Outcome predictors of systemic lupus erythematosus requiring admission to the intensive care unit

Table 1 Baseline characteristics of systemic lupus erythematosus patients admitted to the intensive care unit, n (%)

Parameter	All patients (n = 77)	Survivors (n = 38)	Non-survivors (n = 39)	P value
Age (year), mean ± SD	31.1 (10.3)	31.5 (10.2)	30.8 (10.5)	0.76
Female gender	64 (83.1)	32 (84.2)	32 (82.1)	0.8
Diabetes mellitus	6 (7.8)	3 (7.9)	3 (7.7)	0.98
Hypertension	18 (23.4)	13 (34.2)	5 (12.8)	0.03
Newly diagnosed SLE	18 (23.4)	10 (25.6)	8 (20.5)	0.63
Prior treatment	56 (72.7)	28 (73.7)	28 (71.8)	1.0
Drug defaulter	25 (32.5)	14 (36.9)	11 (28.2)	0.42
Duration of disease, median (IQR) months	12 (1-60)	24 (1-48)	12 (0-72)	0.58
SLEDAI (n = 31), median IQR	25.6 (21.0-30.2)	27.5 (21.2-33.8)	21.6 (15.5-27.7)	0.22
APACHE-II (n = 43), median IQR score	16.3 (14.5-18.2)	15.5 (12.7-18.2)	17.1 (14.5-19.7)	0.37
Lag time, median (IQR) days	3 (0-7)	3 (0-7)	2 (0-7)	0.36
Hemodynamic instability	25 (32.5)	9 (23.7)	16 (41)	0.29
Respiratory failure	36 (46.7)	19 (50)	17 (43.9)	0.65
Status epilepticus	11 (14.3)	8 (21.1)	3 (7.7)	0.11
Low GCS	2 (2.6)	1 (2.6)	1 (2.6)	1.0
Hypertensive urgency	1 (1.3)	0	1 (2.6)	1.0
AKI needing dialysis	1 (1.3)	0	1 (2.6)	1.0
Hematemesis	1 (1.3)	1 (2.6)	0	0.49

All values are percentages unless specified. SLE: Systemic lupus erythematosus; SLEDAI: Systemic Lupus Erythematosus Disease Activity Index; APACHE-II: Acute Physiology and Chronic Health Evaluation score; GCS: Glasgow Coma scale; IQR: Interquartile range; AKI: Acute kidney injury.

Table 2 Laboratory investigations at intensive care unit admission

Parameter		All patients (n = 77)	Survivors (n = 38)	Non-survivors (n = 39)	P value
Hemoglobin, g/dL		8.3 (2.2)	8.4 (2.5)	8.4 (2.5)	0.6
Leucocyte count/mm3		9952 (7984)	10647 (9309)	9274 (6493)	0.77
Platelet count, lakhs/mm3		1.52 (1.03)	1.72 (1.17)	1.33 (0.85)	0.10
Serum creatinine, mg/dL		2.12 (2.0)	2.3 (2.3)	1.9 (1.6)	0.38
Serum albumin, g/dL		2.42 (0.67)	2.28 (0.65)	2.56 (0.67)	0.08
Admission pH		7.39 (0.12)	7.38 (0.13)	7.41 (0.12)	0.27
Bicarbonate, mmol/L		18.2 (6)	18.2 (6.7)	18.2 (5.1)	0.98
Admission lactate, median (IQR), mmol/L		1.5 (0.9-2.8)	1.7 (0.8-2.7)	1.4 (1.1-2.9)	0.12
CRP, (n = 49), median (IQR), mg/L		25 (5.6-100)	25 (7.2-124)	24 (4-100)	0.56
Procalcitonin, (n = 45), median (IQR), μg/dL		3.1 (0.38-25)	4.93 (0.72-30.8)	2.43 (0.37-23)	0.59
Low serum C3 (n = 73)		51.4 (30.2)	51.5 (30.6)	51.4 (30.3)	0.99
Low serum C4 (n = 71)		13.3 (8.7)	13.3 (7.7)	3.2 (9.8)	0.94
ANA (n = 60)	0	3	1	2	0.36
	1+	4	4	0
	2+	28	15	13
	3+	18	8	10
	4+	7	3	4
dsDNA (n = 73)		452 (374)	490 (374)	414 (374)	0.39

All values are mean ± SD unless specified. CRP: C-reactive protein; IQR: Interquartile range; ANA: Antinuclear antibody; dsDNA: Double-stranded DNA; n: Indicates the number of patients in whom the data were available.

Table 3 Organ involvement during intensive care unit stay, n (%)

Parameter	All patients (n = 77)	Survivors (n = 38)	Non-survivors (n = 39)	P value
Central nervous system involvement	33 (42.9)	22 (57.9)	11 (28.2)	0.01
Respiratory involvement	72 (93.5)	33 (86.8)	39 (100)	0.03
Shock during the hospital stay	47 (61.0)	10 (26.3)	37 (94.9)	< 0.001
Myocarditis	30 (39.0)	14 (36.8)	16 (41.0)	0.78
Nephritis	61 (79.2)	31 (81.6)	30 (76.9)	0.62
Serositis	19 (24.7)	7 (18.4)	12 (30.8)	0.21
Autoimmune hemolytic anemia	29 (37.7)	14 (36.8)	15 (38.5)	0.88
Diffuse alveolar hemorrhage	11 (14.3)	2 (5.3)	9 (23.1)	0.03

All values in parentheses are percentages unless specified.

Table 4 Treatment and outcomes of patients with systemic lupus erythematosus admitted to the intensive care unit, n (%)

Parameter	All patients (n = 77)	Survivors (n = 38)	Non-survivors (n = 39)	P value
Prior use of steroids	52 (67.5)	27 (71.1)	25 (64.1)	0.52
Steroids during stay	74 (96.1)	37 (97.4)	37 (94.9)	0.57
Pulse steroids	34 (44.2)	19 (50)	15 (38.5)	0.31
Intravenous immunoglobulin	9 (11.7)	3 (7.9)	6 (15.4)	0.31
Plasma exchange	10 (13)	7 (18.4)	3 (7.7)	0.16
Cyclophosphamide	26 (33.8)	19 (50)	7 (18)	0.003
Mycophenolate mofetil	18 (23.4)	12 (31.6)	6 (15.4)	0.09
Biologics	1 (4.5)	1 (2.6)	0	0.32
Respiratory support	72 (93.5)	33 (86.8)	39 (100)	0.03
Invasive ventilation	57 (74)	18 (47.4)	39 (100)	< 0.001
NIV alone	15 (19.4)	15 (100)	0
NIV and Invasive ventilation	38 (49.4)	20 (52.6)	18 (46.2)	0.57
Need for inotropes	41 (51.7)	2 (5.2)	39 (100)	0.001
Renal replacement therapy	25 (32.5)	14 (36.9)	11 (28.2)	0.42
Packed RBC transfusion	57 (74)	26 (68.4)	31 (79.5)	0.27
ICU length of stay	8.1 (7.2)	7.4 (6.2)	8.9 (8.1)	0.36
Hospital length of stay	18.9 (14.3)	22.3 (16.2)	16.5 (11.5)	0.04

All values are percentages unless specified. NIV: Non-invasive ventilation; RBC: Red blood cell; ICU: Intensive care unit.

Table 5 Factors associated with intensive care unit mortality

Parameter	Bivariate analysis OR (95%CI)	P value	Multivariate analysis OR (95%CI)	P value
Age	0.99 (0.95-1.03)	0.76	-	-
Female gender	1.16 (0.35-3.85)	0.8	-	-
Diabetes mellitus	0.97 (0.18- 5.14)	0.98	-	-
Hypertension	0.28 (0.08-0.89)	0.03	0.32 (0.02-4.38)	0.39
Newly diagnosed SLE	1.29 (0.45-3.73)	0.63	-	-
SLEDAI 2K	0.96 (0.89-1.02)	0.23	-	-
Duration of disease	0.99 (0.98-1.00)	0.33	-	-
Drug defaulter	0.67 (0.25-1.75)	0.42	-	-
APACHE-II score	1.04 (0.94-1.16)	0.37	-	-
Lag time	1.04 (0.96-1.13)	0.36	-	-
Shock at admission	3.01 (0.73-12.5)	0.12	-	-
SLE flare	0.55 (0.22-1.54)	0.26	-	-
Sepsis	2.64 (1.03-6.76)	0.04	-	-
Hemoglobin	1.04 (0.84-1.28)	0.60	-	-
Platelet count	0.99 (0.99-1)	0.10	1.0 (1.0-1.0)	0.06
Serum creatinine	0.89 (0.71-1.13)	0.38	-	-
Serum albumin	1.91 (0.92-3.96)	0.08	0.83 (0.26-2.6)	0.75
Admission pH	8.95 (0.18-442)	0.27	-	-
Bicarbonate	0.99 (0.92-1.08)	0.98	-	-
Admission lactate	1.14 (0.95-1.37)	0.12	1.82 (0.95-3.5)	0.07
Anti-nuclear antibody	1.29 (0.74-2.2)	0.36	-	-
Double-stranded DNA	0.99 (0.98-1.01)	0.39	-	-
Non-invasive ventilation	0.77 (0.31-1.88)	0.57	-	-
Shock during the hospital stay	51.8 (10.5-255)	< 0.001	726 (8.0-65088)	0.004
Need for inotropes	5.57 (2.49-12.5)	0.001	-	-
Renal replacement therapy	0.67 (0.25-1.8)	0.42	-	-
Transfusion	1.78 (0.63-5.03)	0.27	-	-
Immunomodulation1	0.77 (0.31-1.88)	0.56	-	-
ICU length of stay	1.03 (0.96-1.10)	0.36	-	-
Hospital length of stay	0.96 (0.92-0.99)	0.04	-	-

¹Immunomodulation included the use of pulse steroids, intravenous immunoglobulins, and/or plasma exchange (n = 42).

OR: Odds ratio; CI: Confidence interval; SLE: Systemic lupus erythematosus; SLEDAI 2K: Systemic Lupus Erythematosus Disease Activity Index 2000; APACHE: Acute Physiology and Chronic Health Evaluation; ICU: Intensive care unit.

Table 6 Summary of studies on systemic lupus erythematosus patients requiring intensive care unit admission

Ref.	Country, study type	No. of patients	Reasons for ICU admission	Mortality (%)	Factors associated with mortality
Current study, 2024	India, retrospective	77	SLE flare (41.6%), infection (57.1%)	50.7	Shock, thrombocytopenia, admission lactate
Bhargav et al[21], 2023	India, retrospective, prospective	102	Pneumonia	81.3	APACHE II > 16, infection, lymphopenia, creatinine > 1.3, hypotension
Gopalan et al[5], 2023	India, retrospective	87	Infection (58%), disease flare (51%)	21	High APACHE II, fever, AKI, low albumin, low hematocrit, low GCS, sepsis, ventilation, inotropes
Aragón et al[10], 2020	Colombia, retrospective	188	Infection	20.2	Higher SOFA, ventilation, inotrope need, APLA
Alvarez Barreneche et al[28], 2019	Colombia, retrospective	33	Lupus flare	12.1	Infection
Fatemi et al[25], 2017	Iran, retrospective	94	Pneumonia, DAH, seizure	50	High APACHE II, septic shock, duration of mechanical ventilation
Siripaitoon et al[34], 2015	Thailand, retrospective	61	Respiratory failure, shock, AKI	57	High APACHE, ventilator-associated pneumonia, inotrope use
Han et al[29], 2013	United States, retrospective	70	Infectious (35.7%) and non-infectious (64.3%)	21.2	Higher APACHE II
Namendys-Silva et al[11], 2009	Mexico, retrospective	104	Infection	32.7	High APACHE II, inotrope use
Hsu et al[15], 2005	Taiwan, retrospective	51	Pneumonia with ARDS	47	Intracranial and GI hemorrhage, septic shock
Williams et al[26], 2002	United Kingdom, retrospective	61	Infection	28	Leucopenia, high severity of illness score, cyclophosphamide

ICU: Intensive care unit; APACHE: Acute Physiology and Chronic Health Evaluation; AKI: Acute kidney injury; GCS: Glasgow coma scale; SOFA: Sequential Organ Failure Assessment; APLA: Anti-phospholipid antibodies; DAH: Diffuse alveolar hemorrhage; ARDS: Acute respiratory distress syndrome; GI: Gastrointestinal.