Related Experiment Video
Updated: May 5, 2026
07:52
Expired CO2 Measurement in Intubated or Spontaneously Breathing Patients from the Emergency Department
Published on: January 30, 2011
15.9K
Hyperventilation-induced hypotension during cardiopulmonary resuscitation
Tom P Aufderheide1, Gardar Sigurdsson, Ronald G Pirrallo
1Department of Emergency Medicine, Medical College of Wisconsin, Milwaukee, USA.
Circulation
|April 7, 2004
Summary
Excessive ventilation during cardiopulmonary resuscitation (CPR) is common. Animal studies show that hyperventilation significantly decreases coronary perfusion pressure and survival rates, highlighting a critical need for improved CPR techniques.
Area of Science:
- Emergency Medicine
- Cardiopulmonary Physiology
- Resuscitation Science
Background:
- Observational studies indicate frequent hyperventilation by rescuers during out-of-hospital cardiopulmonary resuscitation (CPR).
- Excessive ventilation may negatively impact patient outcomes during resuscitation efforts.
Purpose of the Study:
- To quantify the extent of excessive ventilation in human CPR.
- To determine if excessive ventilation rates in animal models decrease coronary perfusion pressure and survival during CPR.
Main Methods:
- Ventilation rates and durations were electronically recorded in 13 adult patients receiving CPR.
- Hemodynamic parameters and survival rates were assessed in pigs undergoing CPR with varying ventilation rates (12, 20, 30 breaths/min) and gas mixtures.
Main Results:
- Human CPR showed average ventilation rates of 30 breaths/min, with no survivors.
- In pigs, increased ventilation rates (30 vs. 12 breaths/min) significantly elevated intrathoracic pressure (17.5 vs. 7.1 mm Hg/min) and decreased coronary perfusion pressure (16.9 vs. 23.4 mm Hg).
- Survival rates in pigs were significantly lower with 30 breaths/min (1/7) compared to 12 breaths/min (6/7).
Conclusions:
- Professional rescuers frequently hyperventilate patients during out-of-hospital CPR.
- Excessive ventilation during CPR in animal models leads to detrimental hemodynamic changes and reduced survival.
Related Concept Videos
01:30Alterations in Respiration II
2.5K
There are numerous types of normal and abnormal respiration. Based on ventilatory movements, breathing patterns are classified as regular, deep, or shallow. Examples include Biot's breathing, Cheyne-Stokes respiration, Kussmaul's breathing, hyperventilation, and hypoventilation. Each pattern is clinically significant and aids in evaluating patients.
In Biot's breathing, the respiratory rate and depth are irregular, alternating between periods of deep gasping and apnea. Common causes...
In Biot's breathing, the respiratory rate and depth are irregular, alternating between periods of deep gasping and apnea. Common causes...
2.5K
01:25Hyperpnea and Hyperventilation
4.1K
Hyperventilation refers to a higher-than-normal rate and depth of breathing, often associated with anxiety attacks. This excessive breathing surpasses the body's need to expel CO2, leading to a condition known as hypocapnia - an unusually low level of carbon dioxide in the blood. Hypocapnia can constrict cerebral blood vessels, reducing blood flow to the brain, which may result in dizziness or fainting. Early signs include tingling and muscle spasms in the hands and face, caused by falling...
4.1K
01:21Acute Respiratory Failure-I
1.8K
Acute respiratory failure is a condition characterized by the inability of the lungs to perform their primary function: gas exchange. This failure leads to insufficient oxygen levels (hypoxemia) in the blood, elevated carbon dioxide levels (hypercapnia), or both, causing critical impairment in organ function.
Definition: It is defined by specific criteria based on blood gas measurements. Hypoxemia happens when the partial pressure of oxygen (PaO2) falls below 60 mmHg. At the same time,...
Definition: It is defined by specific criteria based on blood gas measurements. Hypoxemia happens when the partial pressure of oxygen (PaO2) falls below 60 mmHg. At the same time,...
1.8K
01:21Acute Respiratory Failure-II
1.8K
Type I Respiratory Failure, or hypoxemic respiratory failure, occurs when the partial pressure of oxygen (PaO2) in arterial blood falls below 60 mmHg while breathing room air without a corresponding increase in arterial carbon dioxide levels (PaCO2). This condition highlights a significant impairment in the lungs' capacity to oxygenate the blood.
The underlying physiological abnormalities that contribute to hypoxemic respiratory failure include:
The underlying physiological abnormalities that contribute to hypoxemic respiratory failure include:
1.8K
01:30Acute Respiratory Failure-III
1.3K
Hypercapnic respiratory failure, also known as Type 2 or ventilatory respiratory failure, is a severe condition characterized by the body's inability to effectively remove carbon dioxide (CO2) from the bloodstream. It leads to an arterial CO2 pressure (PaCO2) exceeding 45 mmHg and a blood pH above 7.35. This situation indicates that the body's ventilatory demand, or the ventilation needed to maintain normal PaCO2 levels, surpasses its supply or the maximum gas flow achievable without...
1.3K
01:23Acute Respiratory Failure-IV
824
Respiratory failure can manifest suddenly or gradually, characterized by a rapid decline in PaO2 and a rapid rise in PaCO2. This situation indicates a severe respiratory problem that may quickly become a life-threatening emergency. One of the early signs of hypoxemic Acute Respiratory Failure (ARF) is a change in mental status due to the brain's sensitivity to oxygen levels and changes in acid-base balance. Symptoms such as restlessness, confusion, and agitation suggest inadequate oxygen...
824