Non-invasive ventilation (PS-IMV) in patients with acute respiratory failure in common wards away from ICU

Objective

Trial of non-invasive ventilation (NIV) in two groups of patients (pts) with postoperative acute respiratory failure (ARF) and acute on chronic respiratory failure, in common hospital wards.

Patients and methods

Two groups of pts (age 50-78). Group A: Surgical (n = 24) with ARF, after major abdominal surgery. Group B: Medical (n = 11) with ARF post COPD, sleep apnea syndrome and stroke. The pts fulfilled at least three of the following criteria: (1)dyspnea-tachypnea (RR > 28/min), (2)the use of the accessory respiratory muscles, (3)abdominal pattern of breathing, (4)PaO₂/FiO₂ < 200 receiving O₂ (Venturi mask), (5)abnormal 0.25 thorax X-ray findings. NIV was used by using the Bi PAP apparatus with nasal mask, with the following settings: PEEP = 5-10 cmH₂O, PS level 10-15 cmH₂O, and IMV breaths 5-12/min, FiO₂ = 0.4-0.5. The application protocol was as follows: first 24 hours - continuous ventilation with short pauses for physical therapy, then with pauses of up to 30 min of spontaneous breathing for the evaluation of the pts respiratory reserve. Pts were monitored with pulse oximeter, BP, CVP, ABG. All the pts were under proper medical treatment (bronchodilators, etc.). The improvement criteria were: sufficient TV, no use of accessory respiratory muscles, FiO₂ < 0.4, PaO₂ > 70 mmHg (FiO₂ = 0.4).

Results

Group A: 16/24 pts (67%) showed significant improvement of ABG values, SaO₂ and respiratory mechanics. They were all cured and left hospital. 8/24 (33%) failed to respond and were intubated and transferred to ICU, owning to bad compliance due to, nasal mask discomfort (n = 4), ARDS (n = 3), acute pulmonary edema (n = 1). Group B: 9/11 pts (82%) were successfully disconnected, 2/11 (18%) failed to be disconnected owning to severe respiratory infection in a COPD, patient (n = 1) and deterioration of mental status in a stroke pts (n = 1). NIV duration: approximately 72 hours.

Conclusions

The application of NIV is very attractive and promising with easy use of the BiPAP in common ward pts with ARF. The majority of our pts responded well and had significant benefit avoiding endotracheal intubation, mechanical ventilation and ICU admission.