Preoperative fasting: Assessment of the practices of Lebanese Anesthesiologists.

BACKGROUND: Although new guidelines developed by the American Society of Anesthesiologists (ASA) recommend a liberalized preoperative nutrition, authorized clinical practice guidelines or recommendations have not yet been proposed by the Lebanese Society of Anesthesia (LSA).
OBJECTIVE: The purpose of this study was to examine Lebanese anesthesiologists' preoperative fasting routines and determine their knowledge and acceptance of the ASA recommendations, their attitude toward liberalized fasting, and the factors favoring their nonadherence to the new recommendations.
MATERIALS AND METHODS: This study was conducted in university hospitals, affiliated hospitals, and nonuniversity hospitals located in different regions of Lebanon. The survey was approved by the local ethics committee. A written questionnaire was emailed to all anesthesiologist members of the LSA which was completed anonymously.
RESULTS: Out of the 294 anesthesiologists registered in the LSA and who read the email, 118 (40.1%) completed the questionnaire. Of respondents, 90% are aware of the latest ASA practice guidelines for preoperative fasting, and 78.7% claim to apply them in their practices; however, 75% of respondents still require adult patients to stop eating after midnight, and only 45% allow them to drink clear fluids up to 2 h preoperatively. One of the main reasons for not complying with the ASA guidelines was "to allow flexibility for changes in the operating schedule."
CONCLUSION: A long preoperative fasting period is still the common practice for Lebanese anesthesiologists. National guideline for preoperative fasting as liberal as that recommended by the ASA should be considered.

Introduction

For many decades, anesthesiologists used to apply routing fasting (12 h) or nil per os (NPO) after midnight before elective surgery to reduce gastric volume and acidity, in order to decrease the risk of aspiration pneumonia and Mendelson syndrome during anesthesia.[1] However, enhanced recovery after surgery protocols, as well as new guidelines developed by the American Society of Anesthesiologists (ASA)[2] and by the European Society of Anesthesiology (ESA)[3] recommend a liberalized preoperative nutrition that was associated, according to many studies,[456] with better clinical outcomes without increasing risks.

Despite the implementation in many institutions of these new fasting routines of 2 h for clear fluids and 6 h for solid food before elective surgery, many studies conducted all over the world suggest that prolonged preoperative fasting continues regardless of the time of day at which surgery is scheduled.[78910]

To date, authorized clinical practice guidelines or recommendations have not yet been proposed by the Lebanese Society of Anesthesia (LSA) or by the Ministry of Public Health. Therefore, a nationwide survey was conducted in Lebanon to examine our anesthesiologists’ practices concerning preoperative fasting for adult and pediatric patients undergoing elective surgery. We also analyzed their knowledge of the new guidelines and recommendations, their attitude toward liberalized fasting, and the factors favoring their non-adherence to the new recommendations.

Methods

The survey was approved by the Ethics Committee of Hôtel Dieu de France Hospital. A written questionnaire was sent by email, between March and June 2018, to all anesthesiologist members of the LSA who completed the questionnaire anonymously.

The details of the questionnaire are described in the Appendix. Its purpose was to examine Lebanese anesthesiologists’ preoperative fasting routines and determine their knowledge and acceptance of the ASA recommendations. The questionnaire was as follows:

Part I (Questions 1–7): Demographics and anesthesiologists’ background

Part II (Questions 8–10): Knowledge and acceptance of the ASA recommendations

Part III (Questions 11–15): Instructions about fasting and number of cases with documented aspiration

Part IV (Questions 16–21): Duration of preoperative fasting for solids, fluids, smoking, and gum chewing for adult patients as well as solid, fluid, breast milk, infant formulas, and pacifiers for pediatric patients, undergoing elective surgery.

Results

Out of 294 anesthesiologists who are registered in the LSA and who read the email, 118 (40.1%) completed the questionnaire; 71.5% of the anesthesiologists worked in university hospitals or affiliated hospitals. Most of the respondents (90%) were aware of the latest ASA practice guidelines for preoperative fasting, and 78.7% have claimed to apply them in their practices. For those who did not comply with the ASA guidelines, the most frequent practice concerning preoperative fasting was “fasting since midnight.” The reasons for not complying with the ASA guidelines are listed in Table 1.

Table 1

Reasons for not complying with the ASA guidelines concerning the minimum preoperative fasting period

Reason	Percentage
Allow flexibility for changes in the operating schedule	32.7
Doubt about the clinical applicability of the ASA guidelines in the Lebanese practice	19.2
Fear of the possible increased risk of pulmonary aspiration	11.6
Frequent use of laryngeal mask	11.4
No reason	7.7
I.V. fluid administration can compensate for the fasting period	3.8
No advantages for patients	3.8
No advantages for anesthesiologists	3.8
No advantages for the hospital	3.8
Other: Difficulty to change the practice of older anesthesiologists	2

Respondents can check all that apply

Preoperative fasting instructions were given by anesthesiologists in 84.7% of the cases. For the rest, they were either given by the nurse (7.2%), the surgeon (6.1%), or by both the anesthesiologist and the surgeon (2%). These instructions were given orally in 71.4% of the cases while written instructions were given in the remaining 28.6% of the cases.

A total of 35 cases of aspiration per year were reported among respondents and the incidence of aspiration was estimated at 3.9/10,000.

When asked about permitted clear fluids that are not contraindicated 2–4 h preoperatively, the most frequent responses were: “noncarbonated water” (35.8%), “juice without pulp” (24.8%), “coffee or black tea without cream or milk” (12.4%), and “carbohydrate-rich drinks, sport drinks” (2.9%). However, 21.2% responded that no fluids should be permitted at all. Moreover, 54.1% of respondents limit the amount of fluid intake before surgery, and the answers to the open question “maximal amount of milliliters (ml) allowed” varied from 0 to 400 ml, while some considered the answer to be “5 ml/kg” or “the lowest possible.”

The duration of preoperative fasting periods for adult and pediatric patients are resumed in Tables 2 and 3, respectively. Adults had markedly longer preoperative fasting hours compared to pediatric patients. Concerning solid food, almost 80 and 60% of respondents were applying longer duration of restriction than was recommended in the ASA guidelines for adult and pediatric patients, respectively. As for clear fluids, 50 and 40% of respondents were applying longer duration of restriction than was recommended in the ASA guidelines for adult and pediatric patients, respectively.

Table 2

Preoperative fasting hours for adult patients

	Until midnight	2 h	4 h	6 h	8 h	12 h	24 h	No definite standard
Solid food	75.5%			19.5%	3%	2%
Clear fluids	36.7%	44.9%	11.2%	4.1%				3.1%
Smoking§	46%	5.2%		3%			13.3%	23.5%
Chewing gum	54.1%	9.2%	3.1%	5.1%	1%			27.5%

Bold: Represent the higher percentage rate in each category. §For 9% of respondents smoking should be stopped at the consultation of anesthesia

Table 3

Preoperative fasting hours for pediatric patients

	Until midnight	2 h	4 h	6 h	8 h	No definite standard
Solid food	45.4%	1%	6.1%	42.5%	4%	1%
Clear fluids	16.3%	62.2%	16.4%	2%		3.1%
Breast milk	11.2%	8.2%	70.4%	7.1%		3.1%
Infant formula	23.5%	3.1%	19.3%	48%	2%	4.1%
Pacifier	7.1%	4.1%		2%		86.7%
Pacifier soaked in sugar water	11.2%	13.2%	4.1%	2%		69.4%

Bold: Represent the higher percentage rate in each category

When it comes to smoking and gum chewing, respondents reported a wide range of practice. They most frequently recommended abstinence after midnight or did not have any determined policy [Table 2]. Regarding circumstances that might force respondents to adopt traditional NPO after midnight routines, the most frequent responses were “all patients” (18.5%), “patients with hernia or upper GI obstruction” (10.3%), “obese patients” (10.3%), “bowel obstruction” (9.6%), “incomplete bowel obstruction” (9.3%), and “pregnant women” (9.3%).

Discussion

Even though preoperative fasting policies have already been established in most developed countries,[238] however, this is the first nationwide survey conducted in Lebanon to evaluate the common practice of anesthesiologists concerning the preoperative fasting period. With a response rate of 40.1%, comparable to the ones reported in other national surveys,[10111213] our results can be extrapolated to represent the current practice in Lebanon regarding preoperative fasting periods for adult and pediatric patients.

This study reveals that even though 90% of respondents are aware of the latest ASA practice guidelines for preoperative fasting, and 78.7% claim to apply them in their practices, however, 75% of respondents still require adult patients to stop eating after midnight, and only 45% allow them to drink clear fluids up to 2 h preoperatively. One of the main reasons for not complying with the ASA guidelines was “to allow flexibility for changes in the operating schedule,” however, a study published by Murphy et al.[14] analyzed the effects of liberalized preoperative fasting policy on operating room utilization and concluded that there was no increase in cancellations or delays of surgical procedures due to inappropriate oral intake.

The overall incidence of aspiration reported in this study was 3.9/10,000, in the range of those reported by other studies [0.6 – 4.7/10,000].[8101315] Even though most of our respondents did not seem to comply with a liberalized preoperative fasting policy, however, many randomized controlled trials have shown that the volume and/or the pH of patients’ gastric contents did not differ significantly whether patients were permitted a standard vs a shortened fast.[816]

Our results show that the duration of preoperative fasting is not only prolonged compared to the latest ASA guidelines but also the longest among other published surveys.[81012] This proves that despite the existence of a good guideline, awareness about it does not always guarantee its application. It may be the lack of official Lebanese recommendations at the time of this survey that could explain Lebanese anesthesiologists’ reluctance toward application of the latest ASA fasting guidelines. Therefore, it is important to publish national guidelines in order to implement evidence-based practice in Lebanon.

Among fluids that are not contraindicated until 2 h preoperatively, only 2.9% of the respondents permitted carbohydrate-rich drinks. However, the latest studies have shown that carbohydrate beverages given preoperatively have the benefit of decreasing the catabolic state associated with starvation[17] and decreasing gastric volume in obese patients when compared with an overnight fast.[18] Moreover, there was no occurrence of pulmonary complications with preoperative carbohydrate beverage treatment.[19]

When it comes to smoking and chewing gum, respondents reported a wide range of practice and most of them recommended abstinence after midnight. In fact, the latest ESA guidelines[3] state that “patients should not have their operation cancelled or delayed just because they are chewing gum, sucking a boiled sweet or smoking immediately prior to induction of anesthesia.” This conclusion concerning gum chewing is based on three (partly) randomized studies concerning the intake of chewing gum during the perioperative fasting period.[202122]

This study has some limitations. First, our response rate of 51.7% is <70%, therefore we cannot completely exclude certain nonresponse bias. Second, when it comes to aspiration survey, all reports were retrospective and totally dependent on the memory of the respondent, which might be different for each of the respondents. Moreover, no definition was provided regarding aspiration, hence its diagnosis was made by each respondent based on clinical factors.

Conclusion

A long preoperative fasting period is still the common practice for Lebanese anesthesiologists. The LSA along with the Ministry of Public Health should consider establishing a Lebanese National Guideline for preoperative fasting as liberal as that recommended by the ASA, given that a national consensus had a significant impact on liberalizing the fasting policy. Finally, an awareness campaign among surgeons about preoperative fasting may also be helpful to apply the latest ASA guidelines.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.