Cardiac arrest and cardiopulmonary resuscitation

Cardiac arrest is the sudden cessation of cardiac function, resulting in loss of circulation. In adults, the most common cause of cardiac arrest is an underlying cardiac condition (e.g., coronary artery disease, valvular heart disease). However, cardiac arrest can also be caused by noncardiac etiologies such as hypovolemia, hypothermia, or tension pneumothorax (e.g., the Hs and Ts). In children, the causes of cardiac arrest are varied but are more frequently caused by profound hypoxia (e.g., due to airway obstruction). Sudden cardiac arrest manifests as apnea, pulselessness, and sudden loss of consciousness.
Cardiopulmonary resuscitation (CPR) is a lifesaving procedure that maintains circulation in patients with sudden cardiac arrest until cardiac function can, ideally, be restored. There are two types of protocols for CPR: basic life support (BLS), for lay rescuers and medical professionals alike, and advanced cardiac life support (ACLS), solely for medical professionals. BLS involves checking the patient's responsiveness, calling for help, performing chest compressions and rescue breaths, and, if available, using an automated external defibrillator (AED). ACLS includes additional procedures such as drug therapy (especially epinephrine), securing the airways (e.g., endotracheal intubation), and finding and treating reversible causes of cardiac arrest. Immediate initiation of high-quality chest compressions is the most important factor in survival after cardiac arrest. Modifications to BLS and ACLS are required for children and neonates. After return of spontaneous circulation, postresuscitation care is essential for good neurological and functional outcomes. This involves neuroprotective measures, hemodynamic support, critical care unit admission, monitoring for organ dysfunction, and treatment of underlying causes and complications.

The resuscitative interventions and algorithms described in this article are consistent with the guidelines of the American Heart Association (AHA) and the International Liaison Committee on Resuscitation (ILCOR) Consensus on Science with Treatment Recommendations (CoSTR). Some details may vary in international healthcare settings, depending on the governing authorities and available resources. Local protocols should be consulted whenever possible.

Chain of survival in cardiac arrest ^[1][2]

The following are elements of standardized care that maximize survival in cardiac arrest.

• Identification of cardiac arrest and initiation of an emergency response
• Early basic life support: immediate cardiopulmonary resuscitation (CPR), especially chest compressions
• Prompt defibrillation of shockable rhythms
• Early access to ACLS and postresuscitative care

Choice of approach in suspected cardiac arrest

• Adults
  • BLS-trained providers (e.g., out-of-hospital settings): See “BLS.”
  • ACLS-trained providers (e.g., in-hospital or specialized settings): See “ACLS.”
• Children
  • See “Basic life support in children” and “Pediatric modifications to ACLS algorithms.”
  • BLS in postpubertal children can follow the adult BLS algorithm.
• Special populations: See cardiac arrest in pregnancy and traumatic cardiac arrest.

General principles

• Start with chest compressions in most patients with suspected cardiac arrest before delivering rescue breaths (circulation-airway-breathing (CAB) approach).
• Minimize interruptions to CPR.
• When in doubt as to whether a collapsed patient is in cardiac arrest, performing CPR is better than withholding it. ^[1]
• Withholding CPR can be appropriate in the following limited situations. ^[3]
  • An advanced directive or valid DNR explicitly prohibiting CPR.
  • Situations in which CPR would expose the rescuer to serious risks, e.g., serious infectious or toxic exposures in the absence of adequate PPE
  • Signs of irreversible death, e.g., rigor mortis

CPR should be started if there is any uncertainty regarding an advanced directive or DNR (e.g., its validity or clarity), or regarding the irreversibility of death

Chest compression technique (in adults and postpubertal children/adolescents) ^[1]

High-quality chest compressions are associated with better survival rates. Chest compression techniques differ in children, infants, and neonates (see “CPR in infants and children” and “Chest compression technique in neonates” for details).

• Key targets of high-quality chest compressions
  • Compression rate: 100–120 per minute
  • Compression depth: 5–6 cm (2–2.5 inches)
  • Full chest recoil is required between compressions.
• Provider positioning
  • Kneel next to the patient.
  • Place hands on the middle of the sternum (on top of one another, fingers interlaced).
  • Keep the arms straight and do not bend the elbows; the shoulders should be directly above the hands.
  • Use full body weight to deliver rapid, firm compressions.
• Patient positioning: supine on a firm surface

Rescue breathing ^[1]

• Mouth-to-mouth
  • Open the airway using the head-tilt/chin-lift maneuver.
  • Pinch the patient's nose closed.
  • Form a tight seal over the patient's mouth.
  • Breathe slowly into the patient's mouth over ∼ 1 second; verify sufficient ventilation by checking for thoracic movement.
  • Move away from the mouth between breaths to allow air to escape and ensure the patient is still positioned correctly so the airway remains open.
• BMV equipment and 100% O₂ available: See “Bag-mask ventilation” for technique.

Continuous compression-only CPR is a reasonable alternative to mouth-to-mouth rescue breathing if the provider is uncomfortable administering rescue breaths or there is concern for infectious disease transmission.

Automated external defibrillator (AED)

• Description: a portable electronic defibrillator designed for use by lay rescuers in out-of-hospital settings that independently identifies shockable rhythms and delivers a shock.
• Applying pads
  • Dry the skin where the pads will be applied, if necessary.
  • Place one pad on the right chest (above the nipple) and the other on the left side of the thorax (below the nipple).
  • Alternatively, place one pad anteriorly on the chest and the other posteriorly on the back.
• Rhythm analysis
  • CPR should be paused during this phase.
  • Analysis should be repeated every 2 minutes (5 cycles of CPR).
• Delivering shocks
  • The AED will indicate if a shock is advised and may begin to charge.
  • Resume CPR while the AED is charging.
  • When advised by the AED, clear the surroundings , then deliver the shock.
  • Resume CPR immediately after a shock is delivered.

Extracorporeal membrane oxygenation (ECMO)

• Extracorporeal CPR (ECPR) uses ECMO for patients in cardiac arrest to support end-organ perfusion while underlying causes are treated.
• Venoarterial ECMO can be started during resuscitation in specialized centers with skilled and experienced providers.
• Not currently routinely recommended ^[4][5]

Algorithm

The following apply to trained healthcare personnel in both in-hospital and out-of-hospital settings. Recommendations vary for lay rescuers.

Minimizing interruptions and delays to initiation of high-quality CPR plus early defibrillation of shockable rhythms are the most important factors in improving patient survival and reducing long-term complications after cardiac arrest.

With a collapsed patient, remember the DRs ABCD: Check the environment for Danger, assess for a Response, Shout for help, open the Airway, check for Breathing, start CPR, attach the Defibrillator.

Precordial thump ^[5]

• Indication: Consider before initiating CPR only if all of the following criteria are met.
  • Patient is on telemetry.
  • Rescuer-witnessed onset of unstable VT
  • A defibrillator is not immediately available.
• Procedure ^[9]
  • Make a fist and, using the ulnar aspect, deliver a firm blow to the sternum from a height of 20 cm.
  • Initiate CPR immediately if there is no sign of conversion.

Alternative BLS techniques like the precordial thump should not delay high-quality CPR or retrieval of the defibrillator.

Overview ^[8]

• In-hospital cardiac arrest survival rates are low.
• Survival chances can be optimized through an organized sequence of care known as advanced cardiac life support (ACLS). ^[8]
• In addition to BLS, ACLS also involves:
  • Specific treatment based on clinician recognition of cardiac rhythm
  • Use of resuscitation medications: requires IV (preferred) or IO access
  • Recognition and treatment of reversible causes of cardiac arrest
  • Consideration of advanced airway management

Crisis resource management ^[8]

• Assign a designated team leader prior to starting the resuscitation.
  • All communication about patient status and treatments delivered should go through the team leader.
  • Final decisions about which treatments to pursue and when to stop resuscitation should be made by the team leader after discussion with other team members.
• Other suggested roles include:
  • At least 2 CPR performers: 1 for chest compressions and 1 for airway and ventilation
    • Providers of chest compressions should be swapped every 2 minutes to prevent fatigue.
    • Coordinate changeovers to minimize interruptions to CPR.
  • Provider(s) in charge of IV/IO access and medications
  • Provider(s) in charge of rhythm and pulse checks and defibrillation
  • Provider in charge of specific procedures (e.g., intubation, pericardiocentesis, point-of-care ultrasound)
  • Timekeeper and/or note-taker
• Prior to each pause, ensure that team members are aware of their roles to minimize interruptions to CPR during the pause.

ACLS algorithm ^[8]

The information is presented here in steps so that the priority of the interventions is clear. In clinical practice, these steps are performed simultaneously by multidisciplinary teams under a single provider's leadership and repeated depending on healthcare resources and the patient's condition.

Evaluate and treat reversible causes of cardiac arrest (e.g., Hs and Ts) without stopping CPR, defibrillation, and administration of resuscitation medications.

Continue CPR and defibrillation attempts as long as the patient remains in a shockable rhythm.

Ensuring high-quality CPR

• Initial steps (identical to BLS algorithm)
  • Assess scene safety.
  • Assess patient responsiveness/signs of life.
  • Call for help.
• Administer high-quality chest compressions.
  • Rate and quality: 100–120/minute at a depth of 5–6 cm
  • Minimize interruptions.
    • Continue CPR during delays between rhythm recognition and shock delivery (including while the defibrillator device is charging).
    • Resume CPR immediately after shock delivery.
• Ventilate with 100% oxygen: Select either of the following options based on patient factors and the expertise of the provider. ^[4]
  • Bag-mask ventilation (BMV) with/without basic airway adjuncts
    • Administer 2 breaths for every 30 chest compressions.
    • See also “Basic airway maneuvers.”
  • Advanced airway (endotracheal tube or supraglottic airway)
    • Maintain an uninterrupted rate of 10 breaths/minute.
    • Do not interrupt CPR for > 10 seconds to facilitate placement of an advanced airway.
    • Return to BMV if advanced airway has not been secured within 10 seconds.
• Consider CPR monitoring method: (e.g., continuous waveform capnography).
  • To identify ineffective CPR (EtCO₂ < 10 mm Hg) ^[5]
  • To detect ROSC

Rhythms in cardiac arrest

Avoid pausing CPR longer than 10 seconds for rhythm and pulse checks.

Defibrillation

• Timing
  • Aim to defibrillate as soon as possible once a shockable rhythm is recognized.
  • Provide interval CPR if there is a delay between rhythm recognition and shock delivery.
• Procedure
  • Set cardioverter/defibrillator to unsynchronized mode.
  • Place paddles or electrode pads firmly on the thorax of the patient (anteroapical or anteroposterior position).
    • Direct and firm contact between the pads/paddles and the skin is essential.
    • Conducting gel may be required for paddles.
  • “Clear” the patient.
    • Ensure that all healthcare staff steps away from the patient.
    • Turn oxygen off or move flow away from the patient's chest.
  • Administer the shock.
    • Handheld paddles have shock buttons for each thumb and both need to be held down until fully charged to deliver the shock.
    • For devices with self-adhesive electrode pads, the shock button is located on the main device.
  • Resume CPR immediately after defibrillation for a full 2-minute cycle. ^[8]
• Defibrillator dosage
  • Biphasic defibrillator (preferred; follow the manufacturer's instructions when available) ^[5][10]
    • First shock: 120–200 J
    • Additional shocks: 200–360 J
  • Monophasic defibrillator: 360 J for all shocks

Ensure the defibrillator is set to unsynchronized mode for treating cardiac arrest due to shockable rhythms.

Resume CPR immediately after each shock is delivered and continue for at least 2 minutes prior to the next rhythm and pulse check.

Resuscitation medications ^[5]

Obtain peripheral IV access or IO access for medications without interrupting CPR. All resuscitation medications should be administered while CPR is ongoing to ensure their circulation to the heart and brain.

• Shockable rhythms
  • Epinephrine 1 mg IV/IO
    • First dose: after second unsuccessful defibrillation attempt
    • Repeat every 3–5 minutes.
  • Amiodarone 300 mg IV/IO (OR lidocaine 1–1.5 mg/kg IV/IO)
    • First dose: after third unsuccessful defibrillation attempt
    • An additional dose of 150 mg of amiodarone or 0.5–0.75 mg/kg of lidocaine can be given after 3–5 minutes.
• Nonshockable rhythms: Administer epinephrine 1 mg IV/IO.
  • Repeat every 3–5 minutes.
  • First dose: as soon as possible

The following applies to patients with VF or pulseless VT identified at rhythm and pulse check after at least 2 minutes of high-quality CPR (or earlier if cardiac monitoring was already in place at the time of cardiac arrest).

• Continue high-quality CPR up until the time for shock delivery.
• Ensure the defibrillator is turned on and set to unsynchronized mode.
• Verify correct placement of self-adhesive pads, if using them.
• Charge the device to 200 J for biphasic defibrillators OR 360 J for monophasic defibrillators.
• When ready, pause CPR, clear the patient, and administer the shock.
• Immediately resume CPR until the next rhythm and pulse check.
• Perform rhythm and pulse check at 2-minute intervals for no more than 10 seconds.
  • If ROSC: Begin postresuscitation care.
  • If PEA or asystole: Immediately resume CPR and follow acute management checklist for nonshockable rhythms.
  • If persistent VF or pulseless VT: Deliver another shock, resume CPR, and repeat cycle until next rhythm and pulse check.
• After 2^nd unsuccessful shock: Administer epinephrine and continue as long as cardiac arrest persists.
• After 3^rd unsuccessful shock: Administer antiarrhythmic and repeat once at half dose after 3–5 minutes as needed.
  • Amiodarone
  • OR lidocaine
• Simultaneously evaluate for and treat reversible causes of cardiac arrest (see “Hs and Ts”).
• Continue CPR and defibrillation attempts as long as a shockable rhythm persists (see “Termination of resuscitation”).

Precharge the defibrillator prior to the next rhythm and pulse check to minimize the time that CPR is interrupted for defibrillation.

The following applies to patients with PEA or asystole identified at the rhythm and pulse check.

• Provide high-quality CPR as continuously as possible throughout the resuscitation.
• Do not attempt defibrillation as long as there is a nonshockable rhythm.
• Administer epinephrine as soon as possible and repeat dosing as long as cardiac arrest persists.
• Perform rhythm and pulse check at 2-minute intervals for no more than 10 seconds.
  • If ROSC: Begin postresuscitation care.
  • If VF or pulseless VT: Defibrillate, resume CPR, and follow acute management checklist for shockable rhythms.
  • If persistent PEA or asystole: Immediately resume CPR and continue cycle until the next rhythm and pulse check.
• Simultaneously evaluate for and treat reversible causes of cardiac arrest (see “Hs and Ts”).
• Only consider pausing CPR if a lifesaving procedure that requires access to the chest must be performed, e.g., pericardiocentesis.
• Consider termination of resuscitation on an individual basis.

There is no recommended duration of asystole at which resuscitation should cease. ^[5][11][12]

In most shockable rhythms, the cause of cardiac arrest may be effectively treated with defibrillation. In nonshockable rhythms and refractory shockable rhythms, the aim of CPR is to provide end-organ perfusion while the underlying cause of arrest is identified and treated.

Diagnostic studies

The patient's history may provide clues as to the cause of arrest. However, in the absence of a clear cause in the history, assessment of the rhythm, point of care ultrasound, and a blood gas analysis may yield further information.

Blood studies

• Laboratory studies: rarely return in time to guide treatment during cardiac arrest
• VBG/ABG typically shows severe acidosis but may reveal an etiology such as:
  • Severe hypokalemia and hyperkalemia
  • Severe anemia: secondary to prolonged internal bleeding in hypotensive cardiac arrests

Point of care ultrasound (POCUS) ^[13]

POCUS should not prolong the rhythm/pulse check.

• Overview: POCUS can be used to help determine the underlying cause of cardiac arrest, assess the response to treatment, and guide therapy.
• Indications: nonshockable rhythms or refractory V-fib
• Findings: may show evidence of DVT/PE, concealed hemorrhage in hypovolemia, cardiac tamponade, or help distinguish between true and pseudo-PEA
• Limitations: operator-dependent; limited prognostic value ^[14]

Evaluate cardiac rhythm to identify potential etiology

• Causes for each rhythm vary (and may overlap) but include:
  • VF/VT: coronary artery disease, conduction disorders, underlying cardiomyopathies
  • PEA: cardiac tamponade, PE, tension pneumothorax
  • Asystole: hypoxia, hyperkalemia
• In prolonged cardiac arrest, rhythms frequently degenerate into asystole; always check with EMS if another rhythm was detected prior to admission.

Reversible causes of cardiac arrest ^[7][10][15]

The Hs and Ts are used to help remember the most common reversible causes of cardiac arrest. ^[10]

Hs

Ts

Other reversible causes of cardiac arrest

Several other reversible causes of cardiac arrest exist and may be screened for and treated during cardiac arrest.

The use of dextrose in cardiac arrest is associated with lower survival rates and poor neurological outcomes. It should not be given to normoglycemic or hyperglycemic patients. ^[21]

Return of spontaneous circulation (ROSC) ^[10]

• Indications of ROSC
  • Clear signs of life, e.g., breathing, coughing or movement
  • Return of palpable pulse and blood pressure or presence of arterial waveform with intraarterial monitoring
  • An abrupt and sustained increase in expiratory CO₂ measured with capnography
• Further management: Tailor supportive care to minimize end-organ damage and increase the likelihood of survival with good neurological recovery (see “Postresuscitative care”).

Termination of resuscitation (TOR) ^[22]

Indications for TOR (in-hospital cardiac arrests)

No clear guidance exists on when to terminate CPR in hospitals. Decisions should take into account the following factors:

• The patient's wishes: Terminate resuscitation efforts if a valid DNR or an advanced directive prohibiting resuscitation is discovered.
• Experience of the provider and resuscitation team
• Factors associated with poor outcomes ^[11]
  • Patient factors: older age, cognitive impairment, terminal malignancy, organ failure
  • Resuscitation factors: delay to onset of CPR, delay to defibrillation.

Important considerations

Evidence does not support the use of any single clinical decision rule to guide in-hospital TOR. See also “Tips and Links” below for AHA guidelines on the ethics of withholding CPR and terminating resuscitative efforts.

• End-tidal CO₂: The AHA suggests that an end-tidal CO₂ < 10 mm Hg after 20 minutes of resuscitation may be considered alongside other factors in the decision to terminate resuscitation; it should not be used alone to determine TOR. ^[5][23]
• Shockable rhythms: Resuscitation should typically continue as long as the patient remains in a shockable rhythm. ^[5][11]
• Nonshockable rhythms: There is no recommended duration of asystole at which resuscitation should cease. ^[12]
• Prolonged resuscitation is typically appropriate in the following circumstances: ^[5][11]
  • Hypothermia: Continue until adequately rewarmed (e.g., core temperature > 35°C/95°F).
  • Poisoning (e.g., local anesthetic toxicity): Prolonged resuscitation can allow toxins to be metabolized and excreted.
  • Pulmonary embolism: Continue for ≥ 60–90 minutes after administration of thrombolytic agents.

Goals of postresuscitation care ^[24]

• Initiate neuroprotective measures as soon as ROSC is confirmed to:
  • Prevent secondary brain injury
  • Preserve brain function
• Determine the cause of arrest (if unknown).
• Manage myocardial dysfunction.
• Screen for organ dysfunction (e.g., liver chemistries, RFTs).
• Optimize organ perfusion.

Goal-directed postresuscitation care provides patients with the best chance of neurologically intact survival.

Management ^{[5][24][25][26]}

All postarrest patients should be admitted to a critical care unit.

Don't forget the ABCs of postresuscitation care: Obtain an ABG, BP, and Chest x-ray, Draw blood for laboratory studies, and ensure an ECG is done. Talk to the Family, Give thanks to the team, consider initiation of Hypothermia, and admit to ICU.

• Obtain a complete set of vital signs.
• Ensure reliable IV access.
• Obtain blood for laboratory studies (e.g., ABG, BMP, liver chemistries, troponin).
• Begin continuous cardiac and respiratory monitoring.
• Secure airway and provide 100% O₂.
• Begin mechanical ventilation, if needed.
• Obtain 12-lead ECG and identify any ST elevations.
• Consider urgent cardiology and cath lab consultation for PCI if indicated.
• Treat hypotension with IV fluids and/or vasopressors.
• Document and monitor neurological status (e.g., GCS, pupillary exam)
• Consider targeted temperature management.
• Consider additional diagnostic testing (e.g., CXR, echocardiogram, CTA chest, CT head, EEG).
• Identify and treat underlying cause (see “Hs and Ts”).
• Identify and treat any complications (e.g., seizures, fever, cardiac arrhythmias).
• Monitor postresuscitation targets: See “Neuroprotective measures.”
  • SpO₂ 92–98%
  • PaCO₂ 35–45 mm Hg
  • Systolic BP > 90 mm Hg
  • MAP > 65 mm Hg
  • Urine output > 0.5 mL/kg/hr
  • Temperature 32–36°C
• Admit to ICU.
• Obtain specialty consultation for neurological assessment and prognostication.

• Definition: global brain injury caused by complete cessation of blood flow during cardiac arrest
• Epidemiology: most common cause of death in patients surviving cardiac arrest ^[27]
• Pathophysiology: cardiac arrest → cessation of blood flow to the brain → anoxia → irreversible neuronal damage and death
• Clinical features
  • Neurological deficits (determined by the severity of injury and the affected structures)
    • Comatose state
    • Absent or abnormal motor response (e.g., extensor posturing)
    • Absent spontaneous eye movements
    • Absent brainstem reflexes (e.g., pupillary light reflex, oculocephalic reflex)
  • Convulsions (e.g., status epilepticus)
• Diagnostics
  • Clinical features consistent with cardiac arrest
  • It is imperative to exclude other causes of coma (e.g., toxic and metabolic encephalopathies, shock).
  • Laboratory studies (e.g., CBC, serum electrolytes, toxicology screens)
  • Imaging
    • CT brain
      • Usually normal within the first 2 days
      • Findings of anoxic injury: cerebral edema, inversion of gray-white matter density
    • MRI brain: allows for early detection of brain injury
  • EEG
    • Characteristic pattern: slowing of the EEG followed by delta activity and, eventually, EEG flattening
    • Some EEG patterns are markers of a poor prognosis (see below).
• Differential diagnosis: hypoxic-ischemic encephalopathy
• Management
  • Postresuscitation care (see above)
  • Avoid hyperthermia. ^[28][29]
  • Prevention of hyperglycemia
• Complications
  • Brain death
  • Coma
  • Persistent vegetative state
  • Minimally conscious state
  • Seizures
• Prognosis
  • The majority of cases have a poor prognosis, indications for which include:
    • Increased duration of anoxia
    • Clinical markers
      • Absent brainstem reflexes (e.g., pupillary light reflex, corneal reflex)
      • Persistent dilated pupils
      • Absent or abnormal motor response
      • Myoclonic status epilepticus
    • Other specific markers
      • Laboratory studies: elevated serum level of neuron-specific enolase
      • EEG: nonreactive or presence of burst-suppression pattern (suggestive of myoclonic status epilepticus)

References:^{[27][30][31][32]}

Prognostication ^[5]

• Determining the neurological prognosis after cardiac arrest is complex and should be done by specialists.
• The extent of irreversible loss of brain function can be estimated using a combination of examination findings, EEG, neuroimaging, and serum biomarkers.
• Assessment for brain death is typically done 72 hours after cardiac arrest or cessation of targeted temperature management.

Organ donation ^[3][33]

• Organ donation should be considered for all patients with ROSC in whom brain death is declared.
• If ROSC does not occur, kidney and liver donation may still be possible, depending on the center.
• For more information on organ donation, see “Principles of medical law and ethics” and “Transplantation.”

Basic life support in infants and children

Modifications to BLS algorithm for infants and children

For simplicity's sake, similar algorithms are recommended for adults and children in North America, despite their physiological differences (see BLS algorithm). ^[36][37]

Hypoxia is a more common cause of cardiac arrest in neonates and children than in other groups. For this reason, greater emphasis is placed on ventilation. ^[36]

Neonatal life support ^[34]

The details of neonatal resuscitation are covered in detail separately. The most important differences in CPR techniques compared to infants and older children are as follows.

• Compression rate: 100–120/min
• Compression-to-ventilation ratio: 3:1 (as hypoxia is the most common cause of arrest).
• Chest compression technique in neonates
  • Single rescuer: two finger technique
    • Perform chest compressions using two fingers (the index and middle fingers) on the lower half of the sternum, just below the intermammary line.
    • Allows for faster alternations between compressions and delivering breaths for the single health care provider.
  • Two rescuers: two thumb-encircling hands technique
    • One rescuer performs chest compressions, while the other delivers breaths.
    • Use both hands to encircle the chest with the thumbs are placed over the lower third of the sternum.
    • Compress the lower sternum with both thumbs.
    • Results in more effective compressions and higher coronary artery perfusion than the two finger technique.

Ventilation is more important in children and newborns than in adults, as hypoxia is a common cause of cardiac arrest in children!

Pediatric modifications to ACLS algorithms ^[34]

Advanced life support for children requires different doses of drugs and different defibrillation energies. The same algorithm for advanced life support in adults should be followed for pediatric patients.

• Defibrillator dosage: If using a manual defibrillator, the energy should be set as follows.
  • First shock: 2 J/kg
  • Second shock: 4 J/kg
  • Subsequent shocks ≥ 4–10 J/kg or until adult level is reached
• Resuscitation medications: Drug doses should be adapted as follows.
  • Epinephrine 0.01 mg/kg (0.1 mL/kg of 1:10,000 concentration) IV/IO every 3–5 minutes (maximum dose 1 mg)
  • Lidocaine 1 mg/kg IV once, followed by 20–50 mcg/kg/minute IV infusion ^[39]
  • Amiodarone 5 mg/kg IV bolus; may be repeated to a maximum of 3 doses in shockable rhythms

Cardiac arrest in pregnancy

• Maternal cardiac arrest is rare.
• The majority of BLS and ACLS algorithms remain the same, including drug doses and defibrillation.

Modifications to BLS and ACLS ^[7][40]

• Initiate appropriate emergency response (e.g., maternal code blue).
• Place IV lines above the level of the diaphragm.
• Anticipate a difficult airway.
• Displace the uterus manually to the left to relieve aortocaval compression. ^[7]
  • One-handed manual displacement: Standing on the patient's right, push the uterus up and away.
  • Two-handed manual displacement: Standing to the patient's left, pull the uterus up and towards the rescuer.
• Consider the following causes in addition to the common causes of cardiac arrest (see “Hs and Ts”): ^[7]
  • Amniotic fluid embolism
  • Uterine atony
  • Placenta abruptio or placenta previa (see “Antepartum hemorrhage” for details on management)
  • Eclampsia
    • Administer magnesium.
    • In patients receiving treatment with magnesium prior to cardiac arrest, consider hypermagnesemia as a potential cause (see “Other reversible causes of cardiac arrest” for further management).

Perimortem cesarean delivery (PMCD) ^[40]

• General overview
  • PMCD reduces aortocaval compression and increases the likelihood of ROSC.
  • Early PMCD also maximizes a viable fetus's chances of survival by reducing anoxia.
• Indications
  • ROSC has not occurred ≤ 4 minutes of cardiac arrest.
  • AND the fetus is viable.
  • OR the uterus is thought to be causing aortocaval compression.
• Target: PMCD ideally within ≤ 5 minutes of cardiac arrest onset
• Technique
  • Preferred: cesarean delivery via vertical incision
  • After the cesarean delivery, normal ACLS should continue for the mother.
  • See also “Neonatal resuscitation.”

Traumatic cardiac arrest ^[41]

• Cardiac arrest in trauma rarely responds to standard ACLS treatment.
• Common causes include tension pneumothorax, cardiac tamponade, and hypotension.
• Management of traumatic cardiac arrest
  • First-line: bilateral chest decompression with finger thoracostomies
  • Consider emergency thoracotomy, followed by:
    • Vertical pericardiotomy
    • Internal cardiac massage
    • Additional procedures to manage exsanguination

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