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S Lacoumenta

Publications and source records attributed to S Lacoumenta.

17 recordsLinked to original sources
PubMed1998

Minimally invasive long saphenous vein harvesting using a laryngoscope.

BACKGROUND: Traditional open incisions for long saphenous vein (LSV) harvesting are common sources of post operative complications after coronary artery bypass grafting (CABG). To reduce pain and wound healing complications, minimally invasive harvesting techniques are being developed. We have investigated the use of a conventional laryngoscope for cost effective saphenous removal using short incisions and long subcutaneous tunnels. METHODS: The LSV was exposed through small incisions connected by long subcutaneous tunnels. Soft tissue retraction, visualization and illumination were provided by a sterilized laryngoscope with a #3 or #4 Macintosh blade. Dissection was performed with standard instruments while branch ligation was performed with vascular clips. Thirty two patients undergoing CABG between October 1997 and January 1998 underwent minimally invasive vein harvesting assisted by a laryngoscope. Clinical outcomes were evaluated. RESULTS: There were 27 males and 5 females with a mean age of 62.6 +/- 9.3 years in this study. Adequate saphenous vein was removed in 29 of 32 cases. (In three patients, the vein was so superficial that an open incision proved easier). The length of harvested conduit averaged 38.2 +/- 11.01 centimeters (21-55 centimeters). Harvesting time average 37.1 minutes (+/-10.8 minutes; range from 20 to 62 minutes). Postoperatively, There were no wound dehiscences, infections, cellulitis, or major hematomas. Pain and leg edema were considerably less than with traditional open harvest. CONCLUSIONS: Minimally invasive vein harvesting is less traumatic to the extremity with fewer complications and superior patient satisfaction. Although commercial disposable systems are now available to permit minimally invasive harvesting of the saphenous vein, a conventional laryngoscope can be used with much reduced costs.

Adult↗
PubMed1997

Fentanyl and the interleukin-6 response to surgery.

It has been suggested that large doses of opioids may suppress the interleukin-6 response to surgery. We examined the effects of the supplementation of inhalational anaesthesia with either 3 or 15 micrograms.kg-1 fentanyl on the circulating interleukin-6, interleukin-8, C-reactive protein, cortisol and glucose concentrations in 16 patients undergoing pelvic surgery. In both groups, surgery evoked the expected glucose, cortisol and interleukin-6 response but no increase in interleukin-8 was detected. There were no significant differences between the two groups. We conclude that the supplementation of inhalational anaesthesia with conventional doses of opioids does not modify the cytokine response to surgery.

Adult↗
PubMed1990

Comparative studies on the release of vasopressin and 7B2 from isolated hypothalami.

A new protein, 7B2, has been found in the anterior, intermediate and posterior pituitary and the hypothalamus. It has been previously suggested that 7B2 is synthesized in the hypothalamus and is transported to the posterior lobe in a similar way to vasopressin (AVP). We examined the in vitro release of AVP and 7B2, using rat hypothalami in a perifused column system. Membrane depolarization with KCl (56 mM) caused a marked stimulation of AVP release (from 116% to 263% above basal values). Release of 7B2 was also stimulated by potassium from 106% to 212% above basal values. Potassium pulses in calcium-free medium failed to release AVP or 7B2. Osmotic and cholinergic stimulation increased AVP secretion by 205% and 282% above basal values, respectively, but had no significant effect on 7B2 secretion. Chromatographic profiles of perifusion media revealed one immunoreactive 7B2 peak eluting at a coefficient of 0.34 corresponding to that of rat hypothalamic 7B2. Similarly AVP coeluted with AVP standard. Thus AVP and 7B2 are differentially released by cholinergic and osmotic stimuli in vitro.

Acetylcholine↗
PubMed1990

Site of action of fentanyl in inhibiting the pituitary-adrenal response to surgery in man.

To determine the site of action of fentanyl in attenuating the pituitary-adrenal response to surgery, we have measured serum concentrations of cortisol and growth hormone during and after a standardized surgical procedure in two groups of patients. One group received fentanyl 15 micrograms kg-1 i.v. immediately before the start of surgery; a second group received fentanyl 15 micrograms kg-1 i.v. together with corticotrophin releasing factor 100 micrograms i.v., growth hormone releasing hormone 100 micrograms i.v. and arginine vasopressin 10 units i.m. The concomitant administration of the releasing factors with the opioid resulted in a significantly greater serum concentration of cortisol 30, 60, 120 and 240 min after surgery commenced, compared with the group which received fentanyl alone. Similarly, the growth hormone response in the combined group was significantly greater than in the fentanyl-alone group 30 min after the start of surgery. We conclude that the inhibitory effect of fentanyl on surgically-induced secretion of pituitary hormone was mediated directly or indirectly via the hypothalamus.

Arginine Vasopressin↗
PubMed1989

Effects of epidural analgesia on plasma calcitonin gene-related peptide.

The effects of epidural analgesia on plasma calcitonin gene-related peptide (CGRP) values during and after hysterectomy were investigated in 14 healthy patients. In seven patients who received general anaesthesia alone for pelvic surgery, there were no significant changes in plasma CGRP concentrations. In the remaining patients, who received extensive epidural blockade in addition to general anaesthesia, there were again no significant changes in plasma CGRP values. This was in spite of profound sympathetic blockade, as shown by marked hypotension and a significant decline in plasma catecholamines. The epidural group of patients showed the expected attenuation of the glucose, cortisol and growth hormone responses to surgery. The results show that circulating CGRP is unlikely to be involved in the modulation of peripheral vascular tone during pelvic surgery under either general or epidural anaesthesia.

Adult↗
PubMed1988

The distribution of melanin-concentrating hormone-like immunoreactivity in the central nervous system of rat, guinea-pig, pig and man.

The distribution of melanin-concentrating hormone-like immunoreactivity was investigated by radioimmunoassay in the CNS of rat, guinea-pig, pig and man. Highest concentrations of melanin-concentrating hormone-like immunoreactivity were found in the hypothalamus of all the species: rat 204.4 +/- 14.9; guinea-pig 159.5 +/- 23.3; pig 10.9 +/- 4.5 and man 80.1 +/- 19.1 pmol/g. Gel chromatographic analysis of hypothalamic extracts showed five immunoreactive peaks of melanin-concentrating hormone-like immunoreactivity in the rat and pig and six in the guinea-pig and man. High-performance liquid chromatography analysis of hypothalamic extracts showed five immunoreactive peaks in rat, guinea-pig, pig and four in man. However, these peaks appeared at different retention times from that of the single peak of salmon melanin-concentrating hormone. Examination of subcellular fractions of whole rat brain showed that most of the melanin-concentrating hormone-like immunoreactivity is found in the synaptosome fraction. Stimulation of melanin-concentrating hormone-like immunoreactivity release from rat hypothalamic slices revealed that potassium in the presence of calcium stimulated melanin-concentrating hormone-like immunoreactivity release. These findings suggest that mammalian melanin-concentrating hormone-like immunoreactivity has a different amino acid sequence from salmon melanin-concentrating hormone and may exist in multiple molecular forms. It is possible that melanin-concentrating hormone may play a role as a neurotransmitter or modulator in the mammalian CNS.

Adult↗
PubMed1987

Fentanyl and the beta-endorphin, ACTH and glucoregulatory hormonal response to surgery.

The effect of the supplementation of nitrous oxide-oxygen anaesthesia with either fentanyl 15 micrograms kg-1 or 0.5% halothane on the beta-endorphin, ACTH, glucoregulatory hormonal and metabolic response to pelvic surgery was investigated. Fentanyl inhibited the increases in circulating beta-endorphin, ACTH, growth hormone, cortisol and glucose concentrations found in the patients receiving halothane. Changes in circulating beta-endorphin concentrations during surgery probably reflect alterations in pituitary secretion and appear to have no major metabolic effects. The suppression of pituitary secretion persisted for at least 4 h after the start of surgery.

Adult↗
PubMed1987

Beta-endorphin infusion fails to modulate the hormonal and metabolic response to surgery.

The effects of an i.v. infusion of synthetic human beta-endorphin on the hormonal, metabolic and cardiovascular responses to surgery were investigated in female patients undergoing pelvic surgery. A beta-endorphin infusion (2 micrograms/kg as a bolus at induction of anaesthesia + 10 micrograms/kg/h for the first hour of surgery) increased plasma beta-endorphin immunoreactivity to values at least 100-fold greater than those seen during surgery in a control group of patients. In spite of this massive increase the only significant findings were a transient augmentation of the expected hyperglycaemic response and increased plasma glucagon values. There were no significant changes in ACTH, GH, insulin and cortisol secretion, in blood concentrations of lactate or glycerol, or in cardiovascular variables. Complete dissociation between plasma and cerebrospinal fluid concentrations of beta-endorphin was found even when plasma values exceeded 10,000 pmol/l in the presence of anaesthesia and surgery. These results show that the increase in circulating beta-endorphin immunoreactivity associated with clinical stress states are unlikely to modulate the associated hormonal, metabolic and cardiovascular changes.

Adult↗
PubMed1987

Hormonal and metabolic responses to cardiac surgery with sufentanil-oxygen anaesthesia.

The effects of sufentanil, 10 and 20 micrograms kg-1 on the hormonal and metabolic responses to coronary artery surgery were compared in 20 patients. The most important finding was that the changes in circulating beta-endorphin, ACTH, cortisol, GH, glucose, lactate and glycerol concentrations during and after cardiac surgery were similar with both doses of sufentanil. Although sufentanil prevented a significant increase in plasma beta-endorphin, ACTH and cortisol values until 6 h after cardiopulmonary bypass (CPB), a significant increase in GH secretion occurred with the onset of CPB. Plasma insulin concentrations declined significantly after 30 min CPB, but recovered after 60 min CPB with the restoration of normothermia. Blood glucose values did not change during surgery before CPB, but started to rise with the onset of CPB and continued to increase significantly in the postoperative period. Changes in blood lactate and plasma glycerol concentrations primarily reflected the load of CPB and the effects of heparin, respectively. The results show that increasing the dose of sufentanil up to 20 micrograms kg-1 does not result in better suppression of the endocrine and metabolic changes associated with cardiac surgery.

Adrenocorticotropic Hormone↗
PubMed1987

The effects of cortisol supplementation on the metabolic and hormonal response to surgery.

The role of cortisol in determining the metabolic and hormonal changes associated with a standardized surgical operation was investigated. Twelve patients undergoing pelvic surgery were studied. Six received steroid supplementation with an infusion of hydrocortisone sodium succinate at a rate of 8 mg/h for 24 h, together with 1.5 g hydrocortisone acetate intraperitoneally at the completion of surgery, while the remainder acted as a control group. Steroid supplementation resulted in plasma cortisol values in the range 1913-2265 nmol/l from 4 to 24 h after the start of surgery. However, this marked hypercortisolaemia had no significant effects on circulating metabolites other than glucose, and did not alter plasma ACTH, GH and insulin values. The usual glycaemic response to surgery was significantly augmented by 1.0-1.5 mmol/l in the cortisol group. We conclude that changes in substrate mobilization observed after cortisol administration in normal volunteers may not accurately predict the effects found after surgery, when catabolic hormones and other modulators such as interleukin-1 may influence metabolism.

Adrenocorticotropic Hormone↗
PubMed1987

Neuropeptide Y directly inhibits growth hormone secretion by human pituitary somatotropic tumours.

Neuropeptide Y (NPY) is a 36 amino acid peptide, widely distributed throughout the brain and is found in hypothalamic neurones. This latter finding suggests that NPY may possess a hypophysiotropic function. A number of studies have demonstrated effects of NPY on LH and GH secretion by rat pituitary cells. We report here the results of experiments investigating the effects of NPY on GH secretion by tumorous human somatotropic pituitary cells in culture. NPY (0.25-25 nmol/l) inhibited GH secretion by 20-53%, the maximal effect depending upon the tumour studied. The potency of NPY was less than that of somatostatin (SRIH). The stimulatory effects of growth hormone releasing factor (GHRH) and theophylline were reduced by NPY, but NPY did not modify the inhibitory effect of SRIH on GH secretion. It is concluded that NPY may be involved in the control of GH secretion, at least by tumorous human pituitary somatotropes.

Cells, Cultured↗
PubMed1986

Effects of two differing halothane concentrations on the metabolic and endocrine responses to surgery.

The effects of two differing concentrations of halothane, 2.1 MAC or 1.2 MAC, on the metabolic and endocrine responses to abdominal hysterectomy were investigated. The changes in blood glucose and lactate values, and plasma glycerol, cortisol, insulin and catecholamine concentrations were similar in both groups. We conclude that high concentrations of halothane do not suppress the responses to pelvic surgery, and that accurate quantification of the dose of halothane, within the concentration range of 1.2 to 2.1 MAC, is not essential in studies of metabolic changes associated with surgery.

Abdomen↗
PubMed1986

Effects of cortisol suppression by etomidate on changes in circulating metabolites associated with pelvic surgery.

The effects of cortisol suppression by etomidate on the changes in circulating metabolites associated with pelvic surgery were investigated in healthy female patients. The use of etomidate resulted in the inhibition of cortisol secretion for 24 h compared with a control group of patients. However, the inhibition of steroidogenesis was not associated with a significant effect on blood glucose, blood lactate and plasma nonesterified fatty acid values, although the glycaemic response to surgery was consistently less in those patients who received etomidate. Heart rate and arterial pressure were significantly decreased during surgery in the etomidate group compared with the control group, but were similar in the postoperative period when the difference in plasma cortisol between the groups was greatest. The results suggest that cortisol has only a minor role in determining changes in circulating metabolites associated with surgery.

Anesthesia, General↗
PubMed1984

Effects of ketamine anaesthesia on the metabolic response to pelvic surgery.

The effects of ketamine anaesthesia on the metabolic and endocrine response to pelvic surgery were investigated, and compared with results obtained in a control group of patients anaesthetized with thiopentone and halothane. Ketamine anaesthesia before the onset of surgery was associated with a significant increase in blood glucose and plasma cortisol concentrations, and in heart rate. However, when surgery was established there were no metabolic, endocrine or haemodynamic differences between ketamine and halothane anaesthesia. We conclude that ketamine does not exacerbate the metabolic response to surgery.

Adult↗
PubMed1984

Liquid crystal thermometry during anaesthesia.

The use of cutaneous liquid crystal thermometry (EZ Temp) as an estimate of core temperature during routine surgery was investigated in 20 patients. Seventeen per cent of the recordings made with the EZ Temp were more than 1 degree C different from oesophageal temperature. There was a poor correlation between EZ Temp values and both oesophageal and aural temperatures (r = 0.54 for both sites). We conclude that liquid crystal thermometry of the forehead is not sufficiently accurate to be used as an indicator of core temperature during routine surgery.

Anesthesia, General↗