Definition of Sepsis in Elderly Patients
The definition of sepsis is the same for elderly patients as for all adults: life-threatening organ dysfunction caused by a dysregulated host response to infection, operationally defined as an acute increase in the Sequential Organ Failure Assessment (SOFA) score of 2 or more points. 1, 2
Core Diagnostic Criteria (Sepsis-3 Definition)
The current Sepsis-3 framework applies universally across age groups, including the elderly:
Sepsis requires two components: (1) documented or suspected infection AND (2) acute organ dysfunction represented by an increase in SOFA score ≥2 points, which correlates with in-hospital mortality >10% 2
The previous SIRS criteria and "severe sepsis" terminology are no longer used in the current definition framework, as these lacked specificity and have been abandoned 2, 3
Septic shock is defined as sepsis requiring vasopressor therapy to maintain mean arterial pressure ≥65 mmHg AND serum lactate >2 mmol/L (>18 mg/dL) despite adequate fluid resuscitation, with mortality exceeding 40% 2, 4
Quick SOFA (qSOFA) for Rapid Bedside Assessment
For rapid identification outside the ICU, qSOFA consists of three clinical variables (≥2 indicates higher risk):
- Respiratory rate ≥22 breaths/minute 2
- Altered mental status (Glasgow Coma Scale score ≤13) 2
- Systolic blood pressure ≤100 mmHg 2
Critical Differences in Elderly Presentation
While the definition remains identical, elderly patients present unique diagnostic challenges that require heightened clinical suspicion:
Elderly patients may present with attenuated inflammatory responses and fewer classic clinical signs despite severe infection, making sepsis more difficult to recognize 2, 5
Any change in mental status with suspected infection warrants immediate evaluation in elderly patients, as altered mentation may be the primary or only presenting sign 6
Elderly patients may not mount a typical fever response (temperature >38°C or <36°C), and subtle symptoms should trigger evaluation 6, 5
The specific pathophysiological changes of aging increase the risk of sudden deterioration to septic shock, necessitating earlier recognition and aggressive treatment 5
Risk Factors Particularly Relevant to Elderly
The elderly population faces disproportionate sepsis risk due to:
- Age itself is an independent risk factor, with the incidence rising in aging populations 1
- Chronic comorbidities (malignancy, diabetes, chronic diseases) that accumulate with age 1, 2
- Immune senescence leading to both increased susceptibility and altered inflammatory responses 2, 5
Clinical Implications for Management
Treatment should follow the same evidence-based guidelines (early antibiotics within 1 hour, fluid resuscitation with 30 mL/kg crystalloid, vasopressors as needed) but with consideration of comorbidities and overall goals of care 5, 4
Early identification is crucial because elderly patients admitted to ICU with sepsis have significantly higher mortality (38% at 1 month, 60% at 1 year) compared to those without sepsis (18% at 1 month, 42% at 1 year) 7
Physicians must clarify overall objectives of care when deciding ICU admission for elderly patients with sepsis, balancing aggressive treatment with patient-centered goals 5
Common Pitfalls in Elderly Sepsis Recognition
- Waiting for classic fever or elevated white blood cell count before considering sepsis—elderly patients may lack these findings 5
- Attributing altered mental status to dementia or delirium without investigating for underlying infection 6
- Underestimating severity due to less dramatic vital sign abnormalities despite significant organ dysfunction 2, 5