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Lindsay Curtis, MD
Postoperative Care of the
Gynecologic Patient
CHAPTER 35
❍ How does postoperative stress affect sodium and water balance?
Surgical stress can induce high levels of antidiuretic hormone (ADH) and aldosterone leading to water and sodium
retention.
❍ How much fluid is usually sequestered in patients with a postoperative ileus?
1 to 3 L.
❍ When in the postoperative period, does third spacing of fluid begin to resolve?
Usually after 3 to 4 days, when the ADH and aldosterone levels normalize.
❍ What is the most common fluid and electrolyte disorder in the postoperative period?
Fluid overload due to excess isotonic intravenous fluids.
❍ How much fluid should be replaced for insensible losses in patients with fever and hyperventilation?
Up to 2 L of free water can be lost a day due to perspiration and hyperventilation. These losses are difficult to
monitor, so trend in body weight can be useful.
❍ What is the most common acid-base abnormality encountered in the postoperative period?
Alkalosis is common, caused by nasogastric suction, hyperventilation, and hyperaldosteronism.
❍ What is considered marked alkalosis, and what dangers does this entity pose?
A pH >7.55 can induce seizures and cardiac arrhythmias, especially with hypokalemia.
❍ How does metabolic acidosis affect the cardiovascular system?
It may cause a decrease in myocardial contractility, venodilation with hypotension, and a decreased responsiveness
to defibrillation.
❍ What are the indications for bicarbonate administration in postoperative metabolic acidosis?
A pH of <7.2 or severe cardiac complications due to the acidosis.