Educational draft · awaiting clinical reviewThe full textbook explains uncertainty but does not replace live national or local guidance, specialist advice, or current prescribing information.
Sepsis in older adults
Medicine of older adults · UK scope · Sources checked 27 Aug 2026 · Clinical review pending
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Suspected sepsis with high-risk features
Hypotension, raised lactate, new oxygen requirement, mottling, reduced urine, altered consciousness, rapidly worsening NEWS2 or clinician concern may indicate life-threatening organ dysfunction even without fever.
Action: Activate the current NICE adult sepsis pathway, obtain bloods and cultures without delaying treatment, give source-appropriate intravenous antimicrobials within the required time, use cautious reassessed crystalloid boluses and obtain urgent senior and critical-care input.
Overview
Recognise sepsis despite absent fever or non-specific decline, stratify risk using physiology and clinical concern, deliver time-critical source, antimicrobial and circulatory care, and prevent treatment complications in frailty and organ impairment.
Recognise the change from baseline. Ask onset, rigors, cough, breathlessness, urinary or abdominal symptoms, wounds, pain, devices, procedures, recent antibiotics, resistant organisms and immune suppression. In frailty, new confusion, sleepiness, fall, reduced intake or lost mobility may be the only early signal. Absence of fever does not reduce concern when physiology or organ function is deteriorating.
Use ABCDE, capillary glucose and NEWS2 under the current NICE adult pathway, adding clinical judgement. Record mental state, oxygen requirement, respiratory effort, perfusion, capillary refill, blood pressure, urine and skin. Examine mouth and chest, abdomen, flanks, perineum, pressure areas, joints and every line or catheter. A concerning source or trajectory can require escalation even before a score crosses a threshold.
Obtain FBC, renal and electrolytes, liver, coagulation, CRP, venous or arterial gas and lactate according to risk. Take blood cultures and source samples before antibiotics when feasible without meaningful delay. Urine, sputum or wound results require clinical interpretation because colonisation is common. Use ECG, chest imaging, ultrasound or CT to identify complication and source-control need.
Aetiology
01
Respiratory infection
Pneumonia and aspiration commonly present with delirium, hypoxia or functional decline rather than prominent cough and fever.
02
Urinary and abdominal sources
Pyelonephritis, obstructed infection, cholangitis, bowel disease and perforation require source-directed imaging and procedures to remove the continuing focus.
03
Skin, bone and device infection
Cellulitis, pressure injury, osteomyelitis, prosthetic infection and vascular or urinary devices can seed systemic disease and require source control.
04
Healthcare and immune factors
Recent antimicrobials, admission, colonisation, immunosuppression and care-home exposure alter organism probability, resistance and the reliability of classical symptoms.
Pathophysiology
1
Dysregulated host response
An uncontrolled immune response causes endothelial injury, vasodilation and microvascular dysfunction beyond the local infection and its anatomical boundaries.
2
Perfusion failure
Reduced vascular tone, capillary leak and myocardial dysfunction lower effective circulation and impair oxygen delivery to organs.
3
Cellular and coagulation injury
Mitochondrial dysfunction and disordered coagulation create tissue hypoxia, thrombosis, bleeding and progressive multiorgan failure despite restored macrocirculation.
4
Frailty-amplified presentation
Limited reserve and blunted inflammatory signalling make delirium, falls and anorexia appear before dramatic fever or tachycardia.
5
Treatment vulnerability
Heart, kidney and respiratory disease narrow tolerance for rapid fluids, nephrotoxic medicines and sedative procedures during source control.
Clinical features and red flags
Atypical frailty presentation
Delirium, falls or anorexia precedes localising infection symptoms in a person with reduced reserve.
High-risk perfusion patternRed flag
Hypotension, mottling, prolonged refill, oliguria or raised lactate indicates threatened organ perfusion.
Respiratory source
New oxygen need, tachypnoea and focal or aspiration features suggest pneumonia with potential respiratory failure.
Obstructed urinary sourceRed flag
Sepsis with flank pain, hydronephrosis or anuria requires urgent drainage rather than antibiotics alone.
Deep soft-tissue sourceRed flag
Pain out of proportion, rapidly spreading change, crepitus or bullae suggests necrotising infection.
Red flags requiring action
New systolic hypotension, lactate elevation, mottling, cyanosis or delayed capillary refill suggests impaired perfusion and high risk.
New oxygen need, respiratory distress or rapidly increasing respiratory rate requires immediate support and source assessment.
Reduced consciousness, new delirium, seizure or sudden functional collapse can be an older adult's principal sepsis manifestation.
Investigations
01NEWS2 and serial physiologyFirst stepFirst line
Why
Risk-stratify and detect deterioration first line.
Interpretation and limitations
Use respiratory, oxygen, pressure, pulse, temperature and consciousness trends with clinician concern and chronic baselines.
02Blood gas and lactate
Why
Assess perfusion, ventilation and metabolic severity.
Interpretation and limitations
A raised or rising lactate increases concern but is not infection-specific; repeat after treatment when clinically indicated.
03Blood cultures before antimicrobials
Why
Identify bloodstream organism and susceptibility.
Interpretation and limitations
Obtain from appropriate sites without delaying urgent treatment; distinguish likely contaminants using organism, sets and clinical context.
04Source-specific microbiology
Why
Guide antimicrobial narrowing and source diagnosis.
Interpretation and limitations
Collect urine, respiratory, CSF, tissue or fluid samples when indicated; colonisation and prior antibiotics affect interpretation.
05Organ and coagulation profile
Why
Identify sepsis-associated dysfunction and dosing constraints.
Differential diagnosis
01
Non-infectious shock
Bleeding, cardiogenic failure, pulmonary embolism and adrenal crisis cause similar hypotension, lactate and organ dysfunction without a primary infection.
02
Medication or metabolic toxicity
Hypoglycaemia, opioid accumulation, anticholinergic toxicity and electrolyte disturbance can mimic or coexist with infection during a frailty crisis.
03
Inflammatory and vascular disease
Pancreatitis, vasculitis, bowel ischaemia and tissue necrosis generate systemic inflammation without a primary microbial cause being responsible.
04
Colonisation without infection
Asymptomatic bacteriuria and colonised wounds are common; clinical source evidence determines whether they explain systemic illness.
05
Viral respiratory disease
Influenza, COVID-19 and RSV can cause severe disease and secondary bacterial infection requiring pathogen and complication assessment.
Additional chapter-specific clues
Colonisation mimic
Positive urine or wound culture lacks compatible local and systemic evidence and may not explain deterioration.
Management
01First-line sepsis sequenceRisk-stratify and treat on the clockFirst stepFirst lineInfection is suspected with new physiological, cognitive or functional deterioration.+
1Use ABCDE, glucose, NEWS2, lactate and source examination and assign current NICE risk with senior concern included.
2Obtain cultures and organ tests without delaying source-appropriate IV antimicrobials within the high-risk treatment window.
3EscalationSupport oxygenation and circulation, identify source-control need and escalate persistent organ dysfunction to critical care.
02Frailty fluid routeImprove perfusion without causing congestionHigh-risk sepsis includes hypoperfusion and heart, kidney or respiratory reserve is limited.+
1Give a 250 mL isotonic crystalloid bolus over 10 to 15 minutes when indicated under NICE guidance.
Complications
01
Shock and multiorgan failure
Persistent circulatory and cellular dysfunction causes kidney, respiratory, hepatic, cardiac, neurological and coagulation failure requiring organ support.
02
Fluid and treatment harm
Excess crystalloid causes pulmonary oedema, while antimicrobial toxicity and interactions worsen renal, hepatic and neurological function.
03
Delirium and deconditioning
Sepsis and immobilisation produce prolonged cognitive, muscle and ADL loss even after infection is microbiologically controlled.
04
Secondary and recurrent infection
Devices, pressure injury, dysphagia and immune impairment create further infection and readmission risk during incomplete functional recovery.
05
Post-sepsis syndrome
Persistent fatigue, weakness, cognitive symptoms, mood disturbance and recurrent illness can delay recovery for months after microbiological control.
Monitoring and follow-up
Repeat observations, NEWS2, perfusion, mental state and urine at a frequency matched to risk and response.
Reassess lungs, oxygen, oedema and circulation after every crystalloid bolus in frailty or organ disease.
Trend lactate and organ function when the result will guide escalation, dosing or resuscitation response.
Review antimicrobial dose after renal and hepatic changes, dialysis, culture results and source control.
Perform a documented 48-to-72-hour antimicrobial review with diagnosis, route and duration decisions.
Track delirium, swallowing, intake, pressure risk, transfers and walking during and after sepsis.
Ensure pending cultures, device plans, medicine restarts and recurrence warnings have named community ownership.
Special situations
Fever is optional
Serious infection can present with hypothermia, delirium or functional loss when inflammatory responses are blunted.
Lactate is not an infection test
It reflects stress and impaired metabolism or clearance and must be interpreted with the whole shock differential.
Small boluses still need a question
Each aliquot tests whether perfusion improves without unacceptable pulmonary or venous congestion.
Antibiotics cannot drain
An obstructed kidney, abscess or necrotic tissue can remain lethal despite microbiologically active treatment.
Recovery exceeds microbial cure
Cognition, muscle, swallowing and confidence may remain impaired long after observations and cultures improve.
Common pitfalls
01
Using absence of fever to lower concern despite organ or functional deterioration.
02
Waiting for cultures or imaging before high-risk time-critical antibiotics.
03
Calling asymptomatic bacteriuria the sepsis source without compatible evidence.
04
Giving repeated large fluid volumes without reassessing congestion in heart or kidney disease.
05
Using one empirical antibiotic regimen for every source, allergy and resistance setting.
06
Failing to obtain urgent source control for obstruction or necrotic infection.
07
Continuing broad-spectrum therapy without a 48-to-72-hour diagnostic review.
08
Discharging after physiological recovery without assessing delirium and mobility.
Practice
Two practice questions
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Medicine of older adultsOriginal SBA
High-risk sepsis timing
An 82-year-old with suspected pneumonia is newly confused, hypotensive and hypoxic with high-risk sepsis features. What is the best antimicrobial action?
Sources and review status5 sources · checked 27 Aug 2026 · clinical review pending+
Sources
Sources and review status
National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.
NICE NG253 stratifies management by risk. High-risk adults require urgent senior clinical assessment and broad-spectrum IV antimicrobials within one hour of the risk being identified. Moderate-risk presentations need prompt investigation and review, with antimicrobial timing guided by the pathway, likelihood of infection and whether deterioration or an alternative diagnosis emerges. Document the risk decision and clock.
Choose empirical antibiotics from the current local guideline because organisms and resistance differ by source and setting. Record immediate allergy phenotype, prior cultures, recent antimicrobials, renal and hepatic function and weight. Avoid vague penicillin allergy labels that force broader or more toxic choices, but do not perform a detailed delabelling challenge during instability. In suspected meningitis, neutropenic sepsis or device infection use the dedicated protocol.
Circulatory treatment must be reassessed repeatedly. For adults at high risk with hypoperfusion, NICE recommends 250 mL isotonic crystalloid containing sodium 130 to 154 mmol/L over 10 to 15 minutes, then reassessment. Further 250 mL boluses may be given up to the pathway limit with senior review. In heart failure, CKD or respiratory disease, examine lungs, oxygen, jugular venous pressure, oedema, perfusion and urine after each aliquot.
Persistent hypotension, lactate, altered consciousness or respiratory failure despite initial treatment requires critical-care input and vasopressor or organ-support planning rather than indiscriminate fluid. Obtain prompt source control: decompress an infected obstructed urinary or biliary system, drain collections, debride necrotic tissue, remove implicated devices when appropriate and operate on perforation or ischaemic bowel.
Review medicines during organ dysfunction. Temporarily adjust nephrotoxic and renally cleared treatment, glucose-lowering medicines and antihypertensives when physiology requires, but preserve time-critical replacement and Parkinson's or antiseizure therapy. Record restart criteria. Use antimicrobial dosing appropriate to loading requirements and subsequent renal trajectory; premature underdosing during resuscitation can also fail treatment.
Prevent secondary harm. Use delirium care, controlled oxygen where hypercapnic respiratory failure is possible, pressure redistribution, VTE assessment, safe swallowing, nutrition and early movement. Remove unnecessary urinary and vascular devices. Use analgesia with renal and respiratory caution. Involve family and carers to support baseline, communication and goals.
At 48 to 72 hours, perform antimicrobial review using cultures, source, imaging, response and an alternative diagnosis. Narrow spectrum, change route, define duration or stop when infection is unsupported. A falling CRP alone does not define cure or duration. Document the decision and any outpatient antimicrobial monitoring.
Before transition, communicate organism and susceptibilities, source control, treatment duration, outstanding cultures, organ recovery, medicine holds, infection-prevention measures and red flags. Assess mobility, cognition, intake and support after sepsis; follow post-sepsis fatigue and function and investigate recurrent infection or incomplete source control promptly.
Key points
Sepsis is life-threatening organ dysfunction from a dysregulated response to infection; fever and leukocytosis are neither required nor sufficient.
Older adults may present with delirium, falls, reduced mobility, poor intake or incontinence, so compare with the stable baseline.
First-line assessment uses ABCDE, glucose, NEWS2, lactate where indicated, focused source examination and clinical concern under NICE NG253.
High-risk features require immediate senior review, blood tests and cultures, source-appropriate IV antibiotics within one hour and escalation planning.
Do not delay antibiotics for cultures, imaging or transfer when the high-risk treatment threshold is met; obtain samples first only when this causes no material delay.
Use current local empirical antimicrobial guidance informed by source, allergy, renal function, previous cultures, recent antibiotics and healthcare exposure.
For high-risk circulatory compromise, NICE uses 250 mL isotonic crystalloid boluses over 10 to 15 minutes with reassessment and caution in cardiac or renal disease.
Source control—draining obstruction or abscess, removing an infected device or operating on perforation—is as important as antimicrobial selection.
Review antibiotics at 48 to 72 hours using cultures, imaging, response and diagnosis; narrow, switch route or stop when appropriate.
Oliguria, acute kidney injury, thrombocytopenia or deranged coagulation indicates evolving organ dysfunction.
Neutropenia, immunosuppression, recent surgery, indwelling device or suspected obstruction lowers the threshold for urgent specialist source control.
Pain out of proportion, crepitus, meningism, purpura or a hot prosthetic joint suggests a source needing immediate specialist intervention.
Interpretation and limitations
Trend FBC, renal, electrolytes, liver, glucose and coagulation against baseline and treatment rather than isolated reference ranges.
06Source-directed imaging
Why
Find obstruction, collection and surgical disease.
Interpretation and limitations
Use radiograph, ultrasound, CT or MRI according to phenotype and urgency and arrange intervention when source control is required.
Reassess lungs, oxygen, pressure, refill, mental state, urine and oedema after every aliquot before repeating.
3Seek senior and critical-care input for persistent shock, pulmonary congestion or need for vasopressor support.
03Source-control routeRemove the continuing infectious driverObstruction, abscess, necrotic tissue, perforation or infected device is suspected.+
1Arrange urgent imaging and surgical, urology, radiology or specialty review without waiting for antimicrobial response.
2Drain, debride, remove or operate using resuscitation and capacity or best-interests planning appropriate to urgency.
3Send high-quality samples and revise antimicrobial choice and duration after findings and susceptibilities return.
04Review and recoveryNarrow treatment and rebuild functionThe person stabilises or 48 to 72 hours of empirical treatment has elapsed.+
1Review diagnosis, cultures, imaging, source control, organ response and competing non-infectious explanations.
2Narrow, switch route, define duration or stop antibiotics with stewardship and medicine-monitoring documentation.
3Treat delirium, swallowing, pressure, nutrition and deconditioning and hand over post-sepsis rehabilitation and recurrence warnings.
Key medicines and prescribing safety2 treatments · regimens, roles and cautions+
Initial circulatory support for adults at high risk of severe illness or death from sepsis with hypoperfusion.
Isotonic crystalloid for sepsis hypoperfusion
Give 250 mL intravenously over 10 to 15 minutes, reassess immediately and repeat 250 mL aliquots only while benefit remains, following the current NICE ceiling and senior-review requirements.
Use sodium 130 to 154 mmol/L crystalloid; reassess for pulmonary oedema after every bolus and involve senior or critical care early in heart, kidney or respiratory disease.
Early treatment of likely bacterial infection while cultures, imaging and source-control assessment proceed.
Empirical intravenous antimicrobial therapy
Give the complete source-specific loading and maintenance regimen from the current local adult sepsis guideline within one hour for high-risk sepsis, adjusting subsequent doses for weight, allergy, renal or hepatic function and dialysis.
Obtain cultures first only if this does not delay treatment; review at 48 to 72 hours, narrow by results and avoid continuing broad therapy for colonisation or an unsupported diagnosis.
After stabilisation, address delirium, swallowing, pressure, nutrition, mobility, medicine accumulation and post-sepsis rehabilitation.