Carbon Monoxide Toxicity Follow-up

Updated: Dec 31, 2020
  • Author: Guy N Shochat, MD; Chief Editor: Gil Z Shlamovitz, MD, FACEP  more...
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Further Outpatient Care

Asymptomatic patients with HbCO levels below 10% may be discharged. In cases of accidental CO poisoning, patients should be followed up in 4-6 weeks to screen for cognitive sequelae. With intentional poisoning, psychiatric follow-up is mandatory, given the high rate of subsequent completed suicide. [3]

A nationwide population-based study from Korea found that the risk of venous thromboembolism was significantly elevated in the first 90 days after CO poisoning (odds ratio [OR] 3.96; 95% confidence interval [CI] 2.50 to 6.25). Risk was especially high in the first 30 days for pulmonary embolism (OR 22.00; 95% CI 5.33 to 90.75) and deep venous thrombosis (OR 10.33; 95% CI 3.16 to 33.80). These researchers recommend monitoring patients for venous thromboembolism risk in the 3 months following CO poisoning. [49]



Further Inpatient Care

See the list below:

  • Admitted patients generally require monitored settings, telemetry beds, or cardiac care unit/medical intensive care unit (CCU/MICU) beds for more severe cases.

  • Patients with cerebral edema may be most appropriately treated in a neurosurgical ICU setting; this may dictate transfer to another facility. Admission or consult by toxicology service is helpful in these cases.



Considerations regarding prognosis include the following:

  • Variability of clinical severity, laboratory values, and outcome limits prognostic accuracy

  • Cardiac arrest, coma, metabolic acidosis, and high HbCO levels are associated with poor outcome

  • Abnormal CT or MRI findings are associated with persistent neurologic impairment

  • Neuropsychiatric testing may have prognostic efficacy in determining delayed sequelae


Patient Education

See the list below:

  • Carbon monoxide (CO) detectors: Home CO detectors with audible alarms are available, and can limit CO toxicity. [50] One study of 911 calls for suspected CO poisoning showed in 80% of calls for detector alarms, verifiable ambient CO levels were present in the home; the mean concentration of CO was 18.6 ppm in homes tested because of detector alarms but was 96.6 ppm in homes without alarms where calls were prompted by suspicious symptoms. [51]

  • Discuss the possibility of delayed neurologic complications, although they are much more common in patients with toxicity severe enough to require hospital admission.

  • Suggest minimizing physical activity for 2-4 weeks.

  • Advise patient to stop smoking.

  • For patient education information, see Carbon Monoxide Poisoning.