Prevention of postoperative hypotension following spinal anesthesia for TURP: a double-blind randomized controlled trial comparing ephedrine with placebo.

Spinal hypotension (SH) is a common side effect of spinal anesthesia and may also occur after the surgical procedure. In this double-blinded, placebo-controlled, randomised clinical trial fifty patients undergoing transurethral prostatectomy under spinal anesthesia received 10 mg of ephedrine IV before being transferred from the operating table into their bed after the procedure, whereas fifty controls received saline IV. The number of per- and postoperative hypotensive episodes and vasopressor use, time delay between the administration of the study medication and the first hypotensive episode, level of spinal blockade at the start of surgery, pre- and postoperative hemoglobine and sodium concentration, cardiovascular co-morbidity and chronic medication were registered. There was no statistically significant difference in the incidence of postoperative hypotension between the two groups, but Poisson regression of the expected number of postoperative hypotensive episodes per patient showed a protective effect of ephedrine (p < 0.05). The occurence of peroperative hypotension was a risk factor for developing postoperative hypotension (p < 0.05). There was no statistically significant relation between age, level of spinal blockade, cardiovascular co-morbidity or biochemical parameters and the risk of developing per- or postoperative hypotension, except for a correlation between preoperative alpha-receptor blocking drugs and peroperative hypotension (p < 0.05). Postoperative hypotension (recorded incidence 31%) was almost as common as peroperative hypotension (recorded incidence 37%) and occurred as late as 190 minutes after the end of surgery. Ephedrine IV at the end of surgery reduced the number of postoperative hypotensive episodes per patient but did not reduce the overall incidence of postoperative SH.

Ex vivo evaluation of a new neonatal/infant oxygenator: comparison of the Terumo CAPIOX Baby RX with Dideco Lilliput 1 and Polystan Safe Micro in the piglet model.

OBJECTIVE: A newly developed neonatal and infant oxygenator with a nonheparin biocompatible polymer coating, low priming volume (43 mL), high oxygen transfer, wide operating range (<1.5 L/min) and low pressure drop represents a promising solution for cardiac surgery in neonates and infants. We compared the new CAPIOX Baby RX, Terumo (BRX) with two commonly used neonatal oxygenators: Dideco Lilliput 1 (DL1) and Polystan Safe Micro (PSM) in a piglet model. METHODS: Fifteen piglets (5.6 +/- 1.3kg) were placed on standardized cardiopulmonary bypass (CPB) for 6 hours using one of the three oxygenators (n = 5 in each group). After 120 min, the system was cooled to 25 degrees C for 60 min and then returned to normothermia. Arterial and venous blood gas data and temperature were recorded continuously by a CDI500 System (Terumo). Pressure drop, FiO2 and gas flow were recorded. Blood samples were taken before CBP, after 10 min, before and after cooling, and at the end. Total blood counts, thrombin-antithrombin complex and plasma-free haemoglobin (PfHb) were measured. RESULTS: All oxygenators showed acceptable performance for the duration of CPB. The BRX had lower mean gas flow (0.33 +/- 0.05 L/min) and FiO2 (0.43 +/- 0.02%) throughout CPB than the DL1 (1.14 +/- 0.25 L/min, p = 0.006 and 0.60 +/- 0.02%, p = 0.009, respectively) or the PSM (1.47 +/- 0.87 L/min and 0.54 +/- 0.08%, p = ns). Pressure drop in the BRX group ranged from 12 to 22 mmHg. This was significantly lower than in the DL1 group (39-65 mmHg, p = 0.005). In the PSM group, values ranged between 24 and 33 mmHg (p = ns). The increase in PfHb at six hours was significantly lower in the BRX (11.3 +/- 4.2 ng/dL) versus the DL1 (42.2 +/- 6.1 ng/dL, p = 0.004) and the PSM (56.7 +/- 15.5 ng/dL, p = 0.045). CONCLUSIONS: The BRX is as safe as the DL1 and the PSM, with superior performance in pressure drop, efficient blood gas management and lower haemolysis. The BRX exhibited the lowest prime, hold-up volume and breakthrough time.

Na(+)/H(+)-exchange inhibition and aprotinin administration: promising tools for myocardial protection during minimally invasive CABG.

OBJECTIVE: Minimally invasive coronary artery bypass grafting (CABG), carried out on the warm beating heart, does not allow conventional myocardial protection. The objective was to investigate the possibility of enhancing tolerance to ischemia during short episodes of coronary artery occlusion, based on a pharmacological approach using a selective Na(+)/H(+)-exchange inhibitor (cariporide) or a serine protease inhibitor (aprotinin). METHODS: Four groups (n=6 in each group) of sheep were subjected to 20 min of normothermic regional ischemia (first lateral branch of the circumflex artery occlusion) followed by 1 h of reperfusion. Regional wall thickening was measured using sonomicrometry, and expressed as the percentage of thickening fraction compared with baseline. Group I was the control with no treatment, group II received cariporide (1 mg/kg administered over 2 min prior to ischemia), group III was treated with aprotinin (2.10(6) kallikrein inactivation units (KIU) load followed by 500.000 KIU/h). Group IV was treated with a combination of cariporide and aprotinin at the same concentrations as in groups II and III, respectively. RESULTS: Wall thickening measurements showed that, compared with control, cariporide was largely able to suppress secondary loss of wall thickening after initial recovery during early reperfusion. Wall thickening in the ischemic/reperfused myocardial area improved from 10+/-31 to 51+/-17% at 1 h of reperfusion (P=0.002). Aprotinin improved wall thickening at the end of 1 h of reperfusion to 70+/-13% (P=0.0001). However, in this group, there was a transient loss of regional contractility similar in amplitude and time course to the one observed in the control group. A combination of cariporide and aprotinin suppressed transient contractile loss and resulted in improved wall thickening at the end of 1 h of reperfusion (65+/-22%, P=0.0002 vs. control). This value was not significantly different from the cariporide (P=0.263) or aprotinin (P=0.704) group. CONCLUSION: These data indicate that both Na(+)/H(+)-exchange inhibition and aprotinin administration are promising tools for cardioprotection during minimally invasive CABG. A combination of both treatments is able to adequately suppress loss of contractility during early reperfusion as a consequence of reperfusion injury, and results in significantly improved wall thickening at the end of 1 h of reperfusion.