Korean J Anesthesiol.  1999 Mar;36(3):377-386. 10.4097/kjae.1999.36.3.377.

Effects of Preoperative NPO and Oral Fluid on Gastric Fluid Volume and pH

• Lee JH
• Oh AY
• Kim SD

• KMID: 2032276
• DOI: http://doi.org/10.4097/kjae.1999.36.3.377

Abstract

BACKGROUND: To reduce the risk of Mendelson's syndrome, it is customary to fast patients for 8 hours before anesthesia. However preoperative fast is unpleasant for patients, who complain frequently of thirst and dry mouth, and this conventional fast may be over-cautious. We have studied the effect of ingestion of barley tea, a Korean popular beverage, 3 hours before anesthesia on gastric contents (volume and pH), blood sugar level, thirst, and anxiety.
METHODS
We studied prospectively 284 adult patients undergoing elective surgery. The patients in the control group (n=142) fasted for at least 8 hours, and those in the experimental group (n=142) received 250 ml of barley tea 3 hours before anesthesia. On arrival in the operating room, subjects were asked to assess thirst and anxiety. After induction of anesthesia, gastric contents were aspirated via 18 French Salem sump tube and gastric volume, pH and blood sugar level were measured.
RESULTS
There were no statistically significant differences in gastric fluid volume and pH and blood sugar level between control and experimental groups. However, patients in experimental group complained of less thirst than those in control group.
CONCLUSIONS
This study demonstrates that in adult patients undergoing elective surgery, allowing patients to drink 250 ml of barley tea until 3 hours before anesthesia may relieve patients from thirst without compromising safety.

Keyword

Anesthesia, general; Gastrointestinal tract, gastric fluid volume, gastric fluid pH, preoperative oral fluid intake

MeSH Terms

Adult
Anesthesia
Anesthesia, General
Anxiety
Beverages
Blood Glucose
Eating
Hordeum
Humans
Hydrogen-Ion Concentration*
Mouth
Operating Rooms
Pneumonia, Aspiration
Prospective Studies
Tea
Thirst
Blood Glucose
Tea