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Biomedical subjects

C W Bryan-Brown

Publications and source records attributed to C W Bryan-Brown.

At least 19 recordsLinked to original sources
PubMed1992

New directions.

Explore the source record for details and available documents.

Critical Care↗
PubMed1989

Cellular oxygen utilization during multiple organ failure.

Organ survival depends on adequate tissue oxygenation and normal metabolic function. In MSOF there are changes in O2 transport and cellular bioenergetics. These metabolic alterations may set in motion mechanisms of cellular damage that will affect microcirculatory control and the ability of the cell to maintain both function and homeostasis.

Adenosine Triphosphate↗
PubMed1988

Blood flow to organs: parameters for function and survival in critical illness.

Tissues are usually considered as being supply-dependent (e.g., heart and brain) and supply-independent (e.g., splanchnic area, kidneys, skin, and resting muscle) for oxygen delivery. When cardiovascular function is compromised, circulatory compensations are aimed at maintaining supply-dependent tissues. In the long term, this leads to the possibility of an inadequate blood flow to supply independent tissues. The perfusion maintenance of all organs requires adequate cardiac output, blood volume, and arterial BP. When BP and cardiac output fail, regional perfusion diminishes. Although the human system tolerates anemia well, optimum Hct levels are probably between 30% to 40%. Inadequate perfusion can be supplemented partially by increasing the FIO2 on a temporary basis. Hyperoxic arterial oxygen tensions may cause maldistribution of blood flow within organs.

Acute Disease↗
PubMed1987

Ionized calcium monitoring during liver transplantation.

Ionized calcium concentration was measured in five patients undergoing liver transplantation. Varying degrees of decreased ionized calcium were observed in all cases and can be attributed to the chelation of calcium by the citrate added during blood transfusions, the inability of the patient to metabolize citrate by the liver during the anahepatic phase of the transplant, and hemodilution of the blood volume with the perfusion prime during venovenous bypass. Calcium chloride was administered when necessary as guided by ionized calcium measurements to restore concentrations to levels that maintain adequate cardiac output. Because of the serious hemodynamic consequences of severe hypocalcemia, regular monitoring of ionized calcium concentration is necessary during this procedure. Total calcium levels are not reliable for this because they do not reflect the extent of anion binding.

Calcium↗
PubMed1986

Central vs peripheral venous catheters in critically ill patients.

A prospective study of 2,209 intravenous catheters was performed in a multidisciplinary intensive care unit to determine when and why catheters were removed and which sites of insertion were associated with the least morbidity. Techniques of insertion were vigorously supervised. Central and peripheral catheters were cared for by identical protocols. Overt phlebitis or inflammation around the site was 14 times as common with peripheral catheters (353/1,024) than with centrally inserted central catheters (18/713), even though peripheral catheters were removed on the average at 2.9 days and centrally inserted central catheters at 6.2 days. Pneumothorax occurred in seven out of 713 patients with centrally inserted central catheterization, one with hemothorax and two with pneumothoraces requiring thoracostomy tubes. Five were treated successfully with simple catheter aspiration. Three patients out of 1,496 with peripheral or peripherally inserted central catheters required phlebectomy for suppurative thrombophlebitis. We concluded that overall morbidity in critically ill patients is lower from centrally inserted central catheters than peripheral intravenous catheters, with peripherally inserted central catheters in an intermediate position. Supervision of techniques of insertion has to be kept at a high level to keep complications of central catheterization at an acceptable level. Peripheral catheter sites would be better maintained with more frequent replacement of the catheter.

Catheterization↗
PubMed1979

"The colouring substance of blood.".

Over a century ago, Stokes wrote on the oxidation and reduction of "the colouring substance of the blood." The mechanisms that govern the binding of oxygen to hemoglobin have been defined in even greater detail and higher orders of accuracy, even to the ends of the oxyhemoglobin dissociation curve. The Bohr effect has ceased to be a reduction in the affinity of hemoglobin for oxygen due to an increasing hydrogen ion concentration and according to a mere logarithmic equilibration constant. The constant has become a variable, subject to the interactions of temperature, carbon dioxide, organic phosphate, and ionic concentrations. This interdependence of so many variables has rendered the once inaccurate, but precise prediction of the effect of tht, well beyond the means of the average physician managing the treatment of a sick patient.

Biological Transport↗
PubMed1977

Extracorporeal membrane oxygenation for massive pulmonary thromboembolism.

This study was undertaken to determine whether extracorporeal membrane oxygenation (ECMO) could modify the effects of massive lethal thromboembolism and prevent death. Twenty anesthetized dogs were prepared for venoarterial perfusion with a demand pump and membrane lung and were perfused slowly for 1 1/2 hours to lessen homologous blood shock; 1 ml per kilogram of 24-hour-old tantalum-impregnated thrombus was injected intravenously. The dogs had profound systemic hypotension with an elevated mean pulmonary artery pressure (62.9 +/-4.5 mm Hg) immediately after embolization. Control animals generally died within 15 minutes. Four of the 10 ECMO-supported animals lived for six days, at which time they were restudied and killed. Not only can ECMO maintain an animal that would otherwise die quickly of massive pulmonary thromboembolism, but such support, even though temporary, can greatly improve the chances of survival.

Animals↗
PubMed1975

Cardiorespiratory response to a new isoquinoline derivative in critically III patients.

NC 7197, a new N-substituted tetrahydroisoquinoline derivative, was given in doses of 0.2 mg/kg body weight on 26 occasions to a series of 23 critically ill postoperative and posttraumatic patients who had been in moderate or severe degrees of shock. This agent was observed to improve pressure-flow and oxygen-transport variables, including increases in cardiac index, mean arterial pressure, central venous pressure, both left and right ventricular stroke work, central blood volume, systemic vascular resistance, oxygen availability, arteriovenous oxygen content difference, and oxygen consumption, and decreases in mean transit time and pulmonary vascular resistance. Previous studies on critically ill patients have suggested that these are the most commonly desired therapeutic actions for this type of patient. The agent has pronounced inotropic effect with minimal chronotropic effects, but with higher doses, chronotropic effects as well as alpha blocking effects may occur. The optimal effects may be obtained by adjusting the dose to an appropriate therapeutic range. It is concluded that, in the dose used, this agent produced both alpha and beta adrenergic actions in critically ill patients.

Adult↗