Risk Factors for Prolonged Intensive Care Unit Stay in Patients with Hypercapnic Respiratory Failure.

Introduction: Hypercapnic respiratory failure (HRF) is one of the most frequent reasons for intensive care unit (ICU) admissions. In this study, we aimed to investigate the risk factors for prolonged ICU stay in HRF patients for longer than 7, 10, and 15 days.

Methods: Impact of demographics, vitals at the admission, comorbid disease severity, respiratory parameters, admission diagnosis, noninvasive mechanical ventilation (NIV) application time and settings, arterial blood gas, and blood biochemistry results were analyzed in patients with HRF to investigate risk factors for longer ICU stay.

Results: A total of 210 patients who were admitted to ICU with HRF (PaCO₂ values of 45 mmHg and higher) were included in this retrospective cohort study. The mean age of the patients was 69 ± 12 years, and the mean ICU duration was 9 ± 7 days. Forty-five percent of the patients stayed in the ICU for more than one week and 10% of them stayed for more than 15 days. Risk factors for a prolonged stay in ICU for more than 7 days were high SOFA score, acute renal failure (ARF) at admission, low PaO₂/FiO₂ on the 2^nd day of admission, and high TSH level. Low FEV1 and FEV1/FVC ratio, ARF at admission, and low PaO₂/FiO₂ ratio on the 2nd day of admission were found to be risk factors for prolonged stay in ICU for longer than 10 days. Significant risk factors prolonging the ICU duration for more than 15 days were high SOFA score, low FEV1, low FEV1/FVC ratio (p = 0.008), and hypothyroidism (p = 0.037). FEV1% predicted less than 25.5% and FEV1/FVC% less than 46.5% were significantly associated with ICU stay longer than 10 days.

Conclusion: Earlier diagnosis and treatment of patients with hypothyroidism and severe airflow obstruction could shorten the length of ICU stay of hypercapnic patients.