RESUMEN
Background: Current ways to diagnose citrate accumulation (CA) in patients receiving regional citrate anticoagulation (RCA) continuous renal replacement therapy (CRRT) are confounded by various clinical factors. Serum citrate measurement emerges as a more direct way to diagnose CA, but its clinical utility and optimal cut-off values remain undefined. This study examined serum citrate kinetics and its diagnostic performance for CA in patients receiving RCA CRRT. Methods: A multicentre prospective study was carried out in two tertiary referral centre intensive care units in Hong Kong with serum citrate levels measured at baseline and 2, 6, 12, 24, 36, 48 and 72 h after initiation of RCA CRRT and their relationships with the development of CA. Results: Among the 133 patients analysed, 18 patients (13.5%) developed CA. The serum citrate levels at baseline and 2, 6 and 12 h after initiation of RCA CRRT in patients who had CA were significantly higher than the non-CA group (P < .001 for all). The CA group also had higher serum citrate levels than the non-CA group {median 0.93 mmol/L [interquartile range (IQR) 0.81-1.16) versus 0.37 mmol/L (IQR 0.26-0.57), P < .001}. Using a cut-off of 0.85 mmol/L, the serum citrate level had a sensitivity of 0.77 and a specificity 0.96 for the diagnosis of CA [area under the receiver operating characteristics curve (AUROC) 0.90, P < .001]. The 2-h and 6-h serum citrate levels had good discriminatory abilities for predicting subsequent development of CA (AUROC 0.86 and 0.83 for 2-h and 6-h citrate levels using cut-off values of 0.34 and 0.63 mmol/L, respectively; P < .001). Conclusion: Serum citrate levels were significantly higher in patients with CA compared with patients without CA. Serum citrate levels showed good performance in diagnosing and predicting the development of CA.
RESUMEN
Severe acute respiratory syndrome (SARS) presents an unprecedented diagnostic and therapeutic challenge to clinicians. Despite recent progress in identifying and analyzing the coronavirus that is responsible for it, few reports have addressed the clinical complications of SARS. The present study was a two-center retrospective cohort study. All patients in the study had SARS, were managed in the two major Hong Kong hospitals (ie, Prince of Wales Hospital and United Christian Hospital), and had developed spontaneous pneumothorax during their hospitalization between March 10, 2003, and April 28, 2003. Spontaneous pneumothorax was reported in 6 of 356 SARS patients who were treated at the two hospitals during the period. This represents an incidence of 1.7%. None of the six patients had a history of smoking or pulmonary disease. The rate of admission to the ICU was 66.7% and the crude mortality rate was 33.3% in this group of patients. There was a trend for the mean neutrophil count in these patients to be higher than in previously reported cohorts of comparable SARS patients (14.5 x 10(9) vs 4.6 x 10(9) neutrophils per liter, respectively). Conservative measures like tube thoracostomy or observation alone offered satisfactory initial symptomatic management in five of six patients. Spontaneous pneumothorax is a specific and potentially life-threatening complication in SARS patients. Patients with extensive lung injury, as indicated by severe clinical courses, and in particular high neutrophil counts, appear to be most at risk. The benefits of surgical management must be balanced against the potential risks to health-care workers.