Biomedical subjects

K Crowley

Publications and source records attributed to K Crowley.

5 recordsLinked to original sources

PubMed1991

The microgenetic method. A direct means for studying cognitive development.

Progress in understanding cognitive developmental change mechanisms requires methods that yield detailed data about particular changes. The microgenetic method is an approach that can yield such data. It involves (a) observations of individual children throughout the period of the change, (b) a high density of observations relative to the rate of change within that period, and (c) intensive trial-by-trial analyses intended to infer the processes that gave rise to the change. This approach can illuminate both qualitative and quantitative aspects of change, indicate the conditions under which changes occur, and yield otherwise unobtainable information about short-lived transition strategies. The cost in time and effort of such studies is often high, but the value of the information about change can more than justify the cost.

Achievement↗

PubMed1990

Serum concentrations of prilocaine following retrobulbar block.

Retrobulbar block for eye surgery is associated with adverse reactions. We performed retrobulbar block in 10 patients using prilocaine (Citanest) and found mean (SD) peak serum concentrations of 851 (165.6) ng ml-1 (range 540-1100 mg ml-1). Peak serum concentrations occurred 3-7 min after the end of administration of the block, and in all cases were less than those associated with toxicity.

Aged↗

PubMed1990

Diuretics after transurethral prostatectomy: a double-blind controlled trial comparing frusemide and mannitol.

Mannitol and frusemide were compared in a randomized, controlled, double-blind trial for their effects in promoting diuresis after prostatectomy and on indices of water intoxication. The drugs had comparable diuretic effects. Sodium loss was greater with frusemide, contributing to sodium depletion after operation. Administration of frusemide was associated with more frequent need for i.v. volume expansion after operation. Plasma osmolality was greater with mannitol (289 (SD 4.2 mosmol kg-1 at 1 h after operation and 285 (5.3) mosmol kg-1 at 4 h after operation) than with frusemide (282 (7.1) mosmol kg-1 and 279 (6.7) mosmol kg-1, respectively) (P less than 0.05). Plasma concentration of sodium was significantly greater with mannitol (136.9 (3.1) mmol litre-1) than with frusemide (134.4 (2.8) mmol litre-1) only on the morning after surgery (P less than 0.05). Mannitol is an effective alternative to frusemide in inducing diuresis after prostatectomy, and may protect against water intoxication.

Diuresis↗

PubMed1990

Septicaemia and the prevention of multiorgan failure--the intensive care perspective.

Septicaemia frequently presents without "classic" signs of infection--tachypnoea, hypotension and confusion are the commonest features. The mortality rate is 40 to 80% and in intensive care units, septicaemia accounts for 70% of all deaths. Despite the use of antimicrobial drugs to which the offending organism is sensitive, patients are still dying. Effects on distant organ systems are due to "Mediators". "Microvascular Failure" resulting in tissue hypoxia is the unifying hypothesis of multiple organ failure in septicaemia. Mortality is correlated with the number of organ system failures. Supportive management is aimed at prevention of organ failure--manipulation of the circulation being the central key. Intravascular volume expansion, vasoactive drugs, mechanical ventilation and invasive monitoring are the means. Antimicrobial therapy must be guided by 'best guess' approach with multiple agents until isolation of the offending organism can recommend specific therapy. Aggressive surgical drainage or excision, is particularly applicable in abdominal sepsis. Several adjunctive therapies aimed at mediators of sepsis, are as yet experimental.

Critical Care↗

PubMed1989

Barbiturate anesthetics inhibit thromboxane-, potassium-, but not angiotensin-induced pulmonary vasoconstriction.

Administration of the oxidant lipid peroxide tertiary butyl hydroperoxide (t-bu-OOH) in the isolated rabbit lung leads to acute pulmonary vasoconstriction, which is caused by the synthesis of thromboxane. The inhalational anesthetics, halothane, nitrous oxide, and cyclopropane, markedly enhance t-bu-OOH-induced pulmonary vasoconstriction and thromboxane production. The effects of the intravenous (iv) barbiturates thiopental and pentobarbital on t-bu-OOH-induced vasoconstriction were studied. Thiopental completely and pentobarbital partially blocked t-bu-OOH-induced vasoconstriction. Thiopental inhibited t-bu-OOH-induced synthesis of thromboxane and prostacyclin but pentobarbital did not. This inhibitory action of thiopental may be due to its antioxidant properties because similar inhibition has been observed of t-bu-OOH-induced thromboxane production with the antioxidants, vitamin E, or butylated hydroxylanisole. Thiopental and pentobarbital also inhibited the vasoconstriction induced by a thromboxane analog, epoxymethano prostaglandin H2 (U46619). Finally, both barbiturates partially inhibited the pulmonary vasoconstriction caused by potassium chloride, which requires calcium entry, but they did not inhibit the constriction caused by angiotensin II, which does not require calcium entry. These results suggest that pentobarbital and thiopental may block pulmonary vasoconstriction by inhibiting calcium entry.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗