Related Experiment Video
Updated: Aug 1, 2026
05:46
A Novel Inhalation Mask System to Deliver High Concentrations of Nitric Oxide Gas in Spontaneously Breathing Subjects
Published on: May 4, 2021
Inhaled nitric oxide in acute respiratory failure: dose-response curves
L Puybasset1, J J Rouby, E Mourgeon
1Department of Anesthesiology, Université Paris VI, France.
Intensive Care Medicine
|May 1, 1994
Summary
Inhaled nitric oxide (NO) effectively reduces pulmonary artery pressure and improves oxygenation in severe acute respiratory failure patients. Therapeutic concentrations of NO are between 100-2000 ppb, with minimal toxicity risk.
Area of Science:
- Critical Care Medicine
- Pulmonary Medicine
- Pharmacology
Background:
- Severe acute respiratory failure (ARF) often involves pulmonary hypertension, leading to hypoxemia.
- Inhaled nitric oxide (NO) is a selective pulmonary vasodilator, but its optimal therapeutic dose in ARF remains debated.
Purpose of the Study:
- To establish the dose-response relationship of inhaled nitric oxide (NO) for pulmonary vasodilation and improved arterial oxygenation (PaO2) in adults with severe ARF.
Main Methods:
- A prospective, randomized study involving 6 critically ill patients with severe ARF and pulmonary hypertension.
- Eight different concentrations of inhaled NO (100–5000 ppb) were administered. Hemodynamic parameters, blood gases, and methemoglobin levels were monitored.
Main Results:
- Inhaled NO (100–2000 ppb) demonstrated a dose-dependent decrease in pulmonary artery pressure and resistance.
- PaO2 and mixed venous oxygen saturation (SvO2) increased dose-dependently, while PaCO2 decreased.
- No significant changes in systemic hemodynamics or methemoglobin levels were observed; NO2 levels remained below toxic thresholds.
Conclusions:
- Therapeutic inhaled NO concentrations for hypoxemic patients with pulmonary hypertension and severe ARF are effectively within the 100–2000 ppb range.
- This dosage range significantly reduces the risk of NO-related toxicity.
- Continuous SvO2 monitoring can aid in determining optimal inhaled NO doses for individual patients.
More Related Videos
Related Concept Videos
01:21Acute Respiratory Failure-I
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,...
01:21Acute Respiratory Failure-II
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:
01:30Acute Respiratory Failure-III
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 causing...
01:23Acute Respiratory Failure-IV
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...
01:29Acute Respiratory Failure-V
The treatment for acute respiratory failure varies based on factors like the underlying cause, overall health, and severity. A collaborative healthcare team is essential for early detection, often through arterial blood gas analysis. Identifying the cause is the primary goal, with treatment strategies adjusted for ventilation/perfusion (V/Q) mismatch, shunting, or diffusion impairment.
Ensure that patients are monitored continuously for their response to therapy, including changes in...
Ensure that patients are monitored continuously for their response to therapy, including changes in...
01:21Dose Response Curve: Conventional Versus Nonmonotonic
The correlation between a drug's dosage and its impact on a biological system is a cornerstone of pharmacology and toxicology. Conventional dose–response curves, which include graded and quantal relationships, are key to this understanding. Graded dose–response curves depict the spectrum of a biological reaction to different doses within an individual, indicating that as the drug dosage increases, so does the intensity of the response. On the other hand, quantal dose–response relationships...