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Biomedical subjects

I M Ledingham

Publications and source records attributed to I M Ledingham.

At least 55 records · Page 3Linked to original sources
PubMed1984

Mixed venous oxygen saturation changes during tension pneumothorax and its treatment.

A case is reported of tension pneumothorax following left subclavian venous cannulation for placement of a fibreoptic pulmonary artery flotation catheter. Mixed venous oxygen saturation was continuously monitored and a fall in this was the first indication of the problem. Observations on the cardiovascular consequences of tension pneumothorax were made and followed during its treatment. The value of continuous monitoring of mixed venous oxygen saturation in the early detection of haemodynamic disturbances is emphasized.

Adult↗
PubMed1984

The plasma kallikrein kinin system in severely ill and traumatised patients.

Serial estimations of plasma prekallikrein in four critically ill patients in intensive care showed reduced values in each case, suggesting activation of the plasma kallikrein kinin system. In contrast, samples taken early from 15 patients attending an accident and emergency department with multiple trauma showed significantly elevated plasma prekallikrein concentrations; the significance of this observation is at present unclear.

Adult↗
PubMed1984

The effect of etomidate on adrenocortical function in dogs before and during hemorrhagic shock.

The effects of the hypnotic agent ethyl phenylethyl imidazole carboxylate (etomidate), on corticosteroidogenesis were studied in greyhound dogs during a 2-h period of anesthetic followed by a further 2 h of anesthetic combined with hemorrhage. Three groups of dogs were studied. The first, a control, received thiopentone and pentobartitone for induction and maintenance of anesthesia. A second control group received the chemically unrelated hypnotic preparation, althesin, after induction with thiopentone and pentobarbitone. In the first control group and the althesin-treated control group, changes in plasma ACTH and in plasma renin and angiotensin II concentrations were followed closely by changes in the levels of their respective dependent corticosteroids. A third experimental group received etomidate after induction of anesthesia with thiopentone and pentobarbitone. In these, in contrast, plasma levels of progesterone, 17 alpha-hydroxyprogesterone, corticosterone, cortisol, and aldosterone decreased during the experiment even failing to respond to massive rises in plasma ACTH concentration, renin, and angiotensin II levels after hemorrhage. However, the ability of 11-deoxycortisol and 11-deoxycorticosterone to respond was retained. These results suggest that etomidate inhibits corticosteroidogenesis directly, probably acting at more than one point in the biosynthetic pathway. It is suggested that it inhibits mitochondrial steroid hydroxylation (e.g. side chain cleavage, 11 beta-hydroxylation), but not 21-hydroxylation which occurs outside the mitochondrion.

Adrenal Cortex↗
PubMed1983

Endotoxaemia in septic shock: clinical and post mortem correlations.

The Limulus amoebocyte lysate assay was used as one of a series of laboratory and clinical investigations on a group of 31 patients suffering from septic shock in order to assess the clinical significance of this assay for the detection of circulating endotoxin in clinical gram-negative sepsis. Four patients with cardiogenic shock served as controls. Endotoxin was detected in the bloodstream of all patients with septic shock during the 24 h following referral and was not detected in the control patients. Eventual clinical recovery was associated with the disappearance of endotoxin from the peripheral blood. Blood cultures were unhelpful as a prognostic indicator in these critically ill patients. A quantitative assay of endotoxin in blood may allow a more precise relationship with the clinical manifestations of major sepsis.

Adolescent↗
PubMed1982

Metabolic acidosis in the critically ill.

The processes that lead to increased blood lactate concentration in shock and critical illness are complex. Although it is widely believed that lactic acidosis develops because of tissue hypoxia and reduced aerobic metabolism, a number of workers have shown that lactate oxidation rate is actually increased. Lactate production is also increased and this is probably the cause of increased blood lactate concentration. The clinical usefulness of lactate estimation in critical illness is also obscure. Suggestions that whole blood lactate concentration is an accurate predictor of the outcome of an episode of shock are unconvincing. At best this method may differentiate between groups of patients. However, the rate of improvement in lactate concentration with intensive resuscitation probably correlates better with survival, and further investigation of this possibility is suggested.

Acidosis↗
PubMed1982

Liver function in septic shock.

Serum liver function tests were estimated in 57 patients admitted to an Intensive Therapy Unit (ITU) with a diagnosis of septic shock. Following an initial biochemical disturbance, persisting hyperbilirubinaemia was associated with a poor prognosis. Post-mortem liver histology in 22 patients showed varying degrees of non-specific reactive change, venous congestion, ischaemic necrosis, fatty change and intrahepatic cholestasis in 16 cases. In the remaining six cases there was moderately severe cholestasis with inspissated bile in the cholangioles. The possible aetiology of the observed cholestasis is discussed.

Cholestasis, Intrahepatic↗
PubMed1982

Candida colonization of the oral cavity.

A quantitative study of candida colonization of the oral cavity was made in 20 normal persons, 20 patients receiving regular dialysis treatment, 21 patients who underwent operation and were in a general surgical ward and in 20 critically ill patients who had undergone operation and were in an intensive therapy unit. Candida colonization was common in the patients who had operations, and levels were highest in those receiving antibiotics. However, the administration of antibiotics was not the only factor accounting for high candida colonization, since many of the patients studied, receiving regular dialysis treatment and antibiotic therapy, had only low levels of colonization. Candida levels in the oral cavity were highest in the critically ill patients, two of whom had candida infection of the oral cavity and one patient who had systemic candidiasis. Within this group, candida colonization was not significantly different, according to the clinical outcome or the response to recall antigens. This increased candida colonization of the oral cavity may be important in the development of candida infection in these patients.

Adolescent↗
PubMed1981

Effect of naftidrofuryl on the metabolic response to surgery.

In a randomised study of 34 patients undergoing elective operations of moderate severity naftidrofuryl infusion significantly improved postoperative nitrogen balance. The control group excreted 26.2 +/- 2.7 g nitrogen in the first three postoperative days. A group treated with naftidrofuryl excreted 18.0 +/- 1.6 g nitrogen in the same period (p less than 0.0005). The preoperative nutritional state of patients treated with naftidrofuryl did not differ from that of the controls. Though hormonal changes causing an improvement in nitrogen balance could not be excluded by this study, the results show that naftidrofuryl infusion may stimulate postoperative catabolism of endogenous carbohydrate and fat, thus sparing tissue protein.

Adolescent↗
PubMed1981

Myocardial contusion in blunt chest trauma: a ten-year review.

A retrospective review was undertaken of 169 patients admitted to an Intensive Therapy Unit with a major chest injury to determine the incidence, clinical features and outcome of patients with myocardial contusion. This injury occurred in 29 (17%) patients, of whom 24 (83%) had significant cardiovascular complications and five died as a direct result of the injury. The interval between injury and diagnosis was 3.2 +/- 2.3 days (mean +/- SD) from injury and in six patients the diagnosis was made only at necropsy. Increased awareness of myocardial contusion is required for earlier diagnosis and prevention of complications.

Adolescent↗
PubMed1981

Assessment of host resistance in critically ill surgical patients by the response to recall skin antigens.

The cell-mediated immunity (CMI) of 47 critically ill surgical patients admitted to an Intensive Therapy Unit was assessed by their response to recall skin antigens and found to be markedly reduced. Thirty-seven patients showed no reaction to initial skin testing (NR), and there were 21 deaths in this group. Ten patients reacted (R) to initial skin testing and only one of these patients died (p less than 0.025). Repeat skin testing was performed on 22 NR patients. Eight became R on repeat testing and there was one death in this group, whilst 14 remained NR and there were 11 deaths in this group (p less than 0.025). The major clinical difference between R and NR patients was a greater incidence of severe sepsis in the NR patients. These findings suggest that the use of recall skin antigens to assess CMI may be a valuable investigation in critically ill surgical patients and that initial and persisting failure to react to skin tests is associated with a poor outcome.

Adolescent↗