Primary Survey

Initial impression:

The initial impression is a form of rapid pattern recognition, a predictor of illness severity. It integrates visual and auditory cues before objective measurements. It prioritises and accelerates the primary survey. Studies have shown that clinicians' first impressions correlate well with patient acuity. 

Look – Listen – Smell

1. Look: Appearance, consciousness, posture, skin colour, bleeding, respiratory effort

2. Listen: Voice quality, stridor, wheeze, grunting, gurgling, ability to speak

3. Smell: Alcohol, ketones (diabetic ketoacidosis), ammonia (uraemia), smoke, chemicals

Clinical clues:

• Drowsy → possible hypoxia, hypercapnia, shock, intoxication

• Agitated → hypoxia, hypoperfusion, delirium

• Tripod position → severe respiratory distress

• Limp child → critical illness

Agitation v/s Delirim  

Agitation = What you observe. Delirium = One possible explanation for what you observe (Delirium is a diagnosis). 

Delirium is an acute disorder of brain function, characterised by disturbed attention and awareness. It can be hyperactive delirium (agitation) or hypoactive delirium (drowsiness). Hypoactive delirium is not the same as drowsiness.

The hallmark of delirium is inattention. 

Delirium is characterised by 

1. Disturbance in attention (difficulty focusing, sustaining, or shifting attention).

2. Disturbance in awareness (reduced orientation to the environment).

3. Acute onset (hours to days).

4. Fluctuating course (better at one time, worse at another).

5. Due to an underlying medical condition, intoxication, withdrawal, or another physiological cause.

Hypoactive delirium v/s drowsiness

A patient with hypoactive delirium may look "drowsy," but the underlying problem is acute brain dysfunction with impaired attention, not simply reduced arousal. Differentiating features

1. Arousal

2. Attention

• Drowsiness; Arousal ↓ + Attention preserved when awakened

• Hypoactive delirium; Arousal-variable + Attention - impaired

Clinically, drowsiness is a descriptive term, whereas lethargy is a defined level of consciousness. 

• Drowsiness: Appears sleepy, opens eyes when spoken to, and answers appropriately.

• Lethargy: decreased level of consciousness; can be awakened but needs repeated stimulation, and response will be slow and reduced interaction.

• Level of consiousness; Alert -> drowsy (somnolent) -> Lethargic -> Obtunded -> Stuporous -> Coma

Agitation

• Hypoxia (Agitated + SpO₂ 78%)| Asthma, pulmonary oedema, PE, pneumonia

• Hypercapnia (Agitated + RR 8 + pinpoint pupils) | COPD, obesity hypoventilation, sedative overdose

• Shock / Hypoperfusion (Agitated + HR 140 + BP 70)| Septic, haemorrhagic, cardiogenic shock

• Hypoglycaemia (Agitated + glucose 32 mg/dL)| Often presents with agitation before coma

• Pain | Trauma, burns, acute abdomen

• Delirium (Agitated + fever + confusion)| Sepsis, elderly, ICU, postoperative

• Drug-related | Cocaine, amphetamines, alcohol withdrawal, opioid withdrawal

• Psychiatric | Acute psychosis, mania, severe anxiety

• Neurological | Stroke, intracranial haemorrhage, post-ictal state, encephalitis

• Metabolic | Hyponatraemia, uraemia, hepatic encephalopathy

• Environmental | Fear, restraint, sensory overload

Primary Examination

(clinically focused)

• Initial impression - How sick is this patient? (Which system is dying)

• A -Airway. Can air/oxygen reach the lungs? (Can they breathe?)

• B -Breathing. Can oxygen cross into the blood? (Are they breathing effectively?)

• C -Circulation. Can (oxygenated) blood reach the tissues? (Are they perfusing/can blood reach the tissue?)

• D -Disability. Is the brain receiving enough oxygen and perfusion, and is it functioning normally? (Is the brain working? or is the organ most sensitive to hypoxia; brain still functioning?)

• E -Exposure. What have I not yet seen? (What underlying condition is threatening this process?)

Physiological logic behind the primary survey

• A - Airflow

• B - Gas exchange and ventilation (oxygen enters & CO2 leaves)

• C - Oxygen delivery; DO2

• D - Cerebral perfusion

• E - Identification of underlying pathology

Air → Alveoli → Blood → Tissues → Brain → Diagnosis