Acute severe asthma treated by mechanical ventilation: a comparison of the changing characteristics over a 17 yr period.

Recorded cases of asthma have increased in recent years. It is unclear, however, whether this apparent increase in prevalence is accompanied by an increase in severity of the disorder. One potential measure of asthma severity is the requirement for mechanical ventilation. This paper examines those patients ventilated for severe asthma in a district general hospital over a 17 yr period. Since the methods used to assess asthma attacks and the criteria for instituting mechanical ventilation in this hospital did not alter between 1973 and 1992 (Jones criteria), it was possible to compare directly characteristics of all ventilated patients during the study period. The comparison showed that there was a significant increase between the two study periods in the number of patients who required mechanical ventilation. Moreover, in the more recent period both the subjective speed of onset of the asthma attack and the objective time between admission and ventilation were significantly shorter. However, despite this increase in asthma severity the mortality and morbidity in the more recent study period were lower. Overall the results of this study support the view that, in the population served by our district general hospital, asthma has increased in severity. This increased severity is indicated by an increase in the number of patients requiring mechanical ventilation and in the rapidity with which attacks evolved. However, for patients in whom ventilation was required, improved care has lowered both morbidity and mortality.

Intestinal permeability in the critically ill.

Alterations in intestinal permeability reflect one component of intestinal epithelial barrier function. The objective of this study was to assess the degree of derangement of intestinal permeability in critically ill patients and to investigate the relationship of this to markers of disease severity and sepsis. Sixteen patients admitted to the intensive care unit for a variety of problems were studied with the severity of illness and degree of sepsis recorded daily. A differential sugar absorption test, using lactulose and mannitol as markers, was performed, and in 10 patients this was repeated after an interval of between 4-11 days. The use of the lactulose/mannitol (L/M) ratio corrects for variables unrelated to permeability such as gastric emptying. The L/M ratio was significantly higher in patients (median 0.98) compared to normal controls (median 0.008). The ratios showed no relation to disease severity or sepsis. These results establish that increased intestinal permeability occurs in the general ICU patient but that it is not uniquely related to sepsis. The extent of this abnormality suggests that further study is required to show the various influences on this process.

Acute severe asthma treated by mechanical ventilation: 10 years' experience from a district general hospital.

A retrospective study was made of patients requiring mechanical ventilation (intermittent positive pressure ventilation--IPPV) for acute severe asthma in a district general hospital during 1974-83. Thirty two patients required IPPV on 34 occasions. Complications included pneumothorax in six (18%) patients, chest infection in 12 (35%) patients, pulmonary collapse in three (9%) patients, hypotension at induction of IPPV in 12 (35%), and gastrointestinal bleeding in three (9%). Three (9%) patients died. Therapeutic bronchial lavage was performed in 19 patients. The procedure produced a rise in effective static compliance from a mean of 17 (SD 6) ml/cm H2O to 24 (9) ml/cm H2O at four hours. Bronchial lavage was associated with a significant excess of respiratory infections. A feature common to most patients was undertreatment before admission to hospital.

Coeliac disease presenting as recurrent pericarditis.

Recurrent pericarditis was the presenting feature in two patients with coeliac disease. Treatment with a gluten-free diet led to clinical and electrocardiographic improvement of the pericarditis.

Effect of an elemental diet (Vivonex) on the absorption abnormalities and histological appearances of the jejunum in untreated adult coeliac disease.

The effect of an elemental diet (Vivonex) together with a gluten-free diet on the absorption of water, sodium and chloride in the jejunum was studied in 4 patients with untreated adult coeliac disease before and after a 1-month course of therapy. The morphology of the jejunum was also studied by jejunal biopsy taken at the same time as the intestinal perfusion. The results were compared with those obtained in 4 patients with adult coeliac disease treated with a gluten-free diet alone. No marked improvement was noted in the transportation of water, sodium and chloride after either treatment with Vivonex and a gluten-free diet or after a gluten-free diet alone, and no marked histological changes were found. Clinical improvement occurred in both groups of patients, in that the diarrhoea improved in all patients and they generally felt better. There appears to be no additional advantage of using an elemental diet with a gluten-free diet in the initial management of adult coeliac disease.

Stomach as source of bacteria colonising respiratory tract during artificial ventilation.

10 adults had intermittent positive-pressure ventilation for 3--34 days. All 10 had paralytic ileus. Microbial overgrowth in the stomach was found in 9 patients (bacterial in 7 and fungal in 2); gram-negative bacteria predominated. The trachea invariably became colonised by bacteria, mainly gram-negative organisms. In 3 instances the gram-negative bacteria were found in the stomach before they appeared in the tracheal aspirate, and in 1 case the pathogen originated in the faeces.

Intravenous infusion of a dextrin, Caloreen, in human subjects: metabolic studies.

1. Caloreen, a glucose-polymer dextrin infused into human volunteers, although producing a clear increase in total plasma carbohydrate did not produce a satisfactory increase in plasma glucose levels or serum insulin levels. 2. Urinary losses were high and although small fragments of the dextrin (suggesting metabolic breakdown of the dextrin) were demonstrated in the urine, no suppression of plasma free fatty acid, glucagon or immediate increase in the respiratory quotient were noted, suggesting that the metabolism is too slow to make it useful for parenteral nutrition in its present form. 3. A dextrin with fewer branch-links might be more suitable.

Use of an elemental diet (Vivonex) in the management of bile acid-induced diarrhoea.

The effect of a low fat containing elemental diet (Vivonex) on faecal bile acid excretion was studied in six patients with cholerheic diarrhoea, two normal controls, and four patients with non-cholerheic diarrhoea. The total faecal bile acid excretion for the patients with bile acid-induced diarrhoea was significantly reduced fron 6-37+/- 1-64 mmol/24 h (mean +/- SEM) to 2-70 +/- 1-12 mmol/24 h during Vivonex treatment (p less than 0-05). A marked improvement in the diarrhoea of these patients occurred; the number of stools per day decreased and there was less urgency associated with the diarrhoea. No significant reduction in faecal bile acid excretion was observed for the control and non-cholerheic diarrhoea groups. An elemental diet of this type may be of value in the management of patients with bile acid-induced diarrhoea unresponsive to other forms of therapy, and may be of particular value in patients with Crohn's disease.

Increasing patients' satisfaction with communications.

This paper reports a successful experimental attempt to increase satisfaction with communications amongst general medical patients. A group of patients who received extra interviews designed to increase their understanding of what they had been told about their illnesses showed significantly greater satisfaction than patients treated in the usual manner, and patients who received extra placebo interviews about their hospital stay. Changes in satisfaction with communications over the period following discharge from hospital are also described and possible reasons for them are discussed.