Status Asthmaticus - When Asthma Gets Serious

Types, Diagnosis and Treatment of Severe Asthma (Status Asthmaticus)

Patient laying in hospital bed in oxygen mask
What are the symptoms, types, and treatments for acute severe asthma (status asthmaticus)?. Credit: Blend Images/ERproductions Ltd / Getty Images

Status Asthmaticus - Definition

Status asthmaticus or SA for short, is a severe asthma attack usually of long duration or abruptly sudden in onset. In SA, asthma symptoms continue on and respiratory function declines, despite standard treatments.

SA can lead to respiratory failure, prolonged hospitalization and even death, and it signifies a medical emergency that requires immediate and aggressive treatments.

As many as 10 percent of people who experience SA will die.

Status asthmaticus is far too common, resulting in over 5,000 deaths each year, and everyone with or without asthma should be familiar with the common warning signs and symptoms. Instead of having this be frightening to hear, keep on reading and learn what you can do to help becoming one of these statistics.

How Common is Severe Asthma (Status Asthmaticus)?

Of the total population, asthma affects approximately eight percent of adults and ten percent of children. Of these, five to ten percent have a severe form of asthma and are at greater risk for status asthmaticus.

What Happens During a Severe Asthma Attack?

During a severe asthma attack, the way the body normally processes respiratory gases in the alveoli is impaired. This leads to lower oxygen levels and higher carbon dioxide levels in the blood, which, in extreme cases, can cause coma and death.

Asthma also creates air trapping in the lungs, a condition that causes increased pressure in the chest. This can cause lung collapse and even cardiac arrest.

Two Types of Status Asthmaticus

There are two types of SA. The first and more common type is a slow-onset attack. This may take a long time to unfold and usually results because of inadequate treatment.

The person with this type of SA will experience days or weeks of worsening symptoms, punctuated by moments of relief, and ending in symptoms that cannot be reversed with medications in the home.

The second type of severe attack is a sudden-onset attack. The person experiencing this type of SA has not experienced any worsening symptoms in the preceding weeks, but is struck with sudden and severe bronchospasm, breathlessness, wheezing and cough. This type of asthma attack is often brought on by a large exposure to trigger substances, such as pollen, dust or food allergens.

How Doctors Diagnosis Status Asthmaticus

The following are signs and symptoms that doctors use to diagnose SA:

  • Breathlessness at rest (with a slow onset attack, shortness of breath may begin with activity alone and progress to where it occurs at rest)
  • Inability to speak in sentences or not being able to speak at all
  • High respiratory rate at rest (greater than 30 breaths per minute is of concern, but even rates greater than 18 in a school age child or adult should raise concern and be watched closely—rates are normally higher in younger children and it's important to ask your allergist or lung specialist about the rate at which you should be concerned in young children)
  • Elevated pulse rate at rest (greater than 120 beats per minute)
  • Agitation and irritability (although as the attack progresses, sleepiness and somnolence is more worrisome)
  • Low levels of oxygen in the blood (hypoxemia and then hypoxia)
  • Diminished breathing capacity, as measured by peak expiratory flow (PEF)

How Doctors Treat Status Asthmaticus

Standard treatment of status asthmaticus in the emergency room includes:

  • Oxygen by mask
  • Measurement of PEF with spirometry (in the most severe asthma these measurements can be difficult)
  • Short acting beta agonists such as albuterol via inhaler or preferably through a nebulizer
  • Corticosteroid medications (such as prednisone) given either by mouth or intravenously
  • Inhaled anticholinergic medications (such as atrovent)

Other medications that may be used during an acute episode include:

  • Beta-agonists injected under the skin (such as Terbutaline)
  • Magnesium sulfate intravenously
  • Leukotriene modifiers (such as Zafirlukast or Zileuton) by mouth

Mechanical ventilation is a treatment of (almost) last resort because of the risk of trauma to the lungs and other serious complications that can occur. About four percent of emergency room visits for asthma will result in the patient needing mechanical ventilation. As a final modality, extracorporeal membrane oxygenation (ECMO) has been effective in a few patients in which asthma would have been fatal even with mechanical ventilation.

ECMO (extracorporeal membrane oxygenation) offers yet another last resort and final treatment modality for those for who all treatments including mechanical ventilation have failed. It's now thought that ECMO should be considered as an early treatment in people who have status asthmaticus with poor gas exchange (poor intake of oxygen and expiration of carbon dioxide) that isn't responding well to treatment available. ECMO offers a way of restoring gas exchange in the body while preventing lung injury related to mechanical ventilation.

People With Asthma Should Know Their PEF Measurement

There are more than 5,000 deaths from asthma in the United States each year. Often the severity of symptoms for a person with asthma are not closely related to the severity of his or her lung dysfunction. Therefore, it is important for all asthmatics to measure their PEF regularly. This is done by using a peak flow meter, which is a small plastic device that is exhaled into forcefully, which measures the PEF.

The PEF measurement gives information about respiratory status, any decline from the person's own normal (baseline) condition, and the need to increase medications or seek medical treatment. Any person with asthma who has a decline of 30 percent or more in PEF, particularly if rescue inhalers are not being effective, should seek medical attention without hesitation.

Risk Factors for a Severe or Fatal Asthma Attack (Status Asthmaticus)

How can you know if you are at risk of developing a fatal asthma attack (status asthmaticus)?

With sudden status asthmaticus, there are, by definition, few warning signs. If you have the type of allergies in which this is likely to occur, your allergist will discuss how severe these attacks can be come and how fast.

With slow onset status asthmaticus there are several warning signs which should alert you to call your doctor or seek emergency treatment. These include:

  • A decline in PEF of 30 percent or more, as noted above, though your allergist may give you different parameters depending on your asthma.
  • Increased need of your rescue inhaler.
  • Nighttime awakenings due to your asthma.
  • Increasing shortness of breath despite consistent use of your medications.
  • If you have a history of a severe asthma attack, you should seek emergency care if you note any of the symptoms you had during your previous attack.
  • If you've used two or more canisters of your short-acting inhaler over the past month.

Bottom Line on Status Asthmaticus

It's important that everyone with asthma, and those loved ones who care for people with asthma, be aware of both the warnings signs of severe asthma and the seriousness of this disease. Despite advances in treatment there are still far too many people who die from this disease each year.

Part of the problem is that many people do not realize how powerful the medications they take at home happen to be, and this can give a false sense of security. If a person has been increasing her inhaler use at home, it can sometimes be very difficult to get the disease under control once she arrives in the emergency room.

That said, having asthma is not a reason to panic. As noted earlier, many people with status asthmaticus have slow onset disease. What learning about this condition should do is to prompt those with asthma, even those with relatively mild asthma, to religiously check their peak flows and to contact their physicians with any signs that their condition is worsening. If you are not familiar with this process, call your allergist today and learn how to be proactive with your asthma.

Sources:

Di Lascio, G., Prifti, E., Messai, E. et al. Extracorporeal Membrane Oxygenation Support for Life-Threatening Acute Severe Status Asthmaticus. Perfusion. 2017. 32(2):157-163.

Miller, A., Breslin, M., Pineda, L., and J. Fox. An Asthma Protocol Improved Adherence to Evidence-Based Guidelines for Pediatric Subjects With Status Asthmaticus in the Emergency Department. Respiratory Care. 2015. 60(12):1759-64.

Tramm, R., Ilic, D., Davies, A., Pellegrino, V., Romero, L., and C. Hodgson. Extracorporeal Membrane Oxygenation for Critically Ill Adults. Cochrane Database of Systematic Reviews. 2015. 1:CD010381.

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