Publications of the Week, July 17

Diagnosis of acute pancreatitis: sensitivity of serum amylase and lipase & urinary trypsinogen and amylase

Tests commonly used for the diagnosis of acute pancreatitis have useful but far-from-perfect characteristics.

This Cochrane meta-analysis included 10 studies involving over 5000 patients with suspected pancreatitis. Almost a quarter of those patients were ultimately diagnosed with acute pancreatitis based on one of the reference standards used in individual studies. The evaluated investigations included commonly used tests for serum lipase and serum amylase and less commonly performed tests for urinary trypsinogen 2 and urinary amylase.

A 3-fold elevation in the levels of serum lipase and serum amylase and an elevation >50 ng/mL in the level of urinary trypsinogen 2 had a sensitivity of 72%, 79%, and 72%, respectively. This translates into about a quarter of patients ultimately diagnosed with pancreatitis being missed by those tests at the provided thresholds. Specificities were similar among the tests, at 93%, 89%, and 90%, respectively. At a 23% observed prevalence of acute pancreatitis among the evaluated patients, such characteristics would translate into about 70 out of 100 people with a positive test result having pancreatitis, and about 8 out of 100 people with negative test results sill having the disease. In addition, about 1 in 10 among the evaluated patients without acute pancreatitis may be wrongly diagnosed as having this disease.

The authors stress the need to interpret the results of those commonly used tests with caution.

Nursing interventions, incidence of delirium, and hospital length of stay in the elderly

A simple nursing intervention decreased the incidence of delirium and reduced the hospital length of stay in elderly patients undergoing elective major abdominal surgery.

In this nursing-led study involving 377 patients at the average age of about 75 years, patients were assigned to either regular postoperative care involving encouraging of early ambulation or to the same care plus daily 30-minute visits by a special study nurse. The intervention provided by that nurse included 3 components: orienting communication, oral and nutritional assistance (for example, brushing teeth and practicing swallowing), and early mobilization. The presence of postoperative delirium was assessed by examining the presence of core symptoms (inattention, sudden onset of fluctuating symptoms, and either an altered level of consciousness or disorganized thinking).

Patients participating in the active intervention group experienced delirium less frequently (6.6% vs 15.1%) and their length of stay was on average 2 day shorter (12 vs 14 days).

Head elevation in acute stroke

The degree of head elevation within hours of stroke had no influence on patients’ outcomes.

The positioning of a patient with acute stroke – lying flat or semi-sitting-up (with the head elevated to 30 degrees) – is a matter of controversy. In this study involving over 11 000 patients with stroke (ischemic or hemorrhagic, but not subarachnoid), individual hospitals were assigned to maintain a flat position or a position with at least a 30-degree head elevation. The position was to be maintained as much as possible for 24 hours after enrollment in the study (on average, after about 14 hours of the start of symptoms), including while eating, drinking, and toileting. Outcomes included mortality and the modified Rankin score, a 6-point scale ranging from 0 (no symptoms) through 2 (slight disability), 4 (moderate disability requiring assistance with daily living), 5 (severe disability with being bed-bound and incontinent), to 6 (death).

The results showed a very similar 90-day mortality rate (7.3% among the patients lying flat and 7.4% among those sitting up) and no significant differences in the distribution of Rankin disability scores between the examined groups.