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


==Diagnosis==
==Clinical Features==
*HA, confusion, lethargy, sz, coma
*[[Headache]], [[confusion]], [[lethargy]], [[seizure]], [[coma]]
*Extreme hypercapnia (acute elevation >100) can result in CV collapse
*Extreme hypercapnia (acute elevation >100) can result in [[shock|cardiovascular collapse]]


==Work-Up==
==Differential Diagnosis==
*ABG
*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 [[the obese patient|obesity]]
*Neuromuscular impairment
**Neuromuscular disease: [[myasthenia gravis]], [[Guillain-Barre]]
**Neuromuscular toxin: [[organophosphate toxicity]], [[botulism]]
*Intrinsic lung disease associated with increased dead space
**[[COPD]]
*[[Upper airway obstruction]]
 
==Evaluation==
*[[ABG]]
**HCO3 increases 1 mEq/L for each 10mmHg increase in PaCO2 (acute)
**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)
**HCO3 increases 3.5 mEq/L for each 10mmHg increase in PaCO2 (chronic)
 
==DDx==
#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


==Treatment==
==Management==
*Increase minute ventilation (rate and/or tidal volume)
*Increase minute ventilation (rate and/or tidal volume)


==See Also==
==See Also==
[[Hypoxemia]]
*[[Hypoxemia]]
*[[Shortness of breath]]
*[[Respiratory acidosis]]


==Source==
==References==
Tintinalli
<references/>


[[Category:Pulm]]
[[Category:Pulmonary]]
[[category:critical Care]]

Latest revision as of 16:04, 12 October 2019

Background

  • PaCO2 >45
  • Exclusively caused by alveolar hypoventilation
    • Results from decrease in respiratory rate, tidal volume, or increase in dead space

Clinical Features

Differential Diagnosis

Evaluation

  • ABG
    • HCO3 increases 1 mEq/L for each 10mmHg increase in PaCO2 (acute)
    • HCO3 increases 3.5 mEq/L for each 10mmHg increase in PaCO2 (chronic)

Management

  • Increase minute ventilation (rate and/or tidal volume)

See Also

References