Negative Troponin in Chest Pain - What It Means

A single negative troponin does NOT rule out ACS

"A single standard troponin on presentation has limited value in excluding AMI in the first hours of symptom onset."

• Rosen's Emergency Medicine

What to do next: Serial testing is required

• Repeat troponin at 3-6 hours from the first draw (or from symptom onset)
• Look for a rising and/or falling pattern (the "delta"), with at least one value above the 99th percentile - this is what diagnoses MI, not a single result

• ESC recommends a 1-hour serial protocol for patients presenting >3 hours from symptom onset - two negative results allow discharge
• A very low or undetectable hs-cTn at presentation alone may rule out acute MI in lower-risk patients presenting >3 hours from onset, but this requires assay-specific cutoffs and validation
• Sensitivity for 30-day MACE exceeds 99% when combined with a non-ischemic ECG and low HEART score

Key caveats

After two negative troponins (low-risk patients)

• Harrison's Principles of Internal Medicine 22E, p. 151
• Rosen's Emergency Medicine, Chap. 64

2-Month-Old with 7 Days of Constipation - Exclusively Breastfed

Step 1: Is This Actually Constipation?

"Stooling once a week or eight times per day may be normal if the clinical history and physical examination are also normal."

• Tintinalli's Emergency Medicine

• Infrequent but soft stools = likely normal breastfed pattern
• Hard, painful stools with straining, abdominal distension, or failure to thrive = pathological

Step 2: Differential Diagnosis - Red Flags to Rule Out

Step 3: History to Gather

• Did the baby pass meconium within 24-48 hours of birth? (Key for Hirschsprung)
• What is the stool consistency when it does come?
• Any abdominal distension?
• Is the baby feeding well and gaining weight?
• Any weakness, poor cry, or hypotonia? (Botulism)
• Any honey exposure? (Botulism risk)
• What did the newborn screening show?
• Is the baby otherwise well and active?

Step 4: Examination

• Weight - is the baby growing appropriately?
• Abdomen - distension, palpable stool mass?
• Anus - inspect for position, patency, stenosis
• Digital rectal exam (DRE) - may reveal tight sphincter; explosive "squirt sign" passage of stool suggests Hirschsprung
• Muscle tone - hypotonia suggests botulism or hypothyroidism
• Thyroid - enlarged?

Step 5: Investigation

1. Plain abdominal X-ray - stool burden, bowel dilation, air-fluid levels
2. Contrast enema (barium) - narrowed aganglionic segment with proximal dilation suggests Hirschsprung; also excludes meconium plug and intestinal atresia
3. Rectal biopsy - gold standard for Hirschsprung (suction biopsy at bedside in this age group; must be taken ≥1 cm above the dentate line)
4. TSH / Free T4 - hypothyroidism
5. Stool for C. botulinum toxin/spores - if botulism suspected

Step 6: Management

• Reassure - this is likely a normal breastfed stool pattern
• No dietary changes needed (do not supplement or switch from breast milk)
• No laxatives needed at this age
• Review in 2 weeks; return if child becomes unwell or develops hard stools, distension, poor feeding, or weakness

• Refer to pediatric gastroenterology
• Hirschsprung confirmed: rectal irrigations with warm NS while awaiting surgical pull-through
• Acute obstruction: rectal tube decompression, IV fluids, surgical consult
• Botulism: supportive care, consider BabyBIG (botulinum immune globulin) - administered early, proven to shorten hospitalization

Bottom Line

• Tintinalli's Emergency Medicine, Chap. 9 (Neonatal Assessment)
• Rosen's Emergency Medicine, Chap. 30 (Hirschsprung Disease)
• Sabiston Textbook of Surgery, Chap. 28 (Hirschsprung Disease)

Management: Right Proximal Ureteral Calculus with Mild Hydroureteronephrosis + Incidental Calcified Hepatic Granuloma

First: Assess for Urgent Decompression (The Critical Step)

Immediate Assessment (ED / First Contact)

1. Urine - urinalysis, urine culture (mandatory before any intervention)
2. Blood - FBC, CMP (creatinine, electrolytes), CRP/WBC
3. Imaging - CT KUB already done; note the stone size - this drives the management decision
4. Stone density on CT (HU) - helps predict likelihood of passage and ESWL success

Pain Management (Immediate)

• NSAIDs are first-line (e.g., diclofenac 75 mg IM/IV or ketorolac 30 mg IV) - superior to opioids for renal colic, reduce ureteral spasm, and decrease ureteral edema
• Opioids (morphine, pethidine) as second-line if NSAIDs are contraindicated (e.g., renal impairment, GI bleed)
• Antiemetic (metoclopramide or ondansetron) as needed
• IV fluids if dehydrated; do not force IV fluids to "flush the stone" - no evidence of benefit

Definitive Management - Driven by Stone Size

Medical Expulsive Therapy (MET)

• Alpha-blocker: Tamsulosin 0.4 mg once daily for 4 weeks
• Mechanism: relaxes ureteral smooth muscle, reduces ureteral spasm, facilitates passage
• Most effective for distal ureteral stones - evidence for proximal ureter is weaker but still used
• According to 2025 EAU Guidelines: alpha-blockers may be considered for selected patients with ureteral stones
• Note: The 2015 SUSPEND trial challenged MET benefit for proximal stones; however, the 2025 EAU and 2026 AUA guidelines still recommend it as an option, especially for stones ≤10 mm

Active Surgical Removal Options

• Non-invasive; preferred for proximal ureteral stones ≤10-15 mm in many centres
• Success rate ~70-80% for proximal ureteral stones
• May need repeat sessions; contraindicated in pregnancy, coagulopathy, uncontrolled UTI, aortic aneurysm near stone

• Preferred for stones >10 mm, ESWL failures, or when rapid clearance is needed
• Holmium:YAG laser fragmentation (or thulium fiber laser - newer)
• Higher single-procedure stone-free rate than ESWL (~90%)
• Requires general/regional anesthesia; risk of ureteral injury, stricture
• AUA Guideline 2026: ureteroscopy is appropriate first-line for most ureteral stones

• Reserved for large proximal stones >20 mm or complex anatomy
• Not typically first-line for a proximal ureteral stone

Indications for Urgent Ureteral Stent or Nephrostomy

• Fever / signs of sepsis (obstructed infected kidney = emergency)
• Solitary kidney
• Bilateral ureteral obstruction
• Acute kidney injury / rising creatinine
• Intractable pain not controlled with analgesia

Follow-Up Plan

• Strain urine to collect the stone for composition analysis
• Repeat imaging at 4 weeks if conservative management chosen - to confirm passage and resolution of hydronephrosis
• If stone has not passed at 4 weeks → proceed to ESWL or ureteroscopy
• Metabolic workup after first stone episode: 24-hour urine (calcium, oxalate, uric acid, citrate, creatinine), serum calcium, PTH if hypercalcemia - to prevent recurrence
• Increase fluid intake to target urine output >2 L/day
• Dietary advice: reduce sodium and protein intake; maintain normal calcium intake

Regarding the Calcified Hepatic Granuloma (Segment 7)

• Histoplasma capsulatum (most common worldwide)
• Mycobacterium tuberculosis (prior TB)
• Echinococcus (hydatid cyst - if patient from endemic area)
• Other fungal or parasitic infections (e.g., Aspergillus, Coccidioides)

• Complete calcification with no soft tissue component
• Stable appearance (if prior imaging available)
• No symptoms attributable to it
• No surrounding inflammation or satellite lesions

• No treatment required in an immunocompetent patient with a simple, completely calcified, single granuloma
• If the patient is from a TB-endemic region or has risk factors - check IGRA/tuberculin test and chest X-ray to ensure latent TB has not been missed
• If there is any doubt about the nature of the lesion (e.g., partial calcification, heterogeneous appearance, patient is immunocompromised) - MRI liver with contrast can characterize it further
• Document it in the notes as an incidental finding so future clinicians do not investigate it repeatedly

Summary Algorithm

Obstructed Right Proximal Ureteral Stone
         ↓
Fever / Sepsis / Rising Cr?
    YES → Emergency stent or nephrostomy → treat infection → interval stone removal
    NO  ↓
Stone size?
    ≤10 mm → MET (tamsulosin) + analgesia → review at 4 weeks
    >10 mm → ESWL (if available) or URS + laser lithotripsy
         ↓
After clearance → Metabolic workup + dietary/fluid advice to prevent recurrence

• Clinical Anesthesia (Barash 9e) - Urolithiasis management & stone types
• AUA Guideline 2026 - Surgical Management of Kidney and Ureteral Stones (PMID 41263323)
• EAU Guidelines 2025 - Urolithiasis (PMID 40268592)

8.5 x 6.4 mm Proximal Ureteral Stone - Specific Management

The Key Numbers

"Spontaneous passage rates are 12%, 22%, and 45% for proximal, middle, and distal ureteral calculi, respectively, and 55%, 35%, and 8% for stones smaller than 4 mm, 4 to 6 mm, and larger than 6 mm."

• Brenner & Rector's The Kidney

Immediate Management (same day)

1. Pain control - NSAIDs first line (diclofenac 75 mg IM or ketorolac 30 mg IV); opioids if NSAIDs contraindicated
2. Urine culture - mandatory before any intervention
3. Bloods - creatinine, FBC, CRP
4. Check for fever/sepsis - if present → emergency ureteral stent or nephrostomy tube first, before any definitive stone treatment
5. Hydration - IV fluids if dehydrated; avoid forced diuresis

Why MET Alone Is Not Enough Here

• MET (tamsulosin 0.4 mg/day) is most beneficial for stones >5 mm by reducing ureteral spasm and expulsion time
• However, at 8.5 mm, the stone is wider than the normal ureteral lumen - it physically cannot pass regardless of how relaxed the ureter is
• MET can be used as an adjunct while awaiting definitive intervention, but should not be relied upon as the sole treatment

Recommended Definitive Treatment

Option 1: Ureteroscopy (URS) + Holmium Laser Lithotripsy - Preferred

• Highest single-procedure stone-free rate: ~85-95%
• Recommended by both AUA 2026 and EAU 2025 guidelines for proximal ureteral stones, especially >10 mm (and strongly considered for 8-10 mm given low spontaneous passage probability)
• Procedure: flexible/semi-rigid ureteroscope passed retrograde up the ureter; laser fragments stone; fragments passed or basket-extracted
• A temporary ureteral stent (JJ stent) is usually placed for 1-2 weeks afterwards to prevent ureteral edema/obstruction
• Requires general or spinal anesthesia

Option 2: Extracorporeal Shock Wave Lithotripsy (ESWL)

• Non-invasive; can be done under sedation/analgesia
• Stone-free rate for proximal ureteral stones ~60-75% - lower than URS
• May need repeat sessions (2-3 sessions common)
• Stone must be radio-opaque and accessible to shock wave targeting
• Not ideal if the stone is impacted or if there is significant hydronephrosis (poor drainage to flush fragments)
• Contraindicated in: pregnancy, coagulopathy, active UTI, aortic aneurysm adjacent to stone

Option 3: Percutaneous Nephrolithotomy (PCNL)

• Not first-line for a ureteral stone this size
• Reserved for stones >20 mm, failed URS/ESWL, or anatomical reasons preventing retrograde access

Practical Decision - URS vs ESWL

Post-Intervention Plan

• Remove JJ stent at 4-6 weeks post-URS
• Repeat CT/ultrasound to confirm stone clearance and resolution of hydronephrosis
• Metabolic workup to prevent recurrence:
  • 24-hour urine: calcium, oxalate, uric acid, citrate, creatinine, volume
  • Serum: calcium, uric acid, PTH (if calcium elevated)
• Lifestyle: fluid intake to achieve urine output >2 L/day; reduce dietary sodium, reduce animal protein, normal calcium intake

Summary

• No emergency decompression needed
• No urosepsis - safe to plan semi-elective intervention
• Kidney is still functioning despite mild hydronephrosis - no urgency to operate tonight

Revised Management Plan - Afebrile, Normal Creatinine, 8.5 mm Proximal Stone

What This Confirms

ED Disposition Right Now

• If pain is controlled with analgesia and patient can tolerate oral intake → discharge home with:
  • Oral analgesia: NSAID (ibuprofen 400 mg TDS or diclofenac 50 mg TDS with food) + paracetamol 1g QDS
  • Tamsulosin 0.4 mg once daily at night - reduces ureteral spasm, improves comfort while awaiting procedure
  • Urine strainer to collect stone if it passes
  • Urology outpatient appointment within 1-2 weeks
  • Clear return instructions: fever, rigors, worsening pain, vomiting, inability to take fluids → return immediately
• If pain is uncontrolled or patient is vomiting → admit for IV analgesia and monitoring

Definitive Plan: Semi-Urgent Ureteroscopy

• Planned within 1-2 weeks (not an emergency, but should not be delayed beyond 4 weeks as prolonged obstruction risks ureteral stricture and progressive renal damage)
• Semi-rigid or flexible ureteroscope retrograde into proximal ureter
• Laser fragmentation of the 8.5 mm stone
• JJ stent placed at end of procedure → removed 4-6 weeks later in clinic

• Spontaneous passage rate for 8.5 mm proximal stone is <5-8%
• Prolonged partial obstruction → risk of ureteral stricture, progressive hydronephrosis, eventual renal impairment
• The mild hydronephrosis already indicates the kidney is under pressure

• ESWL is an option, but for a proximal stone of this size with existing hydronephrosis, stone fragments may not drain well after fragmentation → risk of steinstrasse (stone street blockage)
• URS gives a higher single-procedure success and immediately relieves obstruction
• Either is acceptable if URS expertise or equipment is unavailable - ESWL would then be a reasonable alternative

Instructions to Give the Patient Before Going Home

1. Drink 2-3 litres of fluid per day - keeps urine flowing
2. Take medications as prescribed - do not skip the tamsulosin
3. Strain all urine through a coffee filter or stone strainer - if the stone passes, bring it to the lab for analysis
4. Return immediately if: fever above 38°C, chills/rigors, severe pain not controlled by tablets, inability to keep fluids down, reduced urine output
5. Keep the urology appointment - the stone will need to be removed

Summary in One Line

Afebrile + normal creatinine = stable patient, no emergency decompression needed → discharge with analgesia + tamsulosin → semi-urgent URS + laser lithotripsy within 1-2 weeks.

Drug Review for This Case

1. Ultracet (Tramadol 37.5 mg + Paracetamol 325 mg) ✅ Reasonable

• NSAIDs (diclofenac, ketorolac) are actually superior to opioids for renal colic - they reduce ureteral prostaglandin-mediated spasm and inflammation directly at the site
• Tramadol causes nausea/vomiting in many patients - already a common complaint in renal colic
• If NSAIDs are not contraindicated (GFR is normal here), adding an NSAID like diclofenac 50 mg TDS would give better pain control and address the ureteral spasm mechanism more directly

2. Urispas (Flavoxate 200 mg) ⚠️ Questionable for This Indication

• Flavoxate's primary evidence base is for bladder spasm (urgency, frequency, dysuria from cystitis or post-procedure)
• Evidence for its benefit in ureteral colic is weak - it does not relax the ureter as effectively as alpha-blockers
• For ureteral spasm specifically, tamsulosin (alpha-1 blocker) is far better evidenced - it relaxes the smooth muscle of the distal ureter and has proven benefit in stone passage and symptom control
• The 2025 EAU and 2026 AUA guidelines do not include flavoxate in ureteral stone protocols

3. Citralka (Sodium Citrate + Citric Acid - Alkaline Syrup) ✅ Partially Useful

• Reduce the burning/irritation of hematuria
• Potentially dissolve uric acid stones (which dissolve in alkaline urine)
• Reduce urinary acidity during active stone passage

• The stone composition is unknown at this point (CT cannot tell composition)
• Citralka/citrate is a reasonable empirical choice - it relieves dysuria, and if the stone is uric acid, it may help dissolve it
• However, at 8.5 mm, even uric acid stone dissolution with citrate alone takes weeks to months - this stone needs mechanical removal regardless

What's Missing / What to Add

Summary

Recommended Prescription

1. Diclofenac 50 mg TDS (after food) × 5 days

2. Tamsulosin 0.4 mg OD at night × 4 weeks

3. Ultracet TDS × 5 days (as needed / rescue)

4. Citralka syrup 10 ml TDS in water × 2 weeks ✅ Keep

5. Pantoprazole 40 mg OD (morning, before food)

6. Ondansetron 4 mg TDS OR Metoclopramide 10 mg TDS × 3-5 days

You Can Stop Urispas

Complete Summary Card

Non-Drug Instructions (equally important)

• Drink 2.5-3 litres of fluid/day - water is the best medicine for stones
• Strain urine to collect the stone if it passes
• Return immediately if fever develops - infected obstructed kidney is an emergency
• Urology appointment within 1-2 weeks - 8.5 mm stone needs ureteroscopy

High Fever (103°F / 39.4°C) - New Patient - Systematic Approach

What You've Already Ruled Out Clinically

Remaining Differential - Most Likely Causes of Isolated High Fever

• Most common cause of high isolated fever in tropical countries
• Can present with ZERO localizing signs
• Fever may be intermittent (quotidian in P. vivax, tertian in P. falciparum)
• Must exclude in any febrile patient in a malaria-endemic area

• Sustained high fever (stepladder pattern), relative bradycardia, rose spots (often absent)
• Soft abdomen is consistent - abdominal tenderness comes later
• No diarrhea early; constipation more common initially

• Sudden high fever, severe myalgia/retro-orbital pain, headache
• Rash appears day 3-5 (maculopapular)
• Thrombocytopenia is classic
• No dysuria, clear chest - fits perfectly

• Myalgia, headache, malaise, upper respiratory symptoms
• Especially if sick contacts or seasonal illness

• Hidden focus: endocarditis (especially if history of dental work, IVDU, valvular disease), sinusitis, deep abscess
• Check for subtle signs: new murmur, lymphadenopathy, skin lesions

• Can present WITHOUT dysuria, WITHOUT loin tenderness, especially early
• Urine culture may be positive with no urinary symptoms
• Do not dismiss just because there's no dysuria

• Any new medications in past 1-4 weeks?
• Diagnosis of exclusion - temperature usually 38.5-40°C, relatively well-looking patient

Immediate Investigations (Before Starting Treatment)

• Chest X-ray (if respiratory symptoms develop or diagnosis unclear)
• Dengue IgM/IgG (if NS1 negative but dengue suspected)
• Thick film repeat at 12-24 hours if first smear negative but malaria suspected

Immediate Symptomatic Treatment (While Awaiting Results)

• First-line antipyretic - safe, well-tolerated
• Do NOT use aspirin (thrombocytopenia risk if dengue)
• NSAIDs should be avoided until dengue excluded (bleeding risk)

• Signs of dehydration (tachycardia, dry mucous membranes, decreased urine output)
• Unable to tolerate oral fluids due to vomiting
• Start with NS or Ringer's lactate 500 ml over 2-4 hours

• Tepid sponging
• Fan, cool environment
• Encourage oral fluids

When to Start Empirical Treatment

Red Flags - Admit Immediately if Any Present

• Altered consciousness / confusion
• Hypotension (SBP <90 mmHg)
• HR >120, RR >25
• Platelets <50,000 (dengue hemorrhagic fever)
• Parasitemia >2% (severe malaria)
• Jaundice + fever (leptospirosis, severe malaria, hepatitis)

Bottom Line

103°F fever with no localizing signs = investigate first, treat the diagnosis - not the fever. Paracetamol for comfort now, blood cultures + peripheral smear + CBC + dengue NS1 urgently. Do NOT give antibiotics blind without cultures unless the patient is septic.

1. Peripheral blood smear for malaria
2. CBC + platelets (dengue pattern)
3. Blood cultures (typhoid/bacteremia)
4. Urine culture (silent pyelonephritis)