Case Evaluation — 30/04/26, 3:30 PM

Extracted Clinical Information

• Fever and chills (worse at night)
• Abdominal pain (lower)
• Lower back pain — stated as the 1st/initial symptom
• Dark urine
• Irregular periods
• No nausea/vomiting, no dysuria, no loose stools, no cold/cough at presentation

• Conscious and oriented
• RS → Clear, AEBE (Air Entry Bilateral Equal)
• CVS → S1S2+ (normal heart sounds)
• P/A → Soft, Non-tender
• CNS → NFND (No Focal Neurological Deficit)

Clinical Analysis

Key Pattern Recognition

1. Fever + chills (night spikes) → cyclical or infectious
2. Lower back pain as the first symptom → renal/retroperitoneal origin
3. Dark urine → hemoglobinuria, hematuria, myoglobinuria, or bilirubinuria
4. Irregular periods → hormonal disruption, systemic illness, or pelvic pathology
5. HR 125 + BP 90/70 → early sepsis / SIRS criteria met (fever + tachycardia + hypotension)
6. Non-tender abdomen despite abdominal pain → possible visceral/referred pain

Differential Diagnoses (in order of probability)

1. 🔴 Acute Pyelonephritis (Most Likely)

• Lower back pain as the first symptom = renal origin before full infection establishes
• Dark urine = hematuria or pyuria-related turbidity
• Tachycardia + hypotension = early urosepsis — a well-recognized complication; pyelonephritis is a leading cause of septic shock in women
• Irregular periods = systemic febrile illness disrupting menstrual cycle, or concurrent UTI-related pelvic inflammation
• SpO₂ 96% warrants monitoring (ARDS is a known complication if sepsis progresses)

2. 🟡 Pelvic Inflammatory Disease (PID)

3. 🟡 Malaria (if endemic area/travel history — South Asian context likely)

4. 🟠 Typhoid Fever / Enteric Fever

5. 🟢 Hemolytic Anemia (e.g., G6PD crisis)

Vital Sign Alarm 🚨

This patient meets criteria for early sepsis — the combination of a presumed infection source (likely urinary) + tachycardia + hypotension demands urgent management, not just investigations.

Immediate Management Plan

1. IV access — two large-bore cannulae
2. IV fluid resuscitation — 500 mL crystalloid bolus (0.9% NS or Ringer's Lactate), reassess BP and HR
3. Blood cultures × 2 (before antibiotics)
4. Urine culture + sensitivity (midstream clean catch before antibiotics)
5. Empirical IV antibiotics — Ceftriaxone 1g IV or Piperacillin-Tazobactam (for urosepsis/pyelonephritis)
6. Monitor urine output (catheterise if needed)

Summary

Working Diagnosis: Acute Pyelonephritis with early urosepsis in a young woman, presenting with classic loin pain → fever → dark urine triad, now with haemodynamic compromise (HR 125, BP 90/70). Malaria must be urgently excluded given night chills and dark urine.

SIRS — Systemic Inflammatory Response Syndrome

Definition

"SIRS is the result of proinflammatory cytokines related to tissue malperfusion or injury. The dominant cytokines implicated include IL-1, IL-6, and TNF." — Schwartz's Principles of Surgery, 11e

The 4 Classic SIRS Criteria (1992 Bone Criteria)

Applying to the Case (30/04/26)

• SBP 90 mmHg → meets hypotension criterion from the extended Sepsis-2 criteria
• SpO₂ 96% → possible early respiratory compromise

SIRS → Sepsis → Severe Sepsis → Septic Shock Continuum

SIRS (≥2 criteria)
   ↓ + confirmed/suspected infection
SEPSIS
   ↓ + organ hypoperfusion or dysfunction
SEVERE SEPSIS
   ↓ + hypotension despite adequate fluid resuscitation
SEPTIC SHOCK

• Sepsis = SIRS + infection
• Severe Sepsis = Sepsis + signs of cellular hypoperfusion or end-organ dysfunction
• Septic shock = Sepsis + hypotension after adequate fluid resuscitation

In this patient: suspected urinary infection + tachycardia + borderline hypotension (BP 90/70) = Sepsis with features of early septic shock — pending adequate fluid challenge response.

Mortality by SIRS Criteria Count

Sepsis-3 (2016) — The Modern Update

"Life-threatening organ dysfunction caused by a dysregulated host response to infection" Operationalized by a SOFA score increase of ≥2

• Altered mental status
• SBP ≤100 mmHg
• RR ≥22 breaths/min

This patient: SBP 90 mmHg (≤100) = 1 qSOFA point already. If RR ≥22, qSOFA = 2 → sepsis flag.

Key Points

1. SIRS ≠ Sepsis — SIRS is a response; sepsis requires a confirmed/suspected infectious source
2. SIRS ≠ a diagnosis — it is a physiological stratification tool signalling systemic stress
3. This patient has a presumed infectious source (pyelonephritis/urosepsis) + SIRS physiology = Sepsis
4. The urinary tract is the #1 source of sepsis (48.9% of community-onset sepsis cases per Harrison's 22e)
5. Serum lactate should be ordered — levels 2–4 mmol/L carry ~15% 28-day mortality even without hypotension
6. Don't wait for labs — if SIRS + suspected infection + hypotension → start IV fluids + empirical antibiotics now