Respiratory arrest

Respiratory arrest is a life-threatening condition when a person stops breathing, which requires immediate management. With respiratory arrest, patients are unconscious or about to become so. When a patient goes into respiratory arrest, they are not getting oxygen to their vital organs and may suffer brain damage or cardiac arrest within minutes if not promptly treated. Interruption of pulmonary gas exchange for > 5 minutes may irreversibly damage vital organs, especially the brain. Respiratory arrest often occurs at the same time as cardiac arrest, but not always. Cardiac arrest almost always follows unless respiratory function is rapidly restored. However, aggressive ventilation may also have negative hemodynamic consequences, particularly in the periarrest period and in other circumstances when cardiac output is low.

Regardless of the cause, respiratory arrest is a life-threatening situation which requires immediate management. In most cases, the ultimate goal is to restore adequate ventilation and oxygenation without further compromising a tentative cardiovascular situation.

In some cases, you may be able to identify impending respiratory arrest before it happens. Signs of an impending respiratory arrest include increased work of breathing, which simply means that the patient is working hard for each breath. Eventually, they will deplete their reserves and they will not be able to maintain the effort it is taking to breathe. Respiratory arrest will occur in these patients without prompt intervention.

Additional signs of impending respiratory arrest are gasping, paradoxical breathing movements, cyanosis and intercostal retractions. Some patients may also become confused or excessively sleepy due to hypoxia or increased carbon dioxide levels. In most cases, if signs of respiratory failure are identified early, treatment can be implemented to prevent complete respiratory arrest.

The first thing you will need to do is assess responsiveness. If the patient is unresponsive or is minimally responsive with gasping or abnormal breathing, open the patient’s airway and begin manually ventilating the patient, then call for help. If you are in the hospital and a code blue has not already been activated, hit the code button. A pulse may be present initially, but be prepared to begin chest compressions should the patient deteriorate into cardiac arrest.

Open the patient’s airway and provide positive pressure ventilation with a bag-mask. In most cases, unless the patient has a neck or spinal cord injury, you can open the airway using the head-tilt chin lift method. In the hospital setting, ensure your bag-mask is attached to the oxygen flow meter and the oxygen is turned all the way up.

The use of an oral airway can be helpful in order to prevent the tongue from blocking the airway. An oral airway will cause gagging, so be sure to use one only if the patient is unconscious. In the semi-conscious patient you may use a nasal airway.

Make sure you have a tight seal against the patient’s face when you are holding the mask over the patient’s mouth and nose. Avoid ventilating too quickly. Sometimes in a high stress situation the adrenaline takes over, and it’s easy to hyperventilate the patient. Remember that ventilating too fast or with too large a tidal volume can increase intrathoracic pressure, decrease cardiac output, decrease venous return to the heart and cause gastric distension. Provide breaths at a rate of 10 to 12 breaths/minute in the adult patient in respiratory arrest (1 breath every 5 to 6 seconds).

If you see chest rise with each breath, you are providing adequate ventilation. Attach a pulse oximeter to monitor heart rate and oxygen level while you continue to bag.

Respiratory arrest causes

Respiratory arrest and impaired respiration that can progress to respiratory arrest can be caused by:

• Airway obstruction
• Decreased respiratory effort
• Respiratory muscle weakness

Airway obstruction

Airway obstruction may involve the:

1. Upper airway
2. Lower airway

Upper airway obstruction may occur in infants < 3 mo, who are usually nose breathers and thus may have upper airway obstruction secondary to nasal blockage. At all ages, loss of muscular tone with decreased consciousness may cause upper airway obstruction as the posterior portion of the tongue displaces into the oropharynx. Other causes of upper airway obstruction include blood, mucus, vomitus, or foreign body; spasm or edema of the vocal cords; and pharyngolaryngeal tracheal inflammation (eg, epiglottitis, croup), tumor, or trauma. Patients with congenital developmental disorders often have abnormal upper airways that are more easily obstructed.

Lower airway obstruction may result from aspiration, bronchospasm, airspace filling disorders (eg, pneumonia, pulmonary edema, pulmonary hemorrhage), or drowning.

Decreased respiratory effort

Decreased respiratory effort reflects central nervous system (CNS) impairment due to one of the following:

• Central nervous system disorder
• Adverse drug effect
• Metabolic disorder

Central nervous system (CNS) disorders that affect the brain stem (eg, stroke, infection, tumor) can cause hypoventilation. Disorders that increase intracranial pressure usually cause hyperventilation initially, but hypoventilation may develop if the brain stem is compressed.

Drugs that decrease respiratory effort include opioids and sedative-hypnotics (eg, barbiturates, alcohol; less commonly, benzodiazepines). Combinations of these drugs further increase the risk of respiratory depression. Usually, an overdose (iatrogenic, intentional, or unintentional) is involved, although a lower dose may decrease effort in patients who are more sensitive to the effects of these drugs (eg, the elderly, deconditioned patients, patients with chronic respiratory insufficiency).

CNS depression due to severe hypoglycemia or hypotension ultimately compromises respiratory effort.

Respiratory muscle weakness

Respiratory muscle weakness may be caused by:

• Neuromuscular disorders
• Fatigue

Neuromuscular causes include spinal cord injury, neuromuscular diseases (e.g., myasthenia gravis, botulism, poliomyelitis, Guillain-Barré syndrome), and neuromuscular blocking drugs.

Respiratory muscle fatigue can occur if patients breathe for extended periods at a minute ventilation exceeding about 70% of their maximum voluntary ventilation (eg, because of severe metabolic acidosis or hypoxemia).

Respiratory arrest signs and symptoms

With respiratory arrest, patients are unconscious or about to become so.

Patients with hypoxemia may be cyanotic, but cyanosis can be masked by anemia or by carbon monoxide or cyanide intoxication. Patients being treated with high-flow oxygen may not be hypoxemic and therefore may not exhibit cyanosis or desaturation until after respiration ceases for several minutes. Conversely, patients with chronic lung disease and polycythemia may exhibit cyanosis without respiratory arrest. If respiratory arrest remains uncorrected, cardiac arrest follows within minutes of onset of hypoxemia, hypercarbia, or both.
Impending respiratory arrest

Before complete respiratory arrest, patients with intact neurologic function may be agitated, confused, and struggling to breathe. Tachycardia and diaphoresis are present; there may be intercostal or sternoclavicular retractions. Patients with CNS impairment or respiratory muscle weakness have feeble, gasping, or irregular respirations and paradoxical breathing movements. Patients with a foreign body in the airway may choke and point to their necks, exhibit inspiratory stridor, or neither. Monitoring end-tidal carbon dioxide can alert practitioners to impending respiratory arrest in decompensating patients.

Infants, especially if younger than 3 months, may develop acute apnea without warning, secondary to overwhelming infection, metabolic disorders, or respiratory fatigue. Patients with asthma or with other chronic lung diseases may become hypercarbic and fatigued after prolonged periods of respiratory distress and suddenly become obtunded and apneic with little warning, despite adequate oxygen saturation.

Respiratory arrest diagnosis

Respiratory arrest is usually clinically obvious; treatment begins simultaneously with diagnosis. The first consideration is to exclude a foreign body obstructing the airway; if a foreign body is present, resistance to ventilation is marked during mouth-to-mask or bag-valve-mask ventilation. Foreign material may be discovered during laryngoscopy for endotracheal intubation.

Initial assessment

After determining the scene is safe, approach the patient and attempt to converse with him or her. If the patient responds verbally, you have established that there is at least a partially patent airway and that the patient is breathing (therefore not currently in respiratory arrest). If the patient is unresponsive, look for chest rise, which is an indicator of active breathing. A sternal rub is sometimes used to further assess for responsiveness. Initial assessment also involves checking for a pulse, by placing two fingers against the carotid artery, radial artery, or femoral artery to ensure this is purely respiratory arrest and not cardiopulmonary arrest. Checking a pulse after encountering an unresponsive patient is no longer recommended for non-medically trained personnel ¹. Once one has determined that the patient is in respiratory arrest, the steps below can help to further identify the cause of the arrest.

Clearing and opening the upper airway

The first step to determining the cause of arrest is to clear and open the upper airway with correct head and neck positioning. The practitioner must lengthen and elevate the patient’s neck until the external auditory meatus is in the same plane as the sternum. The face should be facing the ceiling. The mandible should be positioned upwards by lifting the lower jaw and pushing the mandible upward. These steps are known as head tilt, chin lift, and jaw thrust, respectively ². If a neck or spinal injury is suspected, the provider should avoid performing this maneuver as further nervous system damage may occur ². The cervical spine should be stabilized, if possible, by using either manual stabilization of the head and neck by a provider or applying a C-collar. The C-collar can make ventilatory support more challenging and can increase intracranial pressure, therefore is less preferable than manual stabilization ³. If a foreign body can be detected, the practitioner may remove it with a finger sweep of the oropharynx and suction. It is important that the practitioner does not cause the foreign body to be lodged even deeper into the patient’s body. Foreign bodies that are deeper into the patient’s body can be removed with Magill forceps or by suction. A Heimlick maneuver can also be used to dislodge the foreign body. The Heimlick maneuver consists of manual thrusts to the upper abdomen until the airway is clear. In conscious adults, the practitioner will stand behind the patient with arms around the patient’s midsection. One fist will be in a clenched formation while the other hand grabs the fist. Together, both hands will thrust inward and upward by pulling up with both arms ⁴.

Respiratory arrest treatment

Treatment is clearing the airway, establishing an alternate airway, and providing mechanical ventilation.

First aid

If you are first on scene for a respiratory arrest, it can be a stressful situation and it can be easy to forget the basics.

If you find an unconscious person, DO NOT LEAVE THEM ALONE. Shout for someone to call an ambulance. If you are alone, do not leave the person to find help until you are certain they are breathing and have a heartbeat. Remember the acronym DRABC (think Danger, A,B,C) and follow these steps first.

• D- Danger. Remove the patient from danger e.g. a fire, electricity source, pool or road.
• R- Response. Shout the patient’s name, check for pain response by pinching the upper ear. If no response;
• A- Airway. Turn the patient onto their side and gently scoop one finger through the mouth to clear any foreign matter away. Turn them onto their back and gently tilt the head back to open the airway. (Do not tilt the head on babies less than 1 year old.)
• B- Breathing. LOOK for the rise and fall of the chest, LISTEN for breathing and FEEL for air leaving the patient’s mouth or nose. If breathing is present, turn the patient on their side again and wait for help. If there is no breathing, commence EAR.
• C- Circulation. Check the carotid pulse, which is next to the Adam’s apple in the neck. If the pulse is present, continue EAR and wait for help. If the pulse is absent, begin CPR.

How to decide what the patient need?

• A casualty who has stopped breathing and has a pulse needs only EAR (Expired Air Resuscitation)
• A casualty who has both stopped breathing and whose has no pulse needs both EAR and CPR (Cardiopulmonary Resuscitation)
• It is not possible to be breathing if there is no pulse
• Time is critical – 4 minutes or more without oxygen can lead to brain damage

Expired Air Resuscitation (EAR) Technique

Turn the patient onto their back and open the airway by placing one hand on the forehead to tilt the head back. Support the jaw with your fingers in a ‘pistol grip’ position. Only remove dentures if they are broken or loose.

Make a tight seal around the patient’s mouth with your mouth. Close the patient’s nostrils with your cheek. For babies, cover both the nose and mouth with your mouth. Breathe steadily into the patient until you see the chest rise. Each breath should last about 1 to 2 seconds, with a pause in between to let the air flow back out. Watch the chest rise as you breathe in to ensure that your breaths are actually going into the lungs, and watch as the chest falls.

• Step 1. Give 5 quick breaths in 10 seconds.
• Step 2. Check for a carotid pulse after giving the 5 full breaths.
• Step 3. If the casualty has a pulse but is not breathing, continue EAR.
  • Adults and older children need 1 breath every four seconds, 15 breaths per minute.
  • Babies need 1 breath every 3 seconds, 20 breaths per minute.
• Step 4. Recheck the pulse and breathing every two minutes. If breathing returns, place the patient on their side and wait for the ambulance (or call one if you haven’t already).

CPR Technique

Lie the patient completely flat on a firm surface. Kneel beside the patient. Position yourself midway between the chest and the head in order to move easily between compressions and breaths.

Hand position

• Find the mid point of the breastbone (sternum).
• For adults: place the heel of your compressing hand on the breastbone just below the midpoint. Grasp your wrist with your other hand, or place the other hand on top of the first.
• For children: Use one hand only.
• For babies: Use the tips of two fingers.

Compression technique

For adults: Keep your shoulders directly over your hands and keep your arms straight. Lean the weight of your upper body onto your hands to compress the chest. Keep a steady, even rhythm and do not “jab” with your hands or punch the breastbone.

• For adults, compress about 4-5cm
• For children, compress about 2-3cm
• For babies, compress about 1-2cm

Each compression lasts less than one second. After each compression, release the pressure on the chest without losing contact with it and allow the chest to return to its normal position before starting the next compression.

EAR/CPR Breathing/Compression rate

If you are alone:

• For an adult, give 30 compressions followed by 2 breaths over 15 seconds
• For a child or baby, give 30 compressions and 2 breaths over 10 seconds

If there are two people:

• One person does the breathing and one does compressions
• Give 5 compressions followed by 1 breath. The person doing the compressions can count “One, two, three, four, five, BREATHE” to help maintain a rhythm
• Check pulse and breathing every two minutes
• If the pulse returns, STOP compressions immediately. Continue with EAR if there is no breathing
• If breathing and pulse return, place the patient on their side and wait for an ambulance.

Advanced airway management

After providing positive pressure ventilation with a bag-mask, the patient may spontaneously begin to breathe on his/her own. If this occurs, be sure the patient’s breathing is adequate, administer supplemental oxygen and continue to monitor the patient.

If the patient does not begin to breathe on their own, the patient will need to be intubated. While the intubation equipment is being set up, continue to ventilate the patient using the bag-mask.

Prior to the patient being intubated, you may need to suction the mouth and oropharynx in order to remove any secretions so that the vocal cords can be visualized. Confirmation that the trachea has been successfully intubated may be initially indicated by chest rise. In addition, place an end tidal CO2 device, which will indicate the presence of carbon dioxide during exhalation. A chest x-ray can be done as soon as possible to confirm tube placement. At this point, the patient will need to be placed on a mechanical ventilator.

Determine and treat the underlying cause

There are many causes of respiratory arrest. For example, drug overdoses can depress the central nervous system and lead to respiratory arrest. Certain neuromuscular diseases can cause fatigue, which eventually leads to the cessation of breathing. Airway obstruction, metabolic disorders and strokes can also lead to respiratory arrest. Knowing the patient’s history, their chief complaint and medications they are taking can help determine the underlying cause.

In addition, blood tests such as arterial blood gases, a complete blood count, electrolytes and others may provide clues as to cause of the respiratory arrest. A chest x-ray should be performed. Once the pieces of the puzzle are in place, a diagnosis and underlying cause of respiratory arrest can often be identified and treated.

References

1. Myerburg, Robert J; Goldberger, Jeffrey J (2019). Braunwald’s Heart Disease: A Textbook of Cardiovascular Medicine. Philadelphia, PA 19103-2899: Elsevier. pp. 807–847. ISBN 978-0-323-46342-3
2. Tibballs, James (2019). “Paediatric cardiopulmonary resuscitation”. Oh’s Intensive Care Manual. Oxford: Elsevier. pp. 1365–1374. ISBN 978-0-7020-7221-5
3. Kolb, JC; Summers, RL; Galli, RL (March 1999). “Cervical collar-induced changes in intracranial pressure”. Am J Emerg Med. 17(2): 135
4. Ward, Kevin R.; Kurz, Michael C.; Neumar, Robert W. (2014). “Chapter 9: Adult Resuscitation”. In Marx, John A.; Hockberger, Robert S.; Walls, Ron M.; et al. (eds.). Rosen’s Emergency Medicine: Concepts and Clinical Practice. Volume 1 (8th ed.). Philadelphia, PA: Elsevier Saunders. ISBN 978-1455706051.