Page 249 - Critical Care Notes

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Emergency or Resuscitative Phase
■ The resuscitative phase begins at the time of injury and continues during
the first 48–72 hr, until fluid and protein shifts are stabilized.
■ Burn tissue injury occurs → loss of capillary integrity → ↑ permeability of
capillary membrane → fluid shifts from the vascular to the interstitial
spaces → ↓ cardiac output, ↓ BP, and ↑ HR and peripheral vasoconstriction
→ ↓ renal blood flow → ↓ renal function → acute renal failure.
+
■ Fluid loss, ↓ renal blood flow, Na and water retention → ↓ urine output.
+
Na and fluid pass through the burn areas → blisters, local edema, and fluid
exudate → compartment syndrome.
+
+
■ K is released from the tissue injury, and there is ↓ renal excretion of K →
hyperkalemia.
■ Lysis of RBCs occurs → hematuria, myoglobin in the urine, and anemia
(↓ Hgb).
■ Hemoconcentration → increase in Hct.
■ Coagulation abnormalities occur → prolonged clotting and prothrombin
times.
■ Metabolic acidosis occurs.
■ General tissue hypoperfusion results from ↓ circulating blood volume →
burn shock → ↓BP and tachycardia.
■ Hypothermia results from loss of skin barrier → thermoregulation problems.
Intermediate or Acute Phase
■ The acute phase of burn injury is characterized by the onset of diuresis. It
generally begins approximately 48–72 hr after the burn injury and contin-
ues through near completion of wound closure. The last phase is the reha-
bilitation phase.
■ Capillary membrane integrity returns → fluid shifts from interstitial to
intravascular space → ↑ in blood volume → diuresis if good renal function
exists.
■ Fluid overload can occur.
■ Hemodilution causes a ↓ in serum electrolytes and hematocrit.
+
■ Na deficit may continue.
+
■ K moves back into the cells → hypokalemia.
■ Protein continues to be lost from the wound.

MULTISYS