Trigeminocardiac reflex and haemodynamic changes during Le Fort I osteotomy

Trigeminocardiac Reflex: A Review and Key Implications to Dermatologic Surgery

BACKGROUND

The trigeminocardiac reflex is a common but underreported occurrence that can vary from benign to life threatening. This reflex can be elicited by placing direct pressure on the globe of the eye or from traction of the extraocular muscles, stimulating the trigeminal nerve.

OBJECTIVE

To provide a review of potential stimuli for the trigeminocardiac reflex within dermatologic surgery and to discuss management options for the treatment of the trigeminocardiac reflex.

METHODS

PubMed and Cochrane were used to identify articles and case reports that established scenarios in which the trigeminocardiac reflex was provoked and subsequently how the reflex was managed.

RESULTS

Within the field of dermatologic surgery, the trigeminocardiac reflex can be stimulated during biopsies, cryoablations, injections, laser treatments, Mohs micrographic surgery, and oculoplastic interventions, most often occurring in an office setting. The most common presentations include significant bradycardia, hypotension, gastric hypermobility, and lightheadedness. The most definitive treatment is cessation of the inciting stimulus, monitoring, and symptomatic management. Glycopyrrolate and atropine are common treatments for severe, intractable cases of the trigeminocardiac reflex.

CONCLUSION

The trigeminocardiac reflex, while underreported and underrepresented in dermatologic literature and dermatologic surgery settings, should be considered in the setting of bradycardia and hypotension during dermatologic procedures.

The trigeminocardiac reflex: Does the activation pathway of its efferent arc affect the intensity of the hemodynamic drop during the management of maxillofacial fractures?

The study aimed to correlate between the stimulated nerve, intensity of trigeminovagal reflex (TVR), and neuropathophysiological pathway by which the efferent arc is activated. Material and methods: A retrospective study included patients who developed TVR during the surgical management of mandibular, midface, and orbital fractures. The reflex was divided into type I, II, III, and IV-TVR according to the following nerves: ophthalmic, maxillary, mandibular, and non-trigeminal nerves, respectively. The magnitude of hemodynamic drops was identified at the intraoperative baseline, during reflex, and postoperatively. The needed time to elicit the reflex, frequency and duration, need for medical intervention, and sequence of the drop were also recorded. P - values < 0.05 was considered significant. Out of 260 patients' files were reviewed, the TVR was observed in only 30 (11.55 %) patients. The ophthalmic nerve activation significantly caused the greatest intensity and magnitude of hemodynamic drop, followed by maxillary nerve, then mandibular division, and the lowest one was non-trigeminal nerves. The highest mean of drops in the mean arterial blood pressure (MABP) was 62.92 ± 2.39 with the type ITVR, whereas those of the type II, III, and IV were 75.5 ±3.98, 81.02±1.31, and 82.22±1.85, respectively. Also, the type I-TVR led to the greatest decrease in the heart rate (HR) with the mean equaled to 52.31± 3.91. The drop percentage in the MABP was -30.5, -17.5, -12, -10.08 for type I, II, III, and IV, whereas those of the HR were - 33.9, -27.13, -26.6, and -25 with type I, II, III, and IV, respectively. All results showed highly significant differences with p-values less than 0.001 when comparing between the baseline and intraoperative values of each TVR type. There is a positive correlation between the activated pathway of the TVR and the intensity of its efferent arc response due to the neural pathway of each division in the brainstem circuitry. Understanding of the pathophysiology and mechanism of the TVR, together with the rapid recognition and treatment could prevent serious negative outcomes, especially when the ophthalmic nerve is stimulated. 1Introduction.

Postoperative bradycardia following adenotonsillectomy in children: Does intraoperative administration of dexmedetomidine play a role?

INTRODUCTION

Dexmedetomidine is a novel pharmacologic agent that has become a frequently used adjunct during care of pediatric patients with obstructive sleep apnea (OSA) undergoing tonsillectomy. While generally safe and effective, dexmedetomidine is associated with adverse effects of hypotension and bradycardia from its central sympatholytic effects. Due to safety concerns, our institution routinely admits patients with OSA for overnight cardiorespiratory monitoring following tonsillectomy. With such monitoring, we have anecdotally noted bradycardia in our patients and sought to investigate whether this was related to the increased use of intra-operative dexmedetomidine.

METHODS

We retrospectively reviewed records over an 11-month period to compare the incidence of postoperative bradycardia following hospital admission for tonsillectomy in patients who received dexmedetomidine versus those who did not.

RESULTS

The study cohort included 921 patients (371 received dexmedetomidine and 550 did not). Bradycardia was asymptomatically noted in 66 patients (7.2%). No patient required medical intervention for the bradycardia or developed clinical symptoms. There was no association of bradycardia with the intra-operative administration of dexmedetomidine (8.9% of patients who received dexmetomidine vs. 9.4% who did not). In multivariable analysis, bradycardia was more common among older patients, with the administration of topical or injected lidocaine, and with specific associated procedures (inferior turbinate coblation with out-fracture or direct laryngoscopy and bronchoscopy).

CONCLUSION

The increased incidence of asymptomatic bradycardia in our post-adenotonsillectomy patients seemed to relate more to increased utilization of postoperative cardiac telemetry, and did not appear associated with the use of dexmedetomidine use intra-operatively.