Table 1.

Unmatched and matched covariates: Propofol versus midazolam

VariableUnmatched CohortMatched Cohort
Propofol (n=8099)Midazolam (n=735)P ValuePropofol (n=698)Midazolam (n=698)P Value
Age (yr)62.2±16.966.1±17.0<0.00165.5±16.566.0±17.20.55
Men5099 (63.0)395 (53.7)<0.001369 (52.9)375 (53.7)0.87
Hypertension2425(29.9)227 (30.9)0.59203 (29.1)215 (30.8)0.48
Diabetes mellitus1597(19.7)179 (24.4)0.003170 (24.4)167 (23.9)0.85
Congestive heart failure1096 (13.5)276 (37.6)<0.001252 (36.1)258 (37.0)0.74
COPD1158 (14.3)199 (27.1)<0.001169 (24.2)185 (26.5)0.33
Liver disease339 (4.2)57 (7.8)<0.00156 (8.0)55 (7.9)0.92
Solid tumors1075 (13.3)132 (18.0)<0.001128 (18.3)123(17.6)0.73
Neurologic conditions 217 (2.7)50 (6.8)<0.00147 (6.7)46 (6.6)0.75
Obesity186 (2.3)17 (2.3)0.9815 (2.1)17(2.4)0.72
Emergency admission 3272 (40.4)439 (59.7)<0.001359 (51.4)372 (53.3)0.52
ICU first service
 Medical2321 (25.9)366 (49.3)<0.001352 (50.4)333 (47.7)0.52
 Surgical4832 (54.0)155 (20.9)131 (18.8)153 (21.9)
 Cardiac care1244 (13.9)207 (27.9)200 (28.7)197 (28.2)
 Cardiac surgery557 (6.2)15 (2.0)15 (2.1)15 (2.1)
Sepsis362 (4.0)192 (25.8)<0.001129 (18.5)153 (21.9)0.11
SAPS on ICU admission16 (13–19)18 (15–21)<0.00117 (14–20)17 (14–19)0.35
Nonrenal SOFA on ICU admission6.5±3.57.2±3.9<0.0017 (4–10)7 (5–10)0.34
Glasgow Coma Scale score6 (3–10)9 (6–14)<0.0017 (3–11)8 (3–12)0.30
Opioid agent3065 (37.8)577(78.5)<0.001555(79.5)573(82.1)0.25
MAP in the first 48 h (mmHg)78.8±9.576.5±10.1<0.00177.4±9.676.7±10.10.33
Need for vasoactive drugs in the first 48 h 4139 (51.8)309 (42.0)<0.001282 (40.4)295 (42.3)0.48
Serum creatinine at ICU admission (mg/dl)0.8 (0.7–1.1)1.2 (0.8–2.0)<0.0011.1 (0.8–1.7)1.2 (0.8–1.9)0.39
Use of nephrotoxic drugs
 Vancomycin5175 (63.9)607 (82.6)<0.001466 (66.8)484 (69.3)0.33
 Aminoglycoside259 (3.2)43 (5.8)0.00153 (7.6)37 (5.3)0.08
 Amphotericin389 (4.9)46 (6.3)0.0954 (7.7)48 (6.9)0.54
Contrast administration1397 (17.2)137 (18.6)0.33128 (18.3)135 (19.3)0.68
Volume infusion in the first 7 d of ICU (ml/d)2179±18892415±19210.0012132±18102196±18240.51
Chloride-rich solution infusion in the first 7 d of ICU stay (ml/d)679±601836±661<0.001638±606669±5070.30
Use of HES148 (1.8)18 (2.4)0.2514(2.0)12 (1.7)0.84
Dependence of mechanical ventilation<0.0010.24
 48 h2219 (27.4)398 (54.1)372 (53.3)366 (52.4)
 7 d1628 (20.1)322 (42.8)271 (38.7)286 (41.0)
  • Data are presented as mean ± SD, n (%), or median (interquartile range). COPD, chronic obstructive pulmonary disease; ICU, intensive care unit; SAPS, Simplified Acute Physiology Score; SOFA, Sequential Organ Failure Assessment; HES, hydroxyethyl starch.