Respiratory failure
Sponsored Links
This presentation is the property of its rightful owner.
1 / 18

Respiratory Failure PowerPoint PPT Presentation


  • 196 Views
  • Uploaded on
  • Presentation posted in: General

Respiratory Failure. Kenney Weinmeister M.D. Definition. Demand overwhelms the capacity of the system Hypoxemia: PaO2 < 60 mmHg Hypercarbia: PaCO2 > 49 mmHg. Alveolar-arterial Oxygen Tension Difference. PAO2 = FIO2 x atmos. pres. - PaCO2/R PAO2 = 150 - PaCO2/0.8

Download Presentation

Respiratory Failure

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Respiratory Failure

Kenney Weinmeister M.D.


Definition

  • Demand overwhelms the capacity of the system

  • Hypoxemia: PaO2 < 60 mmHg

  • Hypercarbia: PaCO2 > 49 mmHg


Alveolar-arterial Oxygen Tension Difference

  • PAO2 = FIO2 x atmos. pres. - PaCO2/R

  • PAO2 = 150 - PaCO2/0.8

  • P(A-a) O2 gradient = 2.5 + 0.21 x age (yr)


Duration of Hypercarbia

  • Acute minutes to hours

    • Acute Change in pH = .008 x change PCO2

  • Chronic days

    • Chronic Change in pH = .003 x change PCO2

  • Mixed

    • Change in pH is >.003 <.008


Hypoxemic Respiratory Failure

  • Hypoventilation

    • Normal A-a gradient

  • V/Q mismatch

    • Elevated A-a gradient

      • Significantly improves with !00% oxygen

  • Right to left shunts

    • Elevated A-a gradient

      • Does not significantly improve with 100% oxygen


Hypercapnic Respiratory Failure

  • Hypoventilation

    • Extrapulmonary disorders

  • Severe V/Q mismatch


Extrapulmonary Respiratory Failure

  • Hypoxemic with normal A-a gradient

  • Hypercarbic acute or chronic

    • CNS

    • PNS

    • Respiratory muscles

    • Chest Wall

    • Pleura

    • Upper Airways


Central Nervous System Causes of Respiratory Failure

  • Drugs

  • Hypothyroidism

  • Brainstem injury or tumor

  • Primary alveolar hypoventilation

  • Central sleep apnea


Spinal cord

Tetanus

Strychnine

ALS

Guillain Barre Synd.

Shellfish

Bilateral phrenic nerve palsy

Diptheria

Pseudocholinesterase deficiency

Myasthenia Gravis

Eaton-Lambert

Botulism

Organophosphate poisoning

Peripheral Nervous System Causes of Respiratory Failure


Respiratory Muscle Dysfunction

  • Muscular dystrophies

  • Myotonic dystrophies

  • Polymyositis

  • Periodic paralysis

  • Electrolyte disorders


Chest Wall and Pleural Disorders

  • Kyphoscoliosis

  • Obesity hypoventilation

  • Flail chest

  • Fibrothroax

  • Thoracoplasty

  • Ankylosing spondylitis


Acute epiglottitis

Acute laryngeal edema

Anaphylaxis

Trauma

Foreign body aspiration

Retropharyngeal hemorrhage

Bilateral vocal cord paralysis

Tracheal stenosis

Tracheomalasia

Tumors

Upper Airway Obstruction


Pulmonary Causes of Respiratory Failure

  • Lower airway

    • Asthma, COPD

  • Parenchymal

    • Pulm. Edema, infections, interstitial lung dz

  • Pulmonary vasculature

    • PE, Primary pulmonary hypertension


Options for Ventilation

  • Noninvasive positive pressure ventilation

  • Invasive positive pressure ventilation

  • Negative pressure ventilation


Noninvasive Positive Pressure Ventilation

  • Continuous positive airway pressure

    • Hypoxemia

    • Functional airway obstruction

  • Bilevel positive airway pressure

    • Hypercarbia

    • COPD

    • Neuromuscular or chest wall disorders


Invasive Positive Pressure Ventilation

  • Acute decompensation

  • Fail NIPPV

  • Mechanical Airway obstruction

  • Protect airway


Negative Pressure Ventilation

  • Chronic respiratory failure

  • Neuromuscular disease

  • No functional airway obstruction


Conclusion

  • Differentiate type of respiratory failure

    • Hypoxemic vs hypercarbia

    • Hypoventilation vs V/Q mismatch

  • Determine if chronic or acute

  • Most often acute respiratory failure due to V/Q mismatch


  • Login