Indications for IV Fluids During Minor Surgery

Intravenous (IV) fluid administration is often reserved for major operations, yet the physiological stress associated with even brief surgical interventions and anesthesia can produce measurable derangements in fluid balance that warrant clinical attention. While the literature on perioperative fluid therapy has traditionally concentrated on major abdominal, cardiac, and trauma surgery, a smaller but instructive body of evidence addresses IV fluid administration in the context of minor procedures.

The rationale for any IV fluid administration begins with an accurate assessment of the patient's baseline state. Preoperative fasting can leave an adult patient meaningfully fluid-depleted before arrival in the surgical theatre, especially if preoperative guidance has not aligned with updated, more permissive timings (Keane & Murray, 1986). Fluids should be treated with the same prescribing discipline as any pharmacological agent, with indications spanning resuscitation, replacement, and maintenance (Malbrain et al., 2020). For minor surgery, replacement and maintenance are the dominant indications for IV fluid administration, since hemodynamic instability requiring resuscitation is uncommon in this setting.

A randomized study of 212 fasting patients undergoing short operations such as breast biopsy, varicose vein ligation, dilatation and curettage, and inguinal hernia repair provides insights specific to minor procedures. Patients who received one litre of Hartmann's solution intraoperatively and one litre of 5% dextrose postoperatively reported substantially less drowsiness, thirst, and postoperative malaise than those who received no fluid, and objective serum osmolality measurements corroborated a rehydrating effect (Keane & Murray, 1986). These findings suggest that even the modest fluid deficits associated with routine fasting are clinically relevant and correctable with comparatively small volumes.

This is consistent with observations in the ambulatory surgery literature more broadly, where higher-volume crystalloid infusion, in the range of 20–30 mL/kg, has been shown to reduce postoperative nausea, dizziness, and pain and to hasten "street readiness" in healthy patients undergoing low-risk procedures (Doherty & Buggy, 2012). The physiological basis for this relates to correction of preoperative deficits and mitigation of anesthesia-induced venodilation, rather than any need to replace the once-presumed "third space" losses, a concept that has since been discredited (Doherty & Buggy, 2012).

Fluid selection is another part of clinical decision-making. Some research suggests that balanced crystalloid solutions such as Hartmann's or Ringer's lactate/acetate are superior to 0.9% saline for reducing the risk of hyperchloraemic metabolic acidosis, an effect that is dose-dependent and avoidable (Malbrain et al., 2020). The British consensus guidelines similarly recommend balanced solutions as the default for resuscitation and replacement, reserving saline for specific circumstances such as hypochloraemia from vomiting or gastric drainage (Powell-Tuck et al., 2009). For maintenance needs, these guidelines suggest a daily requirement of roughly 25–30 mL/kg of water with modest sodium and potassium supplementation, figures well below the volumes historically infused as a matter of routine.

Although minor surgery rarely demands resuscitative fluid therapy, in many cases, replacement of fasting-related deficits and appropriately dosed maintenance IV fluids can meaningfully improve patient comfort, reduce postoperative symptoms, and support faster recovery. The same principles of careful indication, appropriate fluid choice, and avoidance of excess that govern fluid stewardship in critical care and major surgery apply, in scaled-down form, to the minor surgical setting.