Effect of dexamethasone on perioperative renal function impairment during cardiac surgery with cardiopulmonary bypass.

BACKGROUND: In cardiac surgery with cardiopulmonary bypass (CPB), corticosteroids are administered to attenuate the physiological changes caused by the systemic inflammatory response. The effects of corticosteroids on CPB-associated renal damage have not been documented. The purpose of this study was to evaluate the effects of dexamethasone on perioperative renal dysfunction in patients undergoing cardiac surgery with CPB. METHODS: Renal damage was prospectively studied in 20 patients without concomitant morbidity undergoing coronary artery surgery with CPB. Patients were randomized in a double-blind fashion to receive dexamethasone or placebo. Markers of glomerular function (creatinine clearance) and damage (microalbuminuria), and markers of tubular function (fractional excretion of sodium and free water clearance) and damage (N-acetyl-beta-D glucosaminidase (NAG)) were evaluated in addition to plasma and urinary glucose levels. Plasma and urinary specimens were obtained at the following time periods: (1) baseline, during the 12 h before surgery; (2) skin incision before heparinization; (3) from heparinization until the end of CPB; (4) during the 2 h following weaning from CPB; (5) in the intensive care unit from 2 to 6 h after weaning of CBP; (6) and from 36 to 60 h after weaning of CPB. RESULTS: CPB was associated with an increase in markers in the placebo group, which returned to baseline during the second postoperative day, demonstrating a transient impairment of glomerular and tubular renal function. Similar patterns were observed in patients treated with dexamethasone. While postoperative glycosuria was significantly higher in the dexamethasone-treated group, no other differences between groups were observed. CONCLUSION: Dexamethasone administration before CPB has no protective effect on perioperative renal dysfunction in low-risk cardiac surgical patients.

Echocardiographic diagnosis of left ventricular outflow tract obstruction after mitral valve replacement with subvalvular preservation.

We describe two cases of left ventricular outflow tract obstruction after mitral valve replacement with complete retention of the subvalvular apparatus. The first patient deteriorated immediately after insertion of a high-profile bioprosthesis. In the second patient, chronic left ventricular outflow tract obstruction developed after the insertion of a low-profile mechanical prosthesis. The clinical course of left ventricular outflow tract obstruction after mitral valve replacement with complete retention of the subvalvular apparatus may differ greatly. Evaluation of the left ventricular outflow tract by perioperative transesophageal echocardiography or epicardial echocardiography is essential in the prevention and treatment of this complication.

Post-operative effects of tramadol administered at wound closure.

The aim of this prospective, randomized and double-blind study was to assess the effects of a high dose of the analgesic tramadol administered at the conclusion of surgery on extubation time, sedation, and post-anaesthetic shivering. Forty adult patients, ASA physical status I or II, underwent laparoscopic surgery of about 1 h duration and received a standardized anaesthesia that was maintained with isoflurane in O2/N2O. Tramadol 3 mg kg-1 (n = 20) was administered intravenously at the beginning of wound closure, and was compared with saline (n = 20). Post-anaesthetic shivering did not occur in any patient who received tramadol, whereas it occurred in 60% of the control group (P < 0.001). There were no adverse effects on time to extubation and sedation, and discharge-ready time was shorter in the tramadol group (P < 0.05 compared with control). Pain scores in the post-anaesthesia care unit (PACU) were statistically not different between the two groups, but significantly more supplemental medication was administered in the control group to treat shivering and/or pain. In conclusion, administration of a high dose of tramadol at the end of surgery prevents post-anaesthetic shivering without prolongation of extubation time, and shortens the PACU/discharge-ready time.

Intrauterine growth retardation: prediction of perinatal distress by Doppler ultrasound.

To investigate the ability of umbilical artery Doppler findings to identify true cases at risk of fetal distress among 51 pregnancies clinically judged to be compromised by intrauterine growth retardation (IUGR) Doppler data were related to pregnancy outcome, which was classified into three groups-group 1, healthy babies with normal placental function (16 fetuses), group 2, fetuses with definite signs of placental failure (30), and group 3, non-classifiable pregnancies (5). Group 2 was subdivided into 2A, placental failure with manifest perinatal distress (19), and 2B, placental failure without perinatal distress (11). All 19 compromised and distressed fetuses (group 2A) had extremely pathological Doppler findings, even several weeks before fetal distress became apparent by cardiotocography. The Doppler findings in the 11 small-for-dates fetuses without perinatal distress (group 2B) were inconsistently normal or slightly pathological. All 16 normal infants (group 1) had normal antenatal Doppler data. The Doppler technique thus allows accurate and early recognition of those fetuses who will become distressed perinatally. It also helps to identify which fetuses clinically suspected of IUGR have an adequate placental circulation.