From the Guidelines
Hypotensive shock in a 3-month-old infant is indicated by physical assessment findings such as tachycardia, delayed capillary refill, and hypotension, with systolic blood pressure below 70 mmHg being a late and ominous sign. The most critical signs to look out for include:
- Tachycardia, with a heart rate greater than 160 beats per minute 1
- Delayed capillary refill, with a time greater than 2 seconds 1
- Hypotension, with systolic blood pressure below 70 mmHg 1
- Decreased urine output, with less than 1 ml/kg/hour 1
- Altered mental status, with the infant appearing lethargic or unresponsive 1
- Respiratory distress, with tachypnea and a respiratory rate greater than 60 breaths per minute These signs reflect the body's compensatory mechanisms failing as shock progresses, and early recognition is crucial to prevent increased mortality. It's essential to note that infants can maintain blood pressure despite significant volume loss through strong compensatory mechanisms, making hypotension a particularly concerning late finding indicating decompensated shock requiring immediate intervention 1. The physical assessment findings should be used to direct treatment, with a focus on restoring normal mental status, threshold heart rates, peripheral perfusion, and normal blood pressure for age 1.
From the Research
Physical Assessment Findings for Hypotensive Shock in a 3-Month-Old Infant
The physical assessment findings that indicate hypotensive shock in a 3-month-old infant include:
- Poor skin perfusion, characterized by a capillary refill time (CRT) greater than 2 seconds, mottled skin, cool peripheries, and peripheral cyanosis 2
- Weak peripheral pulse 2
- Age-specific tachycardia and tachypnoea 2, 3
- Oliguria, which is a decreased urine output 2, 3
- Decreased mental status, which can be indicated by restlessness or lethargy 2
- Hypotension, defined as a systolic blood pressure (SBP) less than 70 + (2 x age in years) mmHg 2
- Cold periphery and low cardiac output, which can be indicated by a decreased peripheral perfusion index (PI) 2
Additional Assessment Findings
Other assessment findings that may indicate hypotensive shock in a 3-month-old infant include:
- Elevated serum lactate concentration, which can indicate tissue hypoxia and impaired perfusion 2, 3
- Decreased central venous oxygen saturation, which can indicate impaired oxygen delivery to tissues 2, 4
- Increased central-peripheral temperature difference, which can indicate impaired peripheral perfusion 5
- Abnormalities in echocardiographic evaluation, such as decreased cardiac function or cardiac output, which can indicate impaired hemodynamics 4