01Principles and purposeThe professional or clinical skill and the decisions it supports.
Urosepsis describes sepsis arising from urinary infection: the defining clinical concern is organ dysfunction, not merely a positive culture or fever. The source may be kidney infection, an obstructed collecting system, an abscess, an infected prostate or a complication of instrumentation. Bacteriuria is common in some populations, so the urinary tract must remain a reasoned source attribution rather than a shortcut that prevents examination for pneumonia, abdominal infection or another cause.
Early management has several connected tasks: recognise risk, obtain useful samples, restore perfusion, give an appropriate systemic antimicrobial and control an anatomical source. These tasks should proceed in parallel. A falling temperature after antibiotics is encouraging, but it does not establish that a retained infected device or collection has been addressed. Clear ownership of reassessment and procedural action is essential during transfers between acute medicine, urology, radiology and critical care.
Key points
- In a nonpregnant adult in hospital, use NEWS2 with clinical judgement; a score of seven or more with suspected infection indicates high risk, and concern can escalate a lower score.
- For high risk suspected sepsis, give an appropriate broad intravenous antibiotic within one hour of the initial emergency department NEWS2 assessment or ward deterioration assessment. For a later directed cefalexin switch, exclude cephalosporin allergy and obtain specialist selection after a severe penicillin reaction.
- NG253 adult sepsis fluid resuscitation starts with 250 ml isotonic crystalloid over ten to fifteen minutes, reassessing after every bolus and counting prior fluids towards 1000 ml.
- Urinary source control may require relief of obstruction, abscess drainage or removal or replacement of infected material; a susceptible antibiotic cannot replace those actions.
- Take blood and relevant urine cultures before treatment when feasible without clinically important delay, then narrow treatment once microbiology and the source are understood.
- Pregnancy and recent pregnancy follow NG255; cancer-related neutropenic sepsis follows CG151. Neither population should inherit this adult NEWS2 and antibiotic pathway uncritically.
02Situations and prioritiesThe context, relevant information and actions that matter most.
For adults within NG253’s nonpregnant population, NEWS2 of at least seven indicates high risk with suspected infection. Scores of five or six suggest moderate risk, but a single three-point parameter, hypoperfusion or clinical deterioration can demand escalation.
New confusion, hypotension, oliguria, acute kidney injury, rising oxygen requirement or lactate elevation should change urgency. Moderate-risk patients with hypoperfusion, such as lactate above 2 or acute kidney injury, are managed as high risk.
Ask about recent ureteroscopy, stone procedures, prostate intervention, catheter changes and retained stents or nephrostomies. The procedure, date and device status can identify the imaging and specialist team needed now.
Confirm pregnancy or recent pregnancy and recent anticancer treatment at first assessment. Maternal sepsis uses its own risk and fluid recommendations; suspected neutropenic sepsis requires immediate cancer-specific empirical treatment rather than waiting for a routine score threshold.
03Assessment and interpretationHow to gather information, assess the situation and recognise uncertainty.
Consider the information, its meaning and its limitations before deciding what follows.
- 01
Blood cultures lactate and organ tests - Why
- Identify invasive infection and quantify current organ effects.
- Interpretation and limitations
- Send blood cultures and blood gas with glucose and lactate, full blood count, renal function, liver tests, CRP and coagulation studies for high-risk illness. Collect before antibiotics where feasible, while ensuring the high-risk treatment window is met.
- 02
Source appropriate urine culture - Why
- Recover organisms from the relevant urinary site.
- Interpretation and limitations
- Use midstream urine or an aseptic catheter port sample, and obtain a sample from newly drained upper tract urine or pus when intervention occurs. The source and collection time matter when comparing results after prior antibiotics.
- 03
Urgent targeted imaging - Why
- Identify obstruction collections or device complications needing an intervention.
- Interpretation and limitations
- Ultrasound can show hydronephrosis, while CT can define a perinephric collection or complicated postoperative anatomy. Select imaging with the procedural team and do not let diagnostic perfection delay an already indicated source intervention.
- 04
Alternative source assessment - Why
- Test the urinary attribution against the whole clinical presentation.
- Interpretation and limitations
- Examine respiratory, abdominal, skin and device sites and pursue relevant tests. A positive catheter urine culture does not exclude another infection, and persistent deterioration after urinary treatment should reopen the source assessment.
04Worked approachesCases with ordered reasoning, an action and a check of the outcome.
01Worked caseDrain a postoperative infected collectionA fifty year old nonpregnant woman deteriorates five days after a kidney stone procedure.+
- 1She has rigors, right flank pain, blood pressure 88/54, respiratory rate 26 and new confusion. Blood and urine cultures are collected during urgent senior assessment. She weighs 60 kg, is 165 cm tall, has creatinine 70 micromol/litre with calculated creatinine clearance about 80 ml/min, no beta lactam allergy and no aminoglycoside contraindication or interacting nephrotoxic drug.
- 2Under the cited Oxford adult urinary-sepsis protocol she receives amoxicillin 1 g intravenously every eight hours plus an initial gentamicin dose of 300 mg intravenously, each prepared and administered separately. A 250 ml isotonic crystalloid bolus runs over ten to fifteen minutes, followed by reassessment; further 250 ml boluses are given only while examination supports them, with previous fluids included in the total. NG253’s initial adult bolus is not a 500 ml maternal schedule or a preassigned litre or weight-based three-hour volume; each next bolus depends on reassessment.
- 3After initial treatment she remains poorly perfused, prompting in-person senior and critical care review rather than passive observation. Urgent CT shows a loculated perinephric collection with patent urinary drainage. Interventional radiology drains the collection and sends pus for culture; simply exchanging a freely draining bladder catheter would not control this source.
- 4Within six hours of drainage her blood pressure and mental state improve and lactate falls from 4.2 to 1.8. Gentamicin sampling is obtained in the protocol’s six to fourteen hour window and renal function is followed; subsequent dosing requires the actual result and protocol interpretation, not an automatic daily order.
- 5Cultures identify susceptible Escherichia coli. Microbiology narrows treatment, stops gentamicin within forty eight hours and later selects cefalexin 1 g orally three times daily once she is stable and eating. Three intravenous days plus seven oral days complete an agreed ten day complicated-infection course; the drain is removed after clinical and radiological review confirms control.
02Risk and reassessmentMatch urgency to the adult assessmentA nonpregnant adult has possible infection in an acute hospital setting.+
- 1Assess NEWS2, the individual parameters and clinical concern. High-risk illness receives immediate senior assessment and intravenous treatment within the specified hour; a lower score must not override evidence of hypoperfusion or concerning deterioration.
- 2In moderate or low risk without a reason to escalate, an appropriately skilled clinician may use a bounded diagnostic period before broad antibiotics, up to three or six hours respectively. This is a clinical decision to clarify the diagnosis, not permission to delay once treatment is judged necessary.
- 3Recalculate observations according to risk, at least every thirty minutes for high risk and hourly for moderate risk. If high-risk illness does not respond within one hour of an intervention, ensure senior in-person review, involve critical care and inform the responsible consultant.
03Source decisionDefine the action and verify the resultUrinary infection is likely but the response is inadequate or anatomy is abnormal.+
- 1Name the suspected source precisely: obstructed urine, a prostate or perinephric collection, or infected retained material. Share the findings with urology and interventional radiology early and agree who will act and when. A patent bladder catheter or ureteric stent drains a different compartment from a loculated perinephric abscess; the procedure must reach the demonstrated collection. Preserved renal enhancement and a feasible percutaneous route support assessing targeted drainage before organ-removing surgery.
- 2Perform the appropriate source intervention as soon as possible, with anaesthetic and critical care support when needed. If no source is found or improvement fails, reassess imaging, drainage function, antimicrobial activity and competing diagnoses.
- 3After intervention, review perfusion, lactate when indicated, urine output, kidney function and the new cultures. Document a tailored antimicrobial duration and device follow-up endpoint rather than declaring success solely because a procedure was completed.
05Relevant medicines and safetySpecific regimens and precautions when the skill involves prescribing.
Amoxicillin 1 g intravenous powder with gentamicin
In the cited Oxford adult urinary-sepsis regimen, give amoxicillin 1 g intravenously every eight hours, infused over twenty to thirty minutes, alongside the separately prescribed gentamicin component.Do not use amoxicillin alone as presumed universal empirical Gram-negative cover. Exclude penicillin hypersensitivity or a severe immediate reaction to another beta lactam. The selected intravenous product adjusts at GFR 10–30 ml/min, including 30: give 1 g initially, then 500 mg to 1 g every twelve hours; below 10, give 1 g initially then 500 mg daily. Dialysis requires the separate product schedule. Check sodium burden, rash, diarrhoea and crystalluria with poor urine output, and review methotrexate and anticoagulants. Never mix amoxicillin and an aminoglycoside in the same syringe, infusion container or giving set.
Gentamicin 40 mg per ml injection or infusion
For the worked adult with calculated clearance about 80 and dosing weight 60 kg, Oxford’s 5 mg/kg initial dose is 300 mg intravenously, infused over thirty minutes; draw a level six to fourteen hours after administration.Use Oxford’s Cockcroft–Gault and dosing-weight method, rounding down to 20 mg increments. At creatinine clearance 31 ml/min or greater, the 5 mg/kg initial dose is capped at 480 mg and a six-to-fourteen-hour level is plotted on the specified nomogram to select the supported twenty four, thirty six or forty eight hour interval. At clearance 30 or less, start 3 mg/kg, maximum 240 mg, take a level at twenty four hours and withhold further doses until it is below 1 mg/litre; discuss dialysis with the renal team before the initial dose. Check renal function daily and stop for deterioration or toxicity; Micro/ID agreement is required beyond three days. Myasthenia gravis and gentamicin or formulation hypersensitivity are contraindications. Oxford also excludes known familial susceptibility to aminoglycoside toxicity. Suspected mitochondrial risk or a maternal deafness history requires specialist assessment of alternatives; it is not the same as a confirmed drug allergy. Review nephrotoxic, ototoxic and neuromuscular-blocking combinations.
Cefalexin 500 mg capsules for directed continuation
The Oxford oral switch option used here is 1 g, as two 500 mg capsules, orally three times daily, for the remaining seven days of the agreed ten day total course.Confirm that current susceptibility, absorption and renal clearance support the switch. Adjust for significant renal impairment. Cefalexin or other cephalosporin allergy rules out this switch, while a severe penicillin-allergy history needs specialist selection; assess severe diarrhoea or skin reactions. A fixed ten day total is an individual worked-case decision, not a duration rule for every urinary source or bacteraemia.
06Feedback, follow-up and evidenceReview outcomes, seek feedback and identify what to improve.
- Record fluid already given, examination before and after each bolus, blood pressure, breathing and signs of overload. If response remains inadequate after 1000 ml, seek senior advice; escalate earlier whenever the clinical state requires it.
- Discuss vasopressors and the appropriate care setting with critical care or the senior decision maker when perfusion remains inadequate. Drug concentration and administration require the relevant local critical care protocol.
- Check antimicrobial administration times, cultures and dosing weight or renal estimates. For gentamicin, record the dose time, sample time, concentration and the resulting authorised interval or stop decision.
- At every handover identify the source-control action, its owner, current physiological response and next review. Ensure drains or stents have a planned endpoint and that antimicrobial therapy is reviewed daily.
07Special situationsVariants, exceptions and circumstances that change the usual approach.
A score supports judgement
NEWS2 standardises physiological communication but cannot establish the source or exclude dangerous infection in a lower-scoring patient. Single severe parameters, hypoperfusion and change from baseline remain clinically important.
Use the current bolus
The NG253 adult sepsis starting bolus is 250 ml, with reassessment and cumulative accounting. A generic 500 ml fluid prescription from another context should not silently replace this current population-specific recommendation.
Local regimens have boundaries
Oxford’s amoxicillin and gentamicin example makes the drug, weight calculation and monitoring concrete. Other hospitals may appropriately select a different initial regimen based on resistance, allergies and patient factors; the antibiotic rationale must remain explicit.
Recovery has several measures
Normalising temperature can occur while obstruction or a collection persists. Improved perfusion, renal function, drainage and microbiological information together provide stronger evidence that the infection is controlled.
08Common pitfallsFrequent interpretation and management errors.
- 01
Attributing deterioration to a urinary source solely because the urine is positive can delay identification of another treatable focus.
- 02
Giving repeated fluid boluses without checking breathing, perfusion and previous volumes risks harm and can postpone a needed critical care decision.
- 03
Writing gentamicin as an automatic daily medicine without timed levels and renal review defeats the monitoring that makes the selected regimen safe.
- 04
Waiting for antibiotics to work before contacting the team that can drain an obvious infected collection delays a necessary source intervention.