Do oxygen levels drop with RSV?

RSV, or respiratory syncytial virus, is a common respiratory virus that usually causes mild, cold-like symptoms. However, RSV can be serious in infants and older adults. One concern with RSV is that it can potentially cause oxygen levels to drop. In this article, we’ll explore the link between RSV and oxygen levels and see if oxygen levels do tend to decrease with this infection.

What is RSV?

RSV is a very common virus that infects the lungs and breathing passages. It is the most common cause of bronchiolitis (inflammation of the small airways in the lungs) and pneumonia in children younger than 1 year of age in the United States.

RSV spreads when an infected person coughs or sneezes. The virus can live for many hours on surfaces like countertops and doorknobs. You can get infected by touching a surface with the virus on it and then touching your face before washing your hands. RSV spreads most often during fall, winter, and spring.

What are the symptoms of RSV?

In both children and adults, the most common RSV symptoms include:

– Runny nose
– Decrease in appetite
– Coughing
– Sneezing
– Fever
– Wheezing

These cold-like symptoms usually appear in stages and not all at once. In young infants with RSV, the only symptoms may be irritability, decreased activity, and apnea (pauses in breathing).

In more severe cases, RSV can lead to bronchiolitis, an inflammation of the small airways in the lung, or pneumonia, infection of the lungs. These more serious conditions can cause breathing difficulties.

Who is most at risk from RSV?

RSV can affect people of all ages, but it’s most severe in certain high-risk groups:

– Infants, especially those under 6 months old
– Older adults, especially those over age 65
– People with weakened immune systems
– People with chronic heart and lung disease

Premature infants are particularly vulnerable to complications from RSV due to their underdeveloped lungs and immature immune system. RSV is the most common cause of bronchiolitis and pneumonia in children under 1 year of age.

How might RSV affect oxygen levels?

When RSV infects the respiratory tract, it can inflame and congest the airways. This swelling can obstruct airflow and make it harder to breathe.

In some cases, RSV may reach the lower respiratory tract and infect the lungs, leading to pneumonia. Pneumonia causes fluid and swelling in the tiny air sacs of the lungs. This reduces the lungs’ capacity to absorb oxygen and release carbon dioxide.

Bronchiolitis and pneumonia from RSV can cause parts of the lungs to collapse, either temporarily or permanently. This also impairs gas exchange in the lungs.

If oxygen intake is reduced significantly, oxygen levels in the blood can fall. This condition is called hypoxemia. Severe hypoxemia that persists can be dangerous.

In adults, oxygen saturation levels under 90% are considered abnormally low and require medical treatment. In children, levels under 92% are considered hypoxemic.

Do oxygen levels usually drop with RSV?

Mild RSV cases may not affect oxygen levels at all. But moderate to severe RSV infections frequently cause some degree of hypoxemia, especially in high-risk groups like infants, the elderly, and those with chronic diseases.

One study found that around 15-30% of infants hospitalized for RSV bronchiolitis and pneumonia experienced oxygen desaturation below 90%. The authors conclude these children should receive supplemental oxygen.

Another study found that 41% of elderly patients hospitalized for RSV pneumonia had oxygen saturation levels below 90% during their illness.

However, predicting which individuals will develop hypoxemia is difficult. Even with mild cold-like symptoms, some babies with RSV experience dips in oxygen. One study found that 20% of RSV-infected infants with no respiratory distress had intermittent hypoxemia.

In severe RSV pneumonia, dangerously low oxygen levels are more expected. One study found that children with RSV pneumonia serious enough to require mechanical ventilation had mean saturation levels of 87%.

So while not every case of RSV leads to low oxygen, significant dips are relatively common, especially in those with lower respiratory involvement and vulnerable groups like premature babies, the elderly, and immunocompromised patients. Monitoring oxygenation is important in these patients.

How is oxygen level monitored in RSV?

When someone is diagnosed with RSV, especially moderate to severe cases, one important aspect of care is monitoring their oxygen saturation levels. This allows healthcare providers to identify decreasing oxygen so it can be treated before becoming critically low.

Here are some ways oxygen level can be monitored in RSV patients:

Pulse Oximetry

Pulse oximetry is the most convenient and commonly used way to monitor oxygen saturation. This simple noninvasive test determines the percentage of hemoglobin molecules in the bloodstream that are carrying oxygen.

A small clip-like device called a pulse oximeter probe is placed on the finger, toe, or earlobe. It uses light waves to detect oxygenated vs. deoxygenated hemoglobin. Results appear on a monitor within seconds, showing oxygen saturation as a percent value.

Pulse oximetry allows frequent, continuous monitoring of oxygen levels painlessly. It promptly alerts caregivers to any clinically significant desaturation.


Arterial blood gas (ABG) measurement directly tests oxygen and carbon dioxide levels in an arterial blood sample. It requires collecting blood from an artery, usually the radial artery in the wrist.

ABG also measures acid-base balance in the blood. It provides the most accurate analysis of oxygenation and ventilation, which can better guide treatment decisions.

ABG testing is used to complement pulse oximetry. It may be ordered on RSV patients with significant respiratory distress or hypoxemia. Repeat testing helps assess response to oxygen therapy.


Capnography measures exhaled carbon dioxide. It requires placing a nasal cannula attached to a capnograph machine.

High carbon dioxide levels can signal respiratory distress and inadequate ventilation. Capnography is sometimes used in hospitalized infants and respiratory-compromised patients with RSV. It provides an early warning of apnea and other breathing issues.

Chest Radiography

Chest x-rays allow visualization of the lungs. They can detect infiltrates, collapse, and other abnormalities signaling pneumonia. However, x-ray changes lag behind onset of symptoms and are not required for RSV diagnosis.

Portable bedside chest radiographs may be done on some hospitalized RSV patients to assess lung status. Repeat x-rays help determine if pneumonia is improving or worsening.

How is low oxygen treated in RSV?

When oxygen saturation drops significantly due to RSV, treatment focuses on improving oxygenation and supporting breathing. Options include:

Supplemental Oxygen

Giving additional oxygen is the main treatment for hypoxemia. Supplemental oxygen is humidified and delivered through:

– Nasal cannula: common in infants
– Oxygen mask: often used in very low saturation
– High-flow nasal cannula: may help avoid intubation

Target saturation is usually above 92% in infants and 90% in older children and adults. Pulse oximetry and ABG help titrate oxygen dose.


Bronchodilator medications like albuterol open constricted airways to improve airflow. Nebulized bronchodilators may benefit infants and children with bronchiolitis and significant breathing difficulty.

Airway Clearance

Excess mucus contributes to airway obstruction. Nasal suctioning, chest physiotherapy, and breathing treatments help clear secretions. Helping infants breathe and cough more effectively through positioning also helps mobilize mucus.

Intubation and Ventilation

When supplemental oxygen cannot achieve safe saturation levels, infants and children with severe RSV may require intubation and mechanical ventilation. This involves placing a tube down the windpipe connected to a ventilator machine that breathes for the patient.

Sedation and paralysis medication are needed to tolerate intubation. Ventilation helps “rest” the lungs and optimize oxygenation until the RSV infection improves.


In life-threatening cases where mechanical ventilation fails, extracorporeal membrane oxygenation (ECMO) provides last-resort respiratory support. ECMO oxygenates the blood outside the body before returning it.

ECMO is resource-intensive and reserved for severe cases unresponsive to all other treatments. Overall, less than 1% of children hospitalized for RSV require ECMO.

What are the complications of low oxygen with RSV?

When oxygen saturation drops significantly and remains low, complications can develop, including:

Respiratory Failure

Respiratory failure occurs when the respiratory system cannot provide adequate oxygen to the body or remove carbon dioxide effectively. RSV can cause respiratory failure needing intubation and ventilation.

Organ Damage

Hypoxemia strains other organs like the heart, brain, kidneys, and liver. Low oxygen damages cells and impairs function. Organ damage may require ICU care and circulatory/kidney support.

Pulmonary Hypertension

Persistent lung damage and hypoxemia can cause elevated blood pressure in lung arteries. Pulmonary hypertension impairs heart function. Some infants with severe RSV develop temporary pulmonary hypertension.


In some high-risk infants with preexisting conditions, life-threatening RSV can be fatal despite aggressive treatment. However, the vast majority of children who need hospitalization for RSV hypoxemia recover with adequate respiratory support.

Overall mortality rate from RSV is less than 1% of infected infants. Death is more common in those with multiple high-risk factors like prematurity, congenital heart disease, and neuromuscular impairment.

How can I monitor oxygen levels at home?

Parents of infants at high-risk for serious RSV illness should know the signs of respiratory distress and options for monitoring oxygen at home, including:

– Observe skin color: Cyanosis, a blue tinge to the skin, lips, or nail beds indicates low oxygen levels.

– Listen for changes in breathing: Increased respiratory rate, nasal flaring, head bobbing, retractions, wheezing, and labored breathing signify respiratory distress.

– Invest in a home pulse oximeter to spot check oxygen saturation. Healthy levels are above 92% at rest. Lower levels warrant medical assessment.

– Time apnea events: Pauses over 15-20 seconds signal breathing trouble. Keep notes on apnea duration and frequency.

– Track respiratory rate: Count breaths per minute while the infant is calm and sleeping. Rates consistently over 60 indicate breathing difficulty.

Call your pediatrician promptly for evaluation if you observe worsening work of breathing, significant desaturation on pulse oximetry, apnea, or other concerns at home. Seek emergency care if symptoms are severe. Don’t delay getting help.

When to go to the ER for low oxygen with RSV

Bring your child to the ER immediately if you notice any of the following red flags:

– Oxygen saturation below 90%

– Severe or worsening breathing difficulty (e.g. chest retractions, wheezing)

– Prolonged pauses in breathing

– Blue color to skin, lips, or nail beds

– Dehydration

– Extreme sleepiness, difficulty waking

– Struggling to breathe, gasping for air

– Low body temperature (hypothermia)

Infants under 3 months with fever should also receive urgent care, as they are prone to serious bacterial infections in addition to RSV.

Don’t wait with any breathing concerns in young babies. The goal is preventing respiratory failure, intubation, and ICU care. Go to the ER at first sign of significant distress. Call 911 immediately if the infant has stopped breathing.

Preventing low oxygen levels

The best way to avoid complications like hypoxemia is preventing RSV infection. High-risk groups like premature infants can get injections of RSV immune globulin to reduce risk. A RSV vaccine is in development.

Beyond that, general preventive measures include:

– Avoid exposure to sick contacts and large crowds during RSV season

– Wash hands frequently and disinfect surfaces

– Breastfeed infants to transfer protective antibodies

– Don’t smoke around children

– Follow immunization schedule to prevent other respiratory infections

When RSV is circulating in the community, high-risk infants should stay home as much as possible. Notify caregivers about any cold symptoms before they visit. Prompt care helps reduce the likelihood of respiratory distress and hypoxemia.


RSV frequently causes some degree of low oxygen levels, especially in high-risk groups like babies, older adults, and those with chronic heart/lung conditions. The virus can inflame and congest airways, potentially progressing to pneumonia in some cases. This impairs oxygen exchange in the lungs.

Monitoring oxygen saturation is important in moderate to severe RSV disease. Pulse oximetry allows convenient tracking of levels. Treatment focuses on supplemental oxygen, respiratory support, and managing complications. Though serious RSV cases require hospitalization, most children recover well with proper treatment. Prevention through hygiene and immunization remains key to avoiding this common wintertime virus.

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