P033: MULTI-ORIFICE CATHETER PLACEMENT USING TEE FOR A CRANIOTOMY IN SITTING POSITION
Ricardo Plata Aguilar, MD, Paola Aranda Valderrama, MD, Juan Botero, MD; Cleveland Clinic Florida
Introduction: The sitting position in neurosurgical patients provides a number of advantages such as excellent surgical exposure, improves cerebral venous drainage, lowers intracranial pressure (ICP), decreases blood loss and maintains low airway pressures. This position is associated with potential serious complications like venous Air Embolism (VAR). VAE incidence has been reported as high as 60%. but it varies depending on the detection method used during surgery. Monitoring for VAE includes Precordial Doppler, PA catheter, ETCO2 and trans-esophageal echocardiography (TEE).
VAE is facilitated in the sitting position by the pressure gradient (sub-atmospheric pressure) between an open non collapsible venous channel such as diploic veins and dural sinuses and the right atrium (RA). Morbidity and mortality are directly related to the amount and rate of air entry. A rapidly entrained air bolus may result in an air lock within the right side of the heart and may cause blockage of the right ventricular outflow tract, decreased cardiac output, acute right ventricular dilation and failure, dysrhythmias, myocardial and cerebral ischemia and cardiovascular collapse.
Multi-orifice right atrial catheter is used to aspirate air entering the right side of the heart. This procedure has been demonstrated to be therapeutic when large amounts of air have been entrained. Up to 50 ml of air have been aspirated in symptomatic patients. Optimal catheter placement is crucial in order to increase the amount of air that can be aspirated in the event of VAE. The Superior Vena Cava – RA junction has been recommended as the target place for the catheter. There is a greater air recovery when the tip of the catheter is positioned at or 2 cm below the sinoatrial node. EKG guided positioning has been used but newer technologies like Trans esophageal Echocardiogram provides the advantage of real time image guided positioning of the catheter as well as method for diagnostic of VAE.
Methods: A 28 year old male was scheduled for Inter-hemispheric craniotomy in sitting position for resection of left parietal cavernoma. Patient had history of recent onset seizures and the brain MRI revealed left parietal cavernoma. The anesthetic plan was to provide general anesthesia with Total IV Anesthesia (TIVA) with invasive monitoring and TEE. Propofol and remifentanil were used for induction and maintenance. Neuromuscular paralysis was provided with rocuronium infusion and a radial A. line was placed. A Multi-orifice central venous catheter was inserted using ultrasound and the tip position was confirmed using TEE. Procedure was completed without events and the patient was successfully extubated in the OR and transferred to ICU
Conclusions: Craniotomy in sitting position increases the risk of VEA. Multi-orifice Right atrial catheter is used to aspirate air from right atria and the use of TEE improves the success of proper positioning of the tip and at the same time constitutes the most sensitive monitoring to detect VAE. However TEE is a technique that requires special skills and training.