EBQ:NIPPV in COPD

Complete Journal Club Article

Brochard L et al. "Noninvasive ventilation for acute exacerbations of chronic obstructive pulmonary disease.". NEJM. 1995. 333(13):817-22.
PubMed Full text PDF

Clinical Question

Can NIPPV be used to avoid endotracheal intubation in acute COPD exacerbation?

Conclusion

NIPPV avoids endotracheal intubation, reduces the length of the hospital stay, and reduces the in-hospital mortality rate in selected patients.

Major Points

• In acute COPD exacerbation, noninvasive ventilation helps avoid endotracheal intubation and complications associated with mechanical ventilation

• The use of Noninvasive Ventilation significantly reduced the need for intubation as compared in the standard-treatment group (5 liters/min, nasal canula)

• The frequency of complications was significantly lower in the noninvasive ventilation group.

• Hospital stay was significantly shorter for the noninvasive ventilation group compared to the standard group.

Guidelines

NIV should be considered in all patients with an acute exacerbation of COPD in whom a respiratory acidosis (pH < 7.35, PaCO2 > 6 kPa [45 mm Hg]) is present.

—British Thoracic Society

NIV improves respiratory acidosis (increases pH and decreases PaCO2) and decreases respiratory rate, severity of breathlessness, and length of hospital stay in patients with acute exacerbations of COPD.

—Global Initiative for Chronic Obstructive Lung Disease (GOLD)

Bi-level NIV is a beneficial support strategy that decreases the risk for invasive mechanical ventilation and possibly improves survival in selected hospitalized patients with respiratory failure

—ACCP, ACP-ASIM

Design

Multicenter prospective randomized trial at five hospitals

Population

Adult patients with known or suspected COPD (by history, exam or CXR).

Inclusion Criteria

Respiratory acidosis/elevated HCO3 with exacerbation of dyspnea lasting less than two weeks. And at least two of the following:

1. a respiratory rate above 30 bpm
2. PaO2 <45 mm Hg
3. Arterial pH < 7.35 after 10min RA

Exclusion Criteria

• RR < 12 bmp or need for immediate intubation (as defined below)
• tracheotomy or endotracheal intubation performed before admission
• the administration of sedative drugs within the previous 12 hrs
• CNS disorder unrelated to hypercapnic encephalopathy or hypoxemia
• cardiac arrest (within previous 5 days)
• cardiogenic pulmonary edema
• kyphoscoliosis as the cause of chronic respiratory failure or a neuromuscular disorder
• upper airway obstruction or asthma
• a clear cause of decompensation requiring specific treatment (e.g., peritonitis, septic shock, acute myocardial infarction, pulmonary thromboembolism, pneumothorax, hemoptysis, severe pneumonia, or recent surgery or trauma); a facial deformity; or enrollment in other investigative protocols.
• Refusal to undergo endotracheal intubation

Interventions

Both groups received:

• subcutaneous heparin
• antibiotics
• bronchodilators (subcutaneous terbutaline, aerosolized and intravenous albuterol, and corticosteroids or intravenous aminophylline or both)
• electrolyte corrections

Standard group:

• Supp O2 to max 5L NC to keep arterial O2Sat >90%

NIPPV group:

• At least 6 hours daily of NIPPV by ARM 25 machine keep arterial O2Sat >90% (Duration of noninvasive ventilation was determined on the basis of clinical criteria and arterial-blood gas levels.)

Hard criteria for intubation in either group:

1. respiratory arrest
2. respiratory pauses with loss of consciousness or gasping for air, psychomotor agitation
3. making nursing care impossible and requiring sedation
4. HR ≤ 50 bpm with loss of alertness
5. Hemodynamic instability with systolic arterial blood pressure below 70 mm Hg.

In NIPPV group if a criterion was present after the withdrawal of ventilatory support, it could be reintroduced. If the criterion persisted after ventilation had been resumed, intubation was performed

Outcomes

Primary Outcomes

Need for endotracheal intubation and mechanical ventilation at any point in the study:

Thirty-one of the 42 patients (74 percent) in the standard-treatment group required endotracheal intubation, as compared with only 11 of the 43 patients (26 percent) in the noninvasive-ventilation group (P < 0.001).

Secondary Outcomes

• Complications:
  • The proportion of patients with one or more complications was significantly higher in the standard-treatment group (20 of 42 patients, or 48 percent) than in the noninvasive-ventilation group (7 of 43, or 16 percent; P_ 0.001).

• Duration of ventilator assistance:
  • In the standard-treatment group, the 31 patients who required endotracheal intubation were ventilated for a total of 17_ 21 days.
  • In the noninvasive- ventilation group, the 11 patients who underwent endotracheal intubation were intubated for a total of 25+ 17 days; the other 32 patients were ventilated with a face mask fora mean of 4 +4 days.

• Mortality rate during hospitalization:
  • The proportion of patients who died in the hospital was also significantly higher in the standard-treatment group (12 of 42 patients, or 29 percent, vs. 4 of 43, or 9 percent; P_ 0.02).
  • Ten of the 12 deaths in the standard-treatment group and 3 of the 4 in the noninvasive-ventilation group occurred during mechanical ventilation.
  • Since the numbers of patients requiring intubation were different in the two groups, they compared mortality rates after adjustment for endotracheal intubation, using the Mantel–Haenszel test. After adjustment, they found no significant difference, suggesting that the number of patients requiring intubation was the main factor explaining the difference in mortality

Review Questions

1 What is one group that was excluded from the study that might benefit from NIPPV?

	COPD patients with 1 week of shortness of breath.
	DNI patients with COPD exacerbation.
	Patients with hypoxia and hypercapnea.
	Patients greater that 65 yoa.

2 If a patient in the NIPPV group met criteria for intubation at any time they were intubated immediately.

	False
	True

3 Which was not a statistically significant result found in this study?

	Fewer patients in the NIPPV required intubation
	Mortality was higher in the standard treatment group
	Use of nebulizers was less in the NIPPV group.
	Hospital stay was longer in the standard treatment group

4 What did the authors believe to be the cause for increased mortality seen in the standard treatment group?

	Shock
	Increased need for intubation
	Lack of antibiotics
	Delays in intubation