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Biomedical subjects

H Kehlet

Publications and source records attributed to H Kehlet.

At least 379 records · Page 21Linked to original sources

Comparison of pituitary-adrenocortical response to hypoglycaemia and surgery.

The hypothalamic-pituitary-adrenocortical (HPA) responses to the hypoglycaemic stimulus and to operation (laparotomy) are compared. The studies were carried out in eight patients who were subjected to insulin-induced hypoglycaemia on the day before elective abdominal surgery. Plasma corticotrophin (ACTH) and plasma cortisol concentration increases were virtually indentical during the two procedures, which suggests that hypoglycaemia and surgical trauma are comparable stress factors and that the hypoglycaemia test is reliable in predicting the HPA responses to major surgical trauma.

Adrenocorticotropic Hormone↗

Epidural analgesia inhibits the renin and aldosterone response to surgery.

Renin activity and aldosterone concentration in plasma and excretion of sodium and potassium in urine were measured during a period of 24 hours in 12 patients undergoing hysterectomy under general anaesthesia or epidural analgesia. Analgesia extended from T4 to S5 and was effective throughout the study. The normal stress-induced increase in plasma renin activity and aldosterone was inhibited by epidural analgesia. Urinary excretion of potassium was significantly lower in the epidural group, but sodium and water retention showed no difference between groups. It is concluded that neurogenic stimuli from the surgical area are important release mechanisms of the renin-aldosterone response to surgery. The results suggest that post-operative sodium retention is caused by factors other than the mineralocorticoid system.

Adult↗

Plasma corticotropin and cortisol in patients with pituitary adenomas.

Plasma ACTH and cortisol were measured during insulin-induced hypoglycemia in 39 patients with a pituitary adenoma or after hypophysectomy and in 26 healthy persons. Adrenocortical insufficiency was defined as failure to increase plasma cortisol to at least 500 nmol/liter (18 microgram/dl) during hypoglycemia. No proper distinction was possible between patients with normal and impaired cortisol response to hypoglycemia on the basis of the ACTH results. When all 39 patients were compared to the 26 controls, the cortisol results differed significantly, but those of ACTH did not. These results demonstrate a limited value of ACTH measurements in secondary adrenocortical failure.

Adenoma↗

Strategy in the diagnosis of insulinoma.

A simple diagnostic strategy in the diagnosis of insulinoma in adult subjects is proposed based upon the literature and own experiences. It comprises measurement of plasma proinsulin, insulin and C-peptide as well as blood glucose after an overnight fast. When a low or normal proinsulin concentration is found, organic hyperinsulinaemia is very unlikely, while elevated proinsulin, after exclusion of uremia, hepatic cirrhosis, thyreotoxicosis and surreptitious administration of insulin or sulfonylurea drugs, strongly indicates this condition.

Adenoma, Islet Cell↗

Cimetidine treatment of recurrent ulcer.

Twenty-one consecutive patients with endoscopically proven recurrent ulcer were treated continuously with cimetidine, 1 g daily for 8 weeks. After 4 weeks' treatment 18 (86%) of the patients were free of symptoms, and the ulcers had healed in 17 (81%). At the 8th-week examination symptoms had disappeared, and ulcers were healed in 19 patients (91%). Within 6 weeks after withdrawal of cimetidine six patients (28%) presented recurrence of ulcers and symptoms. This study demonstrates that recurrent ulcer patients respond to cimetidine with regard to healing of ulcers and disappearance of symptoms, as do unoperated duodenal ulcer patients. Because operation for recurrent ulcer carries an increased mortality, we suggest that cimetidine should be attempted in the treatment.

Adult↗

Epidural analgesia improves postoperative nitrogen balance.

Postoperative nitrogen balance was monitored in twelve patients undergoing hysterectomy under either epidural analgesia or general anaesthesia. The mean cumulative five-day nitrogen losses were significantly lower after epidural analgesia than after general anaesthesia. Nitrogen sparing presumably results from inhibiting the stress-induced release of catabolic hormones, since epidural analgesia abolished postoperative hyperglycaemia and increase in plasma cortisol concentrations. No adverse effects of inhibiting the stress response were observed. Neurogenic stimuli thus play a crucial part in the catabolic response to surgery. Inhibiting the endocrine metabolic response to trauma by neurogenic blockade may reduce the morbidity precipitated in high-risk patients by the catabolic response to surgery.

Adult↗

Inhibition of aldosterone response to surgery by saline administration.

The renin-angiotensin system, ACTH and hyperkalaemia are known to induce increased plasma levels of aldosterone. In order to assess the relative significance of these mechanisms during surgical stress, aldosterone, cortisol and electrolytes in plasma were measured in 12 otherwise healthy women during and after cholecystectomy. The patients received either isotonic sodium chloride or 5 per cent glucose in water during the experimental period of 22 h. The results showed that the pronounced increase of aldosterone and the concomitant decrease of sodium in plasma found in patients given glucose in water could almost be inhibited by the administration of saline. Cortisol and potassium concentrations were identical in the two groups of subjects. It is concluded that the aldosterone response to surgery is mainly mediated via the renin-angiotensin system. This response is probably due to a reduced sodium content or volume of extracellular fluid, since it could almost be inhibited by administration of sodium chloride. The rationale of saline restriction during and after surgery is questioned.

Adult↗

Discrepancy between ACTH and cortisol responses to insulin induced hypoglycaemia.

The purpose of this study was to assess the normal relationship between plasma ACTH and cortisol during insulin induced hypoglycaemia. Twenty-six healthy persons were studied. Peak plasma concentration and the amounts of ACTH and cortisol secreted during hypoglycaemia were compared. There was no significant correlation between the ACTH and cortisol values. The ACTH responses varied significantly more than those of cortisol. This probably signifies an over-capacity of ACTH secretion in comparison to the secretory capacity of the adrenal cortex.

Adrenocorticotropic Hormone↗

Influence of morphine anaesthesia on the endocrine-metabolic response to open-heart surgery.

Twelve patients scheduled for aortic valve replacement during extracorporal circulation were randomly allocated to either morphine anaesthesia or fluroxene anaesthesia. Morphine in a total dose of 4 mg/kg was administered before skin incision. At the start of extracorporal circulation all patients received 25 g glucose intravascularly. The endocrine-metabolic response to surgery, as expressed by changes in plasma ACTH, cortisol, insulin, growth hormone, cyclic adenosine-3',-5'-monophosphate (cyclic AMP), glucose, free fatty acids, blood b-hydroxybutyrate and cumulative nitrogen balance was measured before and during anaesthesia and surgery, and on the first five post-operative days. It was found that morphine anaesthesia blocked the increase in ACTH, cortisol, growth hormone, cyclic AMP, and glucose during surgery. However, after initiation of extracorporal circulation only ACTH, cortisol, and, to a lesser degree, the glucose and insulin response to glucose were lowered by morphine anaesthesia. From the first to the fifth days after operation no differences between the two groups could be demonstrated in any parameter. Cumulative nitrogen balance was similar in the two groups. It is concluded that morphine in large doses administered before skin incision inhibits the initial endocrine-metabolic response to open-heart surgery, but that the effect is short-lasting and without effect on overall postoperative protein catabolism.

Adolescent↗

Reliability of the 30-minute ACTH test in assessing hypothalamic-pituitary-adrenal function.

An insulin hypoglycemia test and a 30-min ACTH test were performed in 90 patients with proved or suspected hypothalamic-pituitary-adrenal hypofunction and in 10 normal subjects. The peak plasma cortisol concentration during hypoglycemia and the cortisol concentration at 30 min after injection of 250 micrograms corticotropin 1-24 were compared. A very close correlation (r = 0.92) was found between the the two concentrations, with no major discrepancy in any case. It is concluded that the short ACTH test accurately reflects the integrated hypothalamic-pituitary-adrenal function, as assessed by the insulin hypoglycemia test.

Adenoma↗

Kinetics of human C-peptide in man.

A review of studies concerned with the metabolism of human C-peptide showed that the kidney is the major organ in C-peptide removal. The turnover rate of C-peptide was similar to that of proinsulin but considerably slower than that of insulin. An analysis of corresponding C-peptide and insulin concentrations in normal subjects after the administration of oral glucose or intravenous glucagon was used to define the relationships between the two peptides. These results show that different peripheral vein concentrations of insulin may correspond to identical C-peptide concentrations, depending on sampling conditions.

C-Peptide↗