Effects of resuscitation with crystalloid fluids on cardiac function in patients with severe sepsis

Abstract

Background: The use of hypertonic crystalloid solutions, including sodium chloride and bicarbonate, for treating severe sepsis has been much debated in previous investigations. We have investigated the effects of three crystalloid solutions on fluid resuscitation in severe sepsis patients with hypotension.

Methods: Ninety-four severe sepsis patients with hypotension were randomly assigned to three groups. The patients received the following injections within 15 min at initial treatment: Ns group (n = 32), 5 ml/kg normal saline; Hs group (n = 30), with 5 ml/kg 3.5% sodium chloride; and Sb group (n = 32), 5 ml/kg 5% sodium bicarbonate. Cardiac output (CO), systolic blood pressure, mean arterial pressure (MAP), body temperature, heart rate, respiratory rate and blood gases were measured.

Results: There were no differences among the three groups in CO, MAP, heart rate or respiratory rate during the 120 min trial or the 8 hour follow-up, and no significant differences in observed mortality rate after 28 days. However, improvement of MAP and CO started earlier in the Sb group than in the Ns and Hs groups. Sodium bicarbonate increased the base excess but did not alter blood pH, lactic acid or [HCO3]- values; and neither 3.5% hypertonic saline nor 5% sodium bicarbonate altered the Na+, K+, Ca2+ or Cl- levels.

Conclusion: All three crystalloid solutions may be used for initial volume loading in severe sepsis, and sodium bicarbonate confers a limited benefit on humans with severe sepsis.

Trial registration: ISRCTN36748319.

Figures

Figure 1

Effects of fluid resuscitation on CO in the three groups. The trial program and case grouping were carried out according to the design indicated in Methods. CO was measured by Doppler echocardiography. There were no differences in CO among the three groups at all the six time points. Comparing the CO variables in the same group, CO at T120 and T8h was significantly higher than at T0 in the Ns group; the parameter at T8h was higher than at T0 in the Hs group; and CO at T60, T90, T120 and T8h were higher than that at T0 in the Sb group (*p < 0.05). CO improved earlier in the Sb group than in the Ns and Hs groups.

Figure 2

Effects of fluid resuscitation on MAP in the three groups. MAP in all patients was registered by professional statisticians in the hospitals. There were no differences in MAP among the three groups at all the six time points. Comparing MAP in the same group, MAP at T60, T90, T120 and T8h was significantly higher than that at T0 in the Ns group; the parameter at T90, T120 and T8h was higher than at T0 in the Hs group; and MAP at T30, T60, T90, T120 and T8h were higher than that at T0 in the Sb group (*p < 0.05). MAP increased earlier in the Sb group than in the Ns and Hs groups.

Figure 3

Effects of fluid resuscitation on heart rate in the three groups. Heart rate in all cases was recorded by statisticians. There were no differences in heart rate among the groups during the 120 min trial or the 8 h follow-up. Comparing heart rate in the same group, the heart rate at T8h was lower than that at T0 in the Ns and Sb groups (*p < 0.05), but no change of heart rate appeared in the Hs group. Resuscitation by fluids did not change heart rate in patients during the 120 min trial.

Figure 4

Effects of fluid resuscitation on respiratory rate in the three groups. There were no differences in respiratory rate among the groups during the 120 min trial or the 8 h follow-up. Comparing respiratory rates in the same group, the respiratory rate at T8h was lower than that at T0 in the Sb group (*p < 0.05) only; no change of respiratory rate appeared in the Ns or Hs groups. Resuscitation by fluids did not change the respiratory rate of patients during the 120 min trial.