The importance of intraoperative hyperchloremia.
OBJECTIVE
Hyperchloremia associated with acidosis is associated with worse patient evolution if it is not properly diagnosed and treated. The objective of this study was to determine the intraoperative importance of hyperchloremia.


METHODS
This is a 5-month prospective study. Patients 18 years or older undergoing surgical procedures and admitted to the intensive care unit postoperatively. Terminal patients, diabetics, and with chronic renal failure were excluded. Patients were divided in two groups: CH (hyperchloremia) and SH (without hyperchloremia). Hyperchloremia was determined by analysis of the ROC (Receiver Operating Characteristic) curve, i.e., the point of greater sensitivity and specificity for death was chosen as the limit to differentiate hyperchloremia from normochloremia.


RESULTS
Three hundred and ninety-three patients participated in the study. Serum levels of chloride were 111.9 +/- 6.7 mEq.L-1, pH 7.31 +/- 0.09, and base excess -5.6 +/- 4.6 mmol.L-1. The area under the ROC curve of chloride levels was 0.76 with a cutting point of 114 mEq.L-1, sensitivity = 85.7%, and specificity = 70.1%. The CH group, with chloride levels of 114 mEq.L-1 or more was formed by 31.7% of the patients. Mortality was higher in the CH group than in SH, 19.3% versus 7.4%, p = 0.001, as well as the incidence f metabolic acidosis, pH 7.27 (0.08) versus 7.32 (0.09), p = 0.001, base excess -7.9 (3.8) mmol.L-1 versus -4.2 (4.6) mmol.L-1, p < 0.001, length of surgery 4.5 (1.8) h versus 3.6 (1.9) h, p = 0.001, and volume of intraoperative crystalloid administration, 4,250 (2,500 - 6,000) mL versus 3,000 (2,000 - 5,000) mL, p = 0.002. Other differences between both groups were not observed.


CONCLUSIONS
The incidence of hyperchloremia at the end of surgery is elevated, and it is associated with metabolic acidosis, longer surgeries, greater volumes of crystalloids, and higher postoperative mortality.
Silva Junior
João Manoel
JM
CET/SBA do Hospital Servidor Publico Estadual de São Paulo (HSPE), São Paulo, SP. joao.s@globo.com
Neves
Eliete F
EF
Santana
Thassio C
TC
Ferreira
Ulisses P
UP
Marti
Yara N
YN
Silva
Jose Maria Correa
JM
D000368:Aged; D002712:Chlorides / Q000097:blood*; D005260:Female; D006801:Humans; D007431:Intraoperative Complications / Q000453:epidemiology*; D008297:Male; D008659:Metabolic Diseases / Q000453:epidemiology*; D011446:Prospective Studies
D002712:Chlorides