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Misdiagnosis Not your basic acute sinusitis. Mary Thomason March 8, 2006. No Financial Disclosures. Case Presentation. 55 yo female with PMH significant for presumed acute sinusitis in March/April of 2005 requiring 6 weeks of antibiotics who presented with HA and nasal congestion.
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MisdiagnosisNot your basic acute sinusitis Mary Thomason March 8, 2006
Case Presentation • 55 yo female with PMH significant for presumed acute sinusitis in March/April of 2005 requiring 6 weeks of antibiotics who presented with HA and nasal congestion. • 12/2/05 at urgent care dx: Acute Sinusitis tx: 2 Z-Paks • 12/6/05 in clinic cc: headache dx:? tx: complete antibiotics and follow up in one week
Case Presentation • 12/16/05 clinic followup cc: headache and nasal congestion dx: persistent URI symptoms tx: nasal steroids and sinus CT scan • 12/19/05 radiology CT scan negative for acute sinusitis or congestion
Case Presentation • 12/30/05 clinic follow up • Dx: Carbon Monoxide (CO) Poisoning
Objectives • Recognize symptoms of CO exposure • Diagnosis of CO exposure • Treatment of CO exposure • Prevention of CO exposure
Physiology • CO diffuses rapidly over the alveolar membrane • Binds reversibly with 200-fold affinity to Hgb • Shifts the oxyhemoglobin dissociation curve
Statistics • Leading cause of accidental poisoning death in the US • Estimated 15,000 treated annually in ED • Approximate 500 deaths annually JAMA vol. 293, no. 10, 3/9/05, 1183-86
CO Sources • Furnaces • Generators • Gas heaters • Motor vehicles (cars, trucks, tractors, boats) • Fires
Exposures • Majority of CO exposures occur in the fall and winter months • 64.3% occur in the home • 18.5% due to faulty furnaces • 9% motor vehicles JAMA vol. 293, no. 10, 3/9/05, 1183-86
CO Exposure After Katrina • 51 cases reported by HBO2 facilities of AL, LA, MS • 46 nonfatal, 5 deaths • The source for all but one of the non-fatal cases was exhaust from a portable generator. MMWR vol. 54, no. 39, 10/7/05, 996-998
Symptoms of Mild Poisoning • Throbbing temporal or frontal HA • Fatigue • Weakness • Lightheadedness • Nausea/Vomiting • Shortness of Breath
Symptoms of Moderate Poisoning • Severe HA • Tachycardia/Tachypnea • Flushing, perspiration • Diminished manual dexterity/prolonged reaction time • Impaired judgment/confusion • Vision changes (darkened, blurred) • Tinnitus
Symptoms of Severe Poisoning • Syncope • Seizures • MI • Dysrhythmias • Respiratory failure/ pulmonary edema • Coma • Death
Delayed Effects • Depression • Dementia/Memory Loss • Psychosis • Peripheral neuropathy • Parkinsonism • Visual impairment • Chorea
Diagnosis of CO poisoning • Have a high clinical suspicion • Determine the COHb level when the pt is first seen and repeat q2-4 hours until pt is asymptomatic or the value is normal. • If symptomatic or COHb greater than 20% monitor with ECG, lytes, CK, UA, ABG to evaluate for sequella Poisindex (accessed feb 2006)
Range of Toxicity • Normal COHb is 1-3% • Cigarette smokers increase their levels by 5% per pack per day (may tolerate up to 10%) • Toxic affects appear at 15-20% • COHb levels above 25% are considered severe • Toxicity however is determined symptomatically (cardiovascular and mental status) NEJM vol. 347, no. 14, 10/3/02, 1054-55
When to Hospitalize • Neurologic signs • Abnormal ECG • Metabolic Acidosis
Treatment • Decontamination –move to fresh air • Administer 100% oxygen (x 6 hours) • Consider hyperbaric oxygen for severely poisoned (coma, seizures, MI) and pregnant patients at 3 atmospheres absolute. NEJM vol. 347, no. 14, 10/3/02, 1057-67
Guideline to prevent CO exposure • Service heating system/water heater yearly • Install a battery-operated CO detector and check the batteries twice yearly • Do not use charcoal grill or camp stove inside the home, garage, or near a window • Do not run vehicle inside garage • Do no use stove or fire place that isn’t vented • Do not heat your home with a gas oven JAMA vol. 293, no. 10, 3/9/05, 1183-86
Summary • Leading cause of accidental poisoning death in the US • Mild symptoms are similar to a viral illness, therefore a high index of suspicion is required • CO poisoning is diagnosed symptomatically, but CO level testing can be helpful • The mainstay of treatment is oxygen therapy • Prevention is the key
References • Poisindex • NEJM vol. 347, no. 14, 10/3/02, 1054-55 • NEJM vol. 347, no. 14, 10/3/02, 1057-67 • MMWR vol. 54, no. 39, 10/7/05, 996-998 • JAMA vol. 293, no. 10, 3/9/05, 1183-86 • JAMA vol. 295, no. 4, 1/25/06, 398-402 • American Journal of Emergency Medicine, Vol. 23, 3/23/05, 838-841