Critical care in hematopoietic stem cell transplantation: Common complications and management

Table 1 Epidemiology and outcomes of intensive care unit admission following hematopoietic stem cell transplantation

Parameter	Autologous HSCT	Allogeneic HSCT	Overall
ICU admission rate	3.3%-8%	16%-30%	8.8%-23%
Timing of ICU admission
Early (Days 0-30)	Conditioning toxicity, engraftment syndrome	Conditioning toxicity, SOS, early infections	25%-40% of admissions
Intermediate (Days 31-100)	Infections	Acute GVHD, infections, TA-TMA	30%-45% of admissions
Late (> 100 days)	Late effects	Chronic GVHD, opportunistic infections, BOS	20%-35% of admissions
Primary indications
Respiratory failure	30%-50%	50%-70%	40%-70%
Sepsis/septic shock	25%-40%	35%-50%	30%-50%
Neurological complications	5%-10%	10%-20%	8%-15%
Organ support requirements
Mechanical ventilation	25%-35%	35%-55%	38%
Vasopressor support	20%-30%	30%-50%	25%-45%
Renal replacement therapy	5%-10%	15%-25%	10%-20%
Survival outcomes
ICU survival (30-day)	70%-85%	55%-70%	57.7%
Hospital survival	65%-80%	45%-65%	> 60%
1-year survival	55%-70%	30%-50%	35%-55%

HSCT: Hematopoietic stem cell transplantation; ICU: Intensive care unit; GVHD: Graft-versus-host disease; TA-TMA: Transplant-associated thrombotic microangiopathy.

Table 2 Major complications requiring intensive care unit support: Diagnosis and management

Complication	Incidence	Timing	Diagnostic criteria	First-line management	Established/emerging therapies	Mortality
ARDS	> 15% (allo)	Variable	Berlin criteria + LIPS-BMT score	Low TV ventilation, PEEP optimization	Prone positioning, ECMO	50%-70%
Idiopathic pneumonia syndrome	3.7%	Median 19 days	Multilobar infiltrates, no infection	High-dose steroids	Etanercept (established, multiple trials); JAK inhibitors (emerging, limited data)	Variable
Diffuse alveolar hemorrhage	3%-10%	Median 30 days	Progressive bloody BAL, bilateral infiltrates	Supportive care	Inhaled TXA ± rFVIIa protocols show promise; RCT data limited	56% at day 100
Neutropenic sepsis	Up to 50%	Days 0-30	Fever + ANC < 500	Broad-spectrum antibiotics within 1 hour	Combination therapy for severe sepsis/shock	42.2%
CMV pneumonia	< 6% with prophylaxis	Days 30-100	High viral burden in BAL with clinical-radiologic correlation	Ganciclovir/valganciclovir + IVIG	Resistance monitoring, maribavir for resistant	60%-80%
Invasive aspergillosis	5%-15% (allo)	Variable	Galactomannan + CT findings	Voriconazole or isavuconazole	Combination therapy under investigation	50%-80%
Acute GVHD	39% grade II-IV	Median day 34	Clinical ± biopsy; MAGIC biomarkers (ST2, REG3α)	High-dose steroids	JAK inhibitors (ruxolitinib FDA-approved)	> 50% severe
Sinusoidal obstruction syndrome	5%-60%	Median day 13	EBMT 2023 criteria	Supportive care	Defibrotide (FDA-approved)	20%-80% severe
TA-TMA	10%-40% (allo)	Median 86 days	Clinical + lab criteria	Withdraw/reduce CNI	Complement inhibition (eculizumab)	30%-60%
Engraftment syndrome	10%-20% auto, 35% allo	During engraftment	Fever, weight gain, infiltrates, rash	Supportive care	Steroids for severe cases	5%-15%

HSCT: Hematopoietic stem cell transplantation; ICU: Intensive care unit; SOS: Sinusoidal obstruction syndrome; GVHD: Graft-versus-host disease; TA-TMA: Transplant-associated thrombotic microangiopathy; BOS: Bronchiolitis obliterans syndrome; ARDS: Acute respiratory distress syndrome; LIPS-BMT: Lung Injury Prevention Score for Bone Marrow Transplant; TV: Tidal volume; PEEP: Positive end-expiratory pressure; ECMO: Extracorporeal membrane oxygenation; BAL: Bronchoalveolar lavage; TXA: Tranexamic acid; rFVIIa: Recombinant activated factor VII; RCT: Randomized controlled trial; ANC: Absolute neutrophil count; CMV: Cytomegalovirus; IVIG: Intravenous immunoglobulin; CT: Computed tomography; MAGIC: Mount Sinai Acute GVHD International Consortium; EBMT: European Society for Blood and Marrow Transplantation; CNI: Calcineurin inhibitor; FDA: Food and Drug Administration.