Respiratory Failure
Definition
Respiratory failure is defined as the inability of the respiratory system to meet the body’s oxygenation, ventilation, and/or metabolic requirements.
Acute Respiratory Failure is a medical emergency developing over minutes to hours.
To validate this diagnosis, there must be documentation of signs/symptoms of respiratory compromise with increased work of breathing (WOB) such as:
tachypnea/bradypnea/apnea - wheezing/stridor/crackles
retractions (intercostal, subcostal, suprasternal) - cyanosis
head bobbing - lethargy
grunting - difficulty feeding
Clinical Classification
Respiratory Failure Types
| Diagnosis | Criteria |
|---|---|
| Acute Hypoxic Respiratory Failure | Increased WOB + PaO₂ < 60 mmHg (SaO₂ < 90%) |
| Acute Hypercapnic Respiratory Failure | Increased WOB + PaCO₂ > 50 mmHg with pH < 7.32 |
| Acute Hypoxic & Hypercapnic Respiratory Failure | Increased WOB with both low PaO₂ and elevated PaCO₂ meeting thresholds above |
| Acute Hypoxic Respiratory Failure, Unspecified | Signs of increased work of breathing requiring medical intervention without clearly documented hypoxia or hypercapnia (e.g. asthma on cont. nebs, bronchiolitis on HFNC) |
Most pediatric patients with respiratory failure will have acute hypoxic respiratory failure.
Under typical circumstances, an SaO2 of ≤ 90% on room air is considered hypoxemia (an SaO2 of 90% correlates with a PaO2 of 60 mm Hg)
Therefore, any patient exhibiting signs of increased work of breathing + need for ANY supplemental oxygen delivery has acute hypoxic respiratory failure
Includes ALL levels of support of O2: nasal cannula, HFNC, simple face mask, non-rebreather mask, BiPAP, CPAP, mechanical ventilation
Chronic Respiratory Failure can develop gradually over weeks/months or can be the result of unrecoverable acute respiratory failure. Typically requires chronic respiratory support with home supplemental oxygen or trach/ventilator support (mechanical ventilator, BiPAP, CPAP) of at least 28 days or longer. Metabolic compensation occurs with a near-normal pH.
Acute on Chronic Respiratory Failure is an acute condition where patients with chronic respiratory failure have acute worsening of their respiratory status requiring intervention. If hypoxia is present, ANY increase in their home oxygen requirement is acute failure.
Tips For Documentation
If the patient has hypoxia WITHOUT increased work of breathing, document the hypoxia ONLY. No signs of distress = failure NOT present.
“Respiratory Distress” and “Respiratory Insufficiency” support a diagnosis of respiratory failure but do not reflect a diagnosis of equal severity (must specifically state the diagnosis)
Specify Degree: Acute, Chronic, or Acute on Chronic
Specify Detail: Hypoxic, hypercapnic, hypoxic AND hypercapnic, or unspecified
Specify Cause: Link to the underlying cause, if known
Provide times for initiation & discontinuation of mechanical ventilation
Alkalosis and Acidosis reflect separate diagnoses pertaining to the patient’s course of treatment
Status Asthmaticus
Status Asthmaticus describes an asthma attack in a patient who requires hospitalization for asthma care (not stable for discharge after initial treatment in the ED). This inadequate response is characterized by ongoing wheezing, tachypnea, or increased work of breathing.
If the child received continuous nebulizer treatments administered (at least 2 back to back hour-long treatments) then they have “Acute respiratory failure” (either unspecified or with hypoxia if SaO2 <90%)
Post Operative Respiratory Failure
Under coding guidelines, post-op respiratory failure is defined as a postoperative complication. (See Clinical Definition for Post-Operative Acute Respiratory Failure)
If respiratory support is expected following surgery (e.g. cardiothoracic procedures), please just document “acute resp failure” (not post-op) to minimize triggering a potentially preventable complication.
Documentation: From Symptoms to Diagnosis
Clinical Decision Guide
Respiratory Diagnosis by Presentation
| Symptoms / Exam Findings | Diagnosis |
|---|---|
| Tachypnea, retractions, increased WOB. No hypoxia No respiratory support | Acute Respiratory Distress |
| Hypoxia without signs of increased WOB | Hypoxia |
| Increased WOB + any O₂ support (NC, FM, HFNC, etc.) | Acute Hypoxic Respiratory Failure |
| Increased WOB + wheezing + need for continuous Albuterol nebs | Acute Respiratory Failure (with hypoxia if low O₂ sats) |
| Any home O₂ support or trach/vent for ≥ 28 days | Chronic Respiratory Failure (with hypoxia/hypercapnia if present) |
| Any home O₂ support or trach/vent for ≥ 28 days + any increase in respiratory support | Acute on Chronic Respiratory Failure (with hypoxia/hypercapnia if present) |