Non-Invasive Ventilation in Pulmonary Edema

Non Invasive Positive Airway Pressure And Risk Of Myocardial Infarction In Acute Cardiogenic Pulmonary Edema: Continuous Positive Airway Pressure Vs Non Invasive Positive Pressure Ventilation

This randomized controlled trial is primarily aimed at assessing the rate of acute myocardial infarction with the two noninvasive ventilatory techniques, non-invasive intermittent positive pressure ventilation and non-invasive continuous positive airway pressure.

Objective: To determine whether the application of non-invasive intermittent positive pressure ventilation (n-IPPV) increases the incidence of acute myocardial infarction (AMI) in patients with acute respiratory failure (ARF) secondary to acute cardiogenic pulmonary edema (ACPE), as opposed to non-invasive continuous positive airway pressure (n-CPAP).

Background Both n-CPAP or n-IPPV are used to treat ACPE complicated by ARF. Two previous studies, however, report an increased rate of AMI associated with the use of n-IPPV.

Methods: Fifty-two patients with severe ARF consequent to ACPE were randomized to receive n-CPAP (n=27) or n-IPPV (n=25), both associated with standard medical therapy. Cardiac markers, electrocardiogram and clinical-physiological parameters were monitored at study entry, after 30 and 60 minutes, and every 6 hours for the first two days.

Inclusion Criteria:

• rapid onset of the symptoms
• severe dyspnoea at rest
• respiratory rate > 30 breaths per minute
• use of accessory respiratory muscles
• oxygen saturation (SpO2) inferior to 90% with an inspiratory oxygen fraction of 60% via a Venturi mask
• radiological findings of ACPE

Exclusion Criteria:

• acute ischemic heart disease (myocardial infarction, chest pain, ST elevation)
• hemodynamic instability (i.e. systolic blood pressure < 90 with dopamine or dobutamine infusion ≥ 5 mcgr/Kg/min) or life-threatening arrhythmias
• need for immediate endotracheal intubation (respiratory arrest, bradypnea or gasping)
• inability to protect the airways
• impaired sensorium (i.e. unconsciousness or agitation)
• inability to clear secretions
• respiratory tract infection
• recent oesophageal/gastric surgery
• gastrointestinal bleeding
• facial deformities
• hematological malignancy or cancer with an Eastern Cooperative Oncology Group performance status ≥ 2
• chronic respiratory failure necessitating long-term oxygen therapy
• diagnosis of myocardial infarction, pulmonary embolism, pneumonia, exacerbation of chronic obstructive pulmonary disease, pneumothorax in the previous 3 months
• denial or refusal of intubation
• claustrophobia
• inclusion in other research protocols