Chapter 13: Respiratory Distress

IMMEDIATE MANAGEMENT OF LIFE-THREATENING PROBLEMS

See Figure 13–1.

Assess Severity and Give Immediate Necessary Care

Patients in severe respiratory distress should receive simultaneous evaluation and therapy (see Figure 13–1). Providing and maintaining an adequate airway is the first consideration. Quickly assess the severity of distress by noting the patient’s general appearance. Patients struggling to breathe demonstrate a greater use of chest and accessory muscles than the normal quiet use of the diaphragm. Any patient with severe respiratory distress should receive immediate oxygen supplementation during assessment and treatment. Rapidly perform a focused examination of the oropharynx, neck, lungs, heart, chest, and extremities. A plain film chest X-ray (CXR) with posterior to anterior (PA) and lateral views, if possible, provides valuable information and should be obtained as soon as possible. A faster way to assess a patient with respiratory distress is to use a bedside ultrasound machine. One can look quickly for things like lung sliding, which if absent, is indicative of a pneumothorax for example, or B-lines, indicative of edema. This can be used and seen quickly by even an inexperienced sonographer.

Assess Adequacy of Oxygenation

A. Pulse Oximetry

Bedside pulse oximeters measure the percent saturation of oxygen in capillary blood. Pulse oximetry is particularly useful during procedural sedation and during attempts at endotracheal intubation because of the real-time availability of the information. However, this information is incomplete because there may be a delay of 20–30 seconds from the desaturation event to the reading because of the time of blood flow from central to peripheral circulation—longer in vasoconstricted patients; pulse oximeters do not measure the Pco₂, nor do they detect the presence of hypoventilation leading to respiratory acidosis. It is also important to recall the oxygen delivery equation, which is Do₂ = (1.34 × Hb × Spo₂ × 0.01) + (0.023 × Pao₂), so the two factors we really need to know are the hemoglobin and Spo₂.

B. Arterial Blood Gases

Arterial blood gases (ABGs) provide, in essence, the same information about arterial oxygen saturation as does pulse oximetry, but are necessary to provide valuable information about the effectiveness of ventilation. The blood gas provides measurement of pH, Po₂, and Pco₂. In the emergency department, and most other situations in the hospital, a venous blood gas (VBG) is adequate. It has been shown in multiple studies that pH is similar, that the Pco₂ is similar up to 45 mm Hg, and there is good correlation with bicarbonate as well. In the emergency department, a VBG is much more easily obtainable, and much ...