Analysis of Parameters Determining the Frequency and Intensity of Pneumatocele in Patients with CPA Tumor Operated in Sitting Position with Total Intravenous Anesthesia

Introduction: The sitting position of the patient during CPA surgery enables spontaneous outflow of blood, cerebrospinal fluid, and solutions used for operation site rinsing. This position and its consequences lessen the necessity of coagulation and suction in operating field. Usage of those surgical maneuvers often leads to damage of the facial nerve, cochlear nerve, labyrinthine artery, and other delicate structures. The disadvantage of this position is the risk of pneumatocele. The spontaneous drainage of cerebrospinal fluid predisposes inflow of air to the site of operation, basal cisterns, cranial vault, and ventricular system. This common postoperative complication requires operative evacuation of air if a pneumatocele is massive and symptomatic.

Purpose: The aim of this study was to find if any other modifiable parameters determine the frequency and intensity of pneumatocele.

Methods: Outcome of 178 patients operated for CPA tumor was analyzed. All patients were operated in sitting position with TIVA anesthesia. Three to 12 hours after the surgery, CT examination of the head was performed in all patients. Pneumatocele was evaluated on the basis of the CT examination using a 4-degree scale. Frequency and intensity of pneumatocele were correlated with such parameters as: age and sex of the patient, anesthesia hazard scale (ASA), heart rate and systolic blood pressure during operation, the amount and type of infusions, fluid balance, and duration of surgery.

Results: Frequency and intensity of pneumatocele is correlated with: age and sex of patients, duration of the operation, type of infusions, and fluid balance. Heart rate and systolic blood pressure correlated with circulating blood volume seem to affect the frequency of pneumatocele.

Conclusions: CT head examination must be performed routinely after each surgery that is conducted in sitting position. Men over 60 years old whose operation was longer than 3 hours are particularly susceptible to large postoperative pneumatoceles. Infusion of crystalloids, negative fluid balance, and systolic blood pressure diminution below 100 mmHg are correlated with pneumatocele frequency in patients who underwent CPA surgery.