Delayed but successful response to noninvasive ventilation in COPD patients with acute hypercapnic respiratory failure

Abstract

Background

We evaluated a new noninvasive ventilation (NIV) protocol that allows the pursuit of NIV in the case of persistent severe respiratory acidosis despite a first NIV challenge in COPD patients with acute hypercapnic respiratory failure (AHRF).

Patients and methods

A prospective observational multicentric pilot study was conducted in three tertiary hospitals over a 12-month study period. A total of 155 consecutive COPD patients who were admitted for AHRF and treated by NIV were enrolled. Delayed response to NIV was defined as a significant clinical improvement in the first 48 h following NIV initiation despite a persistent severe respiratory acidosis (pH <7.30) after the first 2 h of NIV trial.

Results

NIV failed in only 10 patients (6.5%). Delayed responders to NIV (n=83, 53%) exhibited similar nutritional status, comorbidities, functional status, frailty score, dyspnea score, and severity score at admission, compared with early responders (n=62, 40%). Only age (66 vs 70 years in early responders; P=0.03) and encephalopathy score (3 [2–4] vs 3 [2–4] in early responders; P=0.015) were different among the responders. Inhospital mortality did not differ between responders to NIV (n=10, 12% for delayed responders vs n=10, 16% for early responders, P=0.49). A second episode of AHRF occurred in 20 responders (14%), equally distributed among early and delayed responders to NIV (n=9, 14.5% in early responders vs n=11, 13% in delayed responders; P=0.83), with a poor survival rate (n=1, 5%).

Conclusion

Most of the COPD patients with AHRF have a successful outcome when NIV is pursued despite a persistent severe respiratory acidosis after the first NIV trial. The outcome of delayed responders is similar to the one of the early responders. On the contrary, the second episode of AHRF during the hospital stay carries a poor prognosis.

Keywords:

• noninvasive ventilation
• acute respiratory failure
• COPD
• hypercapnia
• intubation

Supplementary materials

Patients and methods

Evaluation criteria

Do-not-intubate (DNI) status: decision process

According to good ethical practice and standard of care of our hospital, all patients who were admitted for acute-on-chronic respiratory failure were classified as either a DNI order or not.¹ This decision was made by the patient him/herself whenever possible. When the patient does not have the capacity to make such decision, it was taken by the trusted person mandated by the patient or by a multidisciplinary team including physicians and nurses caring for the patient. Clinicians involved in the decision process included at least an intensivist and either a pulmonologist or an emergency care practitioner, who did not participate in the current study. Patients were classified as DNI when their physical disability and their underlying debilitating conditions made them poor candidates for intubation. The patient’s family was informed in a clear and loyal manner, and all efforts were provided to make them understand and adhere to the medical decision.¹

According to the French law 2005-370 of April 22, 2005 (Leonetti’s law),² which focuses on end-of-life decision-making, everything should be performed to respect the patient’s choices. Thus, the practitioner in charge must respect the patient’s wishes.³ Patients can prepare advanced directives to anticipate a critical situation where they would not be able to express their will.³ Patients can also appoint a trusted person to express their will in the case they cannot express their wishes by themselves.³ The appointment has to be made in writing. For the intensivist or the emergency care practitioner, the classical scenario is the one including a patient unable to express his/her will, for whom there are no advance directives and no previously mandated trusted person. In this particular case, which is unfortunately the most common one in clinical practice regarding patients admitted for acute respiratory failure, physicians should respect a collegial medical procedure. This last point aims at preventing the possibility of a self-fulfilling prophecy regarding the patient’s prognosis.³ Our team is very keen on respecting this law at the bedside and we make everything in our power to have collegiate discussion on each case on a daily basis.

Except for invasive interventions, therapeutic management of DNI COPD patients was similar to every patient with COPD admitted for acute respiratory failure. All the patients with a DNI order were admitted to either the intensive care unit (ICU) or the step-down unit at least for the first 2 days.¹ Once stabilized, they were transferred to a medical ward, where NIV could be pursued if necessary.

Table S1 Clinical frailty score

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Disclosure

The authors report no conflicts of interest in this work.