**4. Physical examination**

An initial assessment of the patient is made of the patient using a systematic approach (**Table 2**).

#### **4.1 Airway and breathing**

Following the return of spontaneous circulation (ROSC), an initial examination of airway, breathing, circulation, and disability (ABCs) is performed. Airway and ventilation support should continue after the return of spontaneous circulation (ROSC) is achieved [3]. Airway potency is assessed, and endotracheal intubation is required for the patient patients if unable to maintain the airway. If the patient is already intubated, then the position of the endotracheal tube should be checked, as a misplaced endotracheal tube can lead to hypoxia and re-arrest.

Once the patient's airway is secured, an assessment of breathing is to be done. Abnormal examination such as asymmetrical sounds, wheeze, crackles, etc. can help identify potential cause or precipitant. This may reveal potential causes such as pneumothorax, mal-positioned endotracheal, cardiac, and respiratory issues.

#### **4.2 Circulation**

Circulation and end-organ perfusion are next assessed. The pulse (weak, thread), blood pressure, skin color (pale, mottled, cold), and prolonged capillary refill time (>2 s) can be indicative of poor peripheral perfusion and the need for IV fluids and vasopressor support. Abnormal cardiac sounds such as the presence of harsh cardiac murmurs, rubs can suggest a cardiac mechanical cause. Diminished heart sounds, jugular venous distension, and hypotension can suggest cardiac tamponade as a potential cause.

a. **Airway**—If the patient is able to speak coherently and is responsive then the airway is patent. Perform either a chin lift or jaw thrust if airway obstruction is identified. A jaw thrust only is preferred if cervical spine injury is suspected, and the cervical spine should be immobilized and maintained in-line.

Foreign bodies, secretions, and facial fractures should be identified if present.

