Acute closed-angle glaucoma has multiple causes. Not all predisposing factors have been definitively identified; above all, there are certain anatomical configurations of the eye that make it more likely to arise. The goals of treatment are to reduce the elevated intraocular pressure rapidly, which usually leads to marked symptom relief, as well as to eliminate the situation that led to closed-angle glaucoma. For proper treatment, the patient should be seen by an ophthalmologist without delay, on the day of symptom onset if possible.

CONCLUSION

Primary prevention of acute closed-angle glaucoma is not always possible. Even physicians who are not ophthalmologists can diagnose markedly elevated intraocular pressure by palpation of the globe. Proper, specific treatment can help patients rapidly and lastingly.

The Oculocardiac Reflex: A Review

BACKGROUND

A typical oculocardiac reflex (OCR) is a moderate trigemino-vagal bradycardia elicited by tension on an extraocular muscle (EOM) during strabismus surgery; however, many other orbital stimuli can elicit cardiac slowing including retinopathy of prematurity examination.

METHODS

World literature related to trigeminovagal and oculocardiac reflex covering over 15,000 patients including 51 randomized clinical trials and case reports are analyzed and reviewed. Under an ongoing observational trial in Alaska, anesthetic, patient and surgical influences on routine strabismus surgery using prospective, uniform EOM tension are compared seeking sufficient sample size to characterize this individually widely variable cardiac response.

RESULTS

With adequate sample size, and emphasizing clinical studies controlling type of EOM, muscle tension amount and duration, anticholinergic and opioid medications, the following augment OCR; rapid-acting opioids and dexmedetomidine while OCR is reduced in older patients, the right eye, less EOM tension, deeper inhaled agents, hypocarbia, anticholinergic medications and orbital block. In re-operations, the former are relatively poor predictors of subsequent OCR.

CONCLUSION

Profound bradycardia can occur in almost 10% of strabismus surgery cases without anticholinergic preventive measures, but reliable prediction of OCR remains elusive. With foreknowledge and careful anesthetic monitoring of the patient before EOM manipulation, residual adverse sequelae from OCR are fortunately very rare. Despite well over a century of experience, the teleology for this occasionally dramatic cardiac response to eye surgery is still not known.

Comparative Study of Retrobulbar Block versus Ketamine Infusion during Eye Enucleation/Evisceration (Randomized Controlled Trial)

Background

The aim of this study is to compare the safety and efficacy of retrobulbar block versus intraoperative ketamine infusion in eye enucleation or evisceration under general anesthesia.

Materials and Methods

Forty-five patients belonging to American Society of Anesthesiologists Physical Status I and II undergoing eye enucleation or evisceration were randomly allocated to three equal groups (15 patients each). General anesthesia was used as the standardized technique in all patients. Group R received a single retrobulbar injection, Group K received intravenous ketamine infusion, and Group C received normal saline with the same rate of ketamine infusion. Intraoperative heart rate and mean arterial pressure, recovery time, postoperative pain score, time to first rescue analgesic, number of patients who required rescue analgesia, and any adverse events were reported.

Results

Postoperative pain Visual Analog Scale was significantly lower in R and K groups in comparison to the C group and was significantly higher in K than R group at 3, 6, 12, and 24 h. In addition, the time to first rescue analgesic was significantly longer in R group (429 ± 54 min) than that in K group (272 ± 34 min), but compared to both groups, it was longer in C group (52 ± 7 min). In K group, the recovery time was longer with higher sedation score in comparison to the other two groups.

Conclusions

Single retrobulbar injection and low-dose ketamine infusion are safe and effective when used as adjuvants to general anesthesia, but retrobulbar block provides better control of postoperative pain with prolonged time to first rescue analgesic and reduced analgesic consumption.

Anaesthetic considerations for strabismus surgery in children and adults

Strabismus correction surgery is the most common eye operation in children. Adults have approximately a 4% lifetime risk of developing strabismus. Current treatment options include pharmacological injection of botulinum toxin or bupivacaine, conventional corrective surgery, adjustable suture surgery and minimally invasive surgery. Repeated surgery is common as each operation has a 60%-80% chance of successful correction. The benefits of early surgical correction in large-angle strabismus in children outweigh the risks of anaesthesia. General anaesthesia is suitable for patients of all age groups, for complicated or repeated surgery, and bilateral eye procedures. Regional ophthalmic block reduces the incidence of oculocardiac reflex and emergence agitation, and provides postoperative analgesia, but requires a cooperative patient as many experience discomfort. Topical anaesthesia has been used in pharmacological injection, minimally invasive surgery, uncomplicated conventional strabismus surgery and some adjustable suture strabismus surgery. Its use, however, is only limited to cooperative adult patients. Prophylactic antiemesis with both ondansetron and dexamethasone is recommended, especially for children. A multimodal analgesia approach, including paracetamol, intravenous non-steroidal anti-inflammatory drugs, topical local anaesthetic and minimal opioid usage, is recommended for postoperative analgesia, while a supplementary regional ophthalmic block is at the discretion of the team.

Association between convergence insufficiency and temporomandibular disorder cross-sectional study

OBJECTIVES

Evaluate whether there is an association between convergence insufficiency and temporomandibular disorder (TMD) and whether there is an association between pain and range of motion in different degrees of TMD.

METHODS

We evaluated 138 individuals with TMD and 46 without TMD using the Research Diagnostic Criteria for temporomandibular disorders, the Fonseca Anamnestic Index (FAI), Numeric Pain Rating Scale, and the measurement of mandibular range of motion (ROM). Convergence insufficiency was diagnosed using the convergence test and Convergence Insufficiency Symptom Survey. Analysis of variance was used to compare age and mandibular ROM. The Kruskal-Wallis was used to compare mandibular ROM and pain between groups. The chi-square test was used to evaluate associations between TMD subgroups and the FAI, sex, and ocular convergence.

RESULTS

The majority of individuals without TMD did not exhibit convergence insufficiency. The frequency convergence insufficiency was significantly higher among individuals with severe TMD (p < 0.003). Mean pain severity differed between individuals with and without TMD. Mandibular ROM diminished with the increase in TMD severity.

CONCLUSIONS

Convergence insufficiency, age, the increase in pain, and the reduction in mandibular range of motion were associated with the degrees of TMD severity. Despite the significant associations between convergence insufficiency and both pain and TMD severity, these variables cannot be indicated as predictive factors due to the low variability in the linear regression analysis.

CLINICAL RELEVANCE

The present findings can assist in decision making regarding the treatment of severe TMD and the evaluation of ocular convergence.

Does Topical Proparacaine Improve Postoperative Comfort After Strabismus Surgery?

Background

Strabismus surgery is often performed on children and adults as a quick-turnover, outpatient procedure under general anesthesia. Ideal methods to reduce post-operative pain and nausea are not yet perfected. We postulated that a simple topical anesthetic drop after surgery might help.

Methods

In a prospective study of oculocardiac reflex (OCR) and strabismus surgery, a cohort of ongoing patients either received proparacaine immediately post-op, or none. Co-variables were Intraoperative opioid and OCR, patient age, type of surgery. Several post-operative recovery outcome variables were prospectively monitored.

Results

Sixty strabismus surgery patients (age 15±22 years) received proparacaine 1% while another 80 (16.5±22 years) received none; both received topical antibiotic-steroid ointment. Pain and nausea (Likert scale) were not impacted by covariables complexity of case, age less than 3.5, OCR >33% drop, intraoperative opioid or neuro-status. Immediate post-op heart rate was lower if OCR >33% and if opioids used. Time until discharge was shorter in younger patients. Proparacaine did not impact outcome variables, except in patients younger than 3.5 years when post-op pain was worse.

Conclusion

Post-op topical anesthetic either produced no difference, or worsened post-op pain and recovery. This prospective study does not support the use of topical anesthetic drop to reduce post-strabismus pain and nausea.

Clinical trials registration

NCT03672435, Strabismus Recovery With Proparacaine and Oculocardiac Reflex (OCRprop).

Surgical factors affecting oculocardiac reflex during strabismus surgery

Background

To investigate surgical factors associated with the occurrence of oculocardiac reflex (OCR) and changes in heart rate (HR) during strabismus surgery.

Methods

Patients who underwent strabismus surgery under general anesthesia were enrolled in this study. The HR during surgery was measured at baseline, and at the following points during surgery: traction of the muscle, maximal increase after traction (adrenergic phase), and the cutting of the muscle. OCR was defined as an HR reduction of more than 20% at traction of the muscle, when compared to baseline HR. The HR at each stage during the surgery was compared between patients with and without OCR.

Results

A total of 162 operated muscles from 99 patients were enrolled. The incidence of OCR was 65% in patients. In patients with two muscle surgeries, there were significantly more OCRs in the first operated muscle than in the second operated muscle (p < 0.01). The difference in the decrease in HR in patients with OCR was significantly lower than that in patients without OCR at traction of the muscle, the adrenergic phase, and the cutting of the muscle (all, p < 0.01). The first operated muscle was a significant risk factor associated with the occurrence of OCR (OR = 3.95, p < 0.01).

Conclusion

The first operated muscle in patients with two muscle surgeries was a significant risk factor for OCR. Decreased HR at the traction of the muscle during surgery did not fully recover in patients with OCR.

Dental Occlusion and Ophthalmology: A Literature Review

Stomatognathic system is strictly correlated to other anatomical regions; many studies investigated relationship between temporomandibular joint and posture, several articles describe cranio-facial pain from dental causes, such as trigger points. Until now less interest has been given to connections between dental occlusion and ophthalmology, even if they are important and involving. Clinical experience in dental practice claims that mandibular latero-deviation is connected both to eye dominance and to defects of ocular convergence. The trigeminal nerve is the largest and most complex of the twelve cranial nerves. The trigeminal system represents the connection between somitic structures and those derived from the branchial arches, collecting the proprioception from both somitic structures and oculomotor muscles. The intermedius nucleus of the medulla is a small perihypoglossal brainstem nucleus, which acts to integrate information from the head and neck and relays it on to the nucleus of the solitary tract where autonomic responses are generated. This intriguing neurophysiological web led our research group to investigate anatomical and functional associations between dental occlusion and vision. In conclusion, nervous system and functional pathways strictly connect vision and dental occlusion, and in the future both dentists and oculists should be more and more aware of this correlation for a better diagnosis and therapy.

The oculocardiac reflex during strabismus surgery: its relationship to preoperative clinical eye findings and subsequent postoperative emesis

PURPOSE

To compare the occurrence of significant bradycardia due to the oculocardiac reflex (OCR) during strabismus surgery and its relationship to preoperative clinical eye findings and subsequent development of postoperative emesis.

METHODS

The medical records of consecutive patients who underwent strabismus surgery August 2006 to June 2009 were retrospectively reviewed. OCR was defined as presence of dysrhythmia or a sudden heart rate decrease ≥ 20% after traction on the extraocular muscle. OCR incidence was compared between the first, second, and third (if any) extraocular muscles in patients who had multiple-muscle strabismus surgery and also between specific muscles (eg, medial rectus vs lateral rectus muscle). Associations with OCR were compared for different strabismus types. Vomiting was considered postoperative if it occurred before discharge of the patient at noon on the day following surgery. Risk factors for OCR and postoperative vomiting were evaluated by logistic regression analysis.

RESULTS

A total of 111 records were reviewed; 41 patients (37%) experienced OCR. Incidence of OCR and absence of OCR during traction of the first muscle were significantly associated with events during traction of the second (χ(2) = 36.681, P < 0.001) and third muscles (Fisher exact test, P = 0.030). The best predictors of OCR were the absence of fine stereopsis and a larger number of surgically treated muscles. Of the 111 patients, 30 (27%) who had postoperative vomiting, the best predictors were female sex and young age.

CONCLUSIONS

In our cohort, patients experiencing intraoperative OCR when the first extraocular muscle was manipulated during multiple-muscle strabismus surgery were likely to experience it again during traction of additional muscles. More severe postoperative vomiting was common in these patients. OCR was associated with the preoperative absence of fine stereopsis.

Association of oculocardiac reflex and postoperative nausea and vomiting in strabismus surgery in children anesthetized with halothane and nitrous oxide

BACKGROUND

Postoperative nausea and vomiting (PONV) occurs frequently after strabismus surgery. The controversy still exists regarding the association of PONV and the oculocardiac reflex (OCR). A recent study has proven that rocuronium attenuates OCR. If these two occurrences are dependent, it is expected that with the diminution of OCR, occurrence of PONV will also be reduced. The goal of this randomized, controlled study was to prove an association between OCR and PONV by attenuating OCR with 0.4 mg x kg(-1) of rocuronium and subsequently diminishing PONV if these occurrences are associated.

METHODS

A total of 119 ASA 1 children, aged between 3 and 10, undergoing surgery of the medial rectus muscle, were randomly assigned to two groups. In group R (n = 59), 0.4 mg x kg(-1) of rocuronium was administered i.v. before intubation. Group C (controls, n = 60) received no muscle relaxant. The anesthesia was induced and maintained with halothane and N(2)O/O(2) (50/50%). Chi-squared test, Fisher's exact test, t-test, and anova were used for statistical analysis; P-value <0.05 was considered statistically significant.

RESULTS

There were no differences between groups regarding patients' characteristics as well as endtidal halothane and duration of surgery and anesthesia. The occurrence of OCR was different between groups (R: 16/59, 27.1%, C: 28/60, 46.7%; P = 0.027), but not the occurrence of PONV (R: 27/59, 45.8%, C: 28/60, 46.7%; P = 0.921). There was an equal number of patients with PONV and bradycardias in both groups (R: 4/27 vs C: 4/28; P = 0.858), whereas there was different, but statistically insignificant distribution of patients (R: 3/27 vs C: 10/28; P = 0.086) with PONV and arrhythmias other than bradycardia. However, simultaneous occurrence of total OCR and PONV in the 24-h period was not different between the two groups (P = 0.964).

CONCLUSIONS

Rocuronium (0.4 mg x kg(-1)) attenuates the occurrence of OCR, but with the reduced occurrence of OCR we were not able to attenuate the occurrence of PONV, therefore the association of OCR and PONV in strabismus surgery in children anesthetized with halothane and nitrous oxide remains unclear, and if there is a link between the two, it could be related to arrhythmias and not bradycardia.

Safety and efficacy of peribulbar block as adjunct to general anaesthesia for paediatric ophthalmic surgery

METHODS

Fifty children (age 5-14 years, ASA I-II) undergoing elective ophthalmic surgery were chosen for the study. Of these, 25 received intravenous pethidine (control group) and 25 received a peribulbar block (block group) for perioperative analgesia, and were monitored intraoperatively and postoperatively by an investigator blinded to the analgesic technique.

RESULTS

Intraoperative values of haemodynamic variables were significantly higher in the control group (P < 0.01). Requirement for intraoperative rescue analgesic and postoperative analgesia was higher in the control group (P < 0.05 and P < 0.001, respectively). Children in the block group had lower postoperative pain scores at all times. Incidence of oculocardiac reflex was significantly higher (P < 0.001) in the control group. Seventy-six percent of children in the control group had postoperative nausea and vomiting compared to 20% children in the block group (P < 0.001).

CONCLUSION

There were no complications related to the block. Peribulbar block appears to be a safe and useful analgesic technique for paediatric ophthalmic surgery.

Effects of peribulbar bupivacaine as an adjunct to general anaesthesia on peri-operative outcome following retinal detachment surgery

Sixty premedicated, ASA physical status I or II patients weighing > 25 kg scheduled for elective retinal detachment repair were randomly assigned to receive either peribulbar block with 10 ml of 0.25% bupivacaine (block group) or intravenous morphine 150 microg.kg-1 (morphine group), prior to the induction of general anaesthesia (n = 30 in each group). Patients were evaluated for intra-operative oculocardiac reflex, peri-operative pain relief, recovery from anaesthesia and postoperative nausea and vomiting. Apart from significantly reducing the incidence of oculocardiac reflex (30% vs. 70%, p = 0.0019), peribulbar bupivacaine also attenuated the severity of the reflex. Postoperative pain relief was superior in the block group. More block group patients had the maximum recovery score in the immediate postoperative period (80% vs. 27%, p < 0. 0001) and they achieved complete recovery significantly faster than the morphine group (17.3 (14.7) min vs. 66.7 (29.7) min, p < 0.0001). The incidence (40% vs. 77%, p = 0.004) and severity of postoperative nausea and vomiting were significantly less in the block group. In summary, peribulbar bupivacaine, when administered together with general anaesthesia, attenuated oculocardiac reflex, provided comparable intra-operative and superior postoperative analgesia, resulted in significantly earlier and better recovery from anaesthesia, and significantly reduced the incidence and severity of postoperative nausea and vomiting.