What fluids should be charted if a patient is nil by mouth (nothing by mouth) prior to surgery?

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From the Guidelines

When a patient is nil by mouth (NPO) before surgery, healthcare providers should chart all fluid intake and output to maintain accurate records, prioritizing the administration of balanced crystalloids, such as Ringer’s lactate, to maintain hydration and electrolyte balance, as recommended by the most recent guidelines 1.

Key Fluids to Chart

  • Intravenous (IV) fluids, including balanced crystalloids like Ringer’s lactate, to maintain hydration and electrolyte balance
  • Avoid the use of 0.9% saline due to the risk of salt and fluid overload, as suggested by recent studies 1

Documentation

  • Type of fluid administered
  • Rate of administration (e.g., 100 mL/hr)
  • Total volume infused
  • Time periods of administration

Output to Record

  • Urine (volume and characteristics)
  • Vomiting
  • Nasogastric drainage (if applicable)
  • Wound drainage
  • Any other fluid losses
  • Blood loss (estimated and documented if applicable)

Importance of Accurate Fluid Charting

Accurate fluid charting is crucial in surgical patients, as it helps the surgical team assess the patient's hydration status, kidney function, and overall fluid balance, influencing anesthetic management and post-operative care decisions, as emphasized by recent guidelines 1.

Preoperative Fluid Management

Patients should be encouraged to drink clear fluids up to 2 hours before surgery, and solids up to 6 hours before, to prevent preoperative fluid depletion without increasing aspiration-related complications, as recommended by the ESPEN expert group 1.

From the FDA Drug Label

When administered intravenously this solution restores blood glucose levels in hypoglycemia and provides a source of carbohydrate calories. Water is an essential constituent of all body tissues and accounts for approximately 70% of total body weight. Average normal adult requirement ranges from two to three liters (1.0 to 1. 5 liters each for insensible water loss by perspiration and urine production).

The key fluids to chart if nil by mouth before surgery include:

  • Water intake and output, as it is essential for maintaining water balance and accounts for approximately 70% of total body weight.
  • Electrolyte levels, such as sodium (Na+), which plays a major role in maintaining physiologic equilibrium.
  • Glucose levels, as dextrose may be administered to restore blood glucose levels in hypoglycemia 2.

From the Research

Fluid Management for Patients Nil by Mouth Before Surgery

  • The type of fluid to be used for patients who are nil by mouth before surgery is crucial for maintaining optimal hydration and electrolyte balance 3, 4.
  • Balanced crystalloid solutions such as lactated Ringer's solution are recommended as they have a sodium, potassium, and chloride content closer to that of extracellular fluid, resulting in fewer adverse effects on acid-base balance 3.
  • Normal saline (0.9% sodium chloride) has been commonly used, but it may cause hyperchloremic metabolic acidosis, inflammation, hypotension, acute kidney injury, and death 3, 4.
  • Lactated Ringer's solution has been shown to be associated with improved survival and more hospital-free days in patients with sepsis-induced hypotension compared to normal saline 4.

Preoperative Fasting Guidelines

  • National and international guidelines recommend preoperative fasting times of 2 hours for clear fluids and 6 hours for solids, as outlined in the '2-4-6 rule' 5, 6.
  • However, actual fasting times may be longer than prescribed, and there are inconsistencies in how guidelines are implemented 5, 6.
  • Anaesthetists have been found to possess greater knowledge of reduced preoperative fasting times than other health professionals, including nurses 6.

Nursing Considerations

  • Nursing management of patients who are nil by mouth includes maintaining optimal nutritional status, administering nutritional support, and monitoring urine output, intravenous therapy, and skin assessment 7.
  • Patient education is also crucial to reduce anxiety and ensure compliance with preoperative fasting instructions 7.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Balanced Crystalloid Solutions.

American journal of respiratory and critical care medicine, 2019

Research

Preoperative fasting: exploring guidelines and evidence to ensure consistent, high-quality care.

Nursing standard (Royal College of Nursing (Great Britain) : 1987), 2022

Research

An exploration of pre-operative fasting practices in adult patients having elective surgery.

British journal of nursing (Mark Allen Publishing), 2020

Research

Nursing management of patients who are nil by mouth.

Nursing standard (Royal College of Nursing (Great Britain) : 1987), 2008

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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