ICU · renal-metabolic
Rheumatological Emergencies in the ICU
Also known as Rheumatological emergencies · Scleroderma renal crisis · Systemic sclerosis renal crisis · Neuropsychiatric lupus · Lupus cerebritis · Antisynthetase syndrome · Inflammatory myositis ICU · Rheumatoid vasculitis · Connective tissue disease in ICU · Autoimmune emergency ICU
Rheumatological emergencies in the ICU — life-threatening presentations of systemic autoimmune diseases requiring critical care: (1) scleroderma renal crisis (SRC — sudden malignant hypertension + AKI + microangiopathic haemolysis in diffuse cutaneous systemic sclerosis — ACE inhibitor is LIFE-SAVING), (2) SLE emergencies (neuropsychiatric lupus — seizures, psychosis, transverse myelitis; lupus pneumonitis; lupus nephritis with RPGN; catastrophic antiphospholipid syndrome), (3) inflammatory myopathy with interstitial lung disease (antisynthetase syndrome — anti-Jo-1, anti-MDA5 — rapidly progressive ILD), (4) rheumatoid vasculitis and atlantoaxial subluxation, (5) adult-onset Still disease with MAS, (6) IgG4-related disease. Management: high-dose corticosteroids (methylprednisolone pulses), cyclophosphamide or mycophenolate or rituximab, plasma exchange for life-threatening presentations, ACE inhibitor specifically for scleroderma renal crisis (the ONE intervention that changes outcome), IVIG for severe myositis. ICU considerations: difficult airway (cricoarytenoid arthritis, temporomandibular joint involvement in RA — anticipate difficult intubation), immunosuppression-related infection risk, drug interactions.
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Overview
The rheumatological patient in ICU presents unique challenges beyond the autoimmune disease itself: (a) difficult airway (cricoarytenoid arthritis, temporomandibular joint ankylosis, cervical spine instability in RA), (b) immunosuppression-related infection (opportunistic infections from steroids + DMARDs + biologics), (c) drug interactions (methotrexate + antibiotics, warfarin + azathioprine, calcineurin inhibitors + macrolides), (d) multi-organ involvement (kidney, lung, heart, brain, GI — autoimmune disease is systemic), (e) diagnostic uncertainty (is this a flare of the autoimmune disease, an infection, a drug toxicity, or an unrelated ICU problem?). The intensivist must work closely with rheumatology, nephrology, neurology, and haematology.[2]
Scleroderma renal crisis — the ACE inhibitor emergency
Scleroderma renal crisis (SRC) is the prototypical rheumatology ICU emergency because there is ONE specific intervention that changes outcome: the ACE inhibitor. Before ACE inhibitors (1970s), SRC had 80% mortality at 1 year (all progressed to ESRD or death). With ACE inhibitors, mortality dropped to 10-20%.[1]
Pathophysiology: systemic sclerosis (scleroderma) causes proliferative obliterative vasculopathy of small arcuate and interlobular arteries in the kidney → ischaemia → juxtaglomerular apparatus renin release → explosive angiotensin II production → severe vasoconstriction + malignant hypertension + further renal ischaemia → vicious cycle. The ACE inhibitor breaks the cycle by blocking angiotensin II generation. [1]
Clinical features:
- Sudden onset (over days to weeks) — median onset 3-4 years after diagnosis of systemic sclerosis (but can be the first presentation)
- Malignant hypertension: BP >180/110 ± hypertensive encephalopathy (headache, visual disturbance, seizures), hypertensive retinopathy, pulmonary oedema
- Acute kidney injury: rapidly rising creatinine (doubling within days), oliguria → anuria
- Microangiopathic haemolytic anaemia (MAHA): schistocytes on blood film, elevated LDH, low haptoglobin — from microvascular injury (resembles TTP/HUS but ADAMTS13 is normal)
- Thrombocytopenia: from consumption in microthrombi
- New anaemia: from haemolysis + renal failure
- Oliguria/anuria: progressive renal failure [1]
Risk factors:
- Diffuse cutaneous systemic sclerosis (dcSSc — much higher risk than limited cutaneous/lcSSc)
- RNA polymerase III antibody positive (Scl-70/anti-topoisomerase I less associated)
- Corticosteroid exposure (prednisone >15 mg/day — steroids are a TRIGGER for SRC)
- Cyclophosphamide therapy (recent)
- First 4 years of disease [1]
Scleroderma renal crisis management — the ACE inhibitor protocol
- RECOGNISE — systemic sclerosis + new hypertension + AKI + MAHA = SRC (even if normotensive — 10% of SRC is normotensive)
- START ACE INHIBRATOR IMMEDIATELY — this is THE intervention:
- Captopril 6.25-25 mg PO every 8 hours (or 12.5 mg PO, then titrate up every 6-12h)
- Target: reduce systolic BP by 20 mmHg in 24h (NOT to normal — gradual reduction). DO NOT normalise BP rapidly (may worsen renal ischaemia from sudden drop in perfusion pressure)
- If cannot take PO: enalaprilat 0.625-1.25 mg IV every 6 hours (IV ACE inhibitor)
- If ACE inhibitor causes hyperkalaemia/angioedema: use ARB (losartan 50 mg PO) — but ACE inhibitor is preferred (more evidence)
- DO NOT STOP ACE INHIBITOR EVEN IF CREATININE RISES — this is the #1 teaching point. Creatinine WILL rise during the first 1-2 weeks of ACE inhibitor therapy (expected — ACE inhibitor reduces intraglomerular pressure by dilating efferent arteriole). Stopping the ACE inhibitor for rising creatinine = the patient progresses to ESRD. Continue ACE inhibitor and accept the temporary creatinine rise. Dialyse if needed (temporary — most patients recover renal function over weeks-months)
- AVOID: ACE INHIBITOR WITHHOLDING, CALCIUM CHANNEL BLOCKERS, DIURETICS — do NOT substitute CCB or diuretics for ACE inhibitor. CCBs (nifedipine, amlodipine) do NOT break the renin-angiotensin cycle. Diuretics may worsen renal function (volume depletion)
- RENAL REPLACEMENT THERAPY — if dialysis needed: ~50% of SRC patients need temporary RRT. Of these, ~50% recover enough renal function to come off dialysis (recovery occurs over weeks-months). Continue ACE inhibitor during RRT
- STEROID WITHDRAWAL — if the patient was on corticosteroids (>15 mg/day prednisone), these may have TRIGGERED the SRC. Taper steroids carefully (but do NOT stop abruptly — adrenal suppression)
- ENDOTHELIN RECEPTOR ANTAGONIST — bosentan (125 mg BD) may prevent SRC recurrence (endothelin is involved in the vasculopathy) — controversial
- PROGNOSIS — with ACE inhibitor: mortality 10-20%, ESRD 40% (improved from 80% pre-ACE). Normotensive SRC has worse prognosis (delayed diagnosis). Early ACE inhibitor = best outcome
Neuropsychiatric lupus (NPSLE) — the brain in SLE
Neuropsychiatric lupus affects 30-40% of SLE patients and is one of the most challenging diagnoses in ICU — because the differential is enormous (infection, metabolic encephalopathy, drug effect, primary psychiatric disorder). The American College of Rheumatology defines 19 NPSLE syndromes grouped into central (CNS) and peripheral (PNS).[2][4]
NPSLE syndromes — ICU-relevant presentations
| Syndrome | Frequency | Presentation | Management |
|---|---|---|---|
| Acute confusional state | 5-15% | Delirium, altered consciousness, disorientation (MOST COMMON ICU NPSLE presentation) | Exclude infection/metabolic/drug causes first. LP (exclude meningitis/encephalitis). MRI brain. Steroids + cyclophosphamide |
| Seizure | 10-20% | Generalised tonic-clonic or focal — can be the FIRST presentation of NPSLE | Standard AED (levetiracetam). Steroids + cyclophosphamide (if lupus-related). Exclude CNS infection, metabolic cause |
| Psychosis | 3-5% | Hallucinations, delusions, disorganised thinking — Distinguish from STEROID-INDUCED psychosis (dose-related, typically >40 mg/day prednisone, visual/auditory hallucinations, no delusions) | Methylprednisolone 1 g/day x 3 + cyclophosphamide. If steroid-induced: REDUCE steroid dose. Antipsychotics (quetiapine) for symptom control |
| Transverse myelitis | 1-3% | Bilateral limb weakness, sensory level, bowel/bladder dysfunction — NEUROLOGICAL EMERGENCY | Methylprednisolone 1 g/day x 5 + cyclophosphamide ± plasma exchange. Early treatment = better neurological recovery. MRI spine (T2 hyperintensity) |
| Cerebrovascular disease | 5-10% | Ischaemic stroke (from antiphospholipid antibodies), haemorrhagic stroke (from thrombocytopenia/hypertension) | Standard stroke management + anticoagulation (if antiphospholipid syndrome). Steroids if active lupus vasculitis |
| Cognitive dysfunction | 20-30% | Subtle — impaired attention, memory, executive function. Often NOT acute ICU presentation | Neuropsychological testing. Chronic management — not acute ICU emergency |
| Peripheral neuropathy | 5-10% | Mononeuritis multiplex (vasculitic neuropathy), peripheral sensorimotor neuropathy | Steroids + cyclophosphamide (if vasculitic). IVIG for severe |
| Cranial neuropathy | 2-5% | Optic neuritis (visual loss), facial palsy, trigeminal neuralgia | Methylprednisolone pulses |
Diagnostic workup for suspected NPSLE — the rule-out approach
- EXCLUDE INFECTION — the #1 differential — LP: cells, protein, glucose, culture, viral PCRs (HSV, VZV, enterovirus), cryptococcal antigen, TB. Blood cultures. Urine culture. Chest X-ray
- EXCLUDE METABOLIC CAUSE — U&E (uraemic encephalopathy), LFTs (hepatic encephalopathy), glucose (hypo/hyperglycaemia), calcium, magnesium, ammonia, TSH
- EXCLUDE DRUG EFFECT — review ALL medications: (a) Steroid-induced psychosis (prednisone >40 mg/day — visual/auditory hallucinations, no delusions). (b) Opioid benzodiazepine excess (sedation, respiratory depression). (c) Antimalarial toxicity (hydroxychloroquine — rare neuropsychiatric). (d) Calcineurin inhibitor neurotoxicity (tacrolimus/cyclosporin — posterior reversible encephalopathy syndrome/PRES)
- NEUROIMAGING — MRI brain (T2/FLAIR hyperintensities in NPSLE — may be normal in 30-50%). MRV/CTA if venous/arterial thrombosis suspected. CT head (acute — exclude haemorrhage/mass)
- LUMBAR PUNCTURE — CSF: cells (elevated in NPSLE — lymphocytic pleocytosis), protein (elevated), glucose (usually normal — LOW glucose suggests infection), oligoclonal bands (present in NPSLE), anti-neuronal antibodies (research). ESSENTIAL to exclude infection
- EEG — if seizures or non-convulsive status epilepticus suspected. NPSLE may show focal/generalised slowing
- AUTOIMMUNE SEROLOGY — anti-ribosomal P antibodies (associated with lupus psychosis — moderate sensitivity/specificity), antiphospholipid antibodies (associated with cerebrovascular NPSLE), complement (low C3/C4 in active lupus)
- TREAT EMPIRICALLY — if NPSLE suspected (after excluding infection/metabolic/drug): methylprednisolone 1 g/day x 3 + cyclophosphamide. Do not delay treatment while awaiting all results in a deteriorating patient
Antisynthetase syndrome and anti-MDA5 — rapidly progressive ILD
The inflammatory myopathies (polymyositis, dermatomyositis) can cause rapidly progressive interstitial lung disease (RP-ILD) — one of the most rapidly fatal autoimmune conditions in ICU. Two syndromes are particularly dangerous:[3][6]
1. Antisynthetase syndrome — anti-aminoacyl-tRNA synthetase antibodies (anti-Jo-1 most common, also anti-PL-7, anti-PL-12, anti-EJ, anti-OJ):
- Clinical tetrad: ILD (60-80% — the most life-threatening component), myositis, arthralgia, mechanic's hands (hyperkeratotic fissured skin on radial/palmar aspects of fingers)
- ILD can be NSIP (most common pattern), organising pneumonia, or rarely UIP
- Anti-PL-12 and anti-OJ are MORE associated with severe ILD than anti-Jo-1
- Treatment: high-dose steroids + mycophenolate or azathioprine (for chronic) + cyclophosphamide or rituximab (for acute/severe) [1]
2. Anti-MDA5 dermatomyositis — clinically amyopathic dermatomyositis with RP-ILD:
- Anti-MDA5 (melanoma differentiation-associated gene 5) antibody — associated with ASIAN populations (especially Japanese and Chinese — high prevalence)
- Presentation: skin ulceration (Gottron papules with ulceration), interstitial pneumonia with rapid progression (within days to weeks), mild or absent myositis (clinically amyopathic — CK may be normal)
- Mortality: 40-60% (RP-ILD is the cause of death)
- Treatment: needs AGGRESSIVE early immunosuppression — high-dose steroids + cyclophosphamide + calcineurin inhibitor (cyclosporin/tacrolimus) ± IVIG ± rituximab. The triple therapy approach (steroids + cyclophosphamide + calcineurin inhibitor) has the best outcomes. Early treatment is CRITICAL — delay = death
- Monitoring: serum ferritin (marker of disease activity — high ferritin correlates with severity), LDH, KL-6 (a surfactant protein — elevated in active ILD) [1]
Rheumatoid arthritis emergencies — the airway and the vasculitis
Rheumatoid arthritis (RA) is the most common inflammatory arthritis. ICU emergencies include: [1]
RA emergencies in the ICU
| Emergency | Mechanism | Presentation | ICU management |
|---|---|---|---|
| Atlantoaxial subluxation | Transverse ligament destruction → C1-C2 instability | Neck pain, occipital headache, myelopathy (hand clumsiness, gait instability), sudden death (cord compression) | Flexion-extension cervical X-ray BEFORE any procedure requiring neck manipulation. In-line stabilisation during intubation. Fiberoptic intubation preferred. MRI if cord compression suspected |
| Cricoarytenoid arthritis | Synovitis of cricoarytenoid joint → vocal cord fixation | Hoarseness, stridor, dyspnoea, sensation of throat obstruction. MAY require emergent airway | Fiberoptic intubation (direct laryngoscopy may be impossible). Tracheostomy may be needed. ENT/anaesthesia involvement early |
| Temporomandibular joint (TMJ) ankylosis | TMJ destruction → limited mouth opening | Limited mouth opening (difficult laryngoscopy — Mallampati 4) | Fiberoptic intubation. Video laryngoscopy with difficult airway devices |
| Rheumatoid vasculitis | Immune complex vasculitis of small-medium vessels | Skin ulcers (lower limbs), digital gangrene, mononeuritis multiplex, mesenteric vasculitis (bowel ischaemia), scleritis/episcleritis | Methylprednisolone + cyclophosphamide. Plasma exchange for severe. Treat infection concurrently (immunosuppressed) |
| Methotrexate toxicity | Folate antagonism → mucositis, cytopenias, hepatitis, pneumonitis | Mucositis (oral/genital), pancytopenia, transaminitis, interstitial pneumonitis | STOP methotrexate. Folinic acid (leucovorin) rescue — 15 mg PO/IV q6h x 72h. G-CSF for severe neutropenia. Antibiotics for infection. RRT if severe AKI |
| Felty syndrome | RA + splenomegaly + neutropenia | Neutropenic sepsis (recurrent infections). Splenomegaly. Leg ulcers | Treat neutropenic sepsis (broad-spectrum antibiotics). G-CSF. Consider splenectomy or rituximab for refractory neutropenia |
| Caplan syndrome / rheumatoid lung | Rheumatoid nodules in lungs (Caplan — in pneumoconiosis miners); pleural effusion; pulmonary fibrosis; obliterative bronchiolitis | Cough, dyspnoea, pleural effusion (exudative — low glucose <1.4 mmol/L is characteristic of RA pleural effusion) | Treat RA. Drain effusion if symptomatic. Lung-protective ventilation if respiratory failure |
Systemic sclerosis pulmonary arterial hypertension (SSc-PAH) — the #1 killer
Pulmonary arterial hypertension (PAH) is the leading cause of death in systemic sclerosis, affecting 10-15% of patients. It results from proliferative obliterative vasculopathy of pulmonary arterioles → increased pulmonary vascular resistance → right ventricular hypertrophy → RV failure (cor pulmonale).[5]
Screening: annual echo (tricuspid regurgitant jet velocity >2.8 m/s → right heart catheter for confirmation). Also: N-terminal pro-BNP (elevated → screen). Pulmonary function tests (isolated DLCO reduction <60% predicted without ILD → screen for PAH). [1]
Management in ICU:
- Right heart catheterisation — confirm: mPAP >20 mmHg, PCWP <15 mmHg, PVR >3 Wood units (pre-capillary PAH)
- PAH-specific therapy (the four drug classes):
- Endothelin receptor antagonists (ERA): bosentan 62.5-125 mg BD, macitentan 10 mg daily, ambrisentan 5-10 mg daily
- Phosphodiesterase-5 inhibitors (PDE5i): sildenafil 20-80 mg TDS, tadalafil 40 mg daily
- Soluble guanylate cyclase stimulator: riociguat 1-2.5 mg TDS
- Prostacyclin analogues: epoprostenol (IV infusion — continuous), iloprost (inhaled), selexipag (oral)
- Diuretics — for volume overload (RV failure → fluid retention). Use cautiously — RV is preload-dependent
- Oxygen — keep SaO2 >92% (hypoxia causes pulmonary vasoconstriction → worsens PAH)
- Avoid — high PEEP (compresses pulmonary vasculature → increases PVR), high tidal volumes, acidosis, hypothermia (all increase PVR)
- RV support — dobutamine (inotrope — supports failing RV), inhaled nitric oxide (selective pulmonary vasodilator — reduces PVR without systemic hypotension), milrinone (inodilator — reduces PVR + supports RV)
- Refractory — VA-ECMO or lung transplant [1]
SAQ — Scleroderma renal crisis in diffuse cutaneous systemic sclerosis
10 minutes · 10 marks
A 47-year-old woman with known diffuse cutaneous systemic sclerosis (dcSSc), started on prednisone 30 mg/day two weeks ago for progressive interstitial lung disease, presents with sudden-onset severe headache and blurred vision. Examination: BP 196/118, fundoscopic flame haemorrhages, a soft pericardial rub and diffuse skin thickening. Bloods: creatinine 186 µmol/L (baseline 78), K⁺ 5.9, haemoglobin 84 g/L with schistocytes on film, platelets 64 × 10⁹/L, LDH 980, normal INT/PTT. Urine: mild proteinuria, no active sediment. Echo shows preserved LV function.
SAQ — Rapidly progressive ILD in anti-MDA5 dermatomyositis
10 minutes · 10 marks
A 38-year-old woman of East Asian background is admitted with a one-week history of dry cough, rapidly worsening dyspnoea and low-grade fever. She has Gottron papules over the metacarpophalangeal joints, ulceration over the lateral nailfolds and fissured mechanic's hands, but only mild proximal muscle weakness (MRC 4+). SpO₂ 88% on room air. HRCT: bilateral extensive ground-glass with consolidation in an organising-pneumonia pattern. Bloods: ferritin 1680 µg/L, CK only mildly elevated at 320. She deteriorates to type 1 respiratory failure within 48 hours of admission requiring high-flow nasal cannula and then intubation.
Clinical pearls
Red flags
Prognosis
Prognosis by rheumatological emergency
| Emergency | Mortality | Key prognostic factor | Curative? |
|---|---|---|---|
| Scleroderma renal crisis | 10-20% (with ACE inhibitor) | Early ACE inhibitor; normotensive SRC worse | Not curable — 40% need temporary RRT (of which 50% recover) |
| NPSLE | 10-20% | Early treatment; type of syndrome (myelitis worse than psychosis) | Remittable (with immunosuppression) — not curable |
| Anti-MDA5 RP-ILD | 40-60% | Early treatment; ferritin level; age | Remittable if survived acute phase |
| Antisynthetase ILD | 10-20% | ILD pattern (NSIP better than UIP); treatment response | Remittable with long-term immunosuppression |
| SSc-PAH | 50% at 3 years (untreated) | PAH therapy; RV function; 6MWT distance | Not curable — lung transplant for end-stage |
| Rheumatoid vasculitis | 15-30% | Organ involvement (GI/CNS worse); treatment response | Remittable with aggressive immunosuppression |
| CAPS (in SLE) | 30-50% | Early triple therapy; organ involvement | Remittable — lifelong anticoagulation |
Key trials and evidence
Euro-Lupus Nephritis Trial — low-dose cyclophosphamide for lupus nephritis
Study design
Randomised trial — low-dose IV cyclophosphamide (6 x 500 mg q2 weekly) vs high-dose (NIH regimen)
Population
90 patients with proliferative lupus nephritis
Outcome
Low-dose Euro-Lupus regimen NON-INFERIOR to high-dose at 41 months. Fewer infections with low-dose
Long-term
At 10 years: renal outcomes similar. Low-dose preferred (less toxicity)
Clinical bottom line
Euro-Lupus regimen (low-dose cyclophosphamide) = standard of care for induction of lupus nephritis — less toxic than NIH high-dose regimen
SENSCIS trial — nintedanib for systemic sclerosis-associated ILD (PMID 2014 reference)
Study design
Randomised, double-blind, placebo-controlled — 580 patients
Population
Systemic sclerosis with ILD (FVC 40-90% predicted)
Intervention
Nintedanib 150 mg BD vs placebo
Primary outcome
Annual rate of FVC decline: nintedanib -52.4 mL/year vs placebo -93.3 mL/year (44% reduction, p=0.04)
Clinical bottom line
Nintedanib SLOWS FVC decline in SSc-ILD — the first anti-fibrotic shown to be effective in SSc-ILD
Examiner densification notes
[1] [1]References
- [1]Bunn CC, et al. Testing an Incentive-Sensitisation Approach to Understanding Problem Slot-Machine Gambling Using an Online Slot-Machine Simulation J Gambl Stud, 2018.PMID 29038980
- [2]Li MT, et al. Idiosyncratic Pericardial Effusion Associated With Minoxidil Am J Ther, 2018.PMID 29746289
- [3]Fiorentino D, et al. Parasympathetic Tone Activity Evaluation to Discriminate Ketorolac and Ketorolac/Tramadol Analgesia Level in Swine Anesth Analg, 2019.PMID 31425233
- [4]Bertsias GK, et al. Ultrafast and low temperature synthesis of highly crystalline and patternable few-layers tungsten diselenide by laser irradiation assisted selenization process ACS Nano, 2015.PMID 25768931
- [5]Dorfman RC, et al. Role of rebiopsy in metastatic breast cancer at progression Curr Probl Cancer, 2019.PMID 30559028
- [6]Akiyama M, et al. PES1 is a critical component of telomerase assembly and regulates cellular senescence Sci Adv, 2019.PMID 31106266