Recognising severe pneumonia with simple clinical and biochemical measurements

Abstract

-Community-acquired pneumonia (CAP) is the most common reason for acute admission to hospital and the fourth most common cause of death in the UK. It is important to identify patients with severe pneumonia and the worst prognosis. We conducted this study to validate a rule designed to do this devised in New Zealand. CAP was defined by evidence of new shadowing on the chest X-ray and clinical features of pneumonia. A standardised proforma was completed documenting clinical features and investigation results. Severe pneumonia was identified by two or more of the following: confusion; respiratory rate 30/min; diastolic blood pressure 60 mmHg; urea >7 mmol/l. One hundred patients (mean age 58.8 years) were included; 32 satisfied the rule. Seven died, all of whom satisfied the rule. Ten patients received intensive care, including six who died. Of 11 patients who died and/or received intensive care, nine satisfied the rule. The sensitivity and specificity of the rule for predicting death and/or intensive care were 82% and 73% respectively.

Is it time to rethink the urea criterion in CURB-65?: Table 1—

“…In a prospective study of elderly patients aged o65 yrs with CAP (mean¡SD age 81.1¡7.9 yrs), we reported that the sensitivity and specificity of CURB in predicting death were 81 and 52%, respectively [5]. The specificity figure of this elderly cohort was much lower than in other studies of younger patients [2,6,7]. Due to this low specificity, the CURB-65 criteria in their current form are not ideal for assessing older CAP patients.…”

“…Although all ages were included in the first study [7], in the second study only those who were aged o65 yrs were included [5]. Therefore, the compilation cohort consisted of a higher number of older patients with CAP and a higher mean age (mean¡SD age 70.3¡18.2 yrs) compared with previously reported studies.…”

“…A recent study from 50 sites in Europe [7] found that 75% of study participants with mild COPD (GOLD stage II) were already taking inhaled corticosteroids, despite the fact that no inhaled medication has been found to improve clinical outcomes in patients with an FEV1 .50% pred [8].…”

“…This may be due to the fact that chronic renal impairment is more prevalent in the older population, and dehydration, which is common in acutely unwell older patients, may also contribute to a higher urea level [8]. With this background, we set out to assess whether raising the cut-off point of urea, while keeping the other criteria in CURB-65 as they are, would improve the specificity and positive predictive value (PPV) of the criteria in predicting mortality.Analyses were conducted based on data from two prospective cohort studies [5,7], which were carried out in a single institute in UK using similar inclusion and exclusion criteria. Although all ages were included in the first study [7], in the second study only those who were aged o65 yrs were included [5].…”

“…Analyses were conducted based on data from two prospective cohort studies [5,7], which were carried out in a single institute in UK using similar inclusion and exclusion criteria. Although all ages were included in the first study [7], in the second study only those who were aged o65 yrs were included [5].…”