Preoperative fasting: current practice and areas for improvement

Preoperative fasting and the risk of pulmonary aspiration-a narrative review of historical concepts, physiological effects, and new perspectives

In the early days of anaesthesia, the fasting period for liquids was kept short. By the mid-20th century 'nil by mouth after midnight' had become routine as the principles of the management of 'full stomach' emergencies were extended to include elective healthy patients. Back then, no distinction was made between the withholding of liquids and solids. Towards the end of the last century, recommendations of professional anaesthesiology bodies began to reduce the fasting time of clear liquids to 2 h. This reduction in fasting time was based on the understanding that gastric emptying of clear liquids is rapid, exponential, and proportional to the current filling state of the stomach. Furthermore, there was no evidence of a link between drinking clear liquids and the risk of aspiration. Indeed, most instances of aspiration are caused by failure to identify aspiration risk factors and adjust the anaesthetic technique accordingly. In contrast, long periods of liquid withdrawal cause discomfort and may also lead to serious postoperative complications. Despite this, more than two decades after the introduction of the 2 h limit, patients still fast for a median of up to 12 h before anaesthesia, mainly because of organisational issues. Therefore, some hospitals have decided to allow patients to drink clear liquids within 2 h of induction of anaesthesia. Well-designed clinical trials should investigate whether these concepts are safe in patients scheduled for anaesthesia or procedural sedation, focusing on both aspiration risk and complications of prolonged fasting.

The safety of preoperative carbohydrate drinks in extremely elderly patients assessed by gastric ultrasonography: a randomized controlled trial

BACKGROUND

Modern perioperative guidelines encourage drinking oral carbohydrates 2 h before management. Nevertheless, research on the safety of preoperative carbohydrate drinks, particularly in extremely elderly patients is lacking. We aimed to evaluate the safety of carbohydrate drinks 2 h before surgery in extremely elderly patients (≥ 80 years) using gastric ultrasonography.

METHODS

We conducted a randomized prospective comparative study of 70 patients aged over 80 years who were scheduled for total knee arthroplasty, hip fracture or humerus fracture surgery. These patients were randomly assigned to the carbohydrate group (n = 35), which fasted from midnight, except for drinking 355 mL of a carbohydrate-containing fluid 2 h before surgery, or the fasting group (n = 35), which fasted from midnight and drank no fluid before surgery. The primary outcome of the study was the cross-sectional area (CSA) of the gastric antrum in the right lateral decubitus position (RLDP) before surgery. The secondary outcomes included CSA in the supine position, intraoperative blood glucose levels and their variability coefficients, Perlas grade, and the visual analog scale of subjective feelings.

RESULTS

The CSA in the RLDP and supine positions revealed no differences between the carbohydrate and fasting groups at 0 h preoperatively (P > 0.05). In the qualitative assessment, preoperative 0-h Perlas grading did not differ significantly between the groups (P > 0.05). From 2 h before surgery to transfer out of the post-anesthesia care unit, the average blood glucose level of patients in the carbohydrate group was significantly higher than that in the fasting group (P < 0.001) but remained within the normal range. Moreover, the blood glucose variability coefficient was significantly lower in the carbohydrate group than in the fasting group (P = 0.009). Oral intake of 355 mL carbohydrates before surgery significantly relieved patients' feelings (P < 0.001).

CONCLUSION

Preoperative consumption of carbohydrate drinks 2 h before surgery is safe in "healthy" extremely elderly patients. In addition, preoperative drinking has potential value in maintaining ideal blood glucose levels and stable blood glucose fluctuations perioperatively and improving subjective perceptions of preoperative preparation. This finding warrants further investigation in clinical practice.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (Registration Number ChiCTR1900024812), first registered on 29/07/2019.

Ultrasonographic Evaluation of Gastric Content and Volume in Pediatric Patients Undergoing Elective Surgery: A Prospective Observational Study

Anesthesia-related complications, such as pulmonary aspiration of gastric contents, occur in approximately 0.02-0.1% of elective pediatric surgeries. Aspiration risk can be reliably assessed by ultrasound examination of the gastric antrum, making it an essential non-invasive bedside tool. In this prospective observational study, since most of our patients are immigrants and have communication problems, we wanted to investigate gastric contents and the occurrence of "high risk stomach" in children undergoing elective surgery for the possibility of pulmonary aspiration, even if the children and/or parents reported their last oral intake time. This risk is defined by ultrasound findings of solid content in the antrum and/or a calculated gastric volume exceeding 1.25 mL/kg. Children aged 2-18 were included in the study. Both supine and right lateral decubitus (RLD) ultrasound examinations were performed on the antrum before surgery. Using a qualitative grading scale from 0 to 2, we evaluated the gastric fluid content. The cross-sectional area (CSA) of the antrum was measured in the RLD position, aiding the calculation of the gastric fluid volume according to an established formula by Perlas. Ultrasound measurements of 97 children were evaluated. The median fasting duration was 4 h for liquids and 9 h for thick liquids and solids. Solid content was absent in all the children. Five children (5.2%) exhibited a grade 2 antrum, implying that fluid content was visible in both the supine and RLD positions. The median antral CSA in the RLD was 2.36 cm2, with a median gastric volume of 0.46 mL/kg. For patients with a grade 0 antrum, a moderate and positive correlation was observed between the antral CSA and BMI, and a strong and positive correlation was evident between the antral CSA and age, similar to a grade 1 antrum. Only a single child (1%) had a potentially elevated risk of aspiration of gastric contents. Hence, the occurrence of a "high risk stomach" was 1% (95% confidence interval: 0.1-4.7%) and is consistent with the literature. As a necessary precaution, we propose the regular use of ultrasound evaluations of gastric contents, given their non-invasive, bedside-friendly, and straightforward implementation, for identifying risks when fasting times are uncertain and for ruling out unknown risk factors in each potential patient.

Safety and effectiveness for oral intake of carbohydrate-rich drink at preoperative 2 hours before painless colonoscopy

The aim of this study was to evaluate the feasibility, safety, and optimal dose of oral intake of carbohydrate-rich drinks 2 hours before painless colonoscopy. All patients receiving painless colonoscopy were randomly divided into 3 groups: control group (no carbohydrate-rich drink, n = 33), low-dose group (5 mL/kg carbohydrate-rich drink, n = 30), and high-dose group (8 mL/kg carbohydrate-rich drink, n = 30). Use of vasoactive drugs, the visual analog scale including thirst and hunger, degree of satisfaction, the time required for Modified Post Anesthetic Discharge Scoring System scale, first urination time, electrolyte level (sodium, potassium, and calcium), and blood glucose level were also determined. A total of 93 patients were recruited in this study. No significant difference was observed in the cross-sectional area (CSA) of the gastric antrum area at T0 between low- and high-dose groups (P = .912). There was a significant difference in CSA of gastric antrum at 120 minutes after oral intake between the low- and high-dose groups (P = .015). No significant difference was observed in the CSA of gastric antrum at 0 minutes and 120 minutes in the low-dose group (P = .177). In the high-dose group, the CSA of gastric antrum significantly differed at 0 minutes and 120 minutes (P < .001). There was a significant difference in the visual analog scale scores of thirst and hunger at 4 and 5 hours after bowel preparation among 3 groups (P = .001, P = .029, P < .001, P = .001). The degree of satisfaction in low- and high-dose groups was significantly higher than that in the control group (both P < .001). In conclusion, it is feasible and safe to deliver an oral intake of 5 mL/kg carbohydrate-rich drink 2 hours before painless colonoscopy. The comfort level and degree of satisfaction of patients can be further improved.

After-hour elective total knee arthroplasty does not affect clinical outcomes but negatively affects alignment

INTRODUCTION

In cases of limited medical resources, elective total knee arthroplasty (TKA) sometimes needs to be performed after typical work hours. However, surgeon fatigue and logistical factors may potentially affect outcomes. This study aimed to detect whether after-hour procedures impair outcomes after TKA.

MATERIALS AND METHODS

Elective unilateral TKA from Jan 1, 2016 to Nov 31, 2018 was retrospectively selected and separated into two groups. Procedures started from 8:00 A.M. to 5:29 P.M. were identified as day-time surgeries, whereas those started from 5:30 P.M. to 11:59 P.M. were considered after-hour surgeries. Operative period, Knee Society Score (KSS), range of motion (ROM), total blood loss, length of hospital stay (LOS), and postoperative adverse events and complications were compared. Additionally, the components were evaluated radiologically.

RESULTS

A total of 321 patients were selected, including 258 (80.37%) patients in the day-time group and 63 (19.63%) patients in the after-hour group. Operative period, LOS, total blood loss were similar between groups. The overall and each specific incidence of postoperative complications were comparable between the two groups, but the incidence of postoperative vomiting (POV) was higher in the after-hour group. There was no significant difference in knee joint function as shown by the KSS and ROM, both on the 3rd day and at 2 years after surgeries. Radiologically, there were no significant differences between the two groups in the femoral notches (P = 0.592). However, better coronal alignment was detected in the day-time group (P = 0.002), consistent with which there were less outliers (P = 0.033).

CONCLUSION

After-hour TKA procedure does not exert an impact on clinical outcomes, but negatively affects lower limb alignment. Besides, after-hour TKA surgery impairs patients' comfort by increasing POV.

Real-World Evidence: How Long Do Our Patients Fast?-Results from a Prospective JAGO-NOGGO-Multicenter Analysis on Perioperative Fasting in 924 Patients with Malignant and Benign Gynecological Diseases

BACKGROUND

Despite the key role of optimized fasting in modern perioperative patient management, little current data exist on perioperative fasting intervals in routine clinical practice.

METHODS

In this multicenter prospective study, the length of pre- and postoperative fasting intervals was assessed with the use of a specifically developed questionnaire. Between 15 January 2021 and 31 May 2022, 924 gynecology patients were included, from 13 German gynecology departments.

RESULTS

On average, patients remained fasting for about three times as long as recommended for solid foods (17:02 ± 06:54 h) and about five times as long as recommended for clear fluids (9:21 ± 5:48 h). The average perioperative fasting interval exceeded one day (28:23 ± 14:02 h). Longer fasting intervals were observed before and after oncological or extensive procedures, while shorter preoperative fasting intervals were reported in the participating university hospitals. Smoking, treatment in a non-university hospital, an increased Charlson Comorbidity Index and extensive surgery were significant predictors of longer preoperative fasting from solid foods. In general, prolonged preoperative fasting was tolerated well and quality of patient information was perceived as good.

CONCLUSION

Perioperative fasting intervals were drastically prolonged in this cohort of 924 gynecology patients. Our data indicate the need for better patient education about perioperative fasting.

Prospective audit on fasting status of elective ambulatory surgery patients, correlated to gastric ultrasound

INTRODUCTION

Recent guidelines advocate a preoperative fasting interval of 6 h for solid food, 4 h for breast milk and 2 h for clear fluids. Long nil per mouth intervals give rise to complications and discomfort in the perioperative period. Gastric ultrasound is easily accessible and generates reliable information about gastric content.

PATIENTS AND METHODS

One hundred patients were offered a questionnaire regarding preoperative fasting. Important outcome measures were hour of last meal, last clear fluids intake, the source of preoperative information. Gastric ultrasound was performed in prone position and lateral decubitus.

RESULTS

The mean duration of fasting for solid food was 13h29 and 9h51 for clear fluids. 48% of patients were well aware of the correct fasting guidelines. The most frequent source of information was the preoperative phone call. Gastric ultrasound only found insignificant amounts of gastric content.

DISCUSSION

Too few patients are aware of the correct guidelines or fear complications and therefore adhere to the nil per mouth from midnight as most conservative measure. A phone call informing patients about the hour of surgery and allowing clear fluid intake until 2 h before surgery, is still not convincing enough. Some health care providers advise their patients the nil per mouth from midnight rule, due to risk of interfering with the operating room schedule.

CONCLUSION

It is still difficult to implement liberal intake of clear fluids according to current guidelines. Ambulatory surgery patients have long fasting intervals with decrease of subjective well-being and increased incidence of hunger and thirst.

Abbreviated perioperative fasting management for elective fresh fracture surgery: guideline adherence analysis

BACKGROUND

Long-term fasting for elective surgery has been proven unnecessary based on established guidelines. Instead, preoperative carbohydrate loading 2 h before surgery and recommencing oral nutrition intake as soon as possible after surgery is recommended. This study was performed to analyze the compliance with and effect of abbreviated perioperative fasting management in patients undergoing surgical repair of fresh fractures based on current guidelines.

METHODS

Patients with fresh fractures were retrospectively analyzed from the prospectively collected database about perioperative managements based on enhanced recovery of surgery (ERAS) from May 2019 to July 2019 at our hospital. A carbohydrate-enriched beverage was recommended up to 2 h before surgery for all surgical patients except those with contraindications. Postoperatively, oral clear liquids were allowed once the patients had regained full consciousness, and solid food was allowed 1 to 2 h later according to the patients' willingness. The perioperative fasting time was recorded and the patients' subjective comfort with respect to thirst and hunger was assessed using an interview-assisted questionnaire.

RESULTS

In total, 306 patients were enrolled in this study. The compliance rate of preoperative carbohydrate loading was 71.6%, and 93.5% of patients began ingestion of oral liquids within 2 h after surgery. The median (interquartile range) preoperative fasting time for liquids and solids was 8 (5.2-12.9) and 19 (15.7-22) hours, respectively. The median postoperative fasting time for liquids and solids was 1 (0.5-1.9) and 2.8 (2.2-3.5) hours, respectively. A total of 70.3% and 74.2% of patients reported no thirst and hunger during the perioperative period, respectively. Logistic regression analysis showed that the preoperative fasting time for liquids was an independent risk factor for perioperative hunger. No risk factor was identified for perioperative thirst. No adverse events such as aspiration pneumonia or gastroesophageal reflux were observed.

CONCLUSIONS

In this study of a real clinical practice setting, abbreviated perioperative fasting management was carried out with high compliance in patients with fresh fractures. The preoperative fasting time should be further shortened to further improve patients' subjective comfort.

Quality-improvement project to reduce actual fasting times for fluids and solids before induction of anaesthesia

Background

Despite well-defined recommendations, prolonged fasting times for clear fluids and solids are still common before elective surgery in adults. Extended fasting times may lead to discomfort, thirst, hunger and physiological dysfunctions. Previous studies have shown that prolonged fasting times are frequently caused by patients being misinformed as well as inadequate implementation of the current guidelines by medical staff.

This study aimed to explore how long elective surgery patients fast in a German secondary care hospital before and after the introduction of an educational note for patients and re-training for the medical staff.

Methods

A total of 1002 patients were enrolled in this prospective, non-randomised interventional study. According to the power calculation, in the first part of the study actual fasting times for clear fluids and solids were documented in 502 consecutive patients, verbally instructed as usual regarding the recommended fasting times for clear fluids (2 h) and solids (6 h). Subsequently, we implemented additionally to the verbal instruction a written educational note for the patients, including the recommended fasting times. Furthermore, the medical staff was re-trained regarding the fasting times using emails, newsletters and employee meetings. Thereafter, another 500 patients were included in the study.

We hypothesised, that after these quality improvement procedures, actual fasting times for clear fluids and solids would be more accurate on time.

Results

Actual fasting times for clear fluids were in the median 11.3 (interquartile range 6.8–14.3; range 1.5–25.5) h pre-intervention, and were significantly reduced to 5.0 (3.0–7.2; 1.5–19.8) h after the intervention (median difference (95%CI) − 5.5 (− 6.0 to − 5.0) h). The actual fasting times for solids also decreased significantly, but only from 14.5 (12.1–17.2; 5.4–48.0) h to 14.0 (12.0–16.3; 5.4–32.0) h after the interventions (median difference (95%CI) − 0.52 (− 1.0 to − 0.07) h).

Conclusions

The study showed considerably extended actual fasting times in elective adult surgical patients, which were significantly reduced by simple educational/training interventions. However, the actual fasting times still remained considerably longer than defined in recommended guidelines, meaning further process optimisations like obligatory fluid intake in the early morning are necessary to improve patient comfort and safety in future.

Trial registration

German registry of clinical studies (DRKS-ID: DRKS 00020530, retrospectively registered).

[Preoperative fluid fasting : Establishment of a liberal fluid regimen using fasting cards]

BACKGROUND

Preoperative fasting times for clear liquids surpass by far the recommendations of the specialist societies. The aim of this study was to introduce a liberal regimen for preoperative fasting of clear liquids using fasting cards as a training tool and to evaluate the implementation.

MATERIAL AND METHODS

We developed a liberalized regimen of preoperative clear fluid fasting times, which allows patients to drink water, apple juice, tea and coffee until being called to the operating theatre. Each patient receives a bed-side fasting card with written information specifying fasting times for solid food and liquids. Patients who are allowed to drink water, apple juice, tea and coffee until the call to the operating theatre receive a blue fasting card. Patients with coexisting diseases or conditions that can affect gastric emptying or who need longer fasting times because of the surgical procedure get a yellow fasting card on which fasting times for fluids and solids can be documented individually. Patients who need to be nil per os (for example patients with ileus or bowel obstruction, emergency care) receive a red fasting card. On the back of the card the information is written in English, Turkish, Russian and Arabic. After a period of 8 months all surgical ward managers were asked to complete a questionnaire to assess the implementation of the new fasting regimen.

RESULTS

The response rate of the questionnaire was 100%. Without exception all interviewees would recommend the use of our liberalized fasting regimen. Almost all would also support the implementation of fasting cards. Out of 11 wards 9 found that patients were more relaxed and asked for intravenous fluids less often while waiting for surgery. The multilingual nature of the cards makes it easier to deal with patients who do not speak German. All ward managers consistently approved the new regimen in the event they themselves would need an operation. In order to make the fasting cards also usable in the future for rescue centers and functional units, such as endoscopy, echo or cardiac catheters, the reasons for fasting on the blue and yellow cards have been extended to operation or examination and on the red card to illness, operation or upcoming examination.

CONCLUSION

Patients should be allowed to drink water and hypotonic clear fluids until shortly before an operation to avoid complications of overly long fasting times. Fasting cards help to implement this by providing easy to understand information for patients and healthcare workers. This concept should be clearly structured, transparent for everyone, written down and brought to the attention of the patient without a language barrier.

Preoperative Fasting Guidelines: Where Are We Now? Findings From Current Practices in a Tertiary Hospital

PURPOSE

New evidence-based fasting guidelines have been published in recent years. However, while water and solid food fasting times before anesthesia are recommended to be 2 and 6 hours, respectively, these times are often longer in clinical practice. This study aimed to investigate the awareness and implementation of the fasting guideline recommendations among nurses and anesthesiologists, as well as evaluate the actual fasting durations in patients in a tertiary hospital.

DESIGN

A cross-sectional study was used.

METHODS

Questionnaires were designed to collect the knowledge of fasting time among registered anesthesiologists and nurses. Data on the instructed and actual fasting durations among patients scheduled for elective surgery were evaluated.

FINDINGS

Approximately half of the nurses indicated that solid food fasting durations were shorter than 6 hours or longer than 8 hours, and two-thirds indicated that clear fluid fasting durations were shorter than 2 hours or longer than 4 hours. However, in clinical practice, nurse-instructed fasting durations were longer than what they knew was optimal. The anesthesiologists also prescribed longer fasting durations than the minimum fasting duration recommended. The actual fasting durations of the patients were significantly longer than the nurse-instructed fasting durations for solid food (13.41 ± 2.64 vs 9.87 ± 2.20 hours, P < .001) and clear fluids (10.27 ± 3.67 vs 8.98 ± 2.90 hours, P < .001). The nurse-instructed durations were significantly longer than the anesthesiologist-instructed durations according to the statements of patients (9.87 ± 2.20 vs 9.00 ± 2.00 hours for solid food, P < .001; 8.98 ± 2.90 vs 6.15 ± 3.25 hours for clear fluids, P < .001).

CONCLUSIONS

Excessive fasting durations were observed among patients. Anesthesiologists and nurses must work together to ensure that updated fasting instructions are implemented in routine clinical practice.

Fasting and surgery timing (FaST) audit

BACKGROUND & AIMS

International guidance advocates the avoidance of prolonged preoperative fasting due to its negative impact on perioperative hydration. This study aimed to assess the adherence to these guidelines for fasting in patients undergoing elective and emergency surgery in the East Midlands region of the UK.

METHODS

This prospective audit was performed over a two-month period at five National Health Service (NHS) Trusts across the East Midlands region of the UK. Demographic data, admission and operative details, and length of preoperative fasting were collected on adult patients listed for emergency and elective surgery.

RESULTS

Of the 343 surgical patients included within the study, 50% (n = 172) were male, 78% (n = 266) had elective surgery and 22% (n = 77) underwent emergency surgery. Overall median fasting times (Q1, Q3) were 16.1 (13.0, 19.4) hours for food and 5.8 (3.5, 10.7) hours for clear fluids. Prolonged fasting >12 h was documented in 73% (n = 250) for food, and 21% (n = 71) for clear fluids. Median fasting times from clear fluids and food were longer in the those undergoing emergency surgery when compared with those undergoing elective surgery: 13.0 (6.4, 22.6) vs. 4.9 (3.3, 7.8) hours, and 22.0 (14.0, 37.4) vs. 15.6 (12.9, 17.8) hours respectively, p < 0.0001.

CONCLUSIONS

Despite international consensus on the duration of preoperative fasting, patients continue to fast from clear fluids and food for prolonged lengths of time. Patients admitted for emergency surgery were more likely to fast for longer than those having elective surgery.

The Effects of Preoperative Fasting on Patients Undergoing Thoracic Surgery

PURPOSE

The purpose of this study was to determine the effects of fasting before surgery on patients undergoing thoracic surgery.

DESIGN

This descriptive cross-sectional study was conducted from January 1 to June 30, 2017.

METHODS

The study was carried out with 85 patients who underwent thoracotomy, mediastinoscopy, or rib resection in the thoracic surgery department of a university hospital. All patients started fasting midnight before day of surgery. Data were collected using a questionnaire, Visual Analog Patient Satisfaction Scale, and preoperative laboratory findings form.

FINDINGS

The mean fasting hours of solids and clear fluids were 8 and 16, respectively, and the mean duration of preoperative fasting (POF) was 10.16 (SD = 1.67), total fasting time average was 28.09 (SD = 7.11). Total protein and albumin levels decreased, and glucose level increased after surgery. The difference between total protein, albumin, and glucose levels preoperatively and postoperatively was significant (P < .05). The difference between patient satisfaction and thirst was found to be statistically significant (P < .05). A positive correlation was found between POF and thirst (r = 0.450; P = .000), hunger (r = 0.402; P = .000), total protein (r = 0.508; P = .000), albumin (r = 0.537; P = .000), and glucose levels (r = 0.371; P = .000).

CONCLUSIONS

POF had an adverse effect on thirst, hunger, and total protein as well as albumin and glucose levels.

Interventions Aimed at Reducing Fasting Times in Acute Hospital Patients: A Systematic Literature Review

Despite current guidelines recommending fasting from solids for ≤6 hours and clear fluids for ≤2 hours prior to surgery, outdated practices endure; patients fast for unnecessarily prolonged periods because of beliefs regarding aspiration risk upon anaesthesia induction. This literature review aimed to identify and evaluate current interventions aiming to reduce preoperative fasting times for acutely ill hospital patients, summarizing effective interventional strategies and associated outcomes. EMBASE, MEDLINE, PreMEDLINE, and CINAHL were systematically searched. Quality of evidence was assessed using Cochrane risk-of-bias tools. Studies, of any type, reporting fasting times as a primary or secondary outcome were included. A total of 1918 potential studies were identified; of these, 16 studies were included. Seven studies investigated the effect of changing fasting protocol on gastric fluid volume/residual gastric volume (GFV/RGV) and gastric pH as surrogate measures for aspiration risk. No significant differences in GFV/RGV and gastric pH due to reduced preoperative fasting were reported, thus no change in aspiration risk. Eight studies documented improvements in patient-reported outcomes with shorter fasting times. However, this review identified a paucity of studies that trialled interventions to reduce fasting times as the primary aim. These interventions were multimodal and multidisciplinary in nature, incorporating principles of implementation science to successfully achieve significant reductions in fasting times. This review highlights that reducing the preoperative fasting period is safe while improving patient's physical and psychological well-being. Further high-quality studies that investigate multimodal interventions, and that utilize implementation science principles, are required in this area.

Is perioperative fasting associated with complications, length of hospital stay and mortality among gastric and colorectal cancer patients? A cohort study

BACKGROUND

During a surgical procedure, patients are often subjected to fasting for times that are more prolonged than the ideal, which may lead to complications.

OBJECTIVE

To evaluate the duration of perioperative fasting and its association with postoperative complications, length of hospital stay (LOS) and mortality among gastric and colorectal cancer patients.

DESIGN AND SETTING

Cohort study developed in a surgical oncology hospital in the city of Natal (Rio Grande do Norte, Brazil).

METHODS

Patients aged over 18 years were included. The Clavien-Dindo surgical complication scale was used to evaluate occurrences of postoperative complications. LOS was defined as the number of days for which patients stayed in the hospital after surgery, or until the day of death.

RESULTS

Seventy-seven patients participated (59.8 ± 11.8 years; 54.5% females; 70.1% with bowel tumor). The incidences of postoperative complications and death were 59.7% and 3.9%, respectively. The duration of perioperative fasting was 59.0 ± 21.4 hours, and it was higher among non-survivors and among patients with prolonged hospital stay (≥ 6 days). For each one-hour increase in the durations of perioperative and postoperative fasting, the odds of prolonged hospitalization increased by 12% (odds ratio, OR = 1.12; 95% confidence interval, CI 1.04-1.20) and 5% (OR = 1.05; 95% CI 1.02-1.08), respectively.

CONCLUSION

Prolonged perioperative fasting, especially in the postoperative period, was observed in a sample of patients with gastric and colorectal cancer, and this was an independent predictor of LOS.

Effects of a Preoperative Carbohydrate-Rich Drink Before Ambulatory Surgery: A Randomized Controlled, Double-Blinded Study

Background

The guidelines recommend oral carbohydrates up to 2 hr before elective surgery. The objective of this study was to explore the safety and feasibility of preoperative carbohydrate drink in patients undergoing ambulatory surgery.

Material/Methods

Patients undergoing ambulatory surgery under general anesthesia were enrolled. They were fasted from midnight and randomly assigned to a study group (200 mL of a carbohydrate beverage) or the control group (pure water) and received the assigned drink 2 hr before surgery. Bedside ultrasonography was performed to monitor gastric emptying at T₀ (before liquid intake), T₁ (5 min after intake), T₂ (1 hr after intake), and T₃ (2 hr after intake). Subjective feelings of thirst, hunger, anxiety, and fatigue were assessed 1 hr after liquid intake using the visual analogue scale (VAS).

Results

In both groups, gastric antrum cross-sectional area, gastric content volume, and weight-corrected gastric content volume increased at T₁ and returned to baseline at T₃. These parameters were significantly higher in the study group at T₂ (6.28±1.38 vs. 4.98±0.78, 67.22±29.49 vs. 49.04±15.4, 1.10±0.51 vs. 0.85±0.37, P<0.05). Thirst and hunger VAS scores were reduced in both groups. The study group suffered significantly less hunger (28.44±10.41 vs. 36.03±14.42, P<0.05). Blood electrolytes (sodium, potassium, calcium) and glucose concentration levels were similar in both groups at T₂. No gastric regurgitation or pulmonary aspiration was recorded.

Conclusions

Administration of 200 mL of oral carbohydrate beverage 2 hr before ambulatory surgery is safe, effective, and can be used for preoperative management of fasting patients.

Feasibility and Safely of Oral Rehydration Therapy before Upper Gastrointestinal Endoscopic Submucosal Dissection

Methods

We used alginade water (125 mL, Nestle Co., Kobe, Japan) for PORT. Alginade water is a flavored sports drink, which is palatable and promotes wound healing due to a high concentration of alginate. We conducted a single-center single-arm prospective feasibility study of PORT in 244 patients who underwent upper gastrointestinal ESD. The group wherein PORT was administered up to two hours before ESD (n = 120) was compared with the historical control group (non-PORT group, n = 120). We investigated the total fluid intake, hematocrit change, complications due to PORT, complications during ESD, ESD procedure time, and length of hospital stay in each group.

Results

The average fluid intake in the PORT group was 462.6 mL. No complications were observed due to PORT and ESD, and significant differences in the ESD procedure time or hospital stay was not noted.

Conclusion

PORT up to two hours before upper gastrointestinal ESD is feasible.

How long are mechanically ventilated patients fasted prior to surgery? An exploratory study examining preoperative fasting practices across trauma centres

For mechanically ventilated patients undergoing surgery, interrupting enteral feeding to prevent pulmonary aspiration is common; however, there are no published preoperative fasting guidelines for these patients, resulting in fasting practices that often vary greatly between hospitals. This retrospective study described fasting practices and surgical outcomes of mechanically ventilated patients across five trauma centres. The primary exposure was hours nil per os before surgery and was stratified into short (<6h) and moderate (≥6h) fasting duration. Shared frailty models assessed the relationship between time to perioperative complication and nil per os category. Three of the five hospitals had preoperative fasting guidelines, and those most compliant required patients to be fed up until surgery. Most patients were fasted ≥6h prior to surgery and no increased risk of complication was found for patients who were fasted <6h. Future studies are needed to establish appropriate preoperative fasting thresholds for mechanically ventilated patients.

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

Background:

Patients fast routinely before elective surgery in order to reduce gastric volume and acidity. The standard fasting time is ‘nil by mouth’ from midnight before surgery. In recent years, new guidelines have recommended that patients remain nil by mouth from clear fluids for 2 hours and from solids for 6 hours. This literature review explored preoperative fasting practices in adult patients from an international perspective.

Methods:

A literature search was undertaken of databases, including CINAHL Plus, PubMed, Medline, the Cochrane Central Register of Controlled Trials, Science Direct, Sage Journals and Embase.

Results:

Anaesthetists were found to possess greater knowledge of reduced preoperative fasting than other health professionals including nurses.

Conclusion:

Actual fasting time was found to be relatively longer than prescribed fasting times.

Ultrasound to guide the individual medical decision by evaluating the gastric contents and risk of aspiration: A literature review

Pulmonary aspiration of gastric contents is one of the most terrible complications following general anesthesia. It is important for patients to prevent this complication by obeying the preoperative fasting protocol strictly. At present, it has been reported by many studies that bedside ultrasound, as a non-invasive and convenient method, could be used to evaluate gastric contents qualitatively and quantitatively. With the advantages of reliability, accuracy and repeatability, it can greatly reduce the risk of aspiration and ensure patients' life security. But most of the data were acquired from the healthy volunteers. For the gastrointestinal disorder, the pregnant women, obesity, children, the elderly and diabetes patients, the accuracy and reliability of ultrasound to predict the risk of aspiration remains to be identified by more further studies. For these patients with increasing risk of aspiration, I-AIM (Indication, Acquisition, Interpretation, Medical decision-making) framework plays an important role in ensuring the safety of patients. It is crucial to make appropriate clinical decisions by evaluating the gastric contents with ultrasound.

Effects of an Individualized Fasting Program on Fasting Time and Comfort in Infants and Young Children During the Perioperative Period

PURPOSE

The study was designed to evaluate the effect of an individualized fasting program on fasting time and comfort in infants and young children during the perioperative period.

DESIGN

A quasiexperimental design was used.

METHODS

The study included 675 children (intervention = 353, control = 322). Data collection tools included Characteristics of Children Form and the Infant Hunger Rating Scale. The fasting program included individualized fasting education and fasting in batches. On the day of the operation, clear liquids were fed 2 hours before surgery and refed after the patient woke after surgery.

FINDINGS

The duration of perioperative fasting and the time to refeeding were shorter, the hunger scores were lower in the intervention group than those in the control group (P < .05). There was no difference in the incidence of vomiting between the two groups (P > .05), and no coughing and bloating occurred.

CONCLUSIONS

The fasting program for infants and young children can shorten the duration of fasting and can reduce the degree of hunger. This program is safe and feasible.

A Pilot Quality Improvement Project to Reduce Preoperative Fasting Duration in Pediatric Inpatients

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Despite guidelines allowing clear liquids up to 2 hours before anesthesia, preoperative fasting for pediatric inpatients is often unnecessarily prolonged. This delay can lead to prolonged recovery time and increased postoperative pain. Efforts to reduce fasting duration in pediatric surgical patients is an evolving standard in pediatric anesthesiology. The primary aim of this quality improvement project was to reduce the average inpatient fasting duration undergoing anesthesia by 25% within a year of our pilot intervention. Secondary aims included measuring the adoption rate of the intervention and comparing aspiration rates as a balancing measure.

Influence of different preoperative fasting times on women and neonates in cesarean section: a retrospective analysis

Background

This study was to evaluate the impact of different preoperative fasting conditions on women and neonates through a retrospective analysis.

Methods

A total of 1599 women were divided into 5 groups according to different preoperative fasting times: group A: solid food ≥8 h; clear fluids ≥6 h; B: solid food ≥8 h; clear fluids ≥2 h < 6 h; C: solid food ≥6 h < 8 h; clear fluids < 2 h; D: solid food ≥2 h < 6 h; clear fluids < 2 h; E: solid food < 2 h; clear fluids < 2 h.

Results

Incidence rate of vomiting of women was lower in group C (solid food ≥6 h < 8 h and clear fluids < 2 h) than other groups (P <  0.05). Compared with the fasting for a long time (groups A and B: solid food > 8 h and clear fluids > 2 h at least), the incidence rate of hypoglycemia and acidosis of neonates in group C displayed a certain decrease (P <  0.05). Although shorter fasting times (solid food < 6 h at least) reduced the incidence of hypoglycemia and acidosis in neonates, it increased the risk of vomiting of women.

Conclusion

The preoperative fasting of solid food ≥6 h < 8 h and clear fluids < 2 h reduces the incidence of vomiting in women’s anesthesia and the risk of hypoglycemia and acidosis in neonates.

Nutritional prehabilitation: physiological basis and clinical evidence

In this narrative review, we describe the physiological basis for nutritional prehabilitation and evaluate the clinical evidence for its current roles in the perioperative period. Surgical stress and fasting induce insulin resistance as a result of altered mitochondrial function. Insulin resistance in the perioperative period leads to increased morbidity in a dose-dependent fashion, while preoperative carbohydrate loading attenuates insulin resistance, minimises protein loss and improves postoperative muscle function. Carbohydrate loading is an established practice in many countries and a key component of enhanced recovery after surgery (ERAS) programs, yet its independent effects on clinical outcomes remain unclear. Amino acid supplements may confer additional positive effects on a number of markers of clinical outcomes in the perioperative period, but their current role is also poorly defined. Clinical studies evaluating nutritional interventions have been marred by conflicting data, which may be due to small sample sizes, as well as heterogeneity of patients and surgical procedures. At present, it is known that carbohydrate loading is safe and improves patients' wellbeing, but does not appear to influence length of hospital stay or rate of postoperative complications. This should be appreciated before its routine inclusion in ERAS programs.

Safety and Feasibility of Early Oral Hydration in the Postanesthesia Care Unit After Laparoscopic Cholecystectomy: A Prospective, Randomized, and Controlled Study

PURPOSE

To assess the safety and feasibility of early oral hydration (EOH) in the postanesthesia care unit (PACU) after laparoscopic cholecystectomy.

DESIGN

Prospective, randomized, controlled trial.

METHODS

Patients were randomly assigned to the EOH group or the conventional oral hydration (COH) group. Outcomes were the incidence of nausea and vomiting, thirst scale, incidence of oropharyngeal discomfort, and patient satisfaction.

FINDINGS

Compared with the COH group, the EOH group had lower incidence of nausea before and after the first drink in the ward (P < .05); lower incidence of vomiting before and after the first drink in the ward (P < .05); lower thirst scale when patients were transferred out of the PACU (P < .05) and at 6 hours postoperatively (P < .05); and greater patient satisfaction on postoperative day 1 (P < .05).

CONCLUSIONS

Early oral hydration in the PACU following laparoscopic cholecystectomy was safe and well-tolerated.

Ultrasound assessment of the prevalence of increased gastric contents and volume in elective pediatric patients: A prospective cohort study

BACKGROUND

Though pulmonary aspiration of gastric contents occurs mainly in the setting of emergency surgery, it may also occur in children scheduled for elective surgery without any obvious clinical risk factor. Increased gastric content volume is one the predisposing factors for pulmonary aspiration that could affect such children and may be identified using ultrasound examination of the gastric antrum.

AIMS

We aimed to assess the prevalence of "at-risk stomach" defined by ultrasound visualization of any solid content in the antrum and/or by calculated gastric fluid volume > 1.25 mL/kg, in children scheduled for elective surgery.

METHODS

Children scheduled for elective surgery were consecutively included into this prospective cohort study. Preoperative ultrasound examination of the antrum was performed in both the supine and the right lateral decubitus positions. Gastric fluid content was assessed using a 0-2 qualitative grading scale. The antral cross-sectional area was also measured in both the supine and the right lateral decubitus positions, allowing the calculation of the gastric fluid volume according to a formula previously described.

RESULTS

We analyzed 200 elective children. Median duration of fasting was 4 hours for liquids and >13 hours for solids. None of the children included in this study had evidence of solid content. Six (3%) children had a Grade 2 antrum (fluid content seen in both the supine and the right lateral decubitus positions). Two children had a gastric fluid volume >1.25 mL/kg. The prevalence of "at-risk stomach" was 1% (95% confidence interval: 0.2%-3.9%).

CONCLUSION

According to our results, only 1% of elective children had potentially increased risk for pulmonary aspiration. Further studies should be performed in order to define the target population of elective children for which ultrasound assessment of gastric content should be performed prior to general anesthesia.

Postoperative fasting after general anaesthesia: A survey of French anaesthesiology practices

BACKGROUND

Preoperative fasting is well codified worldwide. In contrast, the literature on the postoperative fasting (POF) is scarce, leading to potentially wide discrepancies among anaesthesiology practices. This survey assessed French POF practices.

METHODS

From March 2013 to January 2014, a survey was conducted among anaesthesiologists, members of the French Society of Anaesthesiology and Intensive Care Medicine (SFAR). The POF durations of either fluid or solid food intake was assessed according to airway management procedures (endotracheal intubation [EI] or laryngeal mask [LMA]) and age of the patients (adult or paediatric).

RESULTS

Seven hundred and fifty-four surveys were returned (67% from public hospital practitioners and 33% from private hospital and clinic practitioners). The majority of anaesthesiologists allowed fluid intake 2h after EI and immediately after discharge from PACU following LMA. For solid food resumption, it was 2h for children and 4h for adults after EI and 2h for both children and adults after LMA. Regardless of the airway management procedures, fasting was permitted immediately after PACU discharge more frequently in public than in private hospitals (36% vs. 33%, P<0.05). Four hours after the end of surgery, the rate was significantly higher in private than in public hospitals (93% vs. 89 %, P<0.001).

CONCLUSIONS

All in all, POF lasted less than 4hours after surgery regardless of airway management. They were shorter with regard to fluid intake, paediatric patients and LMA in comparison with solid food, adult patients and EI respectively.

Making the experience of elective surgery better

Objective Patient experience is one of the three pillars of quality in healthcare; improving it must be a key aim if we are to make the overall quality of the healthcare we provide better. Methods We devised a quality improvement project to improve the patient experience of elective surgery. We conducted surveys of patients and assessed their experience by using semistructured interviews and patient questionnaires. We gathered data about their overall satisfaction, fasting times and their communication with staff. We used this information to inform strategies aimed at improving patient experience. Results Our initial results showed that patients who had their operations later in the day were significantly less likely to report a positive experience. We found the main reasons for this were long waiting times, poor communication and prolonged fasting. We implemented changes over 'Plan, Do, Study, Act' cycles, including (1) staggering patient arrival times, (2) introducing the concept of the 'Golden Patient', (3) having a single point of contact on the day surgery unit to communicate between theatre staff and patients, (4) using the WHO checklist to finalise list order, and (5) altering patient information letters to include the possibility of a wait on the day of surgery. Conclusion This project increased the percentage of patients reporting an 'Excellent' or 'Good' experience from 65% to 96%. In addition to improving our patients' experience, our project has also delivered shorter waiting times, better dissemination of information and fewer patients reporting hunger or thirst.

Most American Association of Oral and Maxillofacial Surgeons Members Have Not Adopted the American Society of Anesthesiologists-Recommended Nil Per Os Guidelines

PURPOSE

The purpose of this study was to determine if American Association of Oral and Maxillofacial Surgeons members have integrated the current American Society of Anesthesiologists (ASA) nil per os (NPO) guidelines into their preoperative instructions.

MATERIALS AND METHODS

We designed and implemented a cross-sectional study and enrolled a random sample of private-practice American Association of Oral and Maxillofacial Surgeons members who practice in the United States. The predictor variables were year of graduation from residency, dual degree (MD and DDS or DMD) or single degree, and region. The primary outcome variable was adoption of the ASA NPO guidelines, defined as recommending fasting times of 2 hours for clear liquids and 6 hours for solid foods. To collect data, a systematic online search was implemented. Appropriate univariate and bivariate statistics were computed, and the level of significance was set at .05; in addition, 95% confidence intervals were calculated.

RESULTS

The study sample was composed of 431 oral and maxillofacial surgeons (OMSs). Almost all of the study sample (99.1%) did not adopt the ASA guidelines. The fasting recommendations were different from 2 hours for clear liquids and 6 hours for solid foods. However, recommendations of 2 hours or greater for clear liquids were made by 99.8% of OMSs, and recommendations of 6 hours or greater for solid foods were made by 99.3%. Only 4.4% of OMSs made different recommendations for clear liquids and solid foods. No substantial association was found between whether OMSs adopted the most current ASA guidelines and the year they graduated from residency or the obtainment of dual degrees.

CONCLUSIONS

OMSs in private practice are overwhelmingly recommending longer fasting times for clear liquids and solid foods on their Web sites when compared with the current ASA guidelines before ambulatory anesthesia. The ASA guidelines are based on meta-analysis; therefore, deviations in practice, although not incorrect, may call for discussion.

Fasting of less than eight hours in urgent and emergency surgeries versus complication

OBJECTIVE

to verify the occurrence of intraoperative and postoperative complications in patients undergoing urgent and emergency surgical procedures between January and December 2012, with fasting time of less than 8 hours.

METHOD

a quantitative study was conducted, of the retrospective cohort type, through the analysis of medical records.

RESULTS

we included 181 records of patients undergoing surgical procedures with average duration of 59.4 minutes. Fractures correction surgeries stood out, totalling 32% of cases. We observed complications in 36 patients (19.9%), vomiting being the most prevalent (47.2%); followed by nausea (16.7%); need for blood transfusion (13.9%); surgical site infection (11.1%); and death (11.1%). The average fasting time was 133.5 minutes. The fasting time showed no statistically significant correlation with the complications investigated.

CONCLUSION

intraoperative and postoperative complications were associated with the clinical conditions of the patients and not with the fasting time.

Preoperative fasting times in elective surgical patients at a referral Hospital in Botswana

Introduction

Adults and children are required to fast before anaesthesia to reduce the risk of regurgitation and aspiration of gastric contents. However, prolonged periods of fasting are unnecessary and may cause complications. This study was conducted to evaluate preoperative fasting period in our centre and compare it with the ASA recommendations and factors that influence fasting periods.

Methods

This is a cross-sectional study of preoperative fasting times among elective surgical patients. A total numbers of 260 patients were interviewed as they arrived at the reception area of operating theatre using questionnaire.

Results

Majority of patients (98.1%) were instructed to fast from midnight. Fifteen patients (5.8%) reported that they were told the importance of preoperative fasting. The mean fasting period were 15.9±2.5 h (range 12.0-25.3 h) for solids and 15.3±2.3 h (range 12.0-22.0 h) for liquids. The mean duration of fasting was significantly longer for patients operated after midday compared to those operated before midday, p<0.001.

Conclusion

The mean fasting periods were 7.65 times longer for clear liquid and 2.5 times for solids than the ASA guidelines. It is imperative that the Hospital should establish Preoperative fasting policies and teach the staff who should ensure compliance with guidelines.

Randomized Controlled Trial Assessing the Feasibility of Shortened Fasts in Intubated ICU Patients Undergoing Tracheotomy

Objective

American Society of Anesthesiology guidelines recommend preoperative fasts of 6 hours after light snacks and 8 hours after large meals. These guidelines were designed for healthy patients undergoing elective procedures but are often applied to intubated intensive care unit (ICU) patients. ICU patients undergoing routine procedures may be subjected to unnecessary prolonged fasts. This study tests whether shorter fasts allow for better nutrition delivery and patient outcomes without increasing the risk.

Study Design

Randomized blinded controlled trial.

Setting

Tertiary academic medical center.

Subjects

ICU patients undergoing bedside tracheotomy.

Methods

Intubated ICU patients who were receiving enteral feeding and for whom bedside tracheotomy was indicated were enrolled prospectively and randomly allocated to 2 parallel preoperative fasting regimens: a 6-hour fast (control) and a 45-minute fast (intervention). Patients were assessed for aspiration, caloric delivery, metabolic markers, and infectious and noninfectious complications.

Results

Twenty-four patients were enrolled and randomized. There were no complications related to the procedure. There were no cases of intraoperative aspiration identified. There was a single postoperative pneumonia in the control group. Median (interquartile range) length of fast and caloric delivery were significantly different between the control group and the shortened fast group: 22 hours (18, 34) vs 14 hours (5, 25; P < .001) and 429 kcal (57, 1125) vs 1050 kcal (825, 1410; P = .01), respectively.

Conclusions

Shortening preoperative fasts in intubated ICU patients allowed for better caloric delivery in the preoperative period.

A qualitative study into the impact of fasting within a large tertiary hospital in Australia--the patients' perspective

AIMS AND OBJECTIVES

This qualitative study aims to explore the physical and emotional impact of fasting from the patients' perspective.

BACKGROUND

Fasting patients in hospital is common practice and generally viewed as necessary for symptom management or for safety of healthcare provision. Negative impacts of repeated or prolonged fasting on nutritional status have been well researched, but little is documented as to how fasting impacts an individual patient's psyche.

DESIGN

Qualitative descriptive design within a tertiary hospital in Sydney, Australia.

METHODS

Twelve patients having had prolonged periods of continuous or intermittent fasting were invited to participate in a semi-structured interview between January-September 2012. Questions for interview explored each patient's experience of fasting, including physical and emotional impacts, interpretation of communication regarding fasting and the process of recommencing on fluids or foods. An inductive thematic analysis approach was used.

RESULTS

Analyses showed six main themes: physical impacts; emotional impacts; food as structure; nil by mouth as jargon; fear of food re-introduction; and dissatisfaction regarding unnecessary fasting. Overwhelmingly, thirst was reported as the worst physical effect of fasting. In the first few days of fasting, patients became emotionally fixated on food. This quickly dissipated leading to a lack of appetite and fear of starting to eat again.

CONCLUSIONS

Discomfort experienced by patients coupled with lack of appetite resulting from prolonged fasting and difficulty with food re-introduction strengthens the argument for reducing fasting times in hospital. When patients are fasted, proper hydration and establishing alternate routes of medication administration should be a priority.

RELEVANCE TO CLINICAL PRACTICE

It is well recognised that fasting for prolonged periods is detrimental to health outcomes, but this study also shows the distress that fasting can cause. Inadequate hospital systems and out-dated practices need to be replaced with evidence-based, patient-centred governance, addressing the physical, emotional and psychosocial impact of fasting.