Ventilators are life-saving machines, but they must be used properly. Just as they can save lives, they can cause significant and irreparable damage to a patient if used improperly. In this article, the basics of ventilator management were discussed for 3 common causes of respiratory failure in the ED. While respiratory decompensation was the common theme, each disease process is marked by unique pathophysiology. An understanding of the diseases, their pathophysiology, and the ventilator basics presented here will allow for confident management of difficult patients.
Asthma is a major health concern in the United States. This disease affects both young and old, and it can rapidly lead to respiratory insufficiency and arrest. The underlying issue involves obstruction of the lower airway with inflammation, mucous, and airway spasm. Ventilatory management must be approached carefully and individualized to each case. Adequate sedation is the first step. This will allow a tired patient to rest and allow accurate lung mechanics measurements to be obtained. Ensuring adequate expiratory times as well as avoiding excessive airway pressures (plateau not inspiratory pressures) is key. Auscultation and frequent assessment of patients will help clinicians manage these difficult cases correctly.
Emphysema involves a weakened distal airway. The normal elastic recoil is significantly impaired and the alveolar walls are thin and weakened. Be diligent in managing patients with alveolar recruitment while avoiding pressure-induced lung trauma. As with the asthmatic, expiratory times must be monitored closely to ensure complete expiration and to avoid air trapping.
Congestive heart failure is becoming a common problem. Unfortunately, stress on an already weakened heart can lead to infarction, dysrhythmias, and reduced flow to multiple organ systems. Caring for the decompensated patient in acute pulmonary edema involves managing multiple problems at once. The first step is an appropriately set ventilator. Mechanical ventilation can reduce the stress on the heart by reducing preload and afterload. You can maximize oxygenation while avoiding absorption atelectasis. While the task of stabilizing a truly ill CHF patient can be daunting, recognizing the utility of the ventilator is your first step to providing the appropriate care.
Andrea DeGiorgi; Michael White
August 1, 2008