What is Noncardiogenic Pulmonary Edema?
Noncardiogenic pulmonary edema is a condition where the lungs fill with fluid, causing breathing problems and low oxygen levels in the body. This problem can develop rapidly and requires immediate attention. It can be caused by various factors, not related to heart problems, that increase fluid leakage into the lungs or change pressure levels within lung blood vessels.
To tell if the condition is noncardiogenic, doctors check if the pressure in the small blood vessels in the lungs is not too high, less than 18 mmHg. This distinction is important, as the treatment varies based on whether the heart is involved or not. Some initial signs that may point to a non-heart related source include no signs of sudden heart disease or fluid imbalance, no swelling in the neck veins or extremities, and certain changes seen in chest images.
The chest images might show a specific pattern of fluid spreading in both lungs without signs of too much blood in the lung’s blood vessels or an enlarged heart. A heart ultrasound might also be performed to confirm there are no sudden issues with the heart’s ability to squeeze or relax.
One of the most known types of noncardiogenic pulmonary edema is called acute respiratory distress syndrome (ARDS), which comes on suddenly due to an inflammatory condition such as infection throughout the body (sepsis), lung infection (pneumonia), stomach content inhalation, blood transfusion, inflammation of the pancreas (pancreatitis), severe injury, chest wall damage, or drug overdose.
To diagnose ARDS, the doctor might look for two signs on a chest X-ray: fluid in both lungs and a specific ratio of oxygen levels in the blood to the amount of oxygen breathed in. They will also verify that there are no signs of heart failure or fluid overload in the body.
Beyond ARDS, other causes of noncardiogenic pulmonary edema include altitude sickness, brain-to-lung fluid leak, opioid overdose, aspirin poisoning, blood clot in the lungs, lung problems after re-inflation, lung injury after blood flow return, and certain reactions to blood transfusions. Each of these conditions has its own specific treatment and needs to be identified promptly because health can worsen rapidly and severely.
What Causes Noncardiogenic Pulmonary Edema?
Noncardiogenic pulmonary edema is a condition where fluid builds up in the lungs, but it’s not caused by heart problems. This can occur due to a variety of reasons, such as:
* ARDS: This stands for Acute Respiratory Distress Syndrome, a severe lung condition causing breathing difficulties.
* HAPE: High Altitude Pulmonary Edema, which is a dangerous buildup of fluid in the lungs that happens at high altitudes.
* Neurogenic pulmonary edema: Fluid in the lungs resulting from a significant central nervous system event, such as a brain injury or seizure.
* Opioid overdose: Excessive use of opioid drugs, such as prescription pain relievers, can also cause this condition.
* Salicylate toxicity: Overdosing on certain drugs, like aspirin (a salicylate), may lead to fluid buildup in the lungs.
* Pulmonary embolism: This is a blockage in one of the arteries in the lungs, often caused by blood clots.
* Reexpansion pulmonary edema: A rare but potentially life-threatening condition that can occur when large amounts of air or gas are rapidly removed from the lung, during treatment for conditions like a collapsed lung.
* Reperfusion pulmonary edema: This can happen after restoring blood flow to the lung following a period of ischemia, or reduced blood supply.
* TRALI: Also known as Transfusion-Related Acute Lung Injury, it’s a serious complication that can occur following a blood transfusion.
Risk Factors and Frequency for Noncardiogenic Pulmonary Edema
Noncardiogenic pulmonary edema, a condition where excess fluid builds up in the lungs, can be caused by various factors. Though some causes are rare, it’s important to consider them when diagnosing this health condition. One of these causes, ARDS (Acute Respiratory Distress Syndrome), impacts around 200,000 patients in the U.S. each year. About 75,000 of these cases result in death, and ARDS also accounts for 10% of global intensive care unit admissions.
HAPE (High Altitude Pulmonary Edema) is another rare cause of noncardiogenic pulmonary edema, primarily affecting individuals who climb to altitudes over 2250 meters and are prone to acute mountain sickness.
TRALI (Transfusion-Related Acute Lung Injury), is a major source of death from blood transfusion and frequently appears in critically ill patients who need more blood transfusions. It’s also seen in 1 out of 5000 units of packed red blood cells and is more common in blood products with high plasma content.
Interestingly, female donors have a higher incidence of TRALI, likely due to specific antibodies found in women who have given birth.
Here’s the information summarized:
- Noncardiogenic pulmonary edema can have different causes, including ARDS, HAPE, and TRALI.
- ARDS affects around 200,000 patients in the U.S. each year, with about 75,000 cases resulting in death. It also accounts for 10% of intensive care unit admissions worldwide.
- HAPE is a rare condition, primarily affecting individuals who climb to altitudes over 2250 meters and are prone to acute mountain sickness.
- TRALI, a major cause of death from blood transfusion, is more common in critically ill patients who require more blood transfusions. It’s found in 1 out of 5000 units of packed red blood cells and is more prevalent in blood products with high plasma content.
- Female donors have a higher incidence of TRALI, likely due to specific antibodies found in women who have given birth.
Signs and Symptoms of Noncardiogenic Pulmonary Edema
A patient’s history could reveal increasing difficulty in breathing and declining respiratory health, which could worsen very quickly depending on the specific cause. It’s essential to carry out a comprehensive check-up because conditions like ARDS can develop when there’s an escalated inflammatory response in the body due to various factors such as infection in the blood, injuries, pneumonia, or pancreatitis. It’s also important to review the patient’s medication, specifically if they’re using opioids and salicylate, as these drugs can sometimes cause noncardiogenic pulmonary edema, a condition characterized by excess fluid in the lungs.
Other considerations include whether the patient has recently received blood transfusions, has risk factors for pulmonary embolism, and has undergone recent thoracic surgery. In certain geographical areas, a rapid increase in altitude may cause noncardiogenic pulmonary edema, which should be investigated further if suspected. A physical examination can help rule out if the fluid build-up in the lungs is due to heart-related issues. Signs of noncardiogenic pulmonary edema include flat neck veins, normal fluid balance, and the absence of peripheral edema, a swelling often caused by accumulation of fluids in your tissues.
Testing for Noncardiogenic Pulmonary Edema
When trying to determine the cause of a patient’s symptoms, the doctor may exclude heart-related problems by using an imaging test called an echocardiogram. This test shows if there are changes in the way your heart is pumping blood (left ventricular ejection fraction) or any sudden changes in how your heart squeezes (systolic) or relaxes (diastolic).
Sometimes, even after physical examination or echocardiogram, it’s not clear what the problem is. In such cases, the doctor may decide to measure the pressure in the small blood vessels in the lungs (pulmonary capillary wedge pressure). If this pressure is less than 18 mmHg, it’s likely that the problem is not related to the heart.
Next, the doctor may arrange for imaging tests of your chest. If a condition called ARDS (which is a type of severe lung disease) is suspected, the pictures from these tests should show signs of fluid in both lungs.
The doctor may want to find out how much oxygen is in your blood. This is done through a test called an arterial blood gas, which gives a PaO2/FiO2 ratio (P/F ratio). This ratio is usually less than 300 if you have ARDS.
Certain issues like swelling in the lung due to re-inflation or re-routing of blood flow (reexpansion and reperfusion pulmonary edema) may cause fluid to build up in one lung. If you have problems with breathing and low oxygen levels in your blood within 6 hours of getting a blood transfusion, the doctor might suspect a condition called TRALI.
Treatment Options for Noncardiogenic Pulmonary Edema
The treatment for non-cardiogenic pulmonary edema, a condition where fluid fills the lungs not due to heart problems, mainly focuses on addressing the underlying cause that triggered the fluid build-up. Thus far, there’s no specific treatment for reducing fluid leakage into the lungs, as seen in a severe form of lung injury called Acute Respiratory Distress Syndrome (ARDS).
In these circumstances, the treatment plan usually includes providing the necessary supportive care and managing the underlying disease until the lung injury heals. Different treatments like inhaled nitric oxide (a gas that can relax and widen blood vessels), prostacyclin (a drug that widens blood vessels and prevents platelets from clotting), anti-inflammatory therapy, and high-frequency ventilation (a technique used to provide respiratory support) haven’t consistently proven to be beneficial.
For other causes of non-cardiogenic pulmonary edema, the approach is largely the same – supportive care. This may include supplemental oxygen to help with breathing or mechanical ventilation if necessary, all while addressing the root cause of the condition.
What else can Noncardiogenic Pulmonary Edema be?
When evaluating a patient for possible causes of fluid build-up in the lungs (pulmonary edema), several conditions will need to be explored. These include:
- Cardiogenic pulmonary edema, which is a direct result of heart problems,
- Possible complications from severe systemic inflammation, injury or infections like sepsis, known as ARDS,
- High Altitude Pulmonary Edema (HAPE), if the person recently made a rapid climb to a high altitude,
- Possible substance-related issues like an overdose from drugs, particularly opioids and aspirin,
- A blockage in one of the pulmonary arteries (Pulmonary Embolism), especially if symptoms include breathlessness, rapid heart rate or signs of shock,
- TRALI (Transfusion Related Acute Lung Injury), should be considered if the symptoms of lung fluid and low oxygen levels occur within six hours of a blood transfusion.
Understanding these different possibilities helps the healthcare provider to determine the most likely cause and the best treatment approach.
What to expect with Noncardiogenic Pulmonary Edema
The outlook for patients with noncardiogenic pulmonary edema, a condition where fluid builds up in the lungs not due to heart problems, varies greatly depending on its cause. For instance, severe ARDS, a type of severe lung disease, has a mortality rate of 40%.
Additionally, 60% of patients who climb above 4500 meters and have a previous diagnosis of High Altitude Pulmonary Edema (HAPE) – fluid buildup in the lungs due to low oxygen levels at high altitudes – can experience this condition again.
Neurogenic pulmonary edema, fluid accumulation in the lungs following a central nervous system insult, has a poor outlook, with 71% of folks who’ve had a type of stroke known as intracranial hemorrhage experiencing this complication. However, it’s currently unknown how often neurogenic pulmonary edema occurs in conjunction with other neurological conditions like epilepsy.
It’s important to mention that ischemia-reperfusion, a type of injury that can occur during the restoration of blood supply following lung transplantation, contributes to 25% of deaths after such surgery.
Lastly, TRALI, a type of lung injury related to transfusion of blood components, carries a mortality rate between 5-10%, but this number can rise to 47% in severely ill patients.
Possible Complications When Diagnosed with Noncardiogenic Pulmonary Edema
The primary problem arising from noncardiogenic pulmonary edema is a severe type of respiratory failure. This condition may require a breathing machine (ventilator) and possibly the continued need for this machine, making it vital to diagnose and begin treatment quickly.
Main complication:
- Severe respiratory failure requiring breathing machine use
- Potential long-term need for a breathing machine
Preventing Noncardiogenic Pulmonary Edema
Under certain circumstances, one can prevent noncardiogenic pulmonary edema, a condition where the lungs fill up with fluid not caused by heart problems. If someone has shown signs of this condition after quickly moving to a high altitude, it’s important that they understand about High Altitude Pulmonary Edema (HAPE). If such individuals quickly move to an altitude higher than 4500 meters, there’s a 60% chance that the condition will occur again.
Also, those who use salicylates, a type of drug often used to reduce pain and fever, should be aware that they could be at risk of toxicity, which is a harmful amount of the drug in the body. People who use opioids, a strong type of painkiller, should be informed about the negative side-effects of long-term use and the possibility that it might lead to pulmonary edema, a serious condition where the lungs become filled with fluid.