Malnutrition reduces respiratory muscle mass and can contribute to failure to wean and ventilator dependency in patients on prolonged mechanical ventilation (PMV). Creatinine Height Index (CHI), which reflects lean muscle mass, is regarded as the most accurate indicator of malnutrition. No previous studies have assessed the relation between CHI and weaning. The objective of this study was to determine if CHI can predict successful weaning in patients on PMV in comparison with traditional nutritional indices in a regional weaning center (RWC).
We retrospectively studied 146 consecutive patients on PMV, admitted to a RWC with failure-to-wean, between 1999–2001. PMV was defined as being on ventilatory support for > 21 days. The following parameters were obtained from records: age, sex, BMI, total protein, albumin, prealbumin, hemoglobin, total lymhocyte count (TLC). Creatinine clearance is routinely measured in these patients in this facility. CHI was calculated as: daily creatinine excretion/ ideal daily creatinine excretion based on height × 100. Outcome measured was liberation from mechanical ventilation which was defined as > 48 hours off ventilator. Multivariate analysis was performed to determine the association between above varaibles and outcome. p <0.05 was considered statistically significant.
Of 146 patients, 73 were males and 73 females. Mean age was 65.5±16.2 years. Malnutrition was severe (CHI <60%) in 72% patients; moderate (CHI 60–80%) in 24%; and mild (CHI 81–90%) in none. Nutritional status was normal (CHI >90%) in 4%. Seventy-three percent (106/146) were liberated from mechanical ventilation while 27% (39/146) failed to wean. Parameters studied in these two groups of patients is tabulated below.CONCLUSIONS: Higher total protein, albumin and CHI are associated with successful liberation from mechanical ventilation; CHI more so than albumin and total protein. BMI, prealbumin, hemoglobin and TLC have no effect on weaning outcome in PMV.CLINICAL IMPLICATION: Higher CHI is associated with successful liberation from PMV. CHI is a better prognosticator than other nutritional indices for weaning outcome in patients on PMV.
NUTRITIONAL INDICES IN PATIENTSPARAMETERLIBERATEDFAILED TO WEANpWEIGHT (lbs)164.9 ± 53.7159 ± 400.48BMI (kg/ m2)27 ± 8.625.9 ± 7.80.49TOTAL PROTEIN (g/dL)5.9 ± 0.75.4 ± 0.90.01ALBUMIN (g/dL)2.6 ± 0.52.4 ± 0.40.04PREALBUMIN (mg/dL)20 ± 720 ± 70.95HEMOGLOBIN (gm/dL)10.7 ± 0.79.9 ± 1.30.17TLC (cells/ mm3)1584 ± 7251448 ± 8740.34CHI (%)53.7 ± 21.742.4 ± 150.006
D. Datta, None.