Trigemino-cardiac reflex during orbital floor reconstruction: a case report and review

Asystole During Nasopharyngeal Swab: Is COVID-19 to Blame?

The use of nasopharyngeal (NP) swab sampling for the detection of various respiratory pathogens has been a standard procedure in medicine for many years. While this is a fairly common procedure, there has been a significant increase in utilization recently due to the SARS-CoV-2 pandemic. We describe a case of a 40-year-old SARS-CoV-2 positive patient with no prior cardiac history who developed asystole while an NP swab was being used to obtain a sample for a SARS-CoV-2 assay. Return of normal sinus rhythm was achieved with chest compressions alone. The incident was deemed to have been an exaggerated vagal response to intranasal stimulation; better known as the trigeminocardiac reflex. This is the first reported case describing asystole during use of an NP swab. This case occurred in a patient with no known cardiac disease and highlights the potential importance of the arrhythmogenic nature of COVID-19 that could potentiate the vagal response in susceptible individuals undergoing NP sampling.

Asystole Triggered by the Mouth Opening With a Dental Mouth Gag Under General Anesthesia During Pediatric Oral Surgery: Report of a Rare Case

The trigeminovagal reflex manifests as a sudden onset of bradycardia, hypotension, and cardiac arrest in response to the stimulation of the trigeminal nerve. The incidence of trigeminovagal reflex in maxillofacial surgical procedures is approximately 1.6%. We report a case of asystole in a pediatric patient in whom a dental mouth gag triggered the trigeminovagal reflex during oral surgery. The patient was a 5-year-old boy who was scheduled to undergo extraction of maxillary supernumerary teeth. After tracheal intubation, anesthesia was maintained with sevoflurane and remifentanil. At the beginning of the surgery, his mouth was opened with a dental mouth gag, and electrocardigram showed asystole for 20 seconds. Thereafter, his heart rate spontaneously returned to basal value within 60 seconds. Since sufficient mouth opening was required to conduct the surgery, his mouth was opened again with the gag. When the interincisal distance exceeded about 40 mm, his heart rate suddenly decreased, but spontaneously returned to baseline within 60 second. The subsequent anesthetic course was uneventful.

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.

Reflejo trigémino cardíaco durante artroscopia de la articulación temporomandibular. Reporte de caso clínico

Introducción: el reflejo trigémino cardíaco es una respuesta fisiológica parasimpática repentina, que ocasiona alteraciones cardiovasculares importantes durante la estimulación nerviosa en el trayecto del V par craneal, generalmente ocurre al realizar procedimientos quirúrgicos en cirugía oral y maxilofacial, neurocirugía, oftalmología y dermatología. La artroscopia de la articulación temporomandibular ha sido tradicionalmente considerada un procedimiento quirúrgico seguro, mínimamente invasivo, aun así, esta técnica no está exenta de complicaciones neuro y cardiovasculares. Objetivo: presentar un caso clínico que durante una artroscopia de la articulación temporomandibular en la fase de instrumentación del espacio articular superior, y que, bajo monitoreo continuo del anestesiólogo, reportó una bradicardia súbita. Conclusión: el diagnóstico intraoperatorio de reflejo trigémino cardíaco, fue descrito por el servicio de anestesiología recibiendo un tratamiento farmacológico temprano para esta condición, lo que permitió obtener una adecuada evolución trans y postoperatoria.La artroscopia de la articulación temporomandibular ha sido tradicionalmente considerada un procedimiento quirúrgico seguro, mínimamente invasivo, aun así, esta técnica no está exenta de complicaciones.El objetivo de este artículo es presentar un caso clínico que durante una artroscopia de la articulación temporomandibular en la fase de instrumentación del espacio articular superior sufrió una bradicardia súbita, con un diagnóstico intraoperatorio de reflejo trigémino cardíaco, recibiendo un tratamiento temprano por parte del servicio de anestesiología de esta condición, obteniendo una adecuada evolución trans y postoperatoria.

The clinical surrogate definition of the trigeminocardiac reflex: Development of an optimized model according to a PRISMA-compliant systematic review

BACKGROUND

The trigeminocardiac reflex (TCR) is defined as sudden onset of parasympathetic dysrhythmias including hemodynamic irregularities, apnea, and gastric hypermotility during stimulation of sensory branches of the trigeminal nerve. Since the first description of the TCR 1999, there is an ongoing discussion about a more flexible than the existing clinical definition. Aim of this work was to create a clinical surrogate definition through a systematic review of the literature.

METHODS

In this meta-analysis study, literature about TCR occurrences was, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement, systematically identified through various search engines including PubMed (Medline), Embase (Ovid SP), and ISI Web of Sciences databases from January 2005 to August 2015. TCR was defined as a drop of heart rate (HR) below 60 bpm or 20% to the baseline. We extracted detailed data about hemodynamic changes and searched for connections between arterial blood pressure (BP) and HR changes during such episodes.

RESULTS

Overall 45 studies harboring 57 patients were included in the study but only 32 patients showed sufficient data for final analyze. HR showed a nonlinear behavior with a "tipping point" phenomena that differs in variance from the central/peripheral (20-30% drop) to ganglion (40-49% drop). BP showed a linear behavior with a "central limit" phenomena not differing in variance in the whole subgroup (30-39% drop). An analyzation of the correlation between BP and HR showed a trend to a linear correlation.

CONCLUSIONS

We can show for the first time that HR is the dominant variable in the TCR and present a new surrogate definition model. This model and the role of BP must be better investigated in further studies.