Clinical utility of epidural volume extension following reduced intrathecal doses: a randomized controlled trial.

BACKGROUND AND OBJECTIVES: Epidural Volume Extension (EVE) involves instillation of normal saline into the epidural space soon after an intrathecal injection, with the aim to augment the sensory block height. Its clinical relevance lies in the possibility of using reduced intrathecal dose and yet achieving the desired sensory block level. Intrathecal dose is a known determinant of the level of sensory block. Whether EVE is dependent on intrathecal dose is not known. METHODS: We conducted a randomized, controlled, double-blind study to compare the maximum sensory level (Smax) achieved with or without application of EVE to two different reduced intrathecal doses. Eighty four adult male patients of ASA status I or II with body weight between 50-70kg and height in the range of 150-180cm, scheduled for orthopedic lower limb surgery using combined spinal epidural anesthesia were randomized to receive, either intrathecal dose (5 or 8mg) with or without EVE, in accordance to group allocation. RESULTS: Smax was lowered by application of EVE to 5mg intrathecal bupivacaine (T8.9±4.3 vs. T6.4±1.9 with and without EVE respectively; p = 0.030). Smax was similar when EVE was applied to 8mg intrathecal bupivacaine than without it (T5.8±1.8 vs. T6.4±2.2 respectively; p= 0.324). CONCLUSION: EVE should not be applied to 5mg plain bupivacaine during a combined spinal epidural block in patients undergoing lower limb orthopedic surgery as it may result in a decrease in the maximum sensory level.

Intraabdominal pressure in non-laboring preeclamptic vs normotensive patients undergoing cesarean section: A prospective observational study.

INTRODUCTION: It is hypothesized that increased intraabdominal pressure (IAP) may be a cause of preeclampsia. There is, however, a paucity of clinical data regarding IAP in preeclamptics. We evaluated and compared the IAP and its effects on organ functions, in normotensive and preeclamptic patients. MATERIAL AND METHODS: Previously healthy non-laboring patients with a singleton pregnancy scheduled for elective cesarean section under subarachnoid block were enrolled (preeclamptic and normotensive; n = 29 each). IAP was measured using an indwelling Foley catheter, and compared in both cohorts at four predefined time points: just before subarachnoid block, immediately after the onset of sensory block to T6 dermatomal level, just after surgery, and 2 hours later. In addition, the presence of organ dysfunction for respiratory, cardiovascular, renal, hepatic, hematopoietic and central nervous systems were evaluated for association with IAP. RESULTS: Although age, body mass index, gravidity, parity, serum bilirubin, serum creatinine, PaO2 /FiO2 ratio and Glasgow coma score of the preeclamptic and normotensive patients were similar, the mean blood pressure was significantly higher (P < 0.001), the period of gestation less (P = 0.003) and the platelet count lower (P = 0.020) in the former. The IAP was significantly higher in the preeclamptic group at all four time points: respectively, 15.1 (1.0) vs 14.2 (0.9) mm Hg (P = 0.002); 14.9 (0.9) vs 14.1 (1.0) mm Hg (P = 0.002), 10.4 (1.0) vs 9.5 (1.3) mm Hg (P = 0.008) and 10.2 (0.8) vs 9.2 (1.2) mm Hg (P = 0.001). There was no correlation between the IAP and various organ dysfunctions. CONCLUSIONS: Preeclampsia is associated with a significantly higher IAP in patients undergoing a cesarean section. The clinical relevance of this finding needs further investigation.