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Biomedical subjects

M H Irving

Publications and source records attributed to M H Irving.

At least 55 records · Page 3Linked to original sources
PubMed1992

Thermogenic and hormonal responses to amino acid infusion in septic humans.

Metabolic effects of a commercially available amino acid infusate were investigated in five preoperative patients with abdominal sepsis and five healthy subjects. Oxygen consumption (VO2) was measured continuously during the 3-h study, and blood samples were taken regularly for hormone and metabolite analyses. During 1 h of preinfusion measurements, VO2 was 15% higher (P less than 0.05) in the septic patients. Preinfusion plasma cortisol, glucagon, and catecholamines were also significantly elevated in the septic group. The amino acid solution (9 g nitrogen; 950 kJ; 227 kcal) was infused into each subject through their central venous catheter during the 2nd and 3rd h of the study. VO2 increased similarly in both groups by approximately 21% during the infusion (P less than 0.05), whereas respiratory quotient increased significantly in only the controls (P less than 0.05). Plasma insulin and glucagon concentrations rose significantly in both groups during the infusion, despite little change in glucose levels. Plasma norepinephrine increased in both groups, although the response was significant in only the control subjects. In summary, the amino acid infusate stimulated metabolic rate similarly in the septic and nonseptic subjects.

Amino Acids↗
PubMed1992

Intestinal failure--the clinical problem.

Intestinal failure can be the end result of a wide variety of disease processes that impair the ability of the gut to adequately digest and absorb food. Patients with established intestinal failure may require parenteral nutrition support and/or abdominal surgery to reverse the disease process involved. Selected patients with irreversible intestinal failure can be managed in experienced units by home parenteral nutrition.

Chronic Disease↗
PubMed1991

Spectrum of intestinal failure in a specialised unit.

300 consecutive admissions over 7 years to a purpose-built intestinal failure unit are reviewed. The commonest underlying condition was Crohn's disease (42%), and the commonest complication precipitating admission was intestinal fistula (42%). Total parenteral nutrition was used in 85% and surgery in 50%. A multidisciplinary approach to management gave a high success rate--90% of patients were discharged from hospital, although nearly 25% needed home parental nutrition. These results suggest that chronic intestinal failure should be managed in specialised units in the same manner as other types of organ failure.

Adolescent↗
PubMed1991

Cyclic neutropenia--unusual cause of acute abdomen. Report of a case.

Cyclic neutropenia, a rare blood disorder, may be complicated by spontaneous necrosis of the cecum and ascending colon. We describe one such case, where a staged surgical approach achieved a successful outcome. The importance of recognition of this disorder is stressed, since this allows both performance of appropriate surgery and consultation with hematologic colleagues.

Abdomen, Acute↗
PubMed1991

Lipid infusion increases oxygen consumption similarly in septic and nonseptic patients.

This investigation compared the metabolic effects of lipid infusion in five septic and five nonseptic patients. Oxygen consumption was determined by indirect calorimetry over 1 h of rest and during 2 h when Intralipid (20%) was infused [166 mL/h; 23 kJ/min (5.5 kcal/min)]. Septic patients had a resting metabolic rate 17% higher than that of their nonseptic control subjects and a significant (P less than 0.05) rise (13%) in oxygen uptake was measured in both groups of subjects during the 2-h infusion of lipid. Preinfusion respiratory quotient (RQ) was 7% higher in the septic patients (P less than 0.05), and during the infusion period RQ decreased similarly (approximately 6%; P less than 0.05) in both groups. Plasma catecholamines were elevated in the septic patients preinfusion and the concentrations remained unaltered during the infusion. Norepinephrine rose significantly in the nonseptic group with the lipid infusion. The results show that sepsis has little or no influence on the characteristic rise in metabolic rate that occurs with intravenous lipid.

Adult↗
PubMed1990

Changes in cardiovascular homeostasis after injury are mediated by tissue damage and not haemorrhage.

During treatment of the injured patient it is assumed that the cardiovascular responses follow recognized physiological principles. Studies in humans have shown that injury causes a profound suppression of arterial baroreflex function which alters the normal relationship between heart rate and blood pressure and casts doubt on this assumption. To investigate the mechanism of baroreflex suppression, we have studied the effects of the two major components of injury, blood loss and tissue damage, on baroreflex function in healthy volunteers. Baroreflex function was assessed using suction stimulation of the carotid sinus. The loss of 500 ml blood had no effect on baroreflex sensitivity. A human laboratory model of tissue injury reduced the ability of the baroreflex to compensate for a rise in blood pressure (P less than 0.05, Wilcoxon signed rank test). We conclude that tissue damage, rather than hypovolaemia, appears to mediate the effect of injury on baroreflex function in the injured. Blockade of neural signals from damaged tissue may have a role in the treatment of injury.

Adolescent↗
PubMed1990

Accumulation and pepsin solubility of collagens in the bowel of patients with Crohn's disease.

The collagen content of resected strictured intestine, with and without fistulas, from patients with Crohn's disease has been compared with that in macroscopically normal intestine removed from the same patients and from others without inflammatory bowel disease. Collagen content per unit wet or dry weight of tissue was significantly increased in all grossly diseased tissue whether fistulated or not. Although there was a significant increase in collagen types I, III, and V in diseased tissue, the relative proportions of major collagen types extracted by limited pepsin digestion were similar for both Crohn's and non-Crohn's intestine (type I, 65 to 70 percent; type III, 25 to 30 percent; type IV, 2 to 3 percent; and type V, 2.5 to 3 percent). CNBr digestion of pepsin insoluble material showed a similar relative abundance of types I and III, indicating no major change in collagen type distribution between older (insoluble) and more newly synthesized collagen. There was no evidence of the presence of type I trimer collagen. Type VI collagen, although not quantitated, was observed in 70 percent of intestinal specimens. The proportion of total collagen solubilized by pepsin treatment was significantly greater in both grossly diseased and macroscopically normal Crohn's bowel compared with non-inflammatory bowel disease bowel. These findings suggest that there are disturbances of collagen metabolism in Crohn's intestine, which account for the stricturing process and which may predate gross pathologic changes.

Collagen↗
PubMed1990

An effect of trauma on human cardiovascular control: baroreflex suppression.

Survival from injury depends on the interaction between the patient's own homeostatic responses and treatment given. The function of the principal homeostatic reflex of the cardiovascular system, the arterial baroreflex, was studied in 22 healthy controls and in 21 moderately injured patients (ISS range, 9 to 17; median, 9) using suction stimulation of the carotid sinus baroreceptors. When compared to controls, marked baroreflex suppression was evident 3 hours after injury (p less than 0.05), at 3 days after injury (p less than 0.001), and even 15 days after injury (p less than 0.05, all Wilcoxon rank sum test). Partial recovery of baroreflex function occurred between 3 and 15 days after injury (p less than 0.005, all Wilcoxon signed rank test) and was complete by 5 months after injury. The suppression of baroreflex activity was accompanied by a "fixed" rise in heart rate and a rise in systolic blood pressure. This study has shown that moderate injury results in a profound and prolonged suppression of baroreflex function. Further advances in the resuscitation and critical care of the injured may need to take account of such derangements of cardiovascular physiology.

Adolescent↗
PubMed1990

Octreotide and gastrointestinal fistulae.

The place of somatostatin and its analogues in the management of gastrointestinal fistulae is reviewed, drawing attention to the difficulty of assessing treatments that influence spontaneous closure. Sixteen patients with gastric, small bowel, and pancreatic fistulae were randomized to receive octreotide injections (100 micrograms t.i.d.) or placebo for 12 days. Spontaneous fistula closure occurred in 7 at a mean of 37 days after entering the trial. A second study is underway with greater patient numbers recruited from peripheral hospitals and with an increased period of octreotide medication (21 days).

Adult↗
PubMed1989

Ascorbic acid absorption in Crohn's disease. Studies using L-[carboxyl-14C]ascorbic acid.

Total body pool and intestinal absorption of ascorbic acid were studied in 12 patients undergoing operation for Crohn's disease (six with fistulae and six without) and in six control patients undergoing operation for reasons other than Crohn's disease. L-[carboxyl-14C]Ascorbic acid, 0.19-0.40 megabecquerels (MBq), was given orally. After a period of equilibration, the labeled ascorbic acid was flushed out of the patient's body tissues using large doses of unlabeled ascorbic acid. Intestinal absorption of ascorbic acid, assessed from the total cumulative urinary 14C recovery, was found to be similar in patients with fistulizing Crohn's disease (73.9 +/- 8.45%), those without fistulas (72.8 +/- 11.53%), and in controls (80.3 +/- 8.11%). Total body pools of ascorbic acid, calculated using the plasma 14C decay curves, were similar in patients with Crohn's disease with fistulas (17.1 +/- 5.91 mg/kg), patients without fistulas (9.6 +/- 3.58 mg/kg), and in controls (13.3 +/- 4.28 mg/kg). The results indicate that ascorbic acid absorption is normal in patients with both fistulizing and nonfistulizing Crohn's disease. The results suggest that routine supplements of vitamin C are not necessary unless oral ascorbic acid intake is low.

Adult↗
PubMed1989

Preventability of death from penetrating injury in England and Wales.

A total of 1000 deaths from injury in England and Wales have been reviewed to establish the incidence and pattern of penetrating injury and the adequacy of its management. Of the 1000 deaths, 71 (7.1 per cent) were due to penetrating injury. There were 32 knife wounds and 30 firearm injuries. Most of the latter were suicides. Only 17 patients (24 per cent) reached hospital alive. Of these cases, 10 had extracranial injury and all 10 deaths were considered to have been potentially preventable when reviewed by four external assessors. One of seven patients with cranial injury was considered to have been a potentially preventable death. The median age of the 11 cases of potentially preventable death was 37 years (range: 7-61 years). Of these, three did not have any surgery for surgically treatable injuries. Seven patients underwent operation and difficulty was encountered in six of these. It appears from our figures that whilst penetrating injury is an uncommon cause of death, it is poorly managed. The implications of this finding for systems of injury care in the United Kingdom are discussed.

Adolescent↗
PubMed1989

Thermic effect of parenteral nutrition in septic and nonseptic individuals.

This study compared the metabolic responses to parenteral nutrition in five septic and six nonseptic individuals. Oxygen uptake (VO2) was measured for 1 h preinfusion and during the first 2 h of parenteral nutrition infusion. While baseline VO2 was 19% higher in the septic compared with nonseptic patients (p less than 0.01), both groups responded similarly to nutrition: VO2 increased 25% and 27% above baseline in the nonseptic and septic groups, respectively (NS between groups). Respiratory quotient increased 9% in the nonseptic (p less than 0.01) and 5% in the septic (p less than 0.05) patients during infusion. Plasma glucose and insulin increased identically in both groups. Cortisol was consistently higher in the septic patients whereas glucagon decreased similarly in both groups with feeding. Norepinephrine increased 25% in response to the nutrition and remained elevated in the nonseptic group. The results illustrate the effect nutrient-induced thermogenesis may have in the energy balance of parenterally fed patients.

Adult↗
PubMed1988

Home parenteral nutrition: a review of 100 patient years of treatment in 76 consecutive cases.

Over the last 10 years, the Nutrition Unit at Hope Hospital has trained and looked after 76 patients on home parenteral nutrition for a total of 100 patient years. Although 40 per cent of patients have required home parenteral nutrition for 6 months or less one patient has been on treatment for 7 years. The quality of life measured on a 4 point scale was good for the majority of patients. Sepsis and superior vena caval thrombosis are the main problems encountered. Overall mortality rate was 18 per cent and the sepsis rate was 0.14 episodes per patient per year. Home parenteral nutrition is an effective and safe treatment of intestinal failure.

Adolescent↗
PubMed1988

How do patients with Crohn's disease fare on home parenteral nutrition?

The United Kingdom and Ireland Register of Home Parenteral Nutrition (HPN) contains details on 237 cases treated between 1977 and 1987. One hundred courses of HPN were given to 89 patients for complications of Crohn's disease. Six registering centers provided 87 percent of the courses of treatment. The short-bowel syndrome was a factor in 60 patients, fistulas in 29 patients, and exacerbation of the disease in 41 patients. Thirty patients had more than one complication. The age distribution of patients with Crohn's disease was the same as for all HPN patients. Nine patients have died and eight have ceased HPN because of complications from the treatment. Fifty two percent of the patients had no complications. Patients with Crohn's disease on HPN had a significantly better lifestyle than the group as a whole (P less than .05) and had lower sepsis and complication rates (P less than .01 and 0.001, respectively). The 60 Crohn's patients with short-bowel syndrome spent a significantly longer time on HPN than Crohn's patients overall (P less than .05). Only 15 of these have been able to cease treatment and resume enteral feeding, compared with 23 of the other 40 patients who were able to resume enteral nutrition after a median of three months. Analysis of the authors' group of 35 patients included in the 100 showed that the only nutritional parameters of use in monitoring the patients' well-being were weight and serum albumin. Eighty percent of the patients with Crohn's disease who were treated by HPN have either successfully resumed enteral feeding or are successfully managing their own HPN. HPN is a safe and effective treatment for patients with acute or chronic intestinal failure from Crohn's disease.

Adolescent↗
PubMed1988

Problems and organization of a home parenteral nutrition service.

Home parenteral nutrition services have revolutionized the treatment, and improved the survival, of patients with prolonged or permanent intestinal failure. Without such a programme, these patients either would be condemned to continuous in-patient parenteral nutrition or to death. The indications for HPN in the UK remain predominantly intestinal failure resulting from inflammatory bowel disease, and major small bowl resection. Nearly 50% of patients receiving HPN will ultimately have normal intestinal function restored and thus be able to return to enteral feeding. This knowledge is reflected in the selection criteria for instituting HPN. The use of HPN in patients with malignant disease poses significant ethical questions. The success of HPN is dependent upon the organization of nutritional units to allow centralization of HPN programmes and to provide the necessary support to patients. It is clear that not all patients will benefit from HPN, and it is only by careful assessment of patients, based on the experience of specialized nutritional units, that a rational HPN service can be provided.

England↗
PubMed1988

Muscle adenosine 5'-triphosphate and creatine phosphate concentrations in relation to nutritional status and sepsis in man.

1. Intramuscular concentrations of adenosine 5'-triphosphate (ATP) and creatine phosphate were measured in the vastus lateralis muscle of 28 non-septic malnourished patients and 31 septic malnourished patients. Similar measurements were made on the rectus abdominis muscle of about one-third of these patients. All results were compared with those obtained from 15 normally nourished non-septic control subjects. 2. Objective measurements of nutritional status (both anthropometric and biochemical) and sepsis were recorded in all subjects. 3. The vastus lateralis muscle of the non-septic and septic malnourished patients had intramuscular concentrations of ATP and total adenine nucleotides (TAN) that were up to 30% lower than control values, depending on the reference base used. 4. In the rectus abdominis muscle, ATP and TAN concentrations were up to 60% lower than control values, and creatine phosphate up to 47% lower, again depending on the reference base used. 5. In both muscles, the changes were more marked in those patients who were septic as well as malnourished.

Adenosine Triphosphate↗
PubMed1988

Treatment of end stage chronic intestinal pseudo-obstruction by subtotal enterectomy and home parenteral nutrition.

Three cases are described of end stage chronic intestinal pseudo-obstruction successfully treated by subtotal enterectomy and home parenteral nutrition (HPN). In all three patients prior use of drugs to stimulate gastrointestinal motility, antibiotics to suppress bacterial overgrowth and surgical bypass of dilated bowel had failed to alleviate the symptoms of chronic intestinal obstruction. Similarly parenteral nutrition combined with restriction of oral intake, although improving nutrition did not relieve symptoms. The treatment of end stage chronic pseudo-obstruction should relieve intestinal obstruction and correct nutritional deficiency. In our experience this is best achieved by subtotal enterectomy, restoration of continuity by end-to-end anastomosis and total parenteral nutrition.

Adult↗