What are the signs and symptoms of sepsis?

Signs and Symptoms of Sepsis

Sepsis should be suspected when a patient presents with signs of infection combined with physiological derangement, most reliably assessed using the NEWS2 scoring system which incorporates six vital parameters: respiratory rate, oxygen saturation, supplemental oxygen requirement, systolic blood pressure, pulse rate, level of consciousness, and temperature. 1

Core Clinical Presentation

Systemic Inflammatory Response Indicators

The fundamental signs of sepsis reflect systemic inflammation and include 2:

• Temperature dysregulation: Fever >38°C or hypothermia <36°C
• Tachycardia: Heart rate >90 beats per minute
• Tachypnea: Respiratory rate >20 breaths per minute or PaCO2 <32 mmHg
• Leukocyte abnormalities: White blood cell count >12,000/ml or <4,000/ml, or >10% immature band forms

High-Risk Warning Signs

Certain clinical features indicate immediate high risk of severe illness or death from sepsis, regardless of NEWS2 score 1:

• Mottled or ashen skin appearance
• Non-blanching petechial or purpuric rash
• Cyanosis of skin, lips, or tongue

These findings should trigger urgent evaluation even if other vital signs appear stable 1.

Structured Assessment Using NEWS2

The Six Physiological Parameters

The NEWS2 tool provides standardized risk stratification by scoring 1:

• Respiratory rate: Scores increase with rates <8 or >25 per minute
• Oxygen saturation: Lower saturations score higher (adjust targets for hypercapnic patients)
• Supplemental oxygen requirement: Any oxygen use adds points
• Systolic blood pressure: Hypotension <90 mmHg or hypertension ≥220 mmHg score higher
• Pulse rate: Bradycardia <40 or tachycardia >130 beats per minute increase score
• Level of consciousness: New confusion, altered responsiveness (CVPU scale)
• Temperature: Hypothermia <35°C or fever >39.1°C

Risk Stratification by NEWS2 Score

Interpret aggregate scores as follows 1:

• Score ≥7: High risk of severe illness or death from sepsis
• Score 5-6: Moderate risk of severe illness or death from sepsis
• Score 1-4: Low risk of severe illness or death from sepsis
• Score 0: Very low risk of severe illness or death from sepsis
• Single parameter score of 3: May indicate increased sepsis risk regardless of total score

Organ Dysfunction Manifestations

Severe Sepsis Indicators

Severe sepsis is defined by organ dysfunction, hypotension, or hypoperfusion abnormalities 2:

• Lactic acidosis: Elevated lactate levels indicating tissue hypoperfusion
• Oliguria: Reduced urine output indicating renal dysfunction
• Acute mental status changes: Confusion, disorientation, or decreased consciousness
• Hypotension: Despite adequate fluid resuscitation

Septic Shock Criteria

Septic shock represents the most severe presentation 2:

• Persistent hypotension requiring vasopressor therapy to maintain mean arterial pressure >65 mmHg
• Plasma lactate >2 mmol/L despite adequate volume resuscitation
• These patients have substantially increased mortality risk

Infection-Specific Symptoms

Common Presenting Complaints

Beyond systemic signs, patients may present with symptoms related to the infection source 3, 4:

• Respiratory: Cough, severe breathlessness (pneumonia)
• Urinary: Dysuria, burning with urination (kidney/urinary tract infection)
• Abdominal: Abdominal pain (intraabdominal sepsis)
• Neurological: Slurred speech, confusion
• Musculoskeletal: Extreme shivering, severe muscle pain

Subtle or Atypical Presentations

A critical pitfall: approximately 15% of septic patients do not present with classic mnemonic symptoms 3:

• Immunosuppressed patients are significantly more likely to have vague presentations (24.6% vs 8.3%)
• Intraabdominal infections frequently present without typical sepsis symptoms (38.5% vs 12.1%)
• Vague-presenting symptoms are independently associated with higher in-hospital mortality (adjusted OR 2.17)
• Other subtle changes include cold or clammy skin and behavioral changes 5

Monitoring and Re-evaluation

Dynamic Assessment Requirements

NEWS2 scores must be recalculated at specific intervals based on risk level 1:

• High risk (score ≥7): Every 30 minutes
• Moderate risk (score 5-6): Every hour
• Low risk (score 1-4): Every 4-6 hours
• Very low risk (score 0): Per standard protocol

Recognizing Clinical Deterioration

Consider the patient at higher risk than their NEWS2 score suggests if 1:

• Their condition is deteriorating since the previous assessment
• They have not improved despite interventions
• This applies to scores calculated before or after emergency department arrival

Critical Clinical Caveats

Always interpret NEWS2 scores in the context of the patient's underlying physiology and comorbidities 1. The score is a tool, not a replacement for clinical judgment, particularly in patients with chronic conditions that affect baseline vital signs.

Do not rely solely on the "SEPSIS" mnemonic for public awareness, as validation studies show it misses significant proportions of cases, particularly in immunocompromised patients and those with intraabdominal infections 3.