PART XIII Other Important Topics
Chapter 42 Near Drowning PC FWS RBC Figure 42-1. Near wet drowning. Cross-sectional, microscopic view of the alveolar-capillary unit. Illustration shows fluid moving from a pulmonary capillary to an alveolus. PC, Pulmonary capillary; FWS, frothy white secretions; RBC, red blood cell; TI, type I alveolar cell; IE, interstitial edema.
Anatomic Alterations of the Lungs • Largyngospasm and bronchial constriction • Interstitial edema, including engorgement of the perivascular and peribronchial spaces, alveolar walls, and interstitial spaces • Decreased pulmonary surfactant • Increased surface tension of the alveolar fluid • Alveolar shrinkage and atelectasis • Frothy, white secretions throughout the tracheobronchial tree
Etiology • 6000 to 8000 people drown each year in the United States • Children under the age of 5 account for 40% • 20% occur in persons between 5 and 20 years of age • About 8000 victims of near drownings are hospitalized annually
Overview of the Cardiopulmonary Clinical Manifestations Associated with NEAR WET DROWNING The following clinical manifestations result from the pathophysiologic mechanisms caused (or activated) by Atelectasis (see Figure 9-7), Alveolar Consolidation (see Figure 9-8), and Increased Alveolar-Capillary Membrane Thickness (see Figure 9-9), and Bronchospasm (see Figure 9-10)—the major anatomic alterations of the lungs associated with near wet drowning (see Figure 42-1).
Figure 9-9. Increased Alveolar-Capillary Membrane Thickness Clinical Scenario.
Clinical Data Obtained at the Patient’s Bedside Vital Signs • Increased respiratory rate • Increased heart rate, cardiac output, blood pressure
Clinical Data Obtained at the Patient’s Bedside • Cyanosis • Cough and sputum production • Frothy, pink, stable bubbles • Chest Assessment Findings • Crackles and rhonchi
Pulmonary Function Study: Expiratory Maneuver Findings FVC FEVT FEF25%-75% FEF200-1200 N or N or N PEFRMVV FEF50% FEV1% N N or N N or
Pulmonary Function Study: Lung Volume and Capacity Findings VT RV FRC TLC N or VC IC ERV RV/TLC% N
Arterial Blood Gases Early and Advanced Stages of Near Drowning • Acute Ventilatory Failure with Hypoxemia pH* PaCO2 HCO3-* PaO2 (lactic acid) * When tissue hypoxia is severe enough to produce lactic acid, the pH and HCO3- values will be lower than expected for a particular PaCO2 level.
Oxygenation Indices QS/QT DO2 VO2 C(a-v)O2 Normal Normal O2ER SvO2
Radiologic Findings Chest radiograph • Fluffy infiltrates • Pneumothorax and pneumomediastinum
Figure 42-2. This radiograph of a young man, taken just after an episode of near drowning,shows a pulmonary edema pattern. (From Armstrong P et al: Imaging of diseases of the chest, ed 2, St Louis, 1995, Mosby.)
General Management of Near Wet Drowning • The first responder • Management during transport • Management at the hospital