Factor analysis of bowel symptoms in US and Italian populations

BACKGROUND AND AIMS: Functional gastrointestinal disorders are diagnosed by the presence of a characteristic set of symptoms. Aims of this study were to validate the Rome symptom criteria by factor analysis and to determine whether symptoms cluster in the same way in different cultures. METHODS: One thousand forty-one gastroenterology clinic patients in the US (response rate 53%) and 228 family members accompanying clinic patients in Italy (84%) completed a previously validated symptom questionnaire. Factor analysis identified clusters of symptoms which are highly correlated with each other, and these were compared to the Rome diagnostic criteria. RESULTS: In the US, 13 factors were identified. The irritable bowel factor was composed of three core symptoms corresponding to the Rome II classification system. Two dyspepsia factors were identified which correspond to the ulcer- and motility-like subtypes proposed in the Rome I classification system. All symptoms of constipation formed a single cluster as proposed in the Rome II classification system. Symptom clusters in the US agreed well with symptom clusters identified in Italian subjects. CONCLUSIONS: Empirically derived symptom clusters agree in most respects with the Rome II classification system and support their validity. These symptom clusters are independent of cultural differences in diet and behaviour.     

The safety of patient-controlled sedation

We have investigated the safety of a previously described method of patient-controlled sedation in 100 healthy patients presenting for elective surgery. The device used 0.33-ml boluses of propofol (10 mg.ml⁻¹) infused over 6 s with no lockout. All patients attempted to put themselves to sleep by pressing a button on the hand-held device. The oxygen saturation, heart rate, sedation score and airway patency were noted every minute. When the patient stopped pressing the button, the anaesthetist took over the handset and continued pressing the button until the patient became unresponsive. The system allowed rapid sedation. Only five patients were still anxious after 2 min. After 3 min, no patient was still anxious and more than 70 patients had slurred speech. When they stopped pressing the button, 11 patients were judged oversedated, of whom two were unresponsive. One patient's oxygen saturation decreased transiently to 84%: no other patient's oxygen saturation decreased below 90%. There were no other significant changes. We conclude that the system studied works well but carries too high a risk of oversedation for unsupervised use.     

The relationship of the extrinsic blood supply to regeneration in graft reconstructed peripheral nerves

Median nerves of rats were reconstructed with conventional or vascular nerve grafts. After 2, 3 and 4 weeks, Allen Video-Enhanced Contrast, Differential Interference Contrast (AVEC-DIC) microscopy revealed axonal transport in most preparations, with varying degrees of myelination. Radio-isotope tracer was measured in the nerve. Two and 4 week measurements revealed no difference between the graft types. At 3 weeks the vascular graft group exhibited transport along the entire length of the nerve in contrast to a relatively abbreviated path length in the conventional graft group. Nerve conduction velocities (NCV) were measured proximal to, within and distal to the grafts. Three week NCV showed no difference between the graft types. The 4 week NCV revealed normal values in the vascular graft group at points distal to and within the graft. Significant slowing was seen in the conventional grafts at both points.     

The management of injuries--a review of deaths in hospital

A prospective review was undertaken of the management of 111 consecutive patients who died in hospital after admission for treatment of injuries. A standard set of data relating to each patient was reviewed by each member of a trauma death audit committee and then by the whole committee. Autopsy reports were available on all patients. Conclusions were drawn concerning defective aspects of patient management and possible avoidance of each death. Injury severity was assessed using the Trauma Score (TS) and Injury Severity Score (ISS). The possibly avoidable death (PAD) rate was 17%. The most common defects in management were related to inadequate fluid resuscitation and delays in definitive management. The greatest contributions to the PAD rate were from inadequate fluid resuscitation, delays and inadequate perception of the severity of injuries or significance of clinical deterioration. Increasing age was related to a higher frequency of PAD. PAD rate in the presence of severe head injury was 8%, but was 63% in the absence of a severe head injury. It is concluded that review of all trauma deaths is an achievable, beneficial and essential part of a hospital-based integrated trauma service. TS and ISS are not sufficiently sensitive to justify their use in selecting deaths for review. Improved blood volume replacement, earlier and more direct management and supervision by senior specialist staff, and elimination of causes of delay in patient management should all decrease the death rate from injuries particularly in patients without severe head injury.