THE IMPACT OF DEMOGRAPHIC
AND EARLY CLINICAL ADMISSION DATA ON THE DURATION AND OUTCOME FROM MECHANICAL
VENTILATION
Pedro Revuelta
Rabasa, Cayetano Naranjo Jarillo, Juan José Jiménez Rivera, María Teresa
Brouard Martín, Francisca Prieto Valderrey
Servicio de Medicina
Intensiva
Hospital
Universitario de Canarias
La Laguna. Santa
Cruz de Tenerife
España
(Beca concedida por
La Fundación Canaria de Investigación y Salud (FUNCIS) del Gobierno Autonómico
Canario (PI 76/98))
INTRODUCTION:
General objectives: epidemiological study
project of prolonged mechanical ventilation (MV) (acronyme PREVENT®),
focused on the elaboration of a large data-base to describe the patients
characteristics, natural history, and on identifying factors influencing on
outcome. Specific objectives: the
potential impact of early-adquired demographic and clinical admission data on
the duration of MV and on mortality.
PATIENTS
AND METHODS.
Dynamic cohort study of 205
patients requiring MV >12 hours, during a 10 months follow-up period. We
collected previous quality of life, degree of dyspnea and established organ
disfunction (simplified Knauss score, s-OSF), admission category and diagnosis,
demographic and nutritional data, SAPS II, APACHE II and the reason for MV. The
impact on the duration of MV was analyzed by the Kaplan-Meier curves and the
Cox survival regression model. Impact on mortality was analized by univariate and
logistic regression model.
RESULTS.
Incidence of prolonged MV
35%. Age 57.8 ± 1.2 years.
Males 136 (66%). SAPS II 42.0 ± 1.2, APACHE II 17.8 ± 0.5, s-OFS 1.41 ± 0.1. Duration of MV 13.9 ± 2.4 days. Weaning duration
8.8 ± 2.2 days
(62.3% of total). ICU lenght of stay (LOS) 16.6 ± 2.1 days. Hospital LOS 41.9
± 3.3 days. ICU
mortality 25.4 % (52), hospital mortality 33.7% (69). The duration of MV was
longer in respiratory pathology (29.6 ± 13.9 days), followed by
neurologic (14.9 ± 6.3 days) and
trauma (12.8 ± 1.9 days). It
was longer in nonsurvivors 15.6 ± 5.1 versus
10.8 ± 1.6 days in
survivors (log-Rank, p <0.00005).
APACHE II adjusted hazard
ratio: (aHR) 0.92 (95% CI 0.89 to 0.95), sepsis (with/without associated
neumonia): aHR 0.36 (95% CI 0.19 to 0.70), body mass index: aHR 0.97 (95% CI
0.93 to 0.99), and ARDS: aHR 0.20 (95% CI 0.06 to 0.68) reduced the rate of
disconnection. Surgical category
relative to medical: aHR 1.68 (95% CI 1.11 to 2.56), and chronic respiratory
(CRF): attaHR 1.71 (95% CI 1.02 a 2.90) increased the rate of disconnection.
Female gender with an
attributable risk of 15%, an attributable fraction in exposed of 34% (c2 4.49; p 0.034), and an adjusted odds ratio
(aOR) of 2.80 (95% CI 1.22 to 6.41), degree of malnutrition: aOR 2.80 (95% CI
1.35 to 5.84), SAPS II: aOR 1.07 (95% CI 1.03 to 1.10), cardiac arrest: aOR
34.42 (95% CI 6.90 to 171.58), postoperative respiratory failure: aOR 3.65 (95%
CI 1.20 to 11.03), and cardiac failure: aOR 5.93 (95% CI 1.56 to 22.48)
increased mortality risk, whereas age: aOR 0.97 (95% CI 0.94 to 0.99) tended to
decrease mortality risk.
CONCLUSIONS.
Early-adquired demographic
and admission clinical data were useful tools in predicting outcome from
mechanical ventilation in our population.
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