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🌱 來自: Huppert’s Notes
Respiratory Distress🚧 施工中
Respiratory Distress
• Ask for help: Call your team and consider rapid response
• Confirm code status
• Provide respiratory support: Oxygen via nasal canula, non-rebreather, or high-flow nasal canula. Consider non-invasive positive pressure ventilation (NIPPV) if not contraindicated or intubation if needed.
• Perform physical exam: See physical exam under dyspnea above
• First-pass diagnostics: STAT ABG, CBC with differential, CXR, ECG. Consider BMP, BNP, troponin, VBG with lactate, cardiac and/or pulmonary POCUS, CT chest/CTPE (based on stability)
• Differential diagnosis: Consider differential diagnosis based on patient characteristics (Table 2.3)
TABLE 2.3 • Differential Diagnosis for Causes of Acute or Emergent Respiratory Distress
• Use ABG to further characterize the respiratory failure:
- Calculating the A-a gradient
• A-aDO2 = PAO2 – PaO2
PAO2 = partial pressure of O2 in alveolar gas, PaO2 = partial pressure of O2 in arterial blood
- PaO2 is measured directly on ABG
- PAO2 must be calculated:
• PAO2 = [(Patm – PH2O) * FiO2] – (PaCO2/R) = (760 – 47)(0.21) – (PaCO2/0.8) = 150 – 1.25(PaCO2)
- Interpreting the A-a gradient
• There are multiple rules of thumb to age-adjust the A-a gradient normal value
- Normal A-a gradient = (Age/4) + 4
- Normal A-a gradient = 0.3 * Age
FIGURE 2.11: An approach to interpreting arterial blood gas (ABG) using the A-a gradient. Abbreviations: TdV = tidal volume; RR = respiratory rate; PO2 = partial pressure of oxygen; O2 = oxygen; DLCO = diffusing capacity for carbon monoxide; FiO2 = fraction of inspired oxygen; dz = disease