TOX 8 - Carbon monoxide Flashcards
COHb levels in body
Normal COHb is 1% of the whole Hb concentration (5-10% in smokers)
40% - collapse
60% - death
In carbon monoxide poisoning;
o 15% may produce symptoms
o 40% lead to collapse
o 60% to death
Mechanism of action
• Carbon monoxide binds reversibly to the O2 binding site on Hb –> reducing affinity for oxygen.
- There is reduction of oxygen transport and the heart is most affected
- forms carboxyhemoglobin (COHb) –> decrease the oxygen –carrying capacity of the hemoglobin
- and inhibit transport, delivery and utilization of oxygen in the body
- 250 times higher affinity compared to O2
- Shifts the oxygen – dissociation curve to the left
Clinical symptoms
Progressive hypoxia:
- Psychomotor impairment
- Headache
- Blurred vision, loss of visual acuity
- Tachycardia, tachypnea, syncope, coma
- Deep coma, convulsions, respiratory failure, shock
– Headache, confusion, vertigo
– Nausea, malaise, fatigue
– Tachycardia, tachypnea
– Syncope – COHb concentration in blood >50%
– Coma, respiratory failure -> death
Leads to hypoxia –> symptoms first of all in the heart and CNS
Treatment
o Remove exposure source
o Maintain ventilation
o Admin O2
o Hyperbaric O2 treatment
Chronic intoxication
Long term consequences – chronic poisoning
o Headache, nausea and vomiting
o Lightheadness
o Confusion and depression
o Memory loss
Poisoning route
inhalation of CO
CO properties
Colorless and odorless,
non -irritating gas
affinity to O2- O2 and CO
CO has 250 times higher affinity compared to O2
CO shift o2 dissociation curve
Shifts the oxygen – dissociation curve to the left
Syncope – COHb concentration in blood
COHb concentration in blood >50%