By Marcie Lyons MS, RN, CNOR
They won’t know if I sneak a little snack, will they?
Depending on what your procedure is, will determine the type of anesthesia you will need. The different types of anesthesia are general, sedation, regional, and local. With each type, there are a set of guidelines to keep you, the patient, safe. For more invasive surgeries and for this article, we will address general anesthesia. General anesthesia can be blend of inhaled gases and IV administered medications, the patient is fully “asleep” during the procedure. Consciousness and nerve signals are interrupted so that the patient doesn’t have awareness of the pain or remember the procedure once it is complete. With the blend of anesthetics to achieve the unaware and unconscious state, it can often have undesirable side effects, such as post-operative nausea and vomiting (PONV). Proper education, planning, and preventative medications can help avoid PONV.
Once you are scheduled for your surgery, your pre-operative instructions will state that you are not to eat or drink in the hours leading up to your surgical procedure. Specific guidelines may vary depending on age of the patient and type of procedure, but generally they follow the 2-4-6-8 rule:
-2 hours for clear liquids, sips
-4 hours for breast milk
-6 hours for non-breast milk or light, non-fatty meal
-8 hours for heavy or fatty meals
Most often you will see instructions stating that you should adhere to a “nothing after midnight.” These times will vary and be specific to you, as the patient, so that if you are diabetic or have special circumstances, they will be addressed. Your scheduled surgical time may change the day of surgery, so it is important to have nothing by mouth leading up to the hours before your surgery. The last meal you eat needs time to move through your digestive track and out of your stomach.
There is good reason to strictly adhere to the pre-operative instructions. Post operative nausea and vomiting occurs in roughly 30% of patients, either in the post-anesthesia care unit (PACU), or within 4-6 hours after anesthesia. If this happens while you have food or liquid in your stomach, and you are not quite awake, the chances of developing aspiration pneumonia are high. While the anesthesia team will provide preventative medications, it is important to have nothing in your stomach so that you can avoid bringing food or stomach contents into your lungs.
Aspiration pneumonia can be deadly, if not properly treated. Antibiotics will be administered, chest Xray will be ordered, and most likely the patient will spend time in the hospital to be monitored and cared for. If you adhere to your pre-operative instructions and have nothing by mouth in the hours leading up to your procedure, you can avoid aspiration pneumonia and its complications.
Be safe and no sneaking a snack!
Sources:
Hines, Roberta MD; Barash, Paul G. MD; Watrous, Gail RN; O'Connor, Theresa MPH. Complications Occurring in the Postanesthesia Care Unit: A Survey. Anesthesia & Analgesia 74(4):p 503-509, April 1992.
Johansson E, Hultin M, Myrberg T, Walldén J. Early post-operative nausea and vomiting: A retrospective observational study of 2030 patients. Acta Anaesthesiol Scand. 2021; 65: 1229–1239. https://doi.org/10.1111/aas.13936
Sanivarapu RR, Gibson J. Aspiration Pneumonia. [Updated 2023 May 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK470459/
Sanivarapu RR, Gibson J. Aspiration Pneumonia. [Updated 2023 May 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK470459/ Assessed and Endorsed by the MedReport Medical Review Board