Which category describes pre-operative deficits in perioperative fluid planning?

• A. Normal losses (maintenance)
• B. Pre-operative fluid deficits
• C. Surgical losses
• D. Insensible losses

Answer: (B)

Pre-operative deficits are the fluid debt created by fasting before anesthesia. In perioperative fluid planning we think in three buckets: maintenance needs for ongoing daily requirements, losses (like insensible losses and surgical losses), and deficits that cover the shortfall from not drinking while NPO. The pre-operative deficit category specifically describes the amount of fluid missing before the operation that must be replenished to keep the patient euvolemic at induction. Maintenance accounts for daily needs, insensible losses are ongoing unmeasured losses, and surgical losses occur during the procedure, so they don’t describe the preoperative shortfall.