Reducing preoperative fasting time: A trend based on evidence

Actual preoperative fasting time in Brazilian hospitals: the BIGFAST multicenter study

Background

Prolonged fasting increases organic response to trauma. This multicenter study investigated the gap between the prescribed and the actual preoperative fasting times in Brazilian hospitals and factors associated with this gap.

Methods

Patients (18–90-years-old) who underwent elective operations between August 2011 and September 2012 were included in the study. The actual and prescribed times for fasting were collected and correlated with sex, age, surgical disease (malignancies or benign disease), operation type, American Society of Anesthesiologists score, type of hospital (public or private), and nutritional status.

Results

A total of 3,715 patients (58.1% females) with a median age of 49 (18–94) years from 16 Brazilian hospitals entered the study. The median (range) preoperative fasting time was 12 (2–216) hours, and fasting time was longer (P<0.001) in hospitals using a traditional fasting protocol (13 [6–216] hours) than in others that had adopted new guidelines (8 [2–48] hours). Almost 80% (n=2,962) of the patients were operated on after 8 or more hours of fasting and 46.2% (n=1,718) after more than 12 hours. Prolonged fasting was not associated with physical score, age, sex, type of surgery, or type of hospital. Patients operated on due to a benign disease had an extended duration of preoperative fasting.

Conclusion

Actual preoperative fasting time is significantly longer than prescribed fasting time in Brazilian hospitals. Most of these hospitals still adopt traditional rather than modern fasting guidelines. All patients are at risk of long periods of fasting, especially those in hospitals that follow traditional practices.

Preoperative carbohydrate nutrition reduces postoperative nausea and vomiting compared to preoperative fasting

BACKGROUND

The aim of this prospective, randomized, single-blinded study was to compare the effects of a carbohydrate drink 400 mL given 2 h before the surgery with preoperative overnight fasting on the gastric pH and residual volume, postoperative nausea and vomiting (PONV) and antiemetic consumption in patients undergoing laparoscopic cholecystectomy.

MATERIALS AND METHODS

Forty American Society of Anesthesiologists physical status I-II patients who underwent elective laparoscopic cholecystectomy. Randomized, prospective, controlled study, Gulhane Medical Faculty and Guven Hospital Department of Anesthesiology and Reanimation. Patients were randomly assigned into two groups: Pre-operative carbohydrate drink group (group C, n = 20) and preoperative fasting group (group F, n = 20). Group C was given a 400 mL carbohydrate drink 2 h before to the surgery. The patients of group F were fasted 8 h before the surgery. Both groups were operated under general anesthesia with volatile anesthetics.

RESULTS

Hemodynamic parameters, demographic data, gastric acidity and residual volumes were similar for both groups. No complications were observed. PONV and antiemetic consumption was lower in group C compared to group F (P = 0.001). Patient's satisfaction was higher in group C (P < 0.001).

CONCLUSION

This study showed that pre-operative carbohydrate drink may be used safely and also improves patient's satisfaction and comfort in patients undergoing laparoscopic cholecystectomy.

Effects of preoperative oral carbohydrate solution intake on thermoregulation

BACKGROUND

We aimed to investigate the oral carbohydrate solution administered preoperatively on thermoregulation.

MATERIAL AND METHODS

The study included 40 female patients under general anesthesia. Patients were randomly divided into 2 groups: Group CONT (stopped oral implementation 8 h before the operation) and Group CHO (800ml oral carbohydrate fluid 8 h before the operation and 400ml oral carbohydrate fluid 2 h before the operation). Patients were monitored as standard and temperature probes were placed. Temperatures were recorded immediately before anesthetics induction, 5 min after the anesthetics induction, and in the post-anesthesia care unit (PACU) every 10 min. Mean skin temperature (Tsk), mean body temperature (Tb), and vasoconstriction threshold were estimated.

RESULTS

In general, we observed a decrease in tympanic temperature and Tb following anesthetic administration in groups, and increase in Tsk, and an increase in all 3 of these levels in the recovery unit. Tympanic temperature was significantly higher at 25, 55, 65, and 95 min after induction in Group CONT compared to Group CHO (p<0.05). Tsk was found to be lower in Group CONT compared to Group CHO in almost all periods. In PACU, it was found that the tympanic temperature was higher in Group CONT compared to Group CHO at 60 min (p<0.05). Postoperative shivering score was found to be significantly higher in Group C (p<0.01). Vasoconstriction threshold was higher in Group CONT than Group CHO.

CONCLUSIONS

Oral carbohydrate solution administered was established to have effects thought to be negative on tympanic temperature, vasoconstriction, and vasoconstriction threshold.

Periprocedural cessation of nutrition in the intensive care unit: opportunities for improvement

PURPOSE

Delivery of enteral nutrition (EN) to ICU patients is commonly interrupted for diagnostic and therapeutic procedures. We investigated this practice in a cohort of trauma and surgical ICU patients.

METHODS

This was a retrospective single-center study conducted in a 15-bed trauma ICU of a university-affiliated teaching hospital. Descriptive statistics were used.

RESULTS

Of 69 patients assessed, 41 had 121 planned procedures over a mean ICU length of stay of 18.7 days (SD 9.6 days). EN was stopped prior to 108 (89 %, 95 % CI 82-94 %) of these 121 procedures, and 102 of these cessation episodes were related to the planned procedure. EN was stopped in 37 patients for a mean cumulative duration of 30.8 h (SD 22.7 h) per patient, which represented 7.9 % (SD 6.9 %) of the mean total time spent in the ICU leading to a mean energy and protein deficit of 7.2 % (SD 8.5 %) and 7.7 % (SD 9.6 %), respectively. Of the 121 planned procedures, 27 (22 %, 95 % CI 16-31 %) were postponed beyond the scheduled day. For 32 (31 %, 95 % CI 23-41 %) of the 102 EN cessation episodes, EN was stopped without a documented order and 23 (23 %, 95 % CI 16-32 %) episodes were not deemed necessary based on the institution's guidelines.

CONCLUSION

In this ICU cohort, EN cessation for planned procedures was frequent and led to a nutritional deficit due to long periods without EN being delivered. Postponement of procedures and clinically unnecessary EN cessation were important factors that prevented delivery of planned nutrition. EN cessation practice should be a focus for improving EN delivery in ICU patients.

Preoperative fasting in children: An audit and its implications in a tertiary care hospital

Background:

Prolonged preoperative fasting in children is a common problem, especially in highvolume centers. All international professional society guidelines for preoperative fasting recommend 2 h for clear fluids, 4 h for breast milk and 6 h for solids, nonhuman and formula milk in children. These guidelines are rarely adhered to in practice.

Aims:

An audit was undertaken to determine the length of preoperative fasting time in children and its causes.

Settings and Design:

Cross-sectional study of 50 children below 15 years posted for elective surgeries.

Materials and Methods:

An initial audit was performed at our institution on preoperative fasting time in 50 children below 15 years of age for elective surgeries. The mean preoperative fasting times were found to be much longer than the recommended times. Ward nurses were then educated about internationally recommended preoperative fasting guidelines in children. Anesthesiologists started coordinating with surgeons and ward nurses to prescribe water for children waiting for more than 2 h based on changes in surgery schedule by instructing ward nurses through telephone on the day of surgery. A reaudit was done 6 months after the initial audit.

Statistical Analysis Used:

SPSS 16 software.

Results:

The initial audit revealed a mean preoperative fasting time of 11.25 h and 9.25 h for solids and water, respectively. Incorrect orders by ward nurses (74%) and change in the surgical schedule (32%) were important causes. After changing the preoperative system, mean preoperative fasting times in children decreased to 9 h and 4 h for solids and water, respectively in reaudit. Change in surgical schedule (30%) was the major cause for prolonged preoperative fasting in reaudit.

Conclusions:

Simple steps such as education of ward nurses and better coordination among the anesthesiologists, surgeons and nurses can greatly reduce unnecessary preoperative starvation in children.

Controversies in obstetric anesthesia

Obstetric anesthesia has become a widely evidence-based practice, with an increasing number of specialized anesthesiologists and a permanent research production. We believe that with the review of commonly discussed and controversial points the reader will be able to incorporate an evidence-based practice into their routine and offer to parturients and their babies a safe, reliable and consistent anesthesia care.

The effects of carbohydrate-rich drink on perioperative discomfort, insulin response and arterial pressure in spinal aesthesia

BACKGROUND

The aim of this study was to investigate the role of carbohydrate-rich drink (CHO) on perioperative discomfort, hemodynamic changes, and insulin response in patients undergoing surgery with spinal anesthesia.

METHODS

Forty-four adult patients were assigned to one of the two groups of 22, namely preparation with CHO (CHO group) or fasting from midnight (control group). Ten different discomfort variables, blood glucose and insulin concentrations, and hemodynamic changes were recorded during the perioperative period.

RESULTS

Preparation with CHO was effective in reducing hunger, thirst, malaise, unfitness, and, to some extent, anxiety (p < 0.05). Plasma glucose and insulin concentrations were increased in the CHO group (p < 0.05). Plasma glucose increased and insulin decreased in the control group (p < 0.05). In the control group, mean arterial pressure was lower compared to the CHO group (p < 0.05).

CONCLUSIONS

Preparation with CHO before spinal anesthesia is advantageous due to reducing perioperative discomfort, improving insulin response and stabilizing mean arterial pressure.

Preoperative fasting: will the evidence ever be put into practice?

OVERVIEW

Decades of research support the safety and health benefits of consuming clear liquids, including those that are carbohydrate rich, until a few hours before elective surgery or other procedures requiring sedation or anesthesia. Still, U.S. clinicians routinely instruct patients to fast for excessively long preoperative periods. Evidence-based guidelines, published over the past 25 years in the United States, Canada, and throughout Europe, recommend liberalizing preoperative fasting policies. To improve patient safety and health care quality, it's essential that health care professionals abandon outdated preoperative fasting policies and allow available evidence to guide preanesthetic practices.

Reducing preoperative fasting in elective adult surgical patients: a case-control study

BACKGROUND

The practice of fasting from midnight prior to surgery is an outdated one.

AIMS

The aim of this study was to assess the impact of an evidence-based protocol for reduced preoperative fasting on fasting times, patient safety, and comfort.

METHODS

A non-randomised case-control study of preoperative fasting times among adult surgical patients undergoing elective procedures was conducted. Consecutive patients were allocated to a reduced preoperative fasting protocol allowing fluids and solids up to 2 and 6 h prior to anaesthesia, respectively (n = 21). These were compared to control patients identified from an historic study of preoperative fasting times who followed the traditional fast from midnight (n = 29). Fasting times and details of patients' subjective comfort were collected using an interview-assisted questionnaire. Incidence of intraoperative aspirations was obtained from anaesthetic records.

RESULTS

Significant reductions in fasting times for fluids (p = 0.000) and solids (p = 0.000) were achieved following implementation of the fasting protocol. Less preoperative thirst (0.000), headache (0.012) and nausea (0.015) were reported by those who had a shorter fast. Intraoperative aspiration did not occur in either group.

CONCLUSION

Implementation of this protocol for reduced preoperative fasting achieved an appreciable reduction in fasting times and enhanced patient comfort. Patient safety was not compromised. Further modifications of our protocols are necessary to meet the international best practice. We recommend its implementation across all surgical groups in our institution.

"Nil per oral after midnight": Is it necessary for clear fluids?

Fasting before general anaesthesia aims to reduce the volume and acidity of stomach contents, thus reducing the risk of regurgitation and aspiration. Recent guidelines have recommended a shift in fasting policies from the standard ‘nil per oral from midnight’ to a more relaxed policy of clear fluid intake a few hours before surgery. The effect of preoperative oral administration of 150 ml of water 2 h prior to surgery was studied prospectively in 100 ASA I and II patients, for elective surgery. Patients were randomly assigned to two groups. Group I (n = 50) was fasting overnight while Group II (n = 50) was given 150 ml of water 2 h prior to surgery. A nasogastric tube was inserted after intubation and gastric aspirate was collected for volume and pH. The gastric fluid volume was found to be lesser in Group II (5.5 ± 3.70 ml) than Group I (17.1 ± 8.2 ml) which was statistically significant. The mean pH values for both groups were similar. Hence, we conclude that patients not at risk for aspiration can be allowed to ingest 150 ml water 2 h prior to surgery.