Diagnosis of pulmonary embolus using ventilation/perfusion lung scintigraphy: more than 0.5 segment of ventilation/perfusion mismatch is sufficient.

BACKGROUND: To determine the optimal diagnostic cut-off point using a simplified criterion for the detection of pulmonary embolus (PE) and to evaluate the criterion's utility and reporter reproducibility. METHODS: Lung scintigraphy was carried out in 924 patients for the diagnosis of PE. This group consisted of 316 men and 608 women with median age of 63 years (range 18-94 years). Ventilation imaging was carried out with Tc-99m Technegas followed by perfusion imaging using 190 MBq Tc-99m macroaggregated albumin. Studies were classified using a 6-category probability criterion of incremental ventilation/perfusion (V/Q) mismatch: A, normal; B, low (minor matched V/Q defects or segmental matched V/Q defects without opacity on chest X-ray); C, low-moderate (a partial segment of V/Q mismatch); D, moderate (1 segment of mismatch); E, moderate-high (1-2 segments of V/Q mismatch) and F, high probability (=2 segments of V/Q mismatch). Clinical end-points at 3 and 6 months were death by PE or PE treated with anticoagulation therapy. Three-reporter reproducibility was determined by kappa statistic on a subgroup of patients (53/924). RESULTS: A total of 122 patients (13%) had a confirmed diagnosis of PE at 3 months and no additional cases were registered at 6 months. The lung scintigraphy probability classification showed: normal 152 (16%), low 620 (67%), low-moderate 20 (2%), moderate 28 (3%), moderate-high 24 (3%) and high 80 (9%). The respective sensitivities and specificities, where the diagnostic cut-offs were established at F, high; E, moderate-high; D, moderate and C, low-moderate probability, were F, 64 and 100%; E, 82 and 99%; D, 95 and 98% and C, 98 and 96%. The respective false-negative cases for F, E, D and C cut-offs were 44, 22, 7 and 3. Using the revised Prospective Investigation of Pulmonary Embolism Diagnosis reporting classification reporter agreement showed kappa values of 0.31-0.48. Using a simplified 2-category (>0.5 segment of V/Q mismatch positive, all others negative) criterion resulted in a higher reporting agreement (kappa 0.74-0.83). There were only 3% of indeterminate cases if this was defined by the D category and a maximum of 8% if categories C, D and E were included. CONCLUSIONS: Using a simplified diagnostic criterion where all studies showing >0.5 segments of V/Q mismatch are regarded as positive and all others as negative, lung scintigraphy, incorporating Tc-99m Technegas ventilation imaging or its equivalent, can achieve a very high diagnostic accuracy for the detection of PE. Using this technique, less than 5% of scans are indeterminate. A simplified, unambiguous approach to reporting is recommended.

Prognostic factors for continued or rebleeding and death from gastrointestinal haemorrhage in the elderly.

We analysed 103 episodes of upper gastrointestinal bleeding in 88 elderly patients (age 76 +/- 7.7 years) to determine which of a group of 52 clinical and laboratory variables, measured on admission, best predicted continued or rebleeding, and death in these patients. Variables which related directly to the size of the bleed (blood urea, haemoglobin, pulse rate, systolic blood pressure) were all strongly predictive of both outcomes (P less than 0.001). Of the variables unrelated to the size of the bleed, prolonged prothrombin time and elevated serum creatinine were most strongly predictive of a poor outcome, suggesting that haemostatic dysfunction may be a major contributor to death from upper gastrointestinal haemorrhage in elderly patients. Other variables with strong predictive potential were age (P less than 0.001), the presence of multiple disease states (P less than 0.01), therapy with multiple drugs (P less than 0.01) and acute stroke or obtundation on admission (P less than 0.01). In general terms the size of the bleed was as significant as the premorbid condition of the patient in predicting the outcome. This, together with the fact that half the patients died of hypovolaemia, suggests that death from upper gastrointestinal bleeding in the elderly is not inevitable and that further reduction in mortality from this cause is attainable.

Severe symptomatic hyponatremia in elderly outpatients: the role of thiazide therapy and stress.

Severe symptomatic hyponatremia (serum sodium level 112 +/- 5.5 mEq/l) was encountered in six elderly outpatients within four days of the onset of thiazide therapy. Associated polydipsia was present in two of these patients, but the thiazides alone appeared responsible in the others. In three other elderly outpatients, severe hyponatremia (serum sodium level 112 +/- 5.25 mEq/l) developed after the acute emotional stress of relocation from their place of abode to a nursing home or hospital. Recurrent episodes of hyponatremia occurred in two patients following reinstitution of diuretic therapy, and, in two other patients, was precipitated by thiazides and stress on different occasions. Severe neurologic manifestations occurred in all patients and were mostly attributed to atherosclerotic dementia or stroke. Two patients died with severe hyponatremia, although all patients in whom cessation of thiazide therapy and water restriction were instituted promptly recovered without permanent sequelae.

Haematemesis and melaena in the elderly.

Erosive mucosal lesions associated with the ingestion of ulcerogenic drugs or alcohol, or bile reflux, were the major causes of bleeding found in a group of aged patients on endoscopy for upper gastro-intestinal bleeding. Nonsteroidal anti-inflammatory drugs were strongly associated with bleeding from any site, and indiscriminate prescribing of these drugs in the elderly is ill-advised. Mortality from bleeding was similar to that reported for younger groups. A history of prior upper gastro-intestinal pathology, with or without bleeding, is not helpful in predicting the source of blood loss and endoscopy is necessary on each admission for accurate diagnosis. Endoscopy is safe despite the adverse effects of blood loss and intercurrent illness in elderly patients.