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Biomedical subjects

F Carli

Publications and source records attributed to F Carli.

At least 91 records · Page 5Linked to original sources

The independent metabolic effects of enflurane anaesthesia and surgery.

The metabolic effects of enflurane anaesthesia (1MAC) in air/oxygen were investigated in six healthy unpremedicated women scheduled for total abdominal hysterectomy (TAH). The changes in acid-base status, CO2 production, and circulating concentration of total protein, albumin and a variety of metabolites (glucose, lactate, glycerol and alanine) were measured before and during a 2-h period of anaesthesia alone, during 1 h of anaesthesia plus surgery, and in the recovery period. The subjects were maintained normothermic (36.5 +/- 0.3 degrees C), and with an arterial SaO2 above 95% throughout the period of study. The circulating concentration of all metabolites changed little as a result of anaesthesia alone, but the glucose and lactate levels rose rapidly after the onset of surgery (P less than 0.05). Plasma albumin and total protein concentration decreased during the study, reaching values that were significantly lower than the pre-anaesthetic values (P less than 0.05). CO2 production decreased by 9% during anaesthesia and surgery, but returned towards preoperative values during recovery. This study provides no evidence of any significant effect of enflurane anaesthesia alone on human intermediary metabolism. Most of the changes in circulating metabolite concentrations observed during and after anaesthesia and surgery are likely to be due to the surgical stress.

Acid-Base Equilibrium↗

Intermediate filaments in smooth muscle from pregnant and non-pregnant human uterus.

The intermediate filament proteins desmin and vimentin from pregnant and non-pregnant uterine muscle and smooth-muscle cells in culture were analysed using SDS/PAGE. The desmin content in uterine muscle increases dramatically during pregnancy, whereas vimentin remains unchanged or changes very little. When muscle cells are kept in culture, a considerable increase in vimentin content is observed as compared with vimentin in freshly isolated non-pregnant uterine tissue. Our results strengthen the view that vimentin and desmin filaments have independent function and turnover, and point to a predominantly structural role for desmin filaments.

Blotting, Western↗

Aspects of protein metabolism after elective surgery in patients receiving constant nutritional support.

1. The present study was designed in an attempt to resolve conflicting views currently in the literature relating to the effect of surgery on various aspects of protein metabolism. 2. Sequential post-operative (2, 4 and 6 days) changes in whole-body protein turnover, forearm arteriovenous difference of plasma amino acids, glucose, lactate and free fatty acids, muscle concentration of free amino acids, RNA and protein, urinary nitrogen and 3-methylhistidine, plasma concentrations of insulin, cortisol and growth hormone, and resting metabolic rate, were measured in six patients undergoing uncomplicated elective total abdominal hysterectomy. 3. All patients received a constant daily diet, either orally or intravenously, based on 0.1 g of nitrogen/kg and an energy content of 1.1 times the resting metabolic rate for 7 days before and 6 days after surgery. 4. Whole-body protein turnover, synthesis and breakdown increased significantly 2 days after surgery (P less than 0.05) and returned towards pre-operative levels thereafter. 5. Forearm release of branched-chain amino acids and alanine, and efflux of glucose and lactate, were enhanced 4 days after surgery (P less than 0.05). Muscle glutamine and alanine concentrations were decreased on the fourth and sixth days after surgery (P less than 0.05). The RNA/protein ratio (indicating the capacity for protein synthesis) was unaltered. 6. A significant increase in urinary nitrogen and 3-methylhistidine was observed on days 3 and 4 after surgery (P less than 0.05). Thereafter, these parameters remained elevated, although failing to reach statistical significance.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Effect of general anaesthesia on whole body protein turnover in patients undergoing elective surgery.

To determine if general anaesthesia alone or in conjunction with surgery alters body protein turnover, we studied six healthy, unpremedicated females undergoing elective total abdominal hysterectomy. Changes in protein metabolism, synthesis and breakdown were estimated by an isotope dilution technique using a continuous infusion of the stable isotope tracer, L-[1-13C]leucine, before anaesthesia (4 h), during anaesthesia alone (1 h), during anaesthesia and surgery (1 h) and in the recovery period (2 h). General anaesthesia comprised thiopentone, pancuronium, enflurane (1 MAC) and oxygen-enriched air. An isotopic steady state in plasma 13C-alpha-ketoisocaproate (13C alpha-KIC) and expired 13C-carbon dioxide were obtained during the four periods. Collections of plasma and expired air were made during the steady state periods and plasma alpha-KIC enrichment measured to indicate precursor pool labelling from which leucine flux (equal to protein breakdown in the post-absorptive state) and oxidation were calculated, and whole body protein synthesis was derived. Whole body protein breakdown did not change with anaesthesia, but decreased with both surgery and during the acute recovery period (P less than 0.05). Protein synthesis did not change with anaesthesia and surgery, but decreased significantly after surgery (P less than 0.05).

Adult↗

Effects of enflurane and isoflurane in air-oxygen on changes in thermal balance during and after surgery.

The temperatures in the aural canal (core), skeletal muscle and skin surface were measured during anaesthesia and surgery in 32 healthy females undergoing total abdominal hysterectomy and for 4 h after operation. The patients were allocated randomly to one of four groups according to the end-tidal concentration of volatile anaesthetic: 1 MAC isoflurane, 1 MAC enflurane, 1.8 MAC isoflurane and 1.8 MAC enflurane. The lungs were ventilated with an air-oxygen mixture. Neuromuscular block was produced with pancuronium. Room temperature and i.v. fluid administration were standardized. Aural canal, muscle and mean skin temperatures decreased significantly in all groups during surgery (P less than 0.001). The decrease in core and muscle temperatures, and mean body heat was significantly greater in the 1.8 MAC groups than in the 1 MAC groups for both volatile agents (P less than 0.001). However, there was a significantly greater decrease in core temperature and mean body heat in the isoflurane compared with the enflurane group (P less than 0.026). Body temperature returned to preoperative values during the recovery period. There was a significantly greater rate of rewarming during the first 1 h of recovery in the 1.8 MAC groups compared with the 1 MAC equivalent (P less than 0.001), and this was independent of the volatile agent used. The present results are compared with those reported previously in which nitrous oxide was added to the volatile agents. The decrease in body temperature depends upon the concentration of vapour used. However, it appears that isoflurane, without nitrous oxide, caused greater loss of body heat than enflurane.

Adult↗

Maintenance of body temperature in elderly patients who have joint replacement surgery. A comparison between the heat and moisture exchanger and heated humidifier.

The effect of a heat and moisture exchanger on intra-operative aural canal (core) and mean skin temperatures was investigated in elderly patients who had elective total hip arthroplasty under general anaesthesia with artificial ventilation of the lungs. Group 1 (n = 20) did not receive any form of artificial humidification while in group 2 (n = 20) a heat and moisture exchanger was inserted in the breathing system and in group 3 (n = 20) the inspired gases were humidified and warmed at 40 degrees C by means of a heated humidifier. Time of surgery, intravenous fluid administration and operating theatre temperature were standardised. Mean (SD) aural canal (core) temperature decreased significantly in groups 1 and 2 (p less than 0.001), while there was a fall of 0.3 degrees C (0.6) in group 3, which was not significant. Mean skin temperature decreased during anaesthesia and surgery in both groups 1 and 2 (p less than 0.05), while it increased in group 3. There was a significantly greater loss of body heat in groups 1 and 2 compared with group 3 intra-operatively (p less than 0.001). We conclude tha a heat and moisture exchanger did not prevent the decrease in intra-operative body temperature in elderly patients.

Aged↗

Intra-operative epidural blockade with local anaesthetics and postoperative protein breakdown associated with hip surgery in elderly patients.

The effect of epidural anaesthesia of limited duration on postoperative protein breakdown was studied in elderly patients undergoing hip arthroplasty. Two groups of six patients each were studied. One group with halothane (C) and one with an epidural block, T8-S4, (E) as part of their general anaesthetic for surgery. The urinary excretion of urea nitrogen and 3-methylhistidine (3-MeH), an indicator of muscle protein breakdown, increased significantly in both groups after surgery, by the same amount (P less than 0.05). The total concentration of plasma and muscle aminoacids decreased after surgery in both groups. Muscle glutamine was decreased by 50% after surgery on the fourth postoperative day in both groups (P less than 0.05). Therefore epidural anaesthesia, limited to the period of surgery, did not attenuate the loss of body proteins which occurred during the postoperative period.

Aged↗

The relationship between the circulating concentrations of interleukin 6 (IL-6), tumor necrosis factor (TNF) and the acute phase response to elective surgery and accidental injury.

The possible role of Interleukin 6 (IL-6) and tumour necrosis factor (TNF) in the regulation of the acute phase response to injury was studied in thirteen subjects undergoing elective surgery or suffering from multiple accidental injuries. The temporal changes in the circulating concentrations of these cytokines were related to the circulating acute phase protein concentrations (C-reactive protein and alpha 1 antichymotrypsin), white cell count, blood loss and duration of surgery. Circulating acute phase protein concentrations rose in all subjects during a thirty hour period following injury but none of the subjects showed a detectable rise in circulating concentrations of TNF. Peak circulating concentrations of IL-6 were detected between 4-6 hours after surgery/trauma but these showed a poor correlation with blood loss, fever, white cell count or duration of surgery. The peak concentrations of IL-6 typically occurred before the rise in circulating acute phase protein concentration. The data do not suggest a role for circulating TNF in the regulation of the acute phase response to injury. In contrast, IL-6 appears to be variably involved in the acute phase response but its precise role in mediating fever, leucocytosis and synthesis of acute phase proteins is as yet uncertain.

Acute-Phase Proteins↗

Effect of halothane, enflurane and isoflurane on body temperature during and after surgery.

The superficial and deep body temperatures of 40 healthy females undergoing total abdominal hysterectomy were measured during surgery and for 4 h afterwards. The patients were allocated randomly to one of five groups and anaesthetized to produce an end-tidal concentration of 1% halothane, 1% enflurane, 2% enflurane, 1% isoflurane or 2% isoflurane. The patients received also 70% nitrous oxide in oxygen and neuromuscular blockade. The theatre temperature was maintained at 22.0 degrees C. There were significant body temperature changes during operation in all groups. The mean (SD) decrease in core temperature over 85 min was approximately 1.1 (0.3) degrees C in the 1% halothane, 2% enflurane and 2% isoflurane groups, and 0.6 (0.4) degrees C in the 1% enflurane and 1% isoflurane groups (P less than 0.05). During the recovery period the 1% halothane, 2% enflurane and 2% isoflurane groups took 2 h to rewarm to preoperative temperatures, and the rate of rewarming during this time was similar for all groups.

Adult↗

Effect of peroperative normothermia on postoperative protein metabolism in elderly patients undergoing hip arthroplasty.

We have examined in elderly patients the effect of maintenance of normothermia during hip surgery on postoperative protein metabolism. In one group of six patients (warmed group) heat loss was minimized during surgery and in the recovery period by warming fresh gases, i.v. fluids and wrapping the exposed parts of the body with a warming blanket. In a second group of six patients (cold group), routine care was provided. General anaesthesia consisted of thiopentone, tubocurarine and halothane in both groups. Urinary excretion of urea nitrogen and 3-methylhistidine (3-MeH) after surgery was significantly lower in the warmed group compared with the cold group (P less than 0.05). There was little effect of normothermia on amino acid concentrations in plasma after surgery. Muscle glutamine concentration 4 days after surgery decreased by 50% in the cold group and 18% in the warmed group. Total body potassium (TBK), measured as an index of body cell mass, decreased significantly after surgery in both groups. However, 7 days after surgery the reduction in TBK in the cold group remained significantly lower than that of the warmed group (P less than 0.05). Maintenance of normothermia during hip surgery appeared to attenuate, but not eliminate, protein breakdown and nitrogen loss after surgery.

Aged↗

Respiratory arrest after a caudal injection of bupivacaine.

A 3.5-year-old child with Cornelia de Lange syndrome presenting for orchidopexy and herniotomy received general anaesthesia which was supplemented by a caudal injection of bupivacaine. Shortly after this he had a respiratory arrest with fixed dilated pupils. No cardiovascular system instability was observed. Approximately one hour later the child made a rapid and complete recovery. The possible causes of these events are discussed with particular reference to the potential effects of caudal injections on intracranial pressure.

Anesthesia, Epidural↗

The Cyclops 33 radiation thermometer. An appraisal for use in anaesthesia.

The Cyclops 33 is a portable infrared radiation thermometer. It has many potential advantages over existing thermometers in anaesthetic practice. The technical details are described and the benefits over other instruments discussed. This apparatus offers considerable scope for advance in the field of thermometry in anaesthesia.

Anesthesiology↗

The sites of hormone storage in normal and diseased parathyroid glands: a silver impregnation and immunohistochemical study.

The results of Grimelius' silver impregnation method and of two immunohistochemical methods for the demonstration of the sites of storage of parathyroid hormone (PTH) were compared in a series of parathyroid glands from 39 patients affected by either hyperplasia or adenoma and from 10 normal subjects. An indirect immunoperoxidase method using an anti-bovine PTH serum gave unsatisfactory results. In contrast a biotin-streptavidin immunoperoxidase method using an antibody against the 44-68 amino acid sequence of human PTH yielded similar results to those with Grimelius' silver impregnation method. This supports the view that argyrophil granules correspond to the secretory granules of PTH. The degree of silver impregnation, however, varied considerably in duplicate sections, probably because of difficulties in standardization of the Grimelius' method. The biotin-streptavidin method appeared more sensitive and was reproducible. The immunohistochemical demonstration of PTH may prove useful in defining the sites of hormone storage in normal and pathological conditions.

Adenoma↗

Allometry of the perivascular spaces of the putamen in aging.

The equation of simple allometry was used to study the relative growths of the diameters of the perivascular spaces (PSs), the diameters of the arterial vessels and their wall thicknesses in specimens of the putamen from 24 subjects aged 62 to 90 years. Our findings supported the view that the diameters of the PSs were mainly related to the dimensions of their arteries, especially in the elderly, and that they grew isometrically with arterial diameters. In addition, the diameters of the PSs were basically independent of age.

Aged↗

The effects of shivering on oxygen consumption and carbon dioxide production in patients rewarming from hypothermic cardiopulmonary bypass.

Oxygen consumption (VO2), carbon dioxide production (VCO2), end-tidal carbon dioxide partial pressure (PETCO2), mixed venous oxygen saturation (SvO2) and haemodynamic variables were recorded every 30 min for four hours in 15 patients recovering from hypothermic cardiopulmonary bypass (CPB). All patients had been anaesthetised with fentanyl 40 micrograms.kg-1, supplemented with isoflurane, and pancuronium 0.15 mg.kg-1 for muscle relaxation. Three of the 15 patients (20 per cent) shivered, defined as intermittent or continuous, vigorous movements of chest or limb muscles. Patients who shivered had a VO2 of 159 +/- 16.4 ml.min-1.m-2 on arrival in the ICU which rose to a maximum value of 254 +/- 28.3 ml.min-1.m-2 by 150 min post-CPB. In contrast, patients who did not shiver had a significantly lower VO2 of 93.1 +/- 6.9 ml.min-1.m-2 on arrival in the ICU which rose to a maximal value of only 168 +/- 11.5 ml.min-1.m-2 by 180 min post-CPB. Maximal VO2 in both groups was reached when the nasopharyngeal temperature (NPT) was approaching normal. VCO2 paralleled the increase in VO2 in both groups. By four hours there was no significant difference between the two groups; however, the VO2 in both groups (160.5 +/- 21.3 ml.min-1.m-2 and 173.9 +/- 12.3 ml.min-1.m-2 respectively) was approximately twice values commonly measured in anaesthetized patients. Patients who shivered had a significantly higher heart rate and cardiac index and significantly lower SvO2. We conclude that the high VO2 and VCO2 associated with shivering causing increased myocardial work may be detrimental to patients who have impaired cardiac function post-coronary artery surgery (CAS).

Aged↗

Influence of neostigmine on postoperative vomiting.

Thirty-eight patients undergoing elective hip or knee surgery were randomly allocated to two groups. Neuromuscular blockade in group A was antagonized with neostigmine 2.5 mg and atropine 1.2 mg, while group B received no drugs to facilitate antagonism of blockade. The incidence and severity of postoperative nausea and vomiting were assessed 24 h after operation. Nausea and vomiting were significantly reduced in group B. The incidence of nausea in group A was 68%, compared with 32% in group B (P less than 0.01). The incidence of vomiting was 47% in group A, compared with 11% in group B (P less than 0.02). A significant relationship was shown between postoperative emetic symptoms and the antagonism of neuromuscular blockade by neostigmine and atropine.

Aged↗

The effect of induced hypotension and tissue trauma on renal function in scoliosis surgery.

The surgical correction of scoliosis in adolescents involves considerable trauma to bone and muscle which, together with hypotensive anaesthesia, might be expected to compromise renal function. Our recent observation of acute renal failure in two such patients prompted a prospective study of renal function following 52 operations in 43 patients. Despite hypotension, blood loss, muscle damage and evidence of fat embolism, renal function was unaltered in all patients, and there was no impairment of spinal cord function. Careful attention was paid to the maintenance of circulating volume which is essential to protect renal perfusion.

Adolescent↗