Initial resuscitation fluid management
Background
Penetrating versus blunt injury versus head injuries
Clear fluid resuscitation
Blood and blood products
Hemoglobin solutions
Monitoring coagulopathy
Laboratory value | Interpretation | Blood product transfusion |
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R time <4 min | Enzymatic hypercoagulability | Do not treat if bleeding |
R time >11 min | Low clotting factors | FDP/FFP’s and RBC’s |
Alpha angle >45 degrees | Low fibrinogen levels | Cryoprecipitate/fibrinogen/platelets |
MA <54 mm | Low platelet function | Platelets/cryoprecipitate/fibrinogen |
MA >73 mm | Platelet hypercoagulability | Do not treat if bleeding |
LY30 >3% | Primary fibrinolysis | Tranexamic acid 1 g IV over 10 min then 1 g/250 ml NS over 8 h |
CI <1.0 |
Post-resuscitation fluid management
Background
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Hemostasis and correction of coagulopathy (ongoing blood product replacement no longer required) [45].
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Evidence of improving microcirculatory flow (for example, improving lactate and blood gas parameters) [45].
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Hemodynamic stability (systolic blood pressure >100 mmHg with a mean arterial blood pressure of >65 mmHg in most cases; no longer need for inotropic or vasopressor support; an improving pulse rate in the presence of appropriate analgesia).
Resuscitation phase (R) |
Salvage or rescue treatment with fluids administered quickly as a bolus (4 mL/kg over 10–15 min) |
The goal is early adequate goal-directed fluid management (EAFM), fluid balance must be positive, and the suggested resuscitation targets are: MAP > 65 mm Hg, CI > 2.5 L/min/m2, PPV < 12%, LVEDAI > 8 cm/m2
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Optimization phase (O) |
Occurs within hours |
Ischemia and reperfusion |
Degree of positive fluid balance may be a marker of severity in this phase |
Risk of polycompartment syndrome |
Unstable, compensated shock state requiring titrating of fluids to cardiac output |
Targets: MAP > 65 mm Hg, CI > 2.5 L/min/m2, PPV < 14%, LVEDAI 8−12 cm/m2, IAP (<15 mm Hg) are monitored, and APP (>55 mm Hg) is calculated. Preload optimized with GEDVI 640—800 mL/m2
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Stabilization phase (S) |
Evolves over days |
Fluid therapy only for normal maintenance and replacement |
Absence of shock or threat of shock |
Monitor daily body weight, fluid balance and organ function |
Targets: neutral or negative fluid balance; EVLWI < 10−12 mL/kg PBW, PVPI < 2.5, IAP < 15 mm Hg, APP > 55 mm Hg, COP > 16−18 mm Hg and CLI < 60 |
Evacuation phase (E) |
Patients who do not transition from the “ebb” phase of shock to the “flow” phase after the “second hit” develop global increased permeability syndrome (GIPS) |
Fluid overload causes end-organ dysfunction |
Requires late goal-directed fluid removal (“de-resuscitation”) to achieve negative fluid balance |
Need to avoid over-enthusiastic fluid removal resulting in hypovolemia |
Maintenance fluid
Assessing volume status
Fluid responsiveness
The respiratory variation of hemodynamic signals
Other markers
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The passive leg raise (PLR) test carries an excellent ability to serve as a test of preload responsiveness, demonstrated in patients with acute circulatory failure [71, 72]. A 10–12% increase in cardiac output or stroke volume during PLR enables prediction of fluid responsiveness, even patients with cardiac arrhythmias and/or spontaneous ventilator triggering [73]. However, in conditions of increased IAP and pain, the PLR may result in a false negative [55, 74].
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Ultrasonography: This bedside modality has advantages of repeatability, being noninvasive, with the ability to assess dynamic changes in the inferior vena cava (IVC) diameter, left ventricular outflow tract stroke volume variation, and estimate cardiac ejection fraction [76]. This provides the ability for real-time guidance of fluid resuscitation [77]. The most widely used method for assessing fluid responsiveness using IVC parameters is the caval index [78]. This measurement is most useful at extremes of volume status and is influenced by increases in ventilation parameters (tidal volume and positive end-expiratory pressure) and intra-abdominal pressure. As a result, despite positive findings in early studies, research has demonstrated a limited ability to detect those patients that would respond to further fluid resuscitation due to changes in these ventilatory parameters, and other patient factors such as obesity [79, 80]. Other measurements using ultrasonography are possible such as SVV using pulse-wave Doppler, and aortic blood flow velocity using trans-esophageal echocardiography, but require more experience and may prove challenging in the emergency setting [81‐83]. The combination of using ultrasonography to measure aortic velocity–time integral and combining this with a PLR test may be the best technique in skilled hands [84, 85].
Special groups
Pediatrics
Elderly
Burns
Crush injury/syndrome
CK U/l | Risk of renal failure | Admission |
---|---|---|
<500 | Low | Unlikely |
500–5000 | Intermediate | At least overnight |
>5000U/l | High | Admission to ICU/high care |