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A 62-year-old man presents to the emergency department by car complaining of chest pain, air hunger, and extreme weakness. He has a history of hypertension and an anterior wall myocardial infarction (MI) 2 years ago. His electrocardiogram shows a large anterolateral MI, and his chest radiograph shows vascular redistribution and mild interstitial edema. He is on beta blockers. His last echocardiogram was done 2 months ago and showed an ejection fraction of 25%.
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His respiratory rate (RR) is 40 breaths per minute, heart rate (HR) 100 beats per minute (bpm), blood pressure 68/40 mm Hg, and his oxygen saturation is at 86% with a non-rebreather mask. He is intensely diaphoretic and has two-word dyspnea. He has a beard and a normal stature.
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22.2.1 What Is This Patient's Physiological Reserve?
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Many medications employed in airway management possess properties that affect cardiac and respiratory function. For this reason, it is critical that the practitioner evaluates the ability of these systems (physiological reserve) to withstand the effects of administered medications and procedures.
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22.2.1.1 Cardiac Reserve
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This patient is in cardiogenic shock with limited to no cardiac reserve. He has severe systolic dysfunction and almost certainly the same degree of diastolic dysfunction. It appears that his sympathetic nervous system is working at maximum ability just to sustain his present vital signs.
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There is nothing to indicate that this patient will have any CNS problems with induction agents.
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22.2.1.3 Respiratory Reserve
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This patient is in pulmonary edema and will have limited respiratory reserve. Denitrogenation prior to intubation may help but is of questionable value. He is already maximizing his respiratory effort and induction may precipitate acute hypoxemia.
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22.2.2 How Would You Evaluate the Airway of This Patient for Difficulty?
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On MOANS-guided evaluation for difficult BMV (see Sections 1.6.1), you are uncertain that the patient can be ventilated by bag and mask. He has a thick beard and is likely to have gastric air distention due to his increased respiratory effort and air swallowing. His lungs will be stiff (reduced compliance) secondary to his interstitial pulmonary edema. This is of particular concern on initiating positive pressure ventilation following intubation with respect to a reduction in venous return.
On LEMON evaluation to predict difficult laryngoscopy and intubation (see Sections 1.6.2), looking externally his face and neck appear normal, although he has a beard and that may hide a small mandible. He cooperates for a Mallampati evaluation and appears to have a Grade II. He is not obese; his neck is freely mobile.
The mnemonic RODS can be used to guide the evaluation for difficulty in the use of extraglottic devices (EGD) (see Sections 1.6.3). His mouth opening is not restricted, upper airway obstruction is not anticipated, and ...