Asystole after inadvertent intubation of the orbit

Surgical and anesthetic influences of the oculocardiac reflex in adults and children during strabismus surgery

One of the most common untoward occurrences during strabismus surgery at all ages is the oculocardiac reflex. Although typically easily treated, the sudden bradycardia or cardiac arrest may add a few gray hairs to ophthalmologists and anesthesiologists alike as it can be potentially fatal. This updated review of the literature and novel detailed treatment algorithm may prevent patient morbidity and mortality through proper recognition of at-risk patients and rapid treatment through proper communication between surgical and anesthesia physicians/providers.

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.

Complications associated with orthognathic surgery

While most patients undergo orthognathic surgery for aesthetic purposes, aesthetic improvements are most often followed by postoperative functional complications. Therefore, patients must carefully decide whether their purpose of undergoing orthognathic surgery lies on the aesthetic side or the functional side. There is a wide variety of complications associated with orthognathic surgery. There should be a clear distinction between malpractice and complications. Complications can be resolved without any serious problems if the cause is detected early and adequate treatment provided. Oral and maxillofacial surgeons must have a full understanding of the types, causes, and treatment of complications, and should deliver this information to patients who develop these complications.

Trigeminocardiac reflex, bilateral sagittal split ramus osteotomy, Gow-Gates block: a randomized controlled clinical trial

PURPOSE

The behavior of trigeminocardiac reflex (TCR) during maxillofacial surgeries has not yet been sufficiently studied and knowledge of its behavior is limited to some case reports. The present study aimed to assess the occurrence of TCR in bilateral sagittal split ramus osteotomy and to determine the possible effect of Gow-Gates block on its incidence.

MATERIALS AND METHODS

Twenty candidates for bilateral sagittal split ramus osteotomy (included were American Society of Anesthesiologists I Class III patients with a prognathism of 3 to 5 mm) were given routine general anesthesia after at least 12 hours of fasting. All patients received Gow-Gates mandibular nerve block on 1 random side (case ramus; the other side was used as the control) after induction of general anesthesia before surgery. Pulse rate was recorded at baseline, soft tissue cutting, bone cutting, sagittal splitting, setback manipulation, and recovery. Mean pulse rate values were compared statistically using t test for the 2 sides in patients.

RESULTS

No statistically significant differences were found between the blocked and control sides except during ramus sagittal splitting and setback manipulation (P < .0001), when a significantly decreased pulse rate was recorded for the control ramus compared with the blocked ramus.

CONCLUSIONS

The present study provides further evidence for the complex neurophysiologic mechanism and probable prevention of peripheral TCR. The results of the present study should be further validated through future studies but already provide strong evidence that peripheral and central TCR may act differently based on slightly different pathways.

Complications of managing the airway

The inability to secure the airway, with consequent failure of oxygenation and ventilation, is a life-threatening complication. Failure of oxygenation leads to hypoxia followed by brain damage, cardiovascular dysfunction, and finally death. Time is a very crucial factor in this context. Complications vary widely in severity; while some are dramatic and immediately life-threatening (unrecognized esophageal intubation), others can be severe and long-lasting (nerve injuries) or mild and short-lived (sore throat). To minimize injury to the patient, the anesthesiologist should examine the patient's airway carefully, identify any potential problems, devise a plan that involves the least risk for injury, and have a back-up plan immediately available. Each anesthesiology department should establish guidelines/algorithms specific to their institution. Unfortunately, a reliable test for detecting all patients at risk does not exist.