Transcript - Catalyst
Case Conference: Respiratory Failure Andrew M. Luks, MD Medicine 536 Introduction to Critical Care Medicine January 7, 2014 Case 1 • 46 year-old woman presented to the ED with a one week history of fevers, myalgias, headaches and nausea • She had been seen the previous day in ER with similar complaints: – Nasal swab for influenza performed – Sent home on oseltamivir and acetaminophen Case 1: Other History • Past Medical History: – HIV (last CD4 count 63) – Prior history of crack lung • Social History: – Lives with daughter; previously homeless – Daily cocaine use; (+) tobacco use • Medications: – Antiretroviral therapy – TMP/SMX (Opportunistic infection prophylaxis) TMP/SMX: Trimethoprim / Sulfamethoxazole Case 1: ED Presentation • Vitals: T 35.4°C, BP 90/59, HR 127, RR 40 • SpO2: 88% on non-rebreather mask • Exam: – Ill-appearing; accessory muscle use – Crackles on lung exam bilaterally – Holosystolic murmur; neck veins normal – No peripheral edema • Basic Labs: – WBC 2.6, Hematocrit 28% – Chem panel: BUN 15; Creatinine 1.1 Case 1 What studies would you order next? Case 1: Her Arterial Blood Gas pH 7.46 PCO2 23 PO2 86 HCO3 17 Base Deficit: 5.4 Done while on a nonrebreather mask (unknown FIO2) How would you interpret the ABG? Case 1: Chest Radiograph Case 1 What is your differential diagnosis? DDx: Hypoxemia and Diffuse Bilateral Opacities • Cardiogenic pulmonary edema • ARDS • Acute interstitial pneumonitis • Multilobar pneumonia • Viral pneumonia • Pneumocystis pneumonia • Acute eosinophilic pneumonia • Diffuse alveolar hemorrhage • Acute hypersensitivity pneumonitis • Cocaine-induced lung injury Case 1 What additional diagnostic studies would you consider? What can you do to manage her respiratory failure? Case 1: Other Laboratory Studies • Troponin < 0.04 ng/mL • Lactate 1.1 mmol/L • Urine toxicology screen: positive for cocaine and opiates • Urinalysis: – 3+ occult blood – 9-30 Red blood cells – 2+ protein • Sputum Gram’s stain: 4+ gram positive cocci Case 1: What Happened Next Case 1: Post-Intubation Chest Radiograph Case 1 Her PaO2 is only 65 mm Hg on an FIO2 of 0.8 and a PEEP of 5 What should we do with the ventilator now? Case 1: Outcome Case 2 • 45 year-old man presents to the ED complaining of difficult swallowing and muffled speech for the past day • Past Medical History: None • Social History: active IV drug user (skinpopping); Non-smoker • Review of Systems: denies dyspnea, fever, chills but notes problems with diplopia for the past day Case 2: ED Presentation • Vitals: T 37.2°C HR 90 BP 111/87 RR 11 • Oxygen saturation: 88% breathing air • Exam: – Difficulty keeping eyes open – Answers all questions appropriately, follows commands – Drooling; muffled speech – Lung and cardiac exam unremarkable – No lower extremity edema Case 2: Skin Exam Case 2 What studies would you order next? Case 2: Arterial Blood Gas While Breathing Air pH 7.28 PCO2 55 PO2 71 HCO3 28 Base Excess 2.8 How would you interpret the ABG? Case 2: Chest Radiograph Case 2 What should you do to manage his hypoxemia? Why Does The Patient Have Ventilatory Failure? Increased • VE Decreased Drive Muscular Disorder Low Compliance Load High Resistive Load Ability Chest Wall Problem Peripheral Nerve Problem Source: Schmidt and Hall 1992 Case 2 Should you intubate the patient or can you use non-invasive ventilation? Signs of Bulbar Dysfunction • Drooling / oral accumulation of saliva • Weak cough • Absent or impaired gag • Nasal tonality to speech • Cough / choke with food • Nasal regurgitation These are often an indication for intubation Contraindications to Noninvasive Ventilation • Inability to protect airway or clear secretions • Non-respiratory organ failure • Facial surgery, trauma or deformity • High aspiration risk • Prolonged duration of support anticipated • Recent esophageal surgery Case 2: Diagnosis ? Case 3 • 30 year-old man found unresponsive at home by his roommate • The medics arrive and move to intubate the patient for altered mental status and absent gag reflex • He is has a difficult airway and requires 3 attempts before intubation is successful • He is transported to the HMC ED where he has an SpO2 of 90% on FIO2 1.0 Case 3: Chest Radiograph Case 3: Arterial Blood Gas On FIO2 1.0 In The ICU pH 7.02 PCO2 72 PO2 55 HCO3 18 Base Deficit 14.9 How would you interpret the ABG? Case 3 Does hypoventilation explain all of his hypoxemia? Does he need to be on lung protective ventilation? Case 3 How much shunt does this patient have? Case 3 The patient is on a PEEP of 5 cm H2O with an FIO2 of 1.0. Will raising the PEEP help his oxygenation? The End Questions? [email protected]