Increasing mean arterial pressure in patients with septic shock: effects on oxygen variables and renal function.
OBJECTIVE
To measure the effects of increasing mean arterial pressure on oxygen variables and renal function in septic shock.


METHODS
Prospective, open-label, randomized, controlled study.


METHODS
Medical-surgical intensive care unit of a tertiary care teaching hospital.


METHODS
Twenty-eight patients with a diagnosis of septic shock who required fluid resuscitation and pressor agents to increase and maintain mean arterial pressure > or =60 mm Hg.


METHODS
Patients were treated with fluid and norepinephrine to achieve and maintain a mean arterial pressure of 65 mm Hg. Then they were randomized in two groups: In the first group (control group, n = 14), mean arterial pressure was maintained at 65 mm Hg, and in the second group (n = 14), mean arterial pressure was increased to 85 mm Hg by increasing the dose of norepinephrine.


RESULTS
Hemodynamic variables (mean arterial pressure, heart rate, mean pulmonary artery pressure, pulmonary artery occlusion pressure, cardiac index, systemic vascular resistance index, pulmonary vascular resistance index, left and right ventricular stroke indexes), metabolic variables (oxygen delivery, oxygen consumption-calorimetric method, arterial lactate), and renal function variables (urine flow, serum creatinine, creatinine clearance) were measured. After introduction of norepinephrine, similar values of hemodynamic, metabolic, and renal function variables were obtained in both groups. No changes were observed in group 1 during the study period. Increasing mean arterial pressure from 65 to 85 mm Hg with norepinephrine in group 2 resulted in a significant increase in cardiac index from 4.8 (3.8-6.0) to 5.8 (4.3-6.9) L.min.m. Arterial lactate and oxygen consumption did not change. No changes were observed in renal function variables: urine flow, 63 (14-127) and 70 (15-121) mL; serum creatinine, 170 (117-333) and 153 (112-310) mumol.L; and creatinine clearance, 50 (12-77) and 67 (13-89) mL.min.1.73 m.


CONCLUSIONS
Increasing mean arterial pressure from 65 to 85 mm Hg with norepinephrine neither affects metabolic variables nor improves renal function.
Bourgoin
Aurélie
A
Department of Intensive Care Medicine and Trauma Center, Hospital Nord, 13915 Marseille Cedex 20, France.
Leone
Marc
M
Delmas
Anne
A
Garnier
Franck
F
Albanèse
Jacques
J
Martin
Claude
C
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure / Q000502:physiology; D003404:Creatinine / Q000378:metabolism; D005260:Female; D006801:Humans; D006973:Hypertension / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology; D007022:Hypotension / Q000209:etiology* / Q000503:physiopathology*; D007668:Kidney / Q000503:physiopathology*; D019344:Lactic Acid / Q000097:blood; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption / Q000502:physiology; D011446:Prospective Studies; D012772:Shock, Septic / Q000150:complications* / Q000378:metabolism / Q000503:physiopathology*; D014556:Urine / Q000502:physiology
D019344:Lactic Acid; D003404:Creatinine; D010100:Oxygen; D009638:Norepinephrine