NLE Emergency & Critical Care Nursing — Basic & Advanced Life Support (CPR/ACLS)Summary

The Chain of Survival is a sequential framework of five critical links that determine outcomes from cardiac arrest: (1) Early recognition of cardiac arrest and activation of emergency response systems, (2) Early high-quality CPR, (3) Rapid defibrillation, (4) Effective advanced cardiovascular care, and (5) Integrated post-arrest care. In Philippine emergency healthcare contexts where advanced life support may be delayed, the first three links—recognition, BLS, and defibrillation—are often the nursing team's direct responsibility. A weak link anywhere in the chain reduces survival probability; therefore, nursing prioritization must focus on those links most directly under the nurse's control: immediate recognition and immediate, sustained high-quality compressions.

The modern BLS sequence prioritizes chest compressions (C) before airway management (A) and breathing (B). This reversal from the traditional ABC sequence is evidence-based: at the moment of collapse, the victim's lungs contain an oxygen reserve. Immediate chest compressions circulate this oxygenated blood to the brain and heart, which is far more effective than opening the airway first and attempting ventilation. The C-A-B sequence applies to responsive adult assessment, unresponsive adults, children (ages 1 to onset of puberty), and adapted for infants. The sequence is: (1) Ensure scene safety and check responsiveness by tapping shoulders and shouting; (2) Simultaneously assess breathing (normal respiration only; agonal gasping does not count) and pulse for no more than 10 seconds; (3) If unresponsive with no normal breathing and no pulse, activate emergency response immediately; (4) Begin chest compressions without delay.

High-quality compressions are defined by precise, measurable parameters: Rate: 100 to 120 compressions per minute—faster than 120 reduces depth and diastolic filling time; slower than 100 provides inadequate cardiac output. Depth: At least 5 centimeters (2 inches) and not more than 6 centimeters (2.4 inches) in an adult—shallower depth fails to generate sufficient blood flow, while excessive depth risks sternal fracture, rib fractures, and internal injuries. Compression-to-ventilation ratio: 30:2 for a single rescuer in all ages and for two rescuers managing an adult—this means 30 rapid compressions followed by 2 breaths, then immediately resume compressions. Full chest recoil: The chest must completely recoil (return to normal position) between compressions, as leaning on the chest prevents cardiac refilling and reduces effectiveness. Hand position: heel of one hand on the lower half of the sternum, other hand on top, with arms straight and shoulders directly over hands. Minimize interruptions: Aim to keep chest compression fraction (the percentage of arrest time during which compressions are actively being delivered) at 60 percent or higher. Compressor fatigue degrades compression quality within 2 minutes even when the fatigued rescuer does not perceive deterioration; therefore, switch compressors every 2 minutes or sooner if fatigue is evident.

Pediatric and infant CPR differs in depth and technique. Pediatric depth: Approximately one-third of the anteroposterior (AP) chest diameter, which is roughly 5 centimeters for a child aged 1 year to puberty onset. Infant depth: Approximately one-third of the AP chest diameter, roughly 4 centimeters for an infant under 1 year. Infant compression technique single rescuer: Use two fingers (index and middle) placed on the lower sternum, avoiding the xiphoid process. Two-rescuer infant compression: Use the two-thumb encircling technique—place both thumbs on the lower sternum and encircle the chest with both hands to provide support, allowing more effective force delivery. Compression-to-ventilation ratio for two-rescuer pediatric and infant CPR: 15:2 (15 compressions, then 2 breaths), which differs from the 30:2 ratio used for single rescuers or adult two-rescuer teams. Rationale: Pediatric and infant arrests are usually respiratory in origin (hypoxia, airway obstruction) rather than primary cardiac events; therefore, early oxygenation and ventilation are proportionally more important, reflected in the higher ventilation frequency.

After the first cycle of 30 compressions, open the airway using head-tilt/chin-lift maneuver (tilt the head back, lift the chin up) or jaw-thrust maneuver if trauma is suspected (avoid head tilt with trauma). Deliver two rescue breaths, each lasting approximately one second, with just enough volume to produce visible chest rise—excessive volume does not help and causes gastric inflation, which impairs venous return. Once an advanced airway (endotracheal tube, laryngeal mask airway, or combitube) is in place, deliver continuous, uninterrupted chest compressions with one rescue breath every 6 seconds (approximately 10 breaths per minute) delivered between compressions without pausing the compressions. Avoid excessive ventilation, which raises intrathoracic pressure, reduces venous return to the heart, and paradoxically reduces cardiac output—a frequent, avoidable error in nursing practice. End-tidal carbon dioxide monitoring is valuable if available: a sudden rise in CO2 during compressions signals return of spontaneous circulation (ROSC).

Defibrillation is the definitive treatment for ventricular fibrillation (VF) and pulseless ventricular tachycardia (pVT), and every minute without defibrillation reduces survival by approximately 7-10 percent. The AED is a portable device that automatically analyzes cardiac rhythm and advises shock if indicated. AED application: (1) Power on the device and follow voice prompts; (2) Expose the victim's chest; if the chest is wet, dry it with a towel; if there are transdermal medication patches (e.g., nitroglycerin, scopolamine), remove them and wipe the site dry; (3) Attach the pads to bare skin—one pad below the right clavicle, one on the left lower lateral chest at the midaxillary line; ensure pads are at least 2.5 centimeters (1 inch) away from an implanted pacemaker or implantable cardioverter-defibrillator (ICD); if pads cannot be placed at standard locations due to implantable devices, consider anterior-posterior pad placement; (4) Stop all chest compressions and ensure no one is touching the patient while the AED analyzes rhythm; (5) If a shock is advised, verbally and visually clear the patient (announce 'Clear!'), ensure everyone has stepped back, and deliver the shock by pressing the shock button or allowing the device to deliver automatically if configured for hands-free mode; (6) Immediately resume chest compressions for 2 minutes without pausing to recheck pulse or rhythm—the AED will prompt for the next analysis at 2-minute intervals. For pediatric use: Use pediatric pads/attenuators if available; if only adult pads are available, place them anterior-posterior (one on the front of the left chest, one on the back) to prevent pad contact.

Advanced Cardiovascular Life Support (ACLS) uses rhythm classification to guide drug and defibrillation decisions. Rhythms are categorized as shockable (amenable to defibrillation) or non-shockable. Shockable Rhythms: Ventricular Fibrillation (VF)—chaotic, uncoordinated electrical activity with no organized waveform—and Pulseless Ventricular Tachycardia (pVT)—organized rapid electrical activity (>100 beats/min) without a palpable pulse. Management: Immediate defibrillation, followed by 2 minutes of high-quality CPR, then reassess rhythm. Medications: Epinephrine 1 mg IV/IO (intravenous or intraosseous) every 3 to 5 minutes in the 1:10,000 concentration (1 mg in 10 mL normal saline) is given after the second shock if the initial rhythm was shockable; then repeated every 3-5 minutes. Amiodarone 300 mg IV/IO is given for the first dose if VF/pVT persists after two defibrillations; a second dose of amiodarone 150 mg may be given. Lidocaine is an acceptable alternative to amiodarone. Non-Shockable Rhythms: Asystole (a completely flat ECG line, representing no electrical or mechanical activity) and Pulseless Electrical Activity (PEA—organized electrical complexes on the monitor but no detectable pulse and no signs of perfusion). Management: High-quality CPR without defibrillation, plus epinephrine 1 mg IV/IO every 3 to 5 minutes beginning as early as possible. The absence of a shockable rhythm in PEA and asystole necessitates aggressive search for and treatment of reversible causes—often the rhythm itself will not respond to medication, but correcting the underlying cause (e.g., restoring volume in hypovolemia, treating anaphylaxis) may lead to ROSC.

Epinephrine (adrenaline) is the primary medication for cardiac arrest, used in all arrest rhythms. Arrest Epinephrine Dosing: 1 mg IV/IO every 3 to 5 minutes; concentration is 1:10,000 (1 mg in 10 mL), which gives the dose in 1 mL if using pre-filled syringes. Critical distinction: This is DIFFERENT from anaphylaxis epinephrine, which is 0.3 to 0.5 mg IM (intramuscular), 1:1000 concentration. Confusing these concentrations or routes is a serious medication error. Timing in Shockable Rhythms: In VF/pVT, epinephrine is given after the second shock (i.e., after two defibrillation attempts and two minutes of CPR), then repeated every 3-5 minutes. Timing in Non-Shockable Rhythms: Epinephrine is given as early as possible—immediately if feasible—because asystole and PEA do not respond to defibrillation and rely entirely on medication and cause-treatment. Administration: All arrest medications are given IV or IO; if IV/IO access cannot be rapidly established, IO access (intraosseous—needle inserted into the bone marrow) is preferred over IO (and preferred over intravenous routes that require needle placement in veins), as IO access is faster and more reliable during cardiac arrest when perfusion is poor. Medications are followed by a 20 mL saline flush to facilitate drug delivery to the central circulation.

Reversible causes are particularly important in non-shockable rhythms (PEA and asystole), where medications alone do not restore rhythm; instead, aggressive identification and treatment of the underlying cause is the pathway to ROSC. The mnemonic 'Hs and Ts' organizes these causes: Hs (Hypovolemia—inadequate circulating volume from hemorrhage or dehydration; Hypoxia—inadequate oxygenation; Hydrogen ion—severe acidosis; Hypo-/Hyperkalemia—dangerous electrolyte imbalances; Hypothermia—core body temperature below 30°C, which profoundly suppresses metabolism and may mimic death). Ts (Tension pneumothorax—collapsed lung causing compression of heart and great vessels, requiring needle decompression; Tamponade—fluid around the heart compressing the heart, requiring pericardial drainage; Toxins—overdose or poisoning; Thrombosis—pulmonary embolism or acute myocardial infarction). In Philippine emergency contexts, common reversible causes include severe dehydration/hypovolemia (diarrheal diseases, dengue hemorrhagic fever), hypoxia (respiratory infections, airway obstruction), and hyperkalemia (renal failure). The nurse's role during resuscitation includes continuously thinking about which Hs and Ts might be present and advocating for diagnostic and therapeutic interventions (e.g., requesting a chest X-ray to rule out tension pneumotharax, checking electrolytes for hyperkalemia, asking about medication history for toxins).

When ventricular fibrillation or pulseless ventricular tachycardia persists after initial defibrillation attempts and CPR, antiarrhythmic drugs are used to attempt conversion to a perfusing rhythm. Amiodarone: First-line antiarrhythmic for refractory VF/pVT. Initial dose: 300 mg IV/IO after the second shock (i.e., after two defibrillation attempts and CPR). Second dose: 150 mg IV/IO if the rhythm remains refractory; may be repeated every 3-5 minutes if needed. Mechanism: Slows conduction velocity, prolongs refractory period, and decreases automaticity of cardiac tissue. Lidocaine: An acceptable alternative if amiodarone is unavailable. Initial dose: 1 to 1.5 mg/kg IV/IO (approximately 75-100 mg for a 70 kg adult). Second dose: 0.5 to 0.75 mg/kg IV/IO if initial dose fails. Maximum cumulative dose: 3 mg/kg. Mechanism: Blocks sodium channels and suppresses ectopic activity. Timing: Given after initial shock attempts and continued CPR, not on the first defibrillation attempt (epinephrine is given first). The choice between amiodarone and lidocaine depends on availability and institutional protocols; both are acceptable per guidelines.

Return of spontaneous circulation (ROSC) is the restoration of any organized electrical activity with a palpable pulse and signs of perfusion. ROSC is not the end of resuscitation; it is a transition to post-arrest care, which focuses on protecting the brain and organs from secondary injury. Key post-ROSC priorities: (1) Airway and Oxygenation: Secure the airway (endotracheal intubation or other advanced airway) and establish controlled mechanical ventilation, targeting normal oxygen (PaO2 90-120 mmHg) and carbon dioxide (PaCO2 40-45 mmHg) levels—avoid hyperoxia (excessive supplemental oxygen), which increases oxidative stress, and hypoxia or hypercapnia (elevated CO2), both of which worsen neurological outcomes. (2) Perfusion: Maintain adequate mean arterial pressure (MAP) and systemic perfusion using crystalloid fluids and vasopressors (e.g., norepinephrine) as needed; target systolic blood pressure ≥90 mmHg. (3) Targeted Temperature Management: Cool the patient to 32-36°C (select target between 32-36°C and maintain for 24 hours minimum) using ice packs, cold intravenous saline, or cooling devices if available; then allow controlled rewarming—hypothermia reduces metabolic rate and brain damage. (4) Glucose Control: Maintain blood glucose 140-180 mg/dL; avoid hypoglycemia and hyperglycemia, both of which worsen neurological injury. (5) Identify and Treat the Underlying Cause: Perform ECG, troponins, chest X-ray, blood cultures, and other diagnostics to identify the precipitating event (acute MI, sepsis, etc.) and initiate definitive treatment. (6) Seizure Prophylaxis: Consider prophylactic antiepileptic medication if seizures occur. (7) ICU Admission and Monitoring: Continuous cardiac and neurological monitoring, frequent reassessment of consciousness and neurological status.

Choking (foreign-body airway obstruction) is a medical emergency distinguished by severity. Mild Obstruction: The person can cough forcefully, speak, or produce sound; manage by encouraging continued forceful coughing and do not intervene physically, as the victim's own cough is most effective at expelling the object. Severe Obstruction: The person cannot cough, speak, or produce sound; may clutch the throat (the universal choking sign); will rapidly become cyanotic and lose consciousness without intervention. Management differs by age: Responsive Adult or Child (over 1 year): Perform abdominal thrusts (Heimlich maneuver)—stand behind the person, place a closed fist just above the navel and well below the xiphoid process, grasp the fist with the other hand, and deliver quick inward and upward thrusts; repeat until the object is expelled or the person becomes unresponsive. For a pregnant or obese person (where abdominal thrusts risk injury to the uterus or internal organs), use chest thrusts instead—place hands on the lower sternum and deliver quick inward thrusts. Responsive Infant (under 1 year): Never perform abdominal thrusts on infants (risk of internal injury); instead alternate 5 back slaps (firm blows between the shoulder blades with the heel of one hand while supporting the infant) and 5 chest thrusts (using two fingers on the lower sternum, same as infant CPR compression technique). If the victim becomes unresponsive: Lower them to the ground, activate the emergency response system immediately, and begin CPR starting with chest compressions (C-A-B). Each time the airway is opened for rescue breaths, look into the mouth and remove any visible object; however, never perform a blind finger sweep (inserting the finger into the throat without visualizing the object), which can push the object deeper into the airway and worsen obstruction.

Effective resuscitation requires coordinated teamwork, not just individual skills. Key elements: (1) Role Assignment: Designate a team leader who directs the code, verbalizes the plan, and keeps the team oriented to the current rhythm, elapsed time, and next steps. Assign specific roles to each team member (e.g., compressor, airway manager, medication administrator, timer/recorder). (2) Closed-Loop Communication: The team leader gives an order (e.g., 'Give epinephrine 1 mg IV now'), the assigned person repeats it back to confirm understanding ('Giving epinephrine 1 mg IV'), and confirms when complete ('Epinephrine 1 mg IV given at 03:45'). This prevents missed or duplicated medications and errors in a high-stress environment. (3) Call Out Counts and Time: The compressor (or a designated recorder) verbally announces the compression count (to prompt the second rescuer when the 30-compression cycle is complete) and the time at each 2-minute cycle to remind the team when a compressor switch is needed and when the next rhythm check is due. (4) Speak-Up Culture: Team members should be empowered and expected to speak up if they observe a lapse in compression quality, an interruption that is too long, a medication about to be administered in error, or any safety concern. A strong culture where the most junior staff member can stop the code leader if a mistake is about to happen saves lives. (5) Frequent Compressor Switching: As mentioned, switch compressors every 2 minutes or sooner if fatigue is evident; this is best done during the rhythm check. (6) Minimize Interruptions: Any pause in compressions (for pulse checks, rhythm analysis, medication preparation) should be as brief as possible; if a rhythm check reveals a perfusing rhythm, confirm it with a pulse check and other signs of life, but do not delay resuming compressions if there is any doubt.

CPR, when performed correctly at the intensity required for effectiveness, causes injuries. Common Complications: Rib fractures (occur in 20-40% of CPR recipients but should not deter effective compressions), sternal fracture, pneumothorax, hemothorax (air or blood in the pleural space), cardiac contusion, gastric inflation (from excessive ventilation), esophageal intubation (placing the tube in the esophagus instead of trachea, detected by lack of CO2 return and breath sounds over the lungs), and aspiration of gastric contents. These complications, while serious, are the price of CPR; the alternative—no CPR—leads to brain death within minutes. Therefore, nurses must perform compressions at full intensity (at least 5 cm depth, 100-120/min) without hesitation due to fear of rib fractures. When to Stop Resuscitation: Resuscitation is stopped when (1) ROSC is achieved and post-arrest care is initiated, (2) an advanced provider makes the decision that resuscitation is futile (e.g., no organized electrical activity after 20-30 minutes of full ACLS in a patient with no reversible cause, in a non-witnessed arrest, or in a patient with do-not-resuscitate orders), (3) the scene becomes unsafe and CPR cannot be continued, or (4) the rescuer becomes exhausted and unable to continue safe CPR. In Philippine emergency settings, the decision to stop is typically made by a physician if available; if no physician is present and CPR has been ongoing for an extended period without response, the nurse may need to advocate for a trial period (e.g., 20-30 minutes) before discontinuing if protocols allow.

BLS is adapted for age groups because physiology differs. Key differences summarized: (1) Compression Depth: Adult ≥5 cm, ≤6 cm (at least 2 in, not more than 2.4 in). Pediatric (1 year to puberty) ≈one-third AP chest diameter (≈5 cm). Infant (under 1 year) ≈one-third AP chest diameter (≈4 cm). (2) Compression Technique: Adult—heel of one hand with other hand on top, straight arms, shoulders over hands. Pediatric—heel of one hand (or both hands if the child is very large); adjust hand size to deliver appropriate depth. Infant—single rescuer: two fingers (index and middle); two rescuers: two-thumb encircling technique. (3) Compression-to-Ventilation Ratio: Single rescuer (all ages): 30:2. Two rescuers adult: 30:2. Two rescuers pediatric/infant: 15:2. (4) Pulse Check: Check for a pulse in all ages but no more than 10 seconds; if unsure, start compressions. Infants—check brachial artery (inside of upper arm); children and adults—carotid or femoral artery. (5) Breathing Assessment: Agonal gasping does not count as adequate breathing in any age group. (6) AED Use: Adult pads for adults ≥8 years or ≥25 kg. Pediatric pads/attenuators for children 1-8 years or 10-25 kg; if unavailable, adult pads placed anteroposterior. Avoid AED use in children <1 year; use manual defibrillation if available.

The Chain of Survival describes five sequential links (early recognition, early BLS, rapid defibrillation, effective advanced care, integrated post-arrest care). Each BLS and ACLS technique represents implementation of a link. For example, high-quality chest compressions fulfill the 'early BLS' link; AED use fulfills 'rapid defibrillation.' Understanding this relationship helps nurses grasp why the specific technical parameters (compression depth, rate, ratio) matter: they are designed to maximize effectiveness of each Chain link.

The specific compression parameters are chosen based on cardiac physiology. The 100-120/min rate is fast enough to generate adequate cardiac output but not so fast that the heart cannot fill between compressions. The 5-6 cm depth generates sufficient force to eject blood from the ventricles without excessive injury. Full chest recoil is essential because the heart refills during the recoil phase; leaning on the chest prevents refilling and reduces effectiveness. The 30:2 ratio prioritizes compressions (which are the most critical element) while allowing for oxygenation. These relationships mean that if one parameter (e.g., rate too fast) is degraded, others (e.g., depth) automatically suffer, demonstrating the interdependence of compression quality.

The initial rhythm analysis at cardiac arrest is the critical decision point for ACLS. Shockable rhythms (VF and pulseless VT) are amenable to defibrillation and therefore receive immediate shocks followed by CPR; epinephrine is given after the second shock. Non-shockable rhythms (asystole and PEA) do not respond to defibrillation and instead rely entirely on CPR, early epinephrine, and identification and treatment of reversible causes. This binary classification means the entire treatment approach branches differently based on this single initial assessment, illustrating why rhythm interpretation is fundamental to ACLS.

During cardiac arrest with non-shockable rhythms or after initial rhythm management in any arrest, identifying and treating the underlying cause is often the pathway to sustained ROSC. For example, a patient with PEA from severe hypovolemia (hemorrhage) will not convert to a perfusing rhythm with epinephrine alone; aggressive fluid resuscitation and control of bleeding are required. After ROSC is achieved, continued identification of the precipitating cause (via ECG, troponins, imaging, blood cultures) guides definitive treatment and improves survival. This relationship shows that ACLS (medications and defibrillation) is only part of arrest management; the full clinical picture and cause-directed therapy determine long-term outcomes.

Pediatric and infant chests are proportionally smaller and more compliant (flexible) than adult chests; therefore, appropriate compression depth is one-third of the AP chest diameter, which is much shallower than the 5-6 cm used in adults. Compression technique in infants (two fingers or two-thumb) differs because adult hand size would be too large. The 15:2 ratio for two-rescuer pediatric/infant CPR reflects the belief that pediatric arrests are often respiratory in origin (hypoxia) rather than primary cardiac; therefore, early oxygenation and ventilation are proportionally more important. These relationships illustrate that 'correct CPR' is not one-size-fits-all but must be adapted to the patient's age and anatomy.

During a resuscitation code, medications must be administered promptly, compressors must be switched at appropriate intervals, and any safety lapses must be immediately corrected. Closed-loop communication (order given, received, repeated back, action confirmed) ensures that medications are not missed or duplicated, that timing is accurate, and that all team members are oriented to the current status. A team culture where any member can voice safety concerns (speak-up culture) catches errors before they harm the patient. The team leader's clear assignment of roles and consistent verbalization of status and timing keeps everyone working together rather than at cross-purposes. Without these communication structures, even technically skilled rescuers will make errors under stress; with these structures, less experienced rescuers can be effective.

During CPR, the goal of ventilation is to supply oxygen to the lungs; however, excessive volume does not add benefit—it simply inflates the lungs excessively, raises intrathoracic pressure, compresses the superior vena cava, and reduces venous return to the right atrium. This reduces the preload of the heart and lowers cardiac output, paradoxically making compressions less effective. Similarly, prolonged pauses to deliver breaths reduce the compression fraction (the percentage of time compressions are actively being delivered) and lower overall cardiac output. The relationship means that prioritizing compressions (even at the cost of fewer breaths) and limiting breaths to just enough to produce visible chest rise actually improves outcomes compared to more aggressive ventilation.

Muscle fatigue is an objective phenomenon: after 2 minutes of delivering compressions at 100-120/min with a depth of 5-6 cm, even young, fit rescuers experience fatigue in the large muscles of the chest and shoulders. Fatigue degrades compression depth first (the compressor unconsciously presses less hard to reduce effort), followed by rate irregularity. Critically, the fatigued rescuer often does not perceive this degradation—they feel they are still performing well when, in fact, compression depth has fallen to 3-4 cm or less. This relationship explains why frequent compressor switching (every 2 minutes, or sooner if fatigue is evident) is not optional but essential. In Philippine emergency settings where mechanical CPR devices are not universally available, manual compressions must be maintained by a rotating team to preserve quality.