RESUMO
BACKGROUND: We study the occurrence and management of the trigeminocardiac reflex (TCR) during neurosurgical procedures for lesions of the skull base. METHOD: Two hundred patients underwent neurosurgical procedures for various skull base lesions and were evaluated retrospectively for the occurrence of the TCR during surgery. This phenomenon was defined as the onset of bradycardia lower than 60 beats/minute and hypotension with a drop in mean arterial blood pressure of 20% or more due to intra-operative manipulation or traction on the trigeminal nerve. FINDINGS: Sixteen patients (8%) had a TCR intra-operatively (7 vestibular schwannomas, 5 sphenoid wing meningiomas, 3 petroclival meningiomas, 1 intracavernous epidermoid cyst). In all 16 patients with a TCR the postoperative courses presented no complications that could be directly related to this intra-operative phenomenon. CONCLUSIONS: Due to the intracranial course of the trigeminal nerve several surgical procedures at the anterior, middle and posterior skull base may elicit the trigeminocardiac reflex. Continuous monitoring of hemodynamic parameters allows the surgeon to interrupt surgical manoeuvres immediately upon the occurrence of the TCR. This technique is sufficient for the heart rate and the arterial blood pressure to return to normal levels without the necessity of additional anticholinergic medication.
Assuntos
Bradicardia/fisiopatologia , Eletrocardiografia , Coração/inervação , Hipotensão/fisiopatologia , Complicações Intraoperatórias/fisiopatologia , Reflexo Oculocardíaco/fisiologia , Neoplasias da Base do Crânio/cirurgia , Base do Crânio/cirurgia , Nervo Trigêmeo/fisiopatologia , Adulto , Idoso , Bradicardia/terapia , Seio Cavernoso/cirurgia , Craniotomia , Cisto Epidérmico/cirurgia , Feminino , Frequência Cardíaca/fisiologia , Humanos , Hipotensão/terapia , Complicações Intraoperatórias/terapia , Masculino , Neoplasias Meníngeas/cirurgia , Meningioma/cirurgia , Pessoa de Meia-Idade , Monitorização Intraoperatória , Neuroma Acústico/cirurgia , Base do Crânio/inervação , Neoplasias da Base do Crânio/fisiopatologiaRESUMO
The sitting position for operations in the posterior fossa remains controversial in both adults and children, primarily because of the risk of air embolism. The reports on the incidence of this complication are varied. We retrospectively reviewed the data on 704 patients (age range 1-82 years) operated on in a lounging position for varied posterior fossa pathology from January 1984 up to December 1989. As diagnostic monitoring, we uniformly employed a Doppler ultrasound device, an atrial catheter, and capnometry. In 37 adults (5.5%) and 9 children (9/34) air embolism was diagnosed, without either morbidity or mortality. A lounging position, together with adequate infusion therapy and ventilation with PEEP, considerably reduces the risk of air embolism.
