Potassium in hemorrhagic shock: a potential marker of tissue hypoxia.
BACKGROUND
This study was designed to evaluate serum potassium level variation in a porcine model of hemorrhagic shock (HS).


METHODS
Eight pigs were studied in a controlled hemorrhage model of HS. Blood withdrawal began at a 50 mL/min to 70 mL/min rate, adjusted to reach a mean arterial pressure (MAP) level of 60 mm Hg in 10 minutes. When MAP reached 60 mm Hg, the blood withdrawal rate was adjusted to maintain a MAP decrease rate of 10 mm Hg every 2 minutes to 4 minutes. Arterial and mixed venous blood samples were collected at MAP levels of 60 mm Hg, 50 mm Hg, 40 mm Hg, 30 mm Hg, 20 mm Hg, and 10 mm Hg and analyzed for oxygen saturation, Po2, Pco2, potassium, lactate, bicarbonate, hemoglobin, pH, and standard base excess.


RESULTS
Significant increase in serum potassium occurred early in all animals. The rate of rise in serum potassium and its levels accompanied the hemodynamic deterioration. Hyperkalemia (K >5 mmol/L) incidence was 12.5% at 60 mm Hg and 50 mm Hg, 62.5% at 40 mm Hg, 87.5% at 30 mm Hg, and 100% at 20 mm Hg. Strong correlations were found between potassium levels and lactate (R = 0.82), SvO2 (R = 0.87), DeltapH (R = 0.83), and DeltaPco2 (R = 0.82).


CONCLUSIONS
Serum potassium increase accompanies the onset of HS. The rise in serum potassium was directly related to the hemodynamic deterioration of HS and strongly correlated with markers of tissue hypoxia.
Divisão de Anestesia, Hospital das Clínicas da Faculdade de Medicina da USP, Avenida Dr. Enéas de Carvalho Aguiar, São Paulo, SP, Brazil. joelrocha@me.com
Joel Avancini
JA
Rocha Filho
Ricardo S
RS
Nani
Luiz A C
LA
D'Albuquerque
Luíz M S
LM
Malbouisson
Maria J C
MJ
Carmona
Mauricio
M
Rocha-E-Silva
José O C
JO
Auler
D000704:Analysis of Variance; D000818:Animals; D015415:Biomarkers / Q000097:blood; D006801:Humans; D006947:Hyperkalemia / Q000097:blood; D000860:Hypoxia / Q000097:blood*; D008297:Male; D011188:Potassium / Q000097:blood*; D012771:Shock, Hemorrhagic / Q000097:blood*; D013552:Swine
D015415:Biomarkers; D011188:Potassium