Pharmacotherapy Case Study 1: Patient with Cardiac Arrest by Dr. Nehad Ahmed

 

Chief Complaint:

The patient was found unresponsive with no palpable pulse, suspected of experiencing a cardiac arrest.

Subjective Data:

History of Present Illness (HPI):
The patient was discovered by a bystander after collapsing at home. Emergency medical services (EMS) were called immediately. On arrival, the patient was unresponsive, and no pulse was palpable. CPR was initiated at the scene, and the patient was transported to the emergency department (ED) for further management. The patient has a history of hypertension and type 2 diabetes mellitus, though the family reports the patient had been non-compliant with prescribed medications in recent months. No recent complaints of chest pain, shortness of breath, or syncope prior to the incident.

Past Medical History (PMH):

Hypertension

Type 2 Diabetes Mellitus

Hyperlipidemia

Previous myocardial infarction (2 years ago)

History of smoking (quit 5 years ago)

 

Medications:

Metformin 500 mg twice daily

Lisinopril 10 mg daily

Atorvastatin 20 mg nightly

Allergies:

No known drug allergies

Family History:

Father with a history of coronary artery disease (CAD) and myocardial infarction (MI) at age 60.

Mother with type 2 diabetes mellitus and hypertension.

Social History:

Former smoker (quit 5 years ago)

No alcohol or illicit drug use

Sedentary lifestyle

Review of Systems:

Cardiovascular: Denies chest pain or palpitations before the event.

Respiratory: No prior history of respiratory distress or cough.

Gastrointestinal: No nausea or vomiting reported.

Neurological: Denies recent syncope or dizziness.

 

Objective Data:

Vital Signs upon Arrival:

Blood Pressure: Unmeasurable (initially hypotensive in the emergency department)

Heart Rate: 0 (cardiac arrest)

Respiratory Rate: 0 (arrest)

Oxygen Saturation: 0% (initially)

Temperature: 36.8°C (normal)

Glasgow Coma Scale (GCS): 3 (unresponsive)

Physical Exam:

General Appearance: Unresponsive, no signs of life; patient is intubated.

Cardiovascular: No palpable pulse, no heart sounds (cardiac arrest).

Respiratory: Intubated, no spontaneous breathing.

Neurological: Unresponsive, no purposeful movements or verbal responses.

Skin: Pale, cool, and clammy.

Extremities: Cyanotic extremities due to lack of circulation.

Initial Diagnostic Tests:

Electrocardiogram (ECG): Non-shockable rhythm, suspected asystole (initial presentation).

Laboratory Results:

Electrolytes: Sodium 139 mEq/L, Potassium 4.2 mEq/L, Calcium 2.2 mEq/L

Blood Glucose: 212 mg/dL (elevated)

Arterial Blood Gases (ABG): pH 7.28 (acidemia), pCO₂ 50 mmHg, pO₂ 80 mmHg

Troponin I: Elevated (consistent with acute myocardial injury)

Creatinine: 1.2 mg/dL (baseline)

Imaging:

Chest X-ray: No acute pulmonary pathology identified.

Echocardiogram: Reduced left ventricular ejection fraction (LVEF) consistent with heart failure.

Assessment:

The patient is currently in cardiac arrest with a suspected history of myocardial infarction. Given the elevated troponin levels and echocardiogram findings, the likely cause of the arrest is an acute coronary syndrome (ACS), likely due to acute myocardial infarction (MI). The patient’s history of hypertension, diabetes, and prior MI increases the risk for cardiovascular events. Additionally, the non-compliance with medications might have contributed to the worsening of the patient’s condition. Immediate pharmacotherapy interventions and resuscitative efforts are required.

Plan:

Cardiopulmonary Resuscitation (CPR):

Continue high-quality CPR, as per American Heart Association (AHA) guidelines.

Administer advanced cardiac life support (ACLS) protocols, including defibrillation if indicated (initial rhythm non-shockable, consider subsequent re-evaluations).

 

 

Pharmacotherapy:

Epinephrine (1 mg every 3-5 minutes) during CPR to increase myocardial and cerebral perfusion.

Amiodarone or Lidocaine if the rhythm changes to a shockable rhythm during resuscitation efforts.

Aspirin (160-325 mg orally or via nasogastric tube) to reduce platelet aggregation in the setting of ACS.

Nitroglycerin (if systolic blood pressure allows, typically if >90 mmHg) for chest pain relief and coronary vasodilation. Hold if hypotension persists.

Heparin (bolus 60-70 units/kg IV), followed by an infusion for anticoagulation in the setting of acute coronary syndrome.

Beta-blocker (Metoprolol IV 5 mg bolus every 5 minutes, maximum 3 doses), to reduce myocardial oxygen demand, unless contraindicated (e.g., severe bradycardia or hypotension).

Monitoring & Supportive Care:

Continuous ECG monitoring to assess for rhythm changes.

Pulse oximetry, end-tidal CO₂, and arterial blood gases to guide respiratory and hemodynamic management.

IV fluid resuscitation to support circulation and tissue perfusion.

Temperature management: If the patient is successfully resuscitated, initiate therapeutic hypothermia (target temperature 32-34°C) to reduce neurological damage.

 

 

Consultations:

Cardiology for further evaluation of the acute coronary syndrome and consideration for percutaneous coronary intervention (PCI) or thrombolytics.

Critical Care for ongoing management and potential ICU admission.

Post-Resuscitation Care:

Reassessment of neurological status once circulation is restored.

Neuroprotective strategies: Ensure adequate oxygenation and normocapnia.

Rehabilitation: Plan for post-cardiac arrest care, including potential need for long-term cardiac rehabilitation if the patient survives.

Discussion:

Cardiac arrest is a life-threatening emergency with a high mortality rate, but prompt and effective resuscitation can improve survival outcomes. Early use of ACLS medications such as epinephrine and amiodarone (for shockable rhythms) or high-quality CPR can make a significant difference. This patient’s history of cardiovascular disease and acute myocardial infarction is critical in determining the course of management. The focus remains on optimizing resuscitation efforts and addressing the underlying cause of the arrest. Pharmacotherapy should be used to stabilize the patient and prevent further damage, while supportive care measures aim to improve long-term outcomes.

Prognosis:

The patient's outcome remains uncertain at this time, depending on the success of resuscitation, the underlying cause of the cardiac arrest, and the response to treatment. Further interventions will be guided by the patient’s clinical response.