///2009 Abstract Details
2009 Abstract Details2019-08-03T15:55:31-06:00

Pregancy Arterial Stiffness and Tone (PAST) Spinal Anesthesia and The Effects on Central Blood Pressure in Pregnant Women

Abstract Number: 157
Abstract Type: Original Research

Shane A Clark M.D., M.S.1 ; Thom L Archer M.D., M.B.A.2; A. Scott Wheeler M.D.3

Spinal anesthesia is the most commonly used anesthetic for elective cesarean section and post-partum tubal ligation. This method frequently produces hypotension, which results from a decrease in venous return and arteriolar dilation. Many clinicians believe that decreases in venous return are the primary cause of hypotension. The purpose of this study is to determine whether high spinal anesthesia actually induces significant changes in muscular arterial tone. A new monitoring device, the Sphygmacor, calculates augmentation pressure and index from peripheral artery by means of applanation tonography. We studied 23 elective cesearean section patients and 2 woman having postpartum tubal ligation, all of whom received high spinal anesthesia. All subjects studied were free of any medical disorders such as diabetes or hypertension. Following a fast exceeding eight hours, all subjects received 500-1000 ml of NaCl 0.9% prior to spinal anesthesia. A standardized spinal technique included seated position; hyperbaric bupivicaine (12mg) with Fentanyl (25mcg) and PF Morphine (0.2mg); and a 25 ga pencan needle. Then, left lateral tilt position was utilized until delivery and additional IVF were given as needed.

Applanation tonography was determined prior to spinal anesthesia while patient in left lateral tilt position (same position used after spinal injection). Measurements were obtained after spinal sensory level exceeded T-6. Systolic and diastolic blood pressure measurements were recorded.

Differences in measurements before and after treatment were analyzed by paired t-test. The strength of association between variables were determined by Pearson Product Moment Correlation test. Significance was defined at p<0.05. Among subjects, mean age was 29.5 years, weight was 85.6 kg and height was 62.3 inches. Compared to control values ejection duration, systolic blood pressure, diastolic blood pressure, mean blood pressure, central augmented blood pressure and central augmentation index all decreased significantly (p<0.001). Changes in diastolic blood pressure positively correlated with changes in central augmentation index. These findings demonstrate that during high spinal anesthesia in parturient women, muscular arterial tone decreases significantly, partly accounting for reductions in blood pressure commonly occurring during this method.

SOAP 2009