section name header

Information

  1. Background. COPD is a leading cause of death worldwide and is associated with exposure to tobacco, biomass, and pollution. Major symptoms of COPD include dyspnea, cough, and/or sputum production. COPD is

    associated with an increased risk of invasive mechanical ventilation in the postoperative setting. The severity of COPD can be categorized by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria, involving symptom burden, exacerbation history, and forced expiratory volume (FEV1).

  2. Perioperative Considerations

    1. Patients should continue their inhalers on the day of surgery. As with asthmatic patients, pulmonary symptoms (eg, dyspnea), frequency of rescue inhaler use, and recent exacerbations and steroid use need to be assessed. In patients with severe COPD, right heart function via transthoracic echocardiography should be evaluated prior to surgery, as right heart dysfunction and pulmonary hypertension (PH) significantly increases postoperative risk and is more prevalent in this patient population.

    2. Patients with COPD are at risk of developing intrinsic PEEP (iPEEP) due to prolonged respiratory time and airway collapse. iPEEP occurs when alveoli incompletely empty at the end of exhalation, resulting in alveolar overdistention and an increase in airway pressure. iPEEP is difficult to quantify on anesthesia ventilators but is likely present when the expiratory flow-time tracing does not return to zero prior to inspiration.

    3. iPEEP can be minimized by prolonging expiration (eg, reducing respiratory rate or set expiratory time) and avoiding large Vt and PEEP that increase lung volume beyond FRC. During assisted ventilation, iPEEP increases work of breathing and ventilator asynchrony. Application of external PEEP can reduce the work required to initiate a breath yet should not exceed iPEEP, otherwise overdistention will occur.

    4. In patients with evidence of chronic hypercarbia (severe COPD, elevated serum bicarbonate), minute ventilation should not be adjusted to maintain a normal end-tidal CO2.

    5. Patients with COPD may require supplemental oxygen after surgery. In high-risk patients or in the event of postoperative respiratory insufficiency, noninvasive ventilation should be applied as first line therapy provided patient effort and mental status allow. High-flow nasal cannula is as an alternative therapy to decrease the work of breathing and increase alveolar ventilation. Narcotics should be used with caution.