Carbon Monoxide Intoxication In EM PracticeYou must be a full Eusem member to view this file Go backCarbon monoxide intoxication in EM practiceJuliusz JakubaszkoWroclaw Medical University, PolandCarbon monoxide Colorless Odorless Tasteless NonirritatingHistory Aristotle: coal fumes lead to heavy head and death.1772 identified as a distinct gas (Priestly)?Hyperbaric Oxygen Therapy - first used in 1960Carbon monoxide intoxicationSEVEREFREQUENTUNDERDIAGNOSEDCarbon monoxide intoxicationPrimary cause of accidental poisoning:EuropeNorth AmericaEpidemiologyUnited States:3800 deaths/year;1500 accidents;1300 suicide Poland: 2000/year, 90% unintentionalOrigin of COMotor vehicle exhaustrunning engine in closed spacefaulty exhaust systemsPropane-powered equipementlift, water heater, concrete saw, polishersCombustion for heating or cookingcamping equipment, heating systemsSmoke inhalation in firesPatophysiology of CO IntoxicationHypoxic hypoxiaHistotoxic hypoxiaReoxygenation injuryHypoxic hypoxiaHgbs affinity for CO Alteration of oxyhemoglobin dissociation curve (Haldane Effect) Profound tissue hypoxia can resultHypoxic hypoxiaBinding to Myoglobin COMbmyocardial stunningcardiac output drops17 years old girld with chest pain after exposure to CO (lasting 10 min)?Histotoxic hypoxiaDirect toxic effect on the cell: Inhibition of cytochrome a-a3 Inhibition of cytochrome p-450Reduction in ATP productionReoxygenation injuryFormation of free radicals Lipid peroxidation activation of polymorphonuclear leukocytesApoptosisA cortex, globus pallidus, cerebellum basis of delayed neurologic sequelae?COHb elimination half-lifeO2 20.9 % 1 atm320 min O2 100 % 1 atm72 -131 min.O2 100 % HBO3 atm : 23 min 2.5 atm : 27 min Severity of CO intoxicationInhaled CO concentrationDuration of exposureIndividual susceptibilityminute ventilationpregnancyPresence of systemic illnessescardiac and pulmonary diseasesInitial COHb not predictiveClinical manifestationsGeneralheadache, nausea, vomiting, weaknessCardiovascularchest pain, tachypnea, tachycardia, hypotensionpulmonary edema, arrythmias, cardiac arrestNeurologicdizziness, ataxia, seizures, comaOthersretinal hemorrhages, metabolic acidosisDelayed CO toxicityPersistent : present from exposureDelayed : 2 to 40 days post-exposureDementia, psychosis, memory deficitParkinsonism, paralysis, choreaPersonnality changes, gait disturbanceCortical blindness, apraxia, agnosiaPeripheral neuropathy, urinary incontinenceDelayed CO toxicityLesions of cerebral white matterglobus pallidus, cerebellum, hippocampusperivascular injury with blood flow abnormalitiesOften associated with LOC in acute phasePatients > 30 year old more susceptible to delayed CO toxicityClinical evaluationMaintain a high level of suspicionHistory of exposure can be absentCOHb< 3 % non-smokers or < 10 % in smokersnot predictive of outcomecorrelation with symptoms uselessABG : metabolic acidosis ( lactate )?ECG : ischemia, arrythmias Neurologic evaluationNeurologic examinationMental status examinationPsychometric testingNeuroradiologic imaging : CT, MRI Pulse oximetry in CO pois |