Plasma volume during stress in man: osmolality and red cell volume

1999

ABSTRACT. The effect of an intravenous (IV) infusion of hypertonic saline solution (HSS; 7.2%, 2,400 mOsmol/kg·H 2 O) was evaluated by serum electrolyte concentrations and osmotic pressure in the anesthetized beagles. Sixteen beagles were assigned to 3 experimental groups (2.5, 5 or 15 ml/kg of HSS IV infusion) or a control group (5 ml/kg of isotonic saline solution (ISS) IV infusion) and were monitored for 120 min after the initiation of fluid infusion. The relative plasma volume (rPV) in the 5 ml/kg and 15 ml/kg HSS groups progressively expanded to 143.1 ± 7.4% at 3 min and 156.4 ± 5.9% at 5 min after the initiation of the fluid infusion, respectively. Significant increases were not produced by ISS and 2.5 ml/kg HSS infusion. The serum sodium and chloride concentrations in the ISS group were not altered. The 5 ml/kg HSS infusion induced transient high osmotic and sodium levels, and the serum sodium concentration remained under the 160 mM/l after the completion of the HSS infusion. However, the 15 ml/kg HSS infusion induced a constant high osmotic level (340.5-352.8 mOsmol/kg·H 2 O) and hypernatremia (161.4-174.5 mM/l) from 10 to 90 min after the initiation of the fluid infusion. The 15 ml/kg HSS infusion induced significant decreases in the partial pressure of oxygen (PaO 2 ), reaching 63.7 ± 8.0 mmHg at 120 min after the initiation of the fluid infusion compared with an immediately before fluid infusion value. On the basis of these findings, 5 ml/kg HSS infusion can be safely administered to healthy beagles for expanding the plasma volume without inducing hypernatremia. A 5 ml/kg HSS infusion is thus recommended for the initial field resuscitation of dogs.-KEY WORDS: arterial blood pressure, canine (beagle), hypernatremia, hypertonic saline solution, plasma volume.

Section: Resultsmentioning

confidence: 95%

“…Changes in the relative plasma volume (rPV) were calculated from Hb and Ht, using accepted formulas [7,[18][19][20]. The serum osmotic pressure was determined by the freezing point depression method, using a one-ten osmometer (Fiske Association, Norwood, MA, U.S.A.).…”

Section: Methodsmentioning

confidence: 99%

Effect of Intravenous Infusion of a 7.2% Hypertonic Saline Solution on Serum Electrolytes and Osmotic Pressure in Healthy Beagles.

Ajito

1999

“…Some venous blood samples were used to determine the hemoglobin concentration (Hb) and hematocrit value (Ht) with an automatic cell counter (MEK-6248: Nihon Koden). Changes in the relative plasma volume (rPV) were calculated from Hb and Ht, with accepted formulas [5,21]. Relative changes in base excess (rBE) were derived from the following equation: rBE = BE samp -BE pre , where BE samp and BE pre were BE concentrations in each sampling and pre point, respectively.…”

Section: Methodsmentioning

confidence: 99%

Evaluation of Isotonic Sodium Bicarbonate Solution for Alkalizing Effects in Conscious Calves.

Abe

et al. 2002

ABSTRACT. After intravenous (IV) infusion of various volumes of 1.35%-isotonic sodium bicarbonate solution (ISB), acid-base equilibrium, blood pressure, plasma volume and biochemical parameters in healthy Holstein calves were studied. Four calves each were randomly assigned to the low-dose (LD; IV infusion of 5 ml/kg ISB), middle-dose (MD; IV infusion of 10 ml/kg ISB) and the high-dose groups (HD; IV infusion of 15 ml/kg ISB). Administration volumes of ISB in the LD, MD and HD groups were decided based on the first half volumes of 5, 10 and 15 mEq of base requirement by the acceptable equation. Systemic, pulmonary artery and central venous pressures, cardiac output and plasma osmotic pressure were not changed by ISB infusion and remained constant throughout the experiment for all groups. There was good correlation ( r 2 = 0.950) between relative changes in base excess and infused volume of bicarbonate (y=2.491x). The coefficient of distribution for bicarbonate ions was calculated to be 0.401 (=1/2.491). Therefore, it is suggested that a value of 0.4 would be most appropriate when calculating the base requirements in calves. Therefore, the first half volumes of ISB correcting base deficits of 5, 10 and 15 mEq in calves were estimated to be 6, 12 and 18 ml/kg, respectively. On the basis of the findings in this study, ISB may be used to correct metabolic acidosis without altering the plasma osmotic pressure, hemodynamic status and respiratory function in the calves. KEY WORDS: acid-base equilibrium, calf, coefficient of distribution, metabolic acidosis, sodium bicarbonate.

“…The relative changes in plasma volume (rPV) were calculated from the Hb and Ht, using the accepted formula [7]. The serum osmotic pressure was determined by the freezing point depression method, using a One-Ten Osmometer (Fiske Associate, Norwood, MA, U.S.A.).…”

Section: Methodsmentioning

confidence: 99%

“…Figure 2 shows the sequenial changes in the serum sodium, potassium and chloride concentrations in the heifers and serum osmotic pressure caused by fluid infusion in the heifers. The rPV values were calculated from Hb and Ht, using Greenleaf's formulas [7]. Levels of significance (p<0.05) indicated: a: ISS versus 5 ml/kg-HSS, b: ISS versus 15ml/kg-HSS and c: 5 ml/kg-versus 15 ml/kg-HSS.…”

Section: Methodsmentioning

confidence: 99%

Effect of a 7.2% Hypertonic Saline Solution Infusion on Arterial Blood Pressure, Serum Sodium Concentration and Osmotic Pressure in Normovolemic Heifers.

Ajito

1998

ABSTRACT. The effects of an intravenous (iv) infusion of a small volume (5 ml/kg) or large volume (15 ml/kg) of hypertonic saline solution (HSS; 7.2%, 2,400 mOsmol/kg·H 2 O) and those of an iv infusion of 5 ml/kg isotonic saline solution (ISS; 300 mOsmol/kg·H 2 O) on plasma volume, arterial blood pressure, serum sodium concentrations and osmotic pressure were investigated in conscious heifers. Nine heifers (3 heifers/group) were monitored for 120 min after the initiation of fluid replacement. The relative plasma volume (rPV) in the 5 ml/kg HSS and 15 ml/kg HSS progressively increased to 137.7 ± 2.4% at t=5 min and 145.2 ± 5.4% at t=15 min, respectively. The expanding plasma volume in the 5 ml/kg HSS group remained at an up to 10% higher level until 120 min, but not in the 15 ml/kg HSS group. The 5 ml/kg HSS infusion induced transit high-osmotic (305.3 ± 4.0 mOsmol/kg·H 2 O) and sodium levels (155.7 ± 3.5 mM/l) at t=5 min. However, the 15 ml/kg HSS infusion induced constant high-osmotic level (321.7-336.7 mOsmol/kg·H 2 O) and hypernatremia (162.8-170.0 mM/l) from t=10 min to the rest of the experiment period. In the ISS and 5 ml/kg HSS groups, no changes in PaO 2 were observed. The 15 ml/kg HSS infusion induced a significant decrease in the partial pressure of oxygen at the t=30 min compared to the t=0 min values. On the basis of these findings, a small volume (5 ml/kg) HSS infusion can be rapidly and safely administered to cattle for expanding the plasma volume without inducing hypernatremia. A 5 ml/kg HSS infusion is thus recommended for the initial field resuscitation of cattle. -KEY WORDS: heifer, hypernatremia, hypertonic saline solution, plasma volume, serum osmotic pressure.