Can base excess and anion gap predict lactate level in diagnosis of septic shock?

Figures & data

Table 1 Baseline characteristics of septic shock patients (n = 115)

Variables	n (%)
Male	70 (61)
Age (years), median (IQR)	66 (52–80)
BW (kg), median (IQR)	60 (54–65)
Height (cm), median (IQR)	166 (164.5–169)
Comorbidities
Hypertension	46 (40)
Malignancy	24 (20.9)
Diabetes mellitus	23 (20)
Ischemic heart disease	23 (20)
CKD	22 (19.1)
Cerebrovascular disease	7 (6.1)
Liver disease	5 (4.3)
Connective tissue disease	4 (3.5)
HIV/AIDs	3 (2.6)
Respiratory disease	3 (2.6)
Others	3 (2.6)
Source of infection
Respiratory disease	40 (34.8)
Urinary tract	20 (17.4)
Gastrointestinal tract	18 (15.7)
Skin and soft tissue	9 (7.8)
Hepatobiliary tract	6 (5.2)
Others	86 (74.8)
Positive blood cultures	32 (27.8)
Organisms identified in blood cultures
Escherichia coli	15 (46.8)
Staphylococcus aureus	4 (12.5)
Acinetobacter baumannii	3 (9.3)
Others	10 (31.2)
Hemodynamics during diagnosis septic shock
MAP (mmHg), median (IQR)	69 (62–70)
HR (bpm), median (IQR)	112 (103–122)
RR (bpm), median (IQR)	22 (22–28)
Previous IV fluid (mL), median (IQR)	2,000 (2,000–3,000)
Patients received vasoactive agent(s)^a	115 (100)
Norepinephrine dose (mg/kg/min), median (IQR)	0.2 (0.1–0.2)
SOFA, median (IQR)	9 (8–11)
LOS (days), median (IQR)	15 (8–24)
Mechanical ventilation (days), median (IQR)	4(2–8)
ICU LOS (day), median (IQR)	5 (2–10)
Ward LOS(day), median (IQR)	10 (3–17.5)
In-hospital mortality	51 (44.3)
28-day mortality	44 (38.3)
Discharged home	60 (52.2)

Notes: Data are presented as n (%) unless indicated otherwise. ^aAll patients received norepinephrine and one patient received both norepinephrine and dopamine.

Abbreviations: IQR, interquartile range; BW, body weight; CKD, chronic kidney disease; HIV/AIDS, human immunodeficiency virus/acquired immunodeficiency syndrome; MAP, mean arterial pressure; HR, heart rate; RR, respiratory rate; IV, intravenous; ICU, intensive care unit; LOS, length of stay; SOFA, Sepsis-related Organ Failure Assessment.

Table 2 Biomarkers

Parameters	Mean (SD)
Lactate level (mmol/L), median (IQR)	3.5 (1.7–6.2)
SBE	-8.3 (6.7)
Sodium level (mEq/L)	137.2 (6.6)
Chloride level (mEq/L)	99.9 (7.8)
Bicarbonate level (mEq/L)	18.7 (5.6)
Albumin (g/dL) (mEq/L)	2.7 (0.7)
AG^a, median (IQR)	16.7 (14.2–22.1)
Albumin-corrected AG^b, median (IQR)	17.2 (14.7–22.3)
Positive urine ketones^c, n (%)	10 (8.7)

Notes: Data are presented as mean (SD) unless indicated otherwise. ^aAG values were calculated by (Na+-Cl^–-HCO₃^–). ^bAlbumin-corrected AG values were calculated by ([4 - albumin] × 2.5 + AG). ^cUrine ketones were measured in 83 patients. Only two patients had serum ketones measured, and the results were positive.

Abbreviations: AG, anion gap; IQR, interquartile range; SBE, standard base excess.

Figure 1 (AߝC) Correlation of serum lactate to BE, AG, and corrected AG.

Abbreviations: AG, anion gap; BE, base excess.

Figure 2 (AߝD) ROC curves of AG and BE for prediction of lactate level ࣙ2 and ࣙ4 mmol/L.

Abbreviations: AG, anion gap; AUC, area under the curve; BE, base excess; ROC, receiver operating characteristic; Sens, sensitivity; Spec, specificity.