NMS. Surgery

Chapter 1

Part I: Foundations

Principles of Surgical Physiology Ace St. John • Matthew Lissauer • Helena Crowley

Chapter Cuts ◆◆ No one formula best determines fluid and electrolyte management. ◆◆ High insensible losses occur during and after surgical procedures. ◆◆ Hyperkalemia is a common, life-threatening electrolyte disorder that leads to cardiac dysrhythmia. It is treated by shifting potassium into cells (insulin/ glucose), stabilizing cardiac cells (calcium), and increasing potassium excretion (potassium binders). ◆◆ New anemia in a surgical patient is surgical bleeding until proven otherwise. ◆◆ Enteral nutrition is preferred for most patients. ◆◆ Adequate oxygenation is reflected in blood pressure, pulse, urine output (end- organ function), pH, and overall appearance. ◆◆ Patients with inadequate oxygenation or increased work of breathing should be intubated for mechanical ventilation. ◆◆ Shock is the state of physiologic decompensation resulting in oxygen demand outstripping oxygen supply, and inadequate tissue perfusion. Critical Surgical Associations

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Adequate urine output

½ mL/kg/hr, or 250 mL per 8 hr

Maintenance fluid

½ Normal saline + 20 mEq KCl

Maintenance rate

60 mL/hr + 1 mL/hr per kg over 20 kg

Potassium replacement

10 mEq of IV KCL raises serum concentration by 0.1 mEq/L

Prothrombin time

Reflects extrinsic pathway

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