Risk factors in toxic megacolon.

A retrospective analysis of data from a series of 22 patients with toxic megacolon complicating ulcerative colitis was performed in an attempt to detect factors associated with the fatal outcome of the attack. Of the 25 clinical findings studied, significant differences between survivors (17) and nonsurvivors (5) were observed in only seven. In nonsurvivors, duration of the disease was longer and blood pH and standard bicarbonate levels higher, whereas serum potassium, calcium, phosphorus, and beta-globulins were lower. Discriminant analysis showed that three pairs of features, namely potassium-beta-globulins, potassium-bicarbonate, and potassium-blood pH provided a good discrimination between survivors and nonsurvivors. Results of this study indicate that the severity of the electrolyte and metabolic disorder appears to be an important risk factor in toxic megacolon. Intensive fluid and electrolyte replacement should therefore be considered a crucial point for successful management of toxic megacolon.

Intestinal gas in ulcerative colitis.

Intestinal gas was measured planimetrically on plain abdominal films from 25 healthy subjects and 47 patients with active ulcerative colitis (mild, moderate, severe and toxic megacolon). Compared with controls, significant colonic distention was found in toxic megacolon. Gas in the small bowel was significantly increased in toxic megacolon and in severe colitis but was within the normal range in the mild and moderate forms. Two groups of patients with severe colitis were identified, showing either normal or increased gas content in the small bowel. Two of seven patients in the latter group developed toxic megacolon in spite of intensive medical treatment. Intestinal gas values showed a linear correlation with arterial blood pH, ESR and body temperature. No correlation was found between intestinal gas and other features of severity. It is suggested that an abnormal collection of gas in the small bowel loops associated with metabolic alkalosis corresponds to an early stage of a toxic complication ("impending megacolon").

Salt-losing diarrhoea in idiopathic proctocolitis.

The faecal output of chloride, sodium and potassium was studied in 14 patients with active idiopathic proctocolitis, in an attempt to establish a relationship between faecal electrolyte output and acid-base balance data. 7 patients with ileostomy and 8 healthy volunteers were used as controls. The daily faecal excretion of chloride and sodium in proctocolitis was significantly in excess of normal, whereas that of potassium was within the normal range. From the comparison with the results in patients with ileostomy it is concluded that colitic colon has an impaired capacity to absorb chloride and sodium but retains the ability to secrete potassium. The intestinal loss of chloride in addition to that of sodium and water may be regarded as a salt-losing diarrhoea and may account for the metabolic alkalosis commonly found in proctocolitis.

Blood pH: a test for assessment of severity in proctocolitis.

Acid base balance was studied in 58 patients with active idiopathic proctocolitis; the condition of 10 of them was complicated by toxic megacolon. Arterial blood pH increased progressively with increased severity of the colitis and as the lesions became more widespread. Statistically significant differences were observed in pH values between the mild/moderate and severe forms and between the severe and complicated forms ('toxic megacolon'). A linear correlation was found between pH and the amount of intestinal gas, pulse rate, and plasma albumin.