Hypercapnia: Difference between revisions
(Created page with "==Background== *PaCO2 >45 *Exclusively caused by alveolar hypoventilation **Results from decrease in respiratory rate, tidal volume, or increase in dead space ==Diagnosis== *HA,...") |
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**Results from decrease in respiratory rate, tidal volume, or increase in dead space | **Results from decrease in respiratory rate, tidal volume, or increase in dead space | ||
== | ==Clinical Features== | ||
* | *[[Headache]], confusion, lethargy, [[seizure]], coma | ||
*Extreme hypercapnia (acute elevation >100) can result in CV collapse | *Extreme hypercapnia (acute elevation >100) can result in CV collapse | ||
== | ==Differential Diagnosis== | ||
#Depressed central respiratory drive | #Depressed central respiratory drive | ||
##Structural CNS disease: brainstem lesions | ##Structural CNS disease: brainstem lesions | ||
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##COPD | ##COPD | ||
#Upper airway obstruction | #Upper airway obstruction | ||
==Diagnosis== | |||
*[[ABG]] | |||
**HCO3 increases 1 mEq/L for each 10mmHg increase in PaCO2 (acute) | |||
**HCO3 increasess 3.5 mEq/L for each 10mmHg increase in PaCO2 (chronic) | |||
==Treatment== | ==Treatment== | ||
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[[Hypoxemia]] | [[Hypoxemia]] | ||
== | ==References== | ||
[[Category:Pulm]] | [[Category:Pulm]] | ||
Revision as of 19:32, 11 May 2015
Background
- PaCO2 >45
- Exclusively caused by alveolar hypoventilation
- Results from decrease in respiratory rate, tidal volume, or increase in dead space
Clinical Features
- Headache, confusion, lethargy, seizure, coma
- Extreme hypercapnia (acute elevation >100) can result in CV collapse
Differential Diagnosis
- Depressed central respiratory drive
- Structural CNS disease: brainstem lesions
- Drug depression of respiratory center: opioids, sedatives, anesthetics
- Endogenous toxins: tetanus
- Thoracic cage disorders
- Kyphoscoliosis
- Morbid obesity
- Neuromuscular impairment
- Neuromuscular disease: myasthenia gravis, Guillain-Barré
- Neuromuscular toxin: organophosphate poisoning, botulism
- Intrinsic lung disease associated with increased dead space
- COPD
- Upper airway obstruction
Diagnosis
- ABG
- HCO3 increases 1 mEq/L for each 10mmHg increase in PaCO2 (acute)
- HCO3 increasess 3.5 mEq/L for each 10mmHg increase in PaCO2 (chronic)
Treatment
- Increase minute ventilation (rate and/or tidal volume)