Trigeminocardiac reflex during Le Fort I osteotomy: a case-crossover study

Area of Science:

• Oral and Maxillofacial Surgery
• Anesthesiology
• Cardiovascular Physiology

Background:

• The trigeminocardiac reflex (TCR) is a well-documented phenomenon involving cranial nerve V and the cardiovascular system.
• Le Fort I osteotomy is a common maxillofacial surgical procedure that may potentially elicit TCR.
• Understanding TCR occurrence during this surgery is crucial for patient safety and anesthetic management.

Purpose of the Study:

• To evaluate the incidence and characteristics of the trigeminocardiac reflex (TCR) during Le Fort I osteotomies.
• To analyze hemodynamic changes, specifically mean arterial blood pressure and pulse rate, during different phases of the osteotomy.

Main Methods:

• A case-crossover study design was employed with 25 participants undergoing Le Fort I osteotomy.
• Hemodynamic parameters (mean arterial blood pressure and pulse rate) were recorded pre-downfracture, during downfracture, and post-downfracture.
• Repeated measures ANOVA was utilized for statistical analysis with a significance level of alpha = 0.05.

Main Results:

• A statistically significant decrease in pulse rate (PR2) and mean arterial blood pressure (MABP2) was observed during downfracture compared to pre- and post-downfracture values (PR1, PR3, MABP1, MABP3).
• Pulse rate decreased by a mean of 6.5% and mean arterial blood pressure by 9.7% during downfracture.
• These findings highlight a measurable hemodynamic response consistent with TCR during Le Fort I osteotomy.

Conclusions:

• The study demonstrates a significant reduction in hemodynamic parameters during Le Fort I osteotomy, indicative of TCR.
• The observed changes suggest that current definitions or accepted values for TCR may require re-evaluation, particularly in the context of maxillofacial surgery.
• Further research is warranted to refine the understanding and diagnostic criteria for TCR in Le Fort I osteotomies.