Respiratory Care April 2015, 60 (4) e80-e85
Autori: Claudia Maggiorelli, Giuseppina Ciarleglio, Valentina Granese, Uberto Maccari, Carmen Manta, Chiara Madioni e Raffaele Scala
The modern approach (ie, long-term oxygen therapy, rehabilitation, and home mechanical ventilation) has contributed to the survival of patients with chronic respiratory diseases, such as COPD. Every day, physicians have to face end-of-life decisions in exacerbations occurring in end-stage patients when endotracheal intubation and/or tracheostomy may be neither appropriate nor accepted (do not intubate and/or do not cannulate status, respectively) due to the high rate of severe complications of invasive mechanical ventilation.
The treatment of acute-on-chronic respiratory failure without multiple-organ failure is usually performed in respiratory ICUs (RICUs), which may provide different levels of noninvasive and invasive ventilatory assistance at lower costs compared with ICUs. Moreover, the RICU is a setting where end-of life decisions are made and noninvasive ventilation (NIV) in do-not-intubate and/or do-not-cannulate patients is frequently performed.
In the literature, there are many reports showing that, in acute hypercapnic exacerbations of COPD, NIV (in addition to medical and oxygen therapy) reduces the need for endotracheal intubation and avoids invasive mechanical ventilation-related complications. In the case of NIV failure, invasive mechanical ventilation or tracheostomy is needed. The main causes of NIV failure are poor patient compliance, difficult management of bronchial secretions, and worsening or lack of improvement in either blood gas values or sensorium. To reduce the rate of treatment failure, different integrated strategies have been successfully implemented during NIV in expert RICU and ICU settings, such as careful pharmacologic sedation to improve a patient's cooperation, early fiberoptic bronchoscopy, and/or high-frequency chest wall compressions (HFCWC) to promptly remove the excessive burden of secretion in COPD subjects with respiratory muscle fatigue and ineffective cough.
Extracorporeal CO2 removal, which developed from the traditional extracorporeal membrane oxygenation, has been recently proposed as an alternative or an integrated therapeutic option in patients with acute hypercapnic acidotic respiratory failure who are non-responders to an NIV trial. Although extracorporeal membrane oxygenation is a total extracorporeal support that is able to oxygenate severely hypoxemic patients and remove up to 50% of the total body CO2 production, extracorporeal CO2 removal works as a partial extracorporeal support capable of removing lower amounts of CO2 without substantial effects on oxygenation. Less invasive than extracorporeal membrane oxygenation (lower blood flows, smaller diameter cannulation, lower doses of heparin), extracorporeal CO2 removal is associated with fewer severe complications.
There are 2 different extracorporeal CO2 removal approaches: (1) arteriovenous extracorporeal CO2 removal works as a pumpless bypass between a femoral arterial and contralateral femoral vein; and (2) venovenous extracorporeal CO2 removal is a simple, pump-driven, low blood flow, venovenous system composed of a hemofilter and an oxygenator. Serious vascular complications have been reported in 24% of patients treated with the arteriovenous pumpless device, which requires arterial cannulation with large catheters.
In this paper, we report a case of hypercapnic acute-on-chronic respiratory failure occurring in a patient with end-stage COPD who declined endotracheal intubation and was treated with integrated and sequential use of NIV together with fiberoptic bronchoscopy, HFCWC, and venovenous extracorporeal CO2 removal.