THE PULMONARY ARTERY CATHETER IS NECESSARY FOR THE MANAGEMENT OF PATIENTS UNDERGOING COMPLEX SPINE SURGERY

Abstract

S130 INTRODUCTION: In the 1980's perioperative pulmonary artery catheterization (PAC) was established as standard care for patients with cardiac disease undergoing major surgical procedures. However, two large nonrandomized nor controlled studies suggest that the use of PACs in critical patients may lead to increased morbidity and mortality. We present evidence that PAC monitoring may be essential for hemodynamic control in patients undergoing complex spine procedures. METHODS: 30 patients age 18 to 72 years for elective sequential anterior and posterior spinal fusion with instrumentation were included in the analysis. All patients were monitored with a radial artery catheter and a PAC through a 9F canula in the right internal jugular vein. Patients were anesthetized with fentanyl, 70% nitrous oxide, 0.3% isoflurane with controlled hypotension to a mean arterial pressure of 50-60mmHg with sodium nitroprusside and esmolol. Patient were monitored in an ICU for at least 24 h postoperatively. Baseline PA pressures and cardiac index (CI) were recorded prior to incision but after induction of anesthesia; at [similar] 2h intervals during the procedure: at closure; and in the ICU. Data analyzed by ANOVA. RESULTS: Both the mean PA-systolic (22 to 33) and PA-diastolic, PAD (12 to 18), increased during the procedure while left ventricular filling pressures (PCWP) were kept stable (11 at baseline & closure) in order to maintain a CI of 3.0 +/- 0.5 and a urine output of 0.5 ml/kg/h. In 6 patients the PAD to PCWP gradient was 10mmHg or greater at closure, 3 required some inotropic support at closure. This magnitude of a gradient was associated with significantly more blood loss, the need for postoperative ventilation, and longer ICU care (Table 1). Operative time and number of spinal levels fused was similar for both groups.Table 1CONCLUSIONS: Complex spine surgery associated with extensive blood loss is associated with lung injury reflected in elevated PA-pressures. Without an accurate assessment of LV-filling pressures, the patient would become intravascularly depleted and a fall in CI would compromise end organ perfusion. In addition, a PAD to PCWP gradient >or=to 10 was a marker for the need for postoperative ventilation and prolonged ICU care.