Treatment Of Hypovolemia Research Articles

Fluid management of the trauma patient

Hemodynamic instability in the trauma patient is most commonly secondary to blood loss and the accumulation of fluid in injured tissue. The etiologies of shock unrelated to hypovolemia must also be investigated. The treatment of hypovolemia in patients with non-cerebral trauma should begin with Ringer's lactate solution. Normal saline (0.9% sodium chloride) is appropriate for patients with head injury, alkalosis, or hyponatremia, but in large volumes may lead to metabolic acidosis. The role of colloids, hypertonic saline, and hemoglobin solutions in trauma resuscitation is unclear at the present time. Base deficit and lactate levels are useful as predictors of morbidity and mortality and can be used to guide resuscitation.

A New Hydroxyethyl Starch: HES 130/0.4 Voluven®

SUMMARYBlood volume is a critical factor in ma in taining hemody namic equilibrium and tissue oxyge nation. In travascular volume is regulated very closely by means of several complex mechanisms, for which the onset of action varies widely. Insome situations, such as acute bleeding, sepsis or with the use of certain drugs, the body must withstand absolute or relative changes in blood volume that cannot be immediately compensated for by the regulatory mechanisms. In these situations, the main goal of volume therapy is to temporarily increase plasma volume until the body's own mechanisms can correct the hypovolemia.Treatment of hypovolemia has changed significantly in recent years. In the past, fresh frozen plasma (FFP) or its equivalent was long the volume expander most commonly used. Now, indications for FFP are limited to the correction of some hemostatic disorders. A by‐product of this legitimate change in practice was increased use of human albumin. Because of the financial consequences of this strategy, several consensus conferences have issued recommendations on the best indications for the use of various plasma volume expanders.Despite these recommendations, the choice of the appropriate agent in the treatment of hypovolemia has not yet been settled. The debate on crystalloid s versus colloids continues, besides a debate on the choice of colloid.

Crystalloids or Colloids for the Treatment of Hypovolemia?

SUMMARYBlood volume is a critical factor in maintaining hemodynamic equilibrium and tissue oxygenation. Intravascular volume is regulated very closely by means of several complex mechanisms, for which the onset of action varies widely. In some situations, such as acute bleeding, sepsis or with the use of certain drugs, the body must withstand absolute or relative changes in blood volume that cannot be immediately compensated for by the regulatory mechanisms. In these situations, the main goal of volume therapy is to temporarily increase plasma volume until the body's own mechanisms can correct the hypovolemia.Treatment of hypovolemia has changed significantly in recent years. In the past, fresh frozen plasma (FFP) or its equivalent was long the volume expander most commonly used. Now, indications for FFP are limited to the correction of some hemostatic disorders. A by‐product of this legitimate change in practice was increased use of human albumin. Because of the financial consequences of this strategy, several consensus conferences have issued recommendations on the best indications for the use of various plasma volume expanders.Despite these recommendations, the choice of the appropriate agent in the treatment of hypovolemia has not yet been settled. The debate on crystalloids versus colloids continues, along with a debate on the choice of colloid.

Problem-based learning in residency education: a novel implementation using a simulator.

We developed a problem-based learning exercise with a full-scale human patient simulator to teach residents the emergency management and differential diagnosis of acute intraoperative hypotension. We developed the exercise through the following steps: clear definition of learning objectives, preparation of an appropriate case stem, development of clinically realistic scenarios to illustrate objectives, and an interactive instructor to stimulate discussion. The exercise focused on the differential diagnosis of intraoperative hypotension, and the acute treatment of hypovolemia, cardiac tamponade, tension pneumothorax, and anaphylaxis. Exercises on a full-scale patient simulator are a natural extension of problem-based learning. Recent research in learning theory provides the rationale for this teaching modality's potential as a learning tool.

Intraoperative administration of Hextend® versus 6% Hetastrach in saline for the treatment of hypovolemia during major surgery: preliminary results of a randomized clinical trial

Hextend® is a new 6% hydroxyethyl starch (mean molecular weight 550 Kd) in a balanced and buffered electrolyte and glucose solution intended for use as a plasma expander. In animal models Hextend® appears to offer significant advantages over currently available alternatives (e.g Hespan®) in terms of acid/base/electrolyte/glucose balance and survival. Hextend can potentially serve as an economical, sterile, physiologically-balanced replacement for blood volume lost subsequent to trauma related bleeding. It may also be used to induce mild to moderate hypothermia in order to prolong survival time during transport to a critical care center. We report here the preliminary results of the on-going phase III study of Hextend®.

The impact of surfactant replacement therapy on cerebral and systemic circulation and lung function.

The influence of surfactant administration on cerebral and systemic circulation and on lung function was evaluated in 12 premature mechanically ventilated infants (mean birth weight 1,560 +/- 770 g, mean gestational age 30.0 +/- 3.2 weeks) with respiratory distress syndrome (RDS) receiving surfactant replacement therapy. We measured mean cerebral blood flow velocity (MCBFV), heart rate (HR), mean arterial pressure (MAP), static compliance (Crs), resistance of respiratory system (Rrs), functional residual capacity (FRC) and fraction of inspired oxygen (FiO2). In addition to a very low compliance and a moderately elevated resistance of the respiratory system a significant drop in MAP, HR, MCBFV and FiO2 was noticed after surfactant administration. After 30 min HR, MAP and MCBFV values returned to baseline levels. We postulate that the drop in MCBFV, MAP, HR and FiO2 with a minor, though not significant improvement of the FRC can most likely be explained by a "relative" hypovolaemia in other organs and parts of the body due to expansion of the lung vascular bed. Compensation for the redistribution of circulatory volume occurred within several minutes. Blood pressure control and treatment of hypovolaemia is mandatory before surfactant is administered. In RDS patients there is a significant drop of MAP, HR, MCBFV and FiO2 after bolus surfactant administration.

DOSE RESPONSE EFFECTS OF HYPERTONIC SALINE AND DEXTRAN ON CARDIOVASCULAR RESPONSES AND PLASMA VOLUME EXPANSION IN SHEEP

Despite the established efficacy of 7.5% NaCl/6% dextran-70 in the treatment of hypovolemia, the optimal formulation of a hyperosmotic/hyperoncotic small volume resuscitation solution has yet to be defined. The present study investigates the cardiovascular effects of hypertonic saline ranging from 3.75%-25% NaCl (HS) and dextran-70 (D-70) ranging from 3 to 24%. HS and D-70 were studied alone or in specific combinations at a dose of 4 mL/kg, in euvolemic sheep. Blood samples were collected before, during and up to 60 min after infusion of the test solutions. Dose-dependent effects of HS were immediate increases in cardiac output (CO) of 30-85%, falling to 10-35% over baseline after 60 min. HS concentrations over 3.75% significantly reduced systemic vascular resistance, but HS had no significant effect on mean arterial pressure (MAP). Plasma volume (PV) expansion with HS was an immediate, but transient increase of 12-35%. Infusion of D-70 induced sustained 10-20% increases in CO and 10-30% increases in PV, peaking 10 min post-infusion. D-70 also resulted in small (5-12 mmHg) increases in MAP. Cardiovascular effects of D-70 correlated with a dose-dependent increase in plasma dextran concentrations. All HS solutions significantly increased plasma Na, which peaked at > or = 200 mEq/L in the 25% group. The effects of D-70 and HS combined were additive on PV expansion and CO. These data indicate that concentrations of HS and D-70 which are higher than those currently used have a greater capability for expanding PV, but use of HS > 7.5% may be limited by resulting hypernatremia.

Usefulness of consensus conferences: the case of albumin

The usefulness of consensus conferences has been questioned. We have assessed the impact of a 1989 consensus conference about the treatment of hypovolaemia on prescribing practice at our hospital. Data available from the blood bank enabled us to follow albumin use and costs by department between 1987 and 1991. Medical journals, direct mail, and meetings were used to disseminate the recommendations of the consensus conference, which were that the only indications for albumin are massive haemorrhage, plasmapheresis, massive hypoalbuminaemia, and volume expansion in pregnancy; for hypovolaemia caused by septic shock or vasoplegia, fluid gelatins and crystalloids should be used. In the year after the conference, and in subsequent years, albumin use and costs were 40% lower than before the conference, even though total medical expenditure continued to rise and numbers of patients admitted did not change. We believe that consensus conferences can be a useful means of improving medical practice. The features that ensured success in this programme were the small number of prescribers, the homogeneous setting, and the frequent restatement of the recommendations.

Acute and subacute toxicity of 7.5% hypertonic saline/6% dextran-70 (HSD) in dogs. 1. Serum immunoglobulin and complement responses.

Clinical use of modern dextran solutions has been limited by concerns of anaphylactoid reactions. To assess the short-term antigenic response to 7.5% hypertonic saline in 6% Dextran-70 (HSD), sera were obtained from dogs involved in the acute and subacute toxicology testing of HSD and its individual components, and analyzed for IgG, IgM and C3 complement. In separate studies, beagles were infused i.v. with a single dose of HSD or its components at 20 ml kg-1 (the maximum tolerated dose; MTD), or the MTD daily for 14 days, and serum was obtained prior to and at various times after infusion up to 14 days. In both studies, despite serum dextran concentrations exceeding 2000 mg dl-1, no induction of IgG, IgM or C3 complement concentrations were observed. In addition, serum IgG immunoelectrophoretic patterns were of normal curvature, position and intensity; the immunoprecipitin bands were not displaced, bowed, inhibited or thicker than the normal preinfusion immunoelectrophoretograms. The data suggest that single or multiple HSD i.v. injections, as much as five times the proposed therapeutic level for the treatment of hypovolemia, evoked no increase in antibody titers in dogs. Therefore, therapeutic use of HSD in the treatment of hemorrhagic shock should not be associated with widespread concomitant allergic complications.

Application of the medical anti-shock trouser (MAST) increases cardiac output and tissue perfusion in simulated, mild hypovolaemia.

We have studied the haemodynamic effects of the application of the medical anti-shock trouser (MAST) in 10 healthy subjects in the semi-upright position in order to simulate mild hypovolaemia. Left ventricular end diastolic dimension (EDD) was measured by M-mode echocardiography and cardiac output (CO) by the Doppler ultrasound technique. Forearm blood flow (FBF) was measured by plethysmography and blood pressure (BP) by the standard cuff technique. Systematic increases in MAST pressure of up to 80 mm Hg were applied. EDD increased to a maximum of 9.3% (p less than or equal to 0.01) which was associated with a maximum increase in CO of 31.7% (p less than or equal to 0.05). FBF increased by a maximum of 54.2% (p less than or equal to 0.001) whilst BP increased by a maximum of 12% (p less than or equal to 0.001). These results demonstrate that the application of the MAST is an effective means of transferring blood to the central circulation by compression of the capacitance vessels resulting in significant increases in cardiac output and tissue perfusion. At high pressures there was evidence of compression of resistance vessels, which may be useful in reducing blood loss. The ease and rapidity with which his suit can be applied suggests that it may be useful in the short term treatment of hypovolaemia.

Hydroxyethyl Starch for Resuscitation of Patients with Hypovolemia and Shock

The authors evaluated the effectiveness of 6% hydroxyethyl starch (hetastarch) solution for treatment of hypovolemia in 46 critically ill patients. Thirty-two of the patients were studied retrospectively and in 14 patients, cardiopulmonary variables were prospectively measured. A total of 29 patients were in shock secondary to hypovolemia (13), sepsis (13), or myocardial infarction (3). Average hetastarch infusion volume was 829 and 842 ml, respectively, in prospectively and retrospectively studied patients, with maximum of 2000-2500 ml infused over 48 h. Approximately 30% of 24 h fluid needs were supplied with colloids. Infusion of 500 ml of hetastarch in 14 prospective study patients was associated with increases in pulmonary artery wedge pressure (WP) from 9 +/- 1.5 to 12 +/- 2.1 mm Hg, cardiac index (CI) from 2.9 +/- 0.2 to 3.5 +/- 0.3 (p less than 0.05) along with an increase in mean arterial pressure (MAP) from 87-99 mm Hg and reduction in arteriovenous O2 difference [C(a-v)O2] from 4.9 to 4.2 ml/dl. Intrapulmonary shunt (Qsp/Qt) was similar (20 vs. 21% as were alveolar-arterial O2 gradient [P(A-a)O2] (164 vs. 158 torr), whereas O2 consumption (VO2) increased from 224 to 247 ml/min. Immediate survival was 90% in shock patients and 100% in nonshock patients, whereas hospital survival was 65.5% and 88%, respectively. The authors conclude that hetastarch is an effective fluid for resuscitation of hypovolemic patients. This synthetic colloid does not appear to adversely affect pulmonary function.

Modern aspects of the use of infusion therapy

The assessment of infusion therapy in the treatment of hypovolemia, conditions accompanied by severe intoxication and requiring long-term parenteral nutrition. Practical recommendations on the tactics of replenishing the volume of circulating blood in operated patients, the choice of infusion-transfusion media for detoxification therapy and parenteral nutrition are presented.

Metabolic Aspects of Hemorrhagic SHOCK: II. Metabolic Studies on the Need for Erythrocytes in the Treatment of Hypovolemia Due to Hemorrhage

Metabolic Aspects of Hemorrhagic SHOCK: II. Metabolic Studies on the Need for Erythrocytes in the Treatment of Hypovolemia Due to Hemorrhage