Is Coronary Graft Doppler More Sensitive for Indiviual Graft Flows Than TEE During CABG Surgery?

Abstract    In this case report we describe a situation where despite a normal TEE exam immediately postcardiopulmonary bypass, there was no flow in the left internal mammary artery graft to the left anterior descending artery. This was picked up by coronary Doppler and subsequently repaired.     

A controlled trial of dapsone versus pyrimethamine-sulfadoxine for primary prophylaxis of Pneumocystis carinii pneumonia and toxoplasmosis in patients with AIDS

Pneumocystis carinii pneumonia (PCP) is the most common opportunistic human immunodeficiency virus (HIV)-related infection, occurring in 85 % of HIV infected patients without prophylaxis. Preventive treatment is required when CD₄ cell count falls below 200 cells per cubic millimeter. Cotrimoxazole has been shown to be highly effective but alternative drug regimens are often necessary because of the frequent drug hypersensitivity exhibited by HIV infected patients. The aim of this prospective, open, randomized, one-site study, involving HIV-infected patients with a CD₄ cell count below 200/mm³, or a percentage under 20%, randomly assigned to receive either dapsone 50 mg daily or Fansidar^® one tablet weekly, was to compare the efficacy and safety of these drugs in the primary prophylaxis of PCP. Both dapsone and Fansidar^® appear to be safe and effective alternative agents for the prevention of PCP. Their role in Toxoplasma gondii prophylaxis requires further evaluation.     

Increasing Maternal Blood Pressure with Ephedrine Increases Uterine Artery Blood Flow Velocity during Uterine Contraction

Background: During labor, ephedrine is widely used to prevent or to treat maternal arterial hypotension and restore uterine perfusion pressure to avoid intrapartum fetal asphyxia. However, the effects of ephedrine on uterine blood flow have not been studied during uterine contractions. The purpose of the study was to assess the effects of ephedrine on uterine artery velocities and resistance index using the Doppler technique during the active phase of labor.

Methods: Ten normotensive, healthy parturients with uncomplicated pregnancies at term received intravenous ephedrine during labor to increase mean arterial pressure up to a maximum of 20% above their baseline pressure. Peak systolic and end-diastolic Doppler flow velocities and resistance indices were measured in the uterine artery before and immediately after administration of bolus intravenous ephedrine and after ephedrine washout. Umbilical and fetal middle cerebral arterial resistance indices and fetal heart rate were also calculated.

Results: After ephedrine administration, mean arterial pressure increased by 17 +/- 4%. End-diastolic flow velocity in the uterine artery at peak amplitude of uterine contraction was restored to 74% of the value observed in the absence of contraction. The systolic velocity was totally restored, and the uterine resistance index was significantly decreased, compared with the values in the absence of contraction. Between uterine contractions, ephedrine induced similar but less marked effects. Fetal hemodynamic parameters were not altered by ephedrine administration.     

Low molecular weight heparin fractions as an alternative therapy in heparin-induced thrombocytopenia

Eight patients with a delayed-onset heparin-induced thrombocytopenia, with thrombotic complications requiring immediate anticoagulation in 7 of them, were given low molecular weight heparin (LMWH) fractions as alternative therapy. This treatment led to normalization of platelet count within 3-5 days in 6 patients with clinical recovery in 5. In 2 patients, thrombocytopenia persisted despite LMWH therapy. In vitro platelet aggregation tests performed in all patients gave evidence of a relationship between the presence (or absence) of a LMWH-dependent platelet-aggregating factor in the patients' plasma and the persistence (or correction) of the thrombocytopenia with LMWH therapy. Although positive in vitro tests may not necessarily be associated with thrombocytopenia, in vitro testing may prove to be a useful guide before giving LMWH fractions as an alternative therapy in patients with heparin-induced thrombocytopenia requiring immediate anticoagulation.     

Exertional heatstroke and muscle metabolism: an in vivo 31P-MRS study.

An impairment of muscle energy metabolism has been suggested as a predisposing factor for, as well as a consequence of exertional heatstroke (EHS). Thirteen young men were investigated 6 months after a well-documented EHS using 31Phosphorus Magnetic Resonance Spectroscopy (31P-MRS). The relative concentrations of ATP, phosphocreatine (PCr), inorganic phosphate (Pi), phosphomonoesters (PME), and the intracellular pH (pHi) were determined at rest, during a graded standardized exercise protocol (360 active plantar flexions) and during recovery. Also the leg tissue blood flow was determined by venous occlusion plethysmography during the MRS procedure. Sixteen age-matched healthy male volunteers served as control group. In resting muscle, there were no significant differences between the groups as regards pHi, Pi/PCr, and ATP/PCr+Pi+PME ratios. During steady state exercise conditions, effective power outputs were similar for both groups at each level of exercise: 20, 35, and 50% of maximal voluntary contraction (MVC) of the calf muscle. No significant differences were shown between the two groups in Pi/PCr, pHi, or changes of leg blood flow at each level of exercise. At 50% MVC, Pi/PCr was 0.48 +/- 0.08 vs 0.47 +/- 0.05 (P = 0.96), pHi was 6.94 +/- 0.03 vs 6.99 +/- 0.02, respectively (P = 0.13). Finally, the rate of PCr resynthesis during recovery was not significantly different between the two groups: t1/2 PCr = 0.58 +/- 0.07 vs 0.50 +/- 0.05 min, respectively (P = 0.35). Therefore, no evidence of an impairment of muscle energy metabolism was shown in the EHS group during a standardized submaximal exercise using 31P-MRS performed 6 months after an EHS.     

The effect of total arterial grafting on medium-term outcomes following coronary artery bypass grafting

Background  

While it is believed that total arterial grafting (TAG) for coronary artery bypass grafting (CABG) confers improved long-term outcomes when compared to conventional grafting with left internal mammary artery and saphenous vein grafts (LIMA+SVG), to date, this has not become the standard of care. In this study, we assessed the impact of TAG on medium-term outcomes after CABG.     

Incidence and Management of Chyle Leaks Following Pancreatic Resection: A High Volume Single-Center Institutional Experience

Background   No data on incidence, management, or natural history of chyle leaks following pancreatic resection have been published. We sought to identify possible risk factors associated with chyle leaks following pancreatic resection, as well as determine the natural history of this rare complication. Methods   Between 1993 and 2008, 3,532 patients underwent pancreatic resection at a single institution. Data on demographics, operative details, primary tumor status, and chyle leak were collected. To identify risk factors associated with chyle leak, a matched 3:1 paired analysis was performed. Results   Of 3,532 patients undergoing pancreatic resection, 47 (1.3%) developed a chyle leak (n = 34, contained chyle leak versus n = 13, diffuse chylous ascites). Chyle leak was identified at median 5 days following surgery. Median drain triglyceride levels were 592 ng/dl. After matching on tumor size, disease etiology, and resection type, the number of lymph nodes harvested and history of concomitant vascular resection predicted higher risk of chyle leak (both P < 0.05). Total parenteral nutrition (TPN) was required in more patients with chylous ascites (92.3%) than those with chyle leaks (44.1%) (P = 0.003). The median time to resolution was shorter for contained chyle leaks (13 days) versus chylous ascites (36 days) (P < 0.001). Patients with chylous ascites tended to have shorter overall survival (3-year, 18.8%) versus patients with no chyle leak (3-year, 46.9%) (P = 0.12). In contrast, patients with a contained chyle leak had a similar survival as patients with no chyle leak (3-year, 53.4% versus 46.9%, respectively) (P = 0.32). Conclusion   Chyle leak was a rare (1.3%) complication following pancreatic resection that was associated with number of lymph nodes harvested and concomitant vascular resection. In general, chyle leaks were successfully managed with TPN with no adverse impact on outcome. Patients with chylous ascites, however, had a more protracted clinical course and tended to have a worse long-term survival. Presented at the Society for Surgery of the Alimentary Tract, 49th Annual Meeting, San Diego, CA, May 18th, 2008 Support: Dr. Pawlik is supported by Grant Number 1KL2RR025006-01 from the National Center for Research Resources (NCRR), a component of the National Institutes of Health (NIH), and NIH Roadmap for Medical Research. The contents of this publication are solely the responsibility of the authors and do not necessarily represent the official view of NCRR or NIH.