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Biomedical subjects

Patrick Breen

Publications and source records attributed to Patrick Breen.

4 recordsLinked to original sources
PubMed2003

Dopexamine increases internal mammary artery blood flow following coronary artery bypass grafting.

OBJECTIVE: Vasoactive agents and inotropes influence conduit-coronary blood flow following coronary artery bypass grafting (CABG). It was hypothesized that dopexamine hydrochloride, a dopamine A-1 (DA-1) and beta(2) agonist would increase conduit-coronary blood flow. A prospective randomized double blind clinical trial was carried out to test this hypothesis. DA-1 receptors have previously been localized to human left ventricle. METHODS: Twenty-six American Society of Anaesthesiology class 2-3 elective coronary artery bypass graft patients who did not require inotropic support on separation from cardiopulmonary bypass (CPB) were studied. According to a randomized allocation patients received either dopexamine (1 microg/kg per min) or placebo (saline) by intravenous infusion for 15 min. Immediately prior to and at 5,10 and 15 min of infusion, blood flow through the internal mammary and vein grafts (Transit time flow probes, Transonic Ltd.), heart rate, cardiac index, mean arterial pressure and pulmonary haemodynamics were noted. The data were analysed using multivariate analysis of variance. RESULTS: Low-dose dopexamine (1 microg/kg per min) caused a significant increase in mammary graft blood flow compared to placebo at 15 min of infusion (P=0.028, dopexamine group left internal mammary artery (LIMA) flow of 43.3+/-14.2 ml/min, placebo group LIMA flow at 26.1+/-16.3 ml/min). Dopexamine recipients demonstrated a non-significant trend to increased saphenous vein graft flow (P=0.059). Increased heart rate was the only haemodynamic change induced by dopexamine (P=0.004, dopexamine group at 85.2+/-9.6 beats/min and placebo group at 71.1+/-7.6 beats/min after 15 min of infusion). CONCLUSION: This study demonstrates that administration of dopexamine (1 microg/kg per min) was associated with a significant increase in internal mammary artery graft blood flow with mild increase in heart rate being the only haemodynamic change. Low-dose dopexamine may improve graft flow in the early post CABG period with minimal haemodynamic changes.

Adrenergic beta-Agonists↗
PubMed2002

General anesthesia versus regional anesthesia.

No distinct advantage is apparent between regional and general anesthesia when considering perioperative cardiac morbidity and mortality in peripheral vascular surgery. However, there is some evidence to support regional anesthesia over general anesthesia in an effort to optimize graft patency if the regional technique is extended into the postoperative period to provide neuraxial analgesia. An inadequate number of randomized, controlled trials have been conducted to determine whether regional or general anesthesia should be performed for carotid endarterectomy. The nonrandomized trials do support regional anesthesia by virtue of reductions in stroke, myocardial infarction, and death. A randomized, prospective trial is needed to verify these outcomes. The choice of technique does not appear to affect mortality in patients requiring hip fracture surgery, although Urwin et al. (29) reported less 1-month mortality in patients receiving regional anesthesia. General anesthesia has been associated with increased blood loss and thromboembolic complications in patients undergoing hip fracture repair. Epidural anesthesia has been shown to promote quicker return of bowel function postoperatively when the catheter has been sited at T12 or higher. Anastomotic breakdown in patients with epidural anesthesia/analgesia has rarely been reported. Most studies tend to show quicker return of bowel function when local anesthetics alone are administered epidurally.

Anesthesia, Conduction↗