Determination of trigeminocardiac reflex during rhinoplasty

Abstract

In most rhinoplasty procedures, osteotomies are usually required. The osteotomy areas are innervated by sensory branches of the trigeminal nerve. The trigeminocardiac reflex (TCR) is clinically defined as the sudden onset of parasympathetic activity during stimulation of the trigeminal nerve. When an osteotomy is performed or external pressure is applied over the nasal bone, the infraorbital nerve may send signals via this nerve. The aim of this prospective study is to determine the blood pressure changes and occurrence of TCR during rhinoplasty. one hundred and eight patients were enrolled into the study. Lidocaine and adrenaline combination (LAC) was injected only into the left lateral osteotomy sites. All patients underwent median, right-side, then left-side lateral osteotomies and nasal pyramid infracture. The haemodynamic changes were recorded. A 10% or more decrease in the heart rate from baseline was considered a TCR. TCR was detected in nine patients following lateral osteotomies and nasal pyramid infracture procedures (8.3%). The authors determined that LAC injection prior to osteotomy did not prevent TCR. Manipulation at or near the infraorbital nerve during rhinoplasty may cause TCR, even if local anaesthetic infiltration is used.

The trigeminocardiac reflex (TCR) is a reflexive response in which bradycardia, hypotension, and gastric hypermotility are induced via stimulation of either a peripheral branch or the central portion of the trigeminal nerve. It was first described in 1908 by both Aschner and Dagnini. The TCR is known as the oculocardiac reflex when it occurs during ophthalmic surgery. It has been observed during a wide range of procedures, including neurosurgery, abdominal surgery, and maxillofacial surgery. Most rhinoplasties require osteotomies and nasal pyramid infracture to move or alter the osseocartilaginous vault that comprises much of the nose. The nasal bridge and osteotomy areas are innervated by sensory branches of the maxillary division of the trigeminal nerve. Osteotomies and manipulation of nasal bones during rhinoplasty may cause TCR. TCR has not been sufficiently discussed among otolaryngologists.

This study evaluated the incidence of TCR during rhinoplasty procedures and the efficacy of lidocaine and adrenaline combination (LAC) in preventing TCR in patients who underwent an open rhinoplasty. To the authors’ knowledge there is no study about TCR during rhinoplasty in the literature.

Materials and methods

The study was approved by the local research and ethics committee of the Medical School, Dicle University. Informed consent was obtained. The study recruited 108 patients (60 males, 48 females; average age 25.3 ± 3.8 years, range 19–33 years) who underwent open rhinoplasty for nasal deformities. All the patients were in normal general health and classified as ASA PS1 according to the American Society of Anesthesiologists (ASA) Physical Status classification system. Exclusion criteria included contraindications to any of the drugs used in the study, age <18 or >45 years, evidence of severe cardiovascular, renal, haematological, hepatic, or respiratory disease, pre-existing neurological or psychiatric illness, diabetes or peripheral neuropathy, and patients taking chronic analgesic therapy or with a history of alcohol or drug abuse.

Surgical procedures were performed under a standardized anaesthetic protocol. When the patient arrived in the operating theatre, a vein was cannulated, the arterial blood pressure (BP) was measured with an automated oscillometer, and monitoring of arterial oxygen saturation and electrocardiography began. Anaesthesia was induced with 1 μg/kg fentanyl, 2.5 mg/kg midazolam, 2.5 mg/kg propofol, 1 mg/kg lidocaine, and 0.1 mg/kg vecuronium bromide, and maintained with 2–2.5% sevoflurane, 40% oxygen, and 60% air. Muscle relaxation was maintained with 0.01 mg/kg vecuronium bromide every 25–30 min; analgesia was maintained with 1 μg/kg fentanyl every 45–60 min. All haemodynamic changes were monitored continuously and recorded throughout the surgical procedure.

All surgeries were performed by two surgeons (E.Y., R.G.). All patients underwent an open approach rhinoplasty using a W-shaped columellar incision. Although the details of the surgical procedure varied among the patients, most patients underwent the same surgical steps (i.e. skin elevation, periosteal elevation, and a tip-plasty procedure). If septal surgery was required, the septum was exposed subperichondrially between the upper lateral cartilages. Local anaesthetic was not infiltrated into the median and right lateral osteotomy sides (Group I). The left lateral osteotomy side was infiltrated with 2 ml of lidocaine 2%, 1.25:100,000 epinephrine (Jetocaine amp, Adeka, Turkey) in all patients (Group II). Median osteotomy and dorsal hump resection were performed by Moberg bone chisels in all patients. Bilateral small incisions were made with a no. 15 scalpel blade in the nasal vestibule at the pyriform aperture. Slightly curved 4-mm Anderson-Neivert osteotomes (with the guard notch positioned medially) were used through this incision to perform an internal continuous lateral osteotomy in a ‘high to low to high’ pattern along the nasofacial groove, from the lateral point of the pyriform aperture to a point medial to the inner canthus of the eye. To eliminate local anaesthetic effects, all patients first underwent right-side, then left-side, lateral osteotomy. Finally, the nasal pyramid was infractured digitally in all patients. The surgery was stopped for approximately 5 min between each step.

Before each step (median osteotomy, lateral osteotomies and nasal pyramid infracture), heart rate (HR), and systolic (SP), diastolic (DP) arterial blood pressures were noted and recorded as baseline. In this study, a 10% or more decrease in the HR from baseline HR values within seconds after osteotomies or nasal pyramide infracture was considered a TCR. Haemodynamic changes in other surgical steps due to possible effects of general anaesthetics (i.e. anaesthesia-mediated venodilation, hypovolaemia) were excluded.

All data were analysed using the SPSS software (ver. 13.0; SPSS, Chicago, IL, USA) using repeated-measures analysis of variance (ANOVA). P values <0.05 were deemed to indicate statistical significance.

Results

At all osteotomy and infracture procedures, the mean HR, SP, and DP and statistical significances were documented ( Table 1 and Fig. 1 ).

Table 1
The mean heart rate, systolic and diastolic blood pressure changes and statistical significance of the compared pairs. *
Compared pairs (before versus after) Heart rate (bpm) Systolic blood pressure (mmHg) Diastolic blood pressure (mmHg)
Median osteotomy 76 ± 9 versus 77 ± 11 117 ± 11 versus 115 ± 13 74 ± 7 versus 72 ± 10
Right lateral osteotomy (Group I) 75 ± 12 versus 73 ± 12 115 ± 15 versus 116 ± 13 71 ± 11 versus 74 ± 12
Left lateral osteotomy (Group II) 79 ± 12 versus 76 ± 10 115 ± 13 versus 117 ± 14 72 ± 11 versus 75 ± 14
Nasal pyramid infracture 77 ± 11 versus 72 ± 14 112 ± 13 versus 110 ± 9 69 ± 12 versus 70 ± 10

* The results are expressed as mean ± SD.

Statistically significant ( P < 0.05).

Fig. 1
HR changes at each surgical step.

Median osteotomy

No significant BP changes or TCR were detected at the median osteotomies.

Lateral osteotomies

The mean HR, SP, and DP at the lateral osteotomies were documented in Groups I and II ( Table 2 ). The TCR was detected at six lateral osteotomies in Group I (5.5%). Only two patients showed a HR decrease of more than 20% at the time of osteotomy (1.8%). In Group II, TCR was detected in five lateral osteotomies (4.6%). Only one patient showed a HR decrease of more than 20% at the time of osteotomy (0.9%). In two patients, bradycardia was detected during either right-side or left-side osteotomies. The difference in TCR between Groups I and II was not statistically significant ( P > 0.05). There were only two patients (one in Group I, one in Group II) in whom hypotension was detected during or after lateral osteotomy. Between Groups I and II, no significant correlation was observed among the time variables. During the lateral osteotomy, the mean HR decreased continuously in Group II. In contrast, in Group I, HR was slightly increased during the osteotomy. After the osteotomy the mean HR was decreased ( Fig. 2 ). There were significant decreases in mean HR in the two groups during the each lateral osteotomy procedure. In Group I, after the lateral osteotomy, HR values were associated with a mean decrease of 2.1% compared with those before the lateral osteotomy. In Group II, this mean decrease was 3.3%.

Table 2
The mean heart rate, systolic and diastolic blood pressure changes at the lateral osteotomy. *
Group I Group II
Heart rate (bpm) Systolic blood pressure (mmHg) Diastolic blood pressure (mmHg) Heart rate (bpm) Systolic blood pressure (mmHg) Diastolic blood pressure (mmHg)
Before the lateral osteotomy 75 ± 12 115 ± 15 71 ± 11 79 ± 12 115 ± 13 72 ± 11
During the lateral osteotomy 76 ± 13 116 ± 12 72 ± 10 78 ± 13 114 ± 13 71 ± 11
After the lateral osteotomy 73 ± 12 116 ± 13 74 ± 12 76 ± 10 117 ± 14 75 ± 14

* The results are expressed as mean ± SD.

Jan 26, 2018 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Determination of trigeminocardiac reflex during rhinoplasty
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