Intraaortic balloon pumping assist following open heart surgery for coronary artery disease.
(9/1874)
Intraaortic balloon pump (IABP) assist was employed in 36 patients after surgical operation for coronary artery disease. In 31 patients, the aid of IABP was required because cardiopulmonary bypass could not be terminated without it. In three of these patients, IABP assist was started before the surgical procedure because these patients were in cardiogenic shock due to myocardial infarction. In the remaining five patients, IABP assist was applied for refractory cardiogenic shock in the early postoperative period. The overall survival rate was 58 percent. IABP assist was used in 13 patients with an ejection fraction of 0.1 to 0.2 (normal 0.7). Nine of these patients survived. From our experience, it would appear that this temporary mechanical circulatory support provides a significant advantage in saving patients who might otherwise die after surgical procedures involving the coronary artery. (+info)
Coating of extracorporeal circuit with heparin does not prevent sequestration of propofol in vitro.
(10/1874)
Propofol is sequestered in extracorporeal circuits, but the factors responsible for the phenomenon are mostly unknown. We have compared two extracorporeal circuits (oxygenators, reservoirs and tubings) coated with heparin with two corresponding uncoated circuits for their capacity to sequester propofol in vitro. Three experiments were conducted with each circuit. The circuit was primed with a mixture of Ringer's acetate solution and whole blood, and the study conditions (pump flow, temperature, pH) were standardized. Propofol was added to the solution to achieve a concentration of 2 micrograms ml-1. These studies were followed with concentrations of 10- and 100-fold to assess possible saturation of propofol binding. Serial samples were obtained from the circulating solution for measurement of propofol concentration. Propofol concentrations decreased to 22-32% of the initial predicted concentration of 2 micrograms ml-1 in the circuits (no significant difference between circuits). With greater concentrations, the circuits did not become saturated with propofol, even with the highest predicted concentration of 200 micrograms ml-1. We conclude that propofol was sequestered in extracorporeal circuits in vitro, irrespective of coating the circuit with heparin. (+info)
Effects of dopexamine on blood flow in multiple splanchnic sites measured by laser Doppler velocimetry in rabbits undergoing cardiopulmonary bypass.
(11/1874)
Decreased gut perfusion has been reported during cardiopulmonary bypass (CPB). Studies of treatments to avoid splanchnic ischaemia during CPB have given conflicting results. We studied 12 rabbits during mild hypothermic non-pulsatile CPB. Tissue blood flow in three different splanchnic areas (gastric, jejunum and ileum) was measured by laser Doppler velocimetry (LDV) before CPB (T0), after steady state (T1), after administration of dopexamine 2 micrograms kg-1 min-1 (T2) and 4 micrograms kg-1 min-1 (T3), and after return to baseline (T4). Splanchnic blood flow decreased during CPB. Dopexamine increased significantly jejunum LDV (100% at T1 to mean 271 (SD 210)% at T2) and ileum LDV (100% at T1 to 187 (112)% at T2). Gastric LDV was not altered by infusion of dopexamine during CPB. This could partly explain the conflicting results on the value of gastric tonometry as an index of splanchnic injury. (+info)
Pseudo-proteinuria following gelofusine infusion.
(12/1874)
Transient massive proteinuria following cardiopulmonary bypass surgery was observed. It was characterized and attributed to post-operative gelofusine infusion. Gelofusine was found to interfere with dye binding but not immunochemical assays of proteinuria. Proteinuria following gelofusine infusion may not reflect underlying glomerular pathology. (+info)
Antibodies to platelet factor 4-heparin after cardiopulmonary bypass in patients anticoagulated with unfractionated heparin or a low-molecular-weight heparin : clinical implications for heparin-induced thrombocytopenia.
(13/1874)
BACKGROUND: Cardiopulmonary bypass (CPB) induces platelet activation with release of platelet factor 4 (PF4), and patients are exposed to high doses of heparin (H). We investigated whether this contributes to the development of antibodies to H-PF4 and heparin-induced thrombocytopenia (HIT). METHODS AND RESULTS: CPB was performed with unfractionated heparin (UFH) in 328 patients. After surgery, patients received UFH (calcium heparin, 200 IU. kg-1. d-1) (group 1, n=157) or low-molecular-weight heparin (LMWH, Dalteparin, 5000 IU once daily) (group 2, n=171). Eight days after surgery, antibodies to H-PF4 were present in 83 patients (25.3%), 46 in group 1 and 37 in group 2 (P=0.12). Most patients (61%) had IgG1 to H-PF4, but only 8 samples with antibodies induced platelet activation with positive results on serotonin release assay. HIT occurred in 6 patients in group 1, but no thrombocytopenia was observed in subjects receiving LMWH, although 2 had high levels of antibodies with positive serotonin release assay results. When antibodies to H-PF4 were present, mean platelet counts were lower only in patients with FcgammaRIIA R/R131 platelets. CONCLUSIONS: These results provide evidence that the development of antibodies to H-PF4 after CPB performed with UFH is not influenced by the postoperative heparin treatment. The antibodies associated with high risk of HIT are mainly IgG1, which is present at high titers in the plasma of patients continuously treated with UFH. (+info)
A comparative study between hypothermic and normothermic cardiopulmonary bypass in open heart surgery in dogs--effects on systemic hemodynamics.
(14/1874)
Open heart surgery was performed on two groups of dogs under extracorporeal circulation with or without hypothermia to investigate hemodynamic changes during extracorporeal circulation. During hypothermic cardiopulmonary bypass (CPB), arterial O2 tension and postoperative blood pressure were favorably maintained, indicating that hypothermic extracorporeal circulation can be performed for a long period of time. On the other hand, during normothermic CPB, the average surgical duration was significantly shorter, and marked shifts in the concentrations of various enzymes were suppressed. However, due to reductions in arterial O2 tension, the length of cardiac arrest time was restricted, demonstrating that this method is suitable for performing extracorporeal circulation for CPB of relatively short duration. If circulation circuitry can be improved, such as through the development of a surpassing oxygenator, normothermic CPB would incur less stress on the body, thus making it preferential to hypothermic CPB in most cases. (+info)
Cerebral response to haemodilution during cardiopulmonary bypass in dogs: the role of nitric oxide synthase.
(15/1874)
During cardiopulmonary bypass, haemodilution is standard practice and is accompanied by increases in cerebral blood flow (CBF). We investigated if changes in cerebral vascular resistance (CVR) during cardiopulmonary bypass-haemodilution are dependent on nitric oxide synthase. The cerebral response to haemodilution in nine dogs treated with the nitric oxide synthase inhibitor, N omega-nitro-L-arginine methyl ester (L-NAME), was compared with a control group (n = 8). Both groups underwent serial isovolaemic haemodilution (target packed cell volumes 0.39, 0.26, 0.19 and 0.14) using 6% dextran 70. CBF, CVR and cerebral metabolic rate for oxygen (CMRO2) were measured. While initial CVR was different in the two groups, haemodilution-dependent reductions in CVR were equivalent and the curves describing the packed cell volume-CVR relationship were parallel in control and nitric oxide synthase inhibition groups. Our data indicate that nitric oxide synthase does not play a primary role in the cerebral response to haemodilution. (+info)
Isoflurane can indirectly depress lumbar dorsal horn activity in the goat via action within the brain.
(16/1874)
We have examined the response of lumbar dorsal horn cells to a noxious mechanical stimulus during differential delivery of isoflurane to the brain and spinal cord of goats. We hypothesized that isoflurane, acting in the brain, would depress dorsal horn neuronal responses to a noxious mechanical stimulus applied to the hindlimb. Eight goats were anaesthetized with isoflurane and neck dissections performed which allowed cranial bypass. Lumbar laminectomies were performed to allow measurements of single-unit dorsal horn neuronal activity. Isoflurane 1.3% was administered before bypass, and during differential delivery it was administered at each of the following head/torso combinations: 1.3%/1.3%, 0.8%/1.3%, 0.3%/1.3%, 1.3%/0.8%, 0.8%/0.8% and 0.3%/0.8%. When the torso isoflurane concentration was 1.3%, decreasing cranial isoflurane from 1.3% to 0.3% did not significantly affect dorsal horn responses (from mean 325 (SD 262) to 379 (412) impulses min-1; P < 0.05). However, when torso isoflurane was 0.8%, decreasing cranial isoflurane from 1.3% to 0.3% increased mean evoked dorsal horn activity by 42% (388 (359) to 551 (452) impulses min-1; P < 0.05). These data suggest that the major effect of isoflurane on dorsal horn responses to noxious stimuli is direct, but there is an indirect effect occurring via descending projections from supraspinal regions. (+info)