Effectiveness of Noninvasive Ventilation in Acute Respiratory Failure

Abstract
Background: Primary advantage of NIV is the prevention of complications from invasive ventilation, the acute first disorders treated with NIV were exacerbation of COPD and ALE and over the last 20 years the use of it has been extended to patients with hypoxemic RF.
Aim of Study: Was to determine the effectiveness of NIV, the factors predicting failure of it in ARF.
Patients and Methods: This study was prospective obser-vational study on 60 patients with acute respiratory failure which were divided into 3 groups, Group A included 20 patients with ARF type II due to COPD exacerbation, Group B included 20 patients with ARF due to acute lung edema in patients with acute or chronic heart failure and Group C included 20 patients with ARF due to pulmonary causes other than ACPE. NIV applied and complete clinical examination including: Vital signs, (GCS) scale and APACHE II score assessment were done at first. (ABG) the first was at the admission to ICU and the second ABG after 2 hours from the start of NIV.
Results: Regarding the fate of NIV either the success or failure it was found that the total percent of patients in which the NIV successed was 68.33% and the total percent of patients in which the NIV failed was 3 1.67%, group C show the higher percentage of failure of NIV (60%). Logistic regression was assessed at the start of NIV to elucidate parameters that had relation to failure at the start showed that GCS was the parameter most closely related to failure followed by APA-CHEII score then type of the respiratory failure of the studied groups, Logistic regression was assessed for the change of ABG parameters & vital signs at the start after 2 hours from NIV to elucidate parameters that had relation to failure found that the change in HR was the parameter most closely related to failure followed by the change in RR and the change in temperature then the change in PaO2.
Conclusion: The type of acute respiratory failure is inde-pendent risk factor for failure of NIV so, NIV is an effective modality with hypercapnic RF due to exacerbation of COPD and cardiogenic pulmonary edema and can avoid the endotra-cheal intubation, the use of it in hypoxemic RF should be assessed on an individualized basis but the key factor in deciding the use of NIV is the probability of failure which can worsen the prognosis of patients regardless the type of ARF and our results had identified several independent pre-dictors of failure as the GCS and the APACHEII score at the start of NIV, the change of respiratory rate, heart rate and PO2 level from baseline to the second hour from its suspension