Optimum timing of blood tests for monitoring patients with Clostridium difficile-associated diarrhea.
OBJECTIVE
This study aimed to identify optimum timing of blood tests and suitable cutoff values when managing patients with Clostridium difficile-associated diarrhea (CDAD), in relation to early mortality.


METHODS
Review of 204 patients treated as inpatients for a first episode of CDAD from January to December 2008. Differences in values during the first 7 days of CDAD for white cell count (WCC), albumin, C-reactive protein, and creatinine between those who died and survivors to 30 days were compared using Mann-Whitney U tests. Cutoff values were assessed using receiver operating characteristic curves.


RESULTS
Overall 30-day mortality was 27% (n = 56/204). White cell counts were significantly higher in those who died on the first 3 days (P < 0.001, P = 0.015, and P = 0.001, respectively). Median WCC in those who died was 20 x 10(9)/L or greater on both days 1 and 2. Albumin was significantly different on day 1 only (P = 0.003); C-reactive protein, and creatinine did not differ significantly on any day. The highest WCC in the first 3 days produced an area under the curve of 0.718 (P < 0.001). A WCC cutoff at 20 x 10(9)/L or greater when compared with 15 x 10(9) or greater had a higher positive predictive value (0.46 vs 0.34) and specificity (0.82 vs 0.60) but a lower sensitivity (0.49 vs 0.65). Mortality rates in the 2 groups were 46% and 34%, respectively.


CONCLUSIONS
White cell count in the first 3 days is the strongest serum predictor of mortality and should be routinely monitored. A WCC of 20 x 10(9)/L or greater may be the best cutoff value to objectively identify cases at higher risk of death.
Department of Surgery, Good Hope Hospital, Birmingham, United Kingdom. aneelbhangu@doctors.org.uk
Aneel
A
Bhangu
Adam
A
Czapran
Sonia
S
Bhangu
Devadas
D
Pillay
D000368:Aged; D000369:Aged, 80 and over; D002097:C-Reactive Protein / Q000378:metabolism*; D016360:Clostridioides difficile / Q000302:isolation & purification*; D003404:Creatinine / Q000097:blood*; D003967:Diarrhea / Q000382:microbiology* / Q000401:mortality; D004761:Enterocolitis, Pseudomembranous / Q000097:blood* / Q000401:mortality; D004768:Enterotoxins / Q000032:analysis; D005243:Feces / Q000382:microbiology; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D008991:Monitoring, Physiologic / Q000379:methods; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D012016:Reference Values; D012709:Serum Albumin / Q000378:metabolism*; D015996:Survival Rate; D013997:Time Factors
D004768:Enterotoxins; D012709:Serum Albumin; C035598:enterotoxin, Clostridium; D002097:C-Reactive Protein; D003404:Creatinine