Fasting guidelines in different countries

Effect of Preoperative Oral Carbohydrate Administration on Patients Undergoing Cesarean Section with Epidural Anesthesia: A Pilot Study

PURPOSE

The aim of this study was to evaluate the effect of preoperative oral carbohydrate administration on patients undergoing Cesarean section with epidural anesthesia.

DESIGN

Randomized controlled clinical study.

METHODS

A total of 75 patients undergoing Cesarean section (American Society of Anesthesiologists physical status grade I-II) were randomized to preparation with a carbohydrate drink (CHO group), flavored water (placebo group), or to the fasting group. The CHO and placebo groups were double-blinded and given 300 mL of the drink 2 hours before surgery. Visual analog scores of the patient were assessed to evaluate thirst, hunger, and anxiety level, and the gastric antral cross-sectional areas were recorded by ultrasonography during the operative period. Insulin resistance was calculated on the basis of the blood glucose and insulin levels assessed before administration and after surgery.

FINDINGS

The CHO and placebo groups did not show an increase in gastric fluid volumes in terms of gastric antral cross-sectional area, and there were no adverse events. The visual analog scale scores at preoperative baseline were not different between groups . During the preoperative waiting period, preparation with CHO reduced not only thirst and anxiety more efficiently than water (placebo) but also hunger (P < .05), whereas water did not. No difference was observed in insulin resistance between groups before intake of the drink. Compared with the preoperative levels, insulin resistance showed a statistically significant increase in all groups (P < .05); however, the increase was significantly higher in the fasting and placebo groups than in the CHO group (P < .05).

CONCLUSIONS

Preoperative administration of CHO decreases postoperative insulin resistance and enhances pregnant women's comfort, leading to a reduced sense of thirst, hunger, and anxiety during the preoperative period for Cesarean section.

Advancing the Time to the Initiation of Adjuvant Chemotherapy and Improving Postoperative Outcome: Enhanced Recovery after Surgery in Pancreaticoduodenectomy

Early initiation of chemotherapy could improve overall survival after pancreaticoduodenectomy (PD). The concept of enhanced recovery after surgery (ERAS), which aims to reduce the stress response to surgery and accelerate recovery, is relatively limited in PD. The aim of the study was to retrospectively analyze the relationships of ERAS with the time of initiation of postoperative chemotherapy and recovery in PD patients. Between January 1, 2008 and December 31, 2017, all patients who underwent open PD for malignant tumor at our unit were studied retrospectively. Patients were divided into ERAS and conventional groups. The time to initiation of adjuvant chemotherapy and postoperative outcomes were analyzed. There were 344 consecutive patients in this study, with 203 patients in the ERAS group. There were no significant differences between the ERAS and conventional groups in morbidity, mortality, and readmission. The median time of initiation of adjuvant chemotherapy in the ERAS group (54.1 days) was significantly shorter than that of initiation of adjuvant chemotherapy in the conventional group (67.8 days). The ERAS group had a shorter postoperative length of stay than the conventional group (14.9 vs 19.3 days). The ERAS program is safe and feasible in PD. These protocols improve postoperative recovery and advance the time of initiation of adjuvant chemotherapy.

Enhanced Recovery After Surgery (ERAS®) in thoracic surgical oncology

Enhanced recovery after surgery (ERAS®) is a strategy that seeks to reduce patients’ perioperative stress response, thereby reducing potential complications, decreasing hospital length of stay and enabling patients to return more quickly to their baseline functional status. The concept was introduced in the late 1990s and was first adopted for use with patients undergoing open colorectal surgery. Since that time, the concept of ERAS has spread to multiple surgical specialties. This article explores the key elements for patient care using an ERAS protocol applied to minimally invasive thoracic surgery.

A Carbohydrate-Rich Beverage Prior to Surgery Prevents Surgery-Induced Immunodepression: A Randomized, Controlled, Clinical Trial

BACKGROUND

Fasting before surgery is still common care in a lot of western hospitals. Overnight fasting can induce postoperative insulin resistance. Insulin resistance has been shown to be related to infectious morbidity. It was shown that postoperative insulin resistance can be attenuated by preoperative intake of a clear carbohydrate-rich beverage. The aim of this study was to investigate whether preoperative intake of carbohydrate-rich beverages could postoperatively influence the immune system.

METHODS

In this randomized, controlled study, we investigated the effect of surgery on the postoperative immune response in 10 preoperatively fasted patients (control) and 2 groups of 10 patients receiving 2 different carbohydrate-rich beverages preoperatively, by measuring human leukocyte antigen (HLA)-DR expression on monocytes on the day before and on the day after surgery. Furthermore, we studied perioperative fluid homeostasis and preoperative well-being of the patients.

RESULTS

HLA-DR expression decreased significantly after surgery in the control group. Patients receiving any of the 2 carbohydrate-rich beverages did not show this postoperative decrease. Fluid homeostasis was not affected in any of the groups, and well-being tended to be better in patients receiving carbohydrate-rich beverages compared with controls.

CONCLUSION

This study suggests that preoperative intake of a carbohydrate-rich beverage can prevent surgery-induced immunodepression and thus might reduce the risk of infectious complications.

A “Light Meal” Three Hours Preoperatively Decreases the Incidence of Gastro-Esophageal Reflux in Dogs

Emerging evidence from veterinary and medical clinical research shows that reducing preoperative fasting time may reduce the incidence of gastro-esophageal reflux (GER) intraoperatively. In order to evaluate the effect of two different preoperative fasting times on the incidence of GER during general anesthesia, 120 dogs were randomly assigned to two groups: administration of canned food 3 h before premedication (group C3, n = 60) and administration of canned food 10 h before premedication (group C10, n = 60). The animals were premedicated with propionyl-promazine. Anesthesia was induced with thiopental sodium and maintained with halothane. A pH electrode was introduced into the esophagus, and the esophageal pH was constantly monitored. Esophageal pH of less than 4 or greater than 7.5 was taken as an indication of GER. Three of the 60 dogs of group C3 and 12 of the 60 dogs of group C10 experienced a GER episode, the difference being statistically significant (P = .025). Feeding the dog 3 h before anesthesia at a half daily rate reduces significantly the incidence of GER during anesthesia, compared to the administration of the same amount and type of food 10 h before anesthesia. The administration of a half daily dose of an ordinary canine diet may be useful in clinical practice.

Perioperative care with fast-track management in patients undergoing pancreaticoduodenectomy

BACKGROUND

It has been considered that allowing patients to return to daily life earlier after surgery helps recovery of physiological function and reduces postoperative complications and hospital stay. We investigated the usefulness of fast-track management in perioperative care of patients undergoing pancreaticoduodenectomy (PD).

METHODS

Patients (n = 90) who received conventional perioperative management from 2005 to 2009 were included as the 'conventional group' (historical control group), and patients who received perioperative care with fast-track management (n = 100) from 2010 to March 2013 were included as the 'fast-track group'. To evaluate the efficacy of perioperative care with fast-track management, the incidence of postoperative complications and the length of hospital stay were compared between the two groups (comparative study). For statistical analysis, univariate analysis was performed using the χ (2) test or Fisher's exact test.

RESULTS

There was no significant difference between the two groups in sex, mean age, presence/absence of diabetes mellitus, preoperative drainage for jaundice, previous disease, operative procedure, mean duration of operation, or blood loss (p < 0.01). The incidence of surgical site infection in the conventional group and fast-track group was 28.9 and 14.0 %, respectively, with a significant difference between the two groups (p = 0.019). In addition, the incidence of pancreatic fistula (grade B, C) significantly differed between the two groups (27.8 % in the conventional group, 9.0 % in the fast-track group; p = 0.001). The mean postoperative hospital stay was 36.3 days in the conventional group and 21.9 days in the fast-track group (p < 0.001).

CONCLUSIONS

Perioperative care with fast-track management may reduce postoperative complications and decrease the length of hospital stay in patients undergoing PD.

Improved patient education facilitates adherence to preoperative fasting guidelines

Preoperative fasting is recognised as an important factor in perioperative patient care. Implementation of guidelines on preoperative fasting remains sub-optimal. We audited perioperative fasting in a district general hospital, implemented changes to the preoperative information leaflet and improved fasting practices. The manner in which information is presented to patients impacts behavior and adherence to recommendations. Improving this domain of clinical practice requires thorough and conscious effort and repeated reassessment.

Single-dose carbohydrate treatment in the immediate preoperative phase diminishes development of postoperative peripheral insulin resistance

BACKGROUND & AIMS

Preoperative oral carbohydrate (CHO) treatment is known to reduce postoperative insulin resistance, but the necessity of a preoperative evening dose is uncertain. We investigated the effect of single-dose CHO treatment two hours before surgery on postoperative insulin sensitivity.

METHODS

Thirty two pigs (∼ 30 kg) were randomized to 4 groups (n = 8) followed by D-[6,6-(2)H2] glucose infusion and hyperinsulinemic-euglycemic step clamping. Two groups received a morning drink of 25 g carbohydrate (CHO/surgery and CHO/control). Animals in the other two groups were fasted overnight (fasting/surgery and fasting/control). Counter-regulatory hormones, free fatty acids (FFA) and liver and muscle glycogen content were measured serially.

RESULTS

Glucose infusion rates needed to maintain euglycemia were higher after CHO/surgery than fasting/surgery during low (8.54 ± 0.82 vs. 6.15 ± 0.27 mg/kg/min, P < 0.05), medium (17.26 ± 1.08 vs. 14.02 ± 0.56 mg/kg/min, P < 0.02) and high insulin clamping (19.83 ± 0.95 vs. 17.16 ± 0.58 mg/kg/min, P < 0.05). The control groups exhibited identical insulin sensitivity. Compared to their respective controls, insulin-stimulated whole-body glucose disposal was significantly reduced after fasting/surgery (-41%, P < 0.001), but not after CHO/surgery (-16%, P = 0.180). CHO reduced FFA perioperatively (P < 0.05) and during the clamp procedures (P < 0.02), but did not affect hepatic insulin sensitivity, liver and muscle glycogen content or counter-regulatory hormone profiles. A strong negative correlation between peripheral insulin sensitivity and mean cortisol levels was seen in fasted (R = -0.692, P = 0.003), but not in CHO loaded pigs.

CONCLUSIONS

Single-dose preoperative CHO treatment is sufficient to reduce postoperative insulin resistance, possibly due to the antilipolytic effects and antagonist properties of preoperative hyperinsulinemia on the suppressant actions of cortisol on carbohydrate oxidation.

Parenteral nutrition and preOp preparation in prevention of post-operative insulin resistance in gastrointestinal carcinoma

PURPOSE

The aim was to compare preventive effect of total parenteral nutrition (TPN) and oral nutrition (preOp) on the perioperative insulin resistance prevention in surgical gastrointestinal cancer patients.

MATERIAL/METHODS

The study was conducted in a group of 75 elective gastric and large intestine cancer patients. Patients were randomly divided into 3 study groups, 25 patients each: group I (NIL) - no preparations influencing tissue sensitivity to insulin, group II (TPN) - total parenteral nutrition in its preoperative stage and group III (TPN + preOp) parenteral nutrition and preOp in the preoperative phase.

RESULTS

Immediately after the surgery, no statistically significant differences in insulin resistance level between groups were observed. During the first 6 postoperative hours, a statistically significant decrease of insulin resistance level in the TPN+ preOp group in comparison to others, was observed. During the first 24 postoperative hours, the NIL group was the only one to keep the insulin resistance level the same as in the preoperative phase.

CONCLUSIONS

Application of TPN in the preoperative phase leads to shortening of perioperative insulin resistance time. Combining TPN with oral application of carbohydrate before surgical procedure is an effective and the best method in postoperative insulin resistance syndrome prevention.

Guidelines for perioperative care in elective colonic surgery: Enhanced Recovery After Surgery (ERAS®) Society recommendations

BACKGROUND

This review aims to present a consensus for optimal perioperative care in colonic surgery and to provide graded recommendations for items for an evidenced-based enhanced perioperative protocol.

METHODS

Studies were selected with particular attention paid to meta-analyses, randomised controlled trials and large prospective cohorts. For each item of the perioperative treatment pathway, available English-language literature was examined, reviewed and graded. A consensus recommendation was reached after critical appraisal of the literature by the group.

RESULTS

For most of the protocol items, recommendations are based on good-quality trials or meta-analyses of good-quality trials (quality of evidence and recommendations according to the GRADE system).

CONCLUSIONS

Based on the evidence available for each item of the multimodal perioperative-care pathway, the Enhanced Recovery After Surgery (ERAS) Society, International Association for Surgical Metabolism and Nutrition (IASMEN) and European Society for Clinical Nutrition and Metabolism (ESPEN) present a comprehensive evidence-based consensus review of perioperative care for colonic surgery.

The impact and safety of preoperative oral or intravenous carbohydrate administration versus fasting in colorectal surgery--a randomized controlled trial

BACKGROUND AND AIMS

Increasing evidence suggests that preoperative fasting, as was the clinical practice for many decades, might be associated with untoward consequences and that a standardized preoperative intake of nutrients might be advantageous; this is a component of the enhanced recovery after surgery (ERAS) concept. Thus, in a randomized controlled trial we compared preoperative fasting with preoperative preparation with either oral or intravenous intake of carbohydrates, minerals and water. Biochemical, psychosomatic, echocardiographic and muscle-power parameters were assessed in surgical patients with colorectal diseases during the short-term perioperative period. We also assessed the safety of peroral intake shortly before surgery.

METHODS

A total of 221 elective colorectal surgery patients in this bicentric, randomized, prospective and blinded clinical trial were divided into three groups: A - patients fasting from midnight (control group); B - patients supported preoperatively by glucose, magnesium and potassium administered intravenously; C - patients supported preoperatively by oral consumption of a specifically composed solution (potion).

RESULTS

The general perioperative clinical status of patients in groups C and B was significantly better than those in group A. Psychosomatic conditions postoperatively were found to be best in group C (P < 0.029). The rise in the index of insulin resistance (QUICKI) from the preoperative to the postoperative state was significant in group A (P < 0.05). The systolic and diastolic function of the left ventricle improved postoperatively in group C vs. group A (P < 0.04), and the ejection fraction was also significantly higher postoperatively in group C vs. group A (P < 0.03). The gastric residual volume was 5 ml and the pH of stomach juice was 3.5-5 in all groups without statistically significant difference. No difference was found in the length of hospital stay or the rate of complications.

CONCLUSIONS

Preoperative fasting does not confer any benefit or advantage for surgical patients. In contrast, consumption of an appropriate potion composed of water, minerals and carbohydrates offers some protection against surgical trauma in terms of metabolic status, cardiac function and psychosomatic status. Peroral intake shortly before surgery did not increase gastric residual volume and was not associated with any risk.

A carbohydrate-rich drink shortly before surgery affected IGF-I bioavailability after a total hip replacement. A double-blind placebo controlled study on 29 patients

BACKGROUND AND AIMS

In response to surgical stress, the body reacts with a change in metabolism to a catabolic state. This is further aggravated by the fasting state preoperatively. We aimed to determine the effects on catabolism i.e., body composition and IGF-I bioavailability as measured by the serum IGF-I/IGFBP-1 ratio, of a carbohydrate rich drink given shortly before surgery.

METHODS

Twenty-nine patients scheduled for a total hip replacement (THR) were randomized in a double-blind placebo-controlled pilot study to a carbohydrate-rich drink or to placebo pre-operatively. The nutritional supplementation consisted of an iso-osmolar carbohydrate-rich drink (12.5 g carbohydrates/100 ml, pH 5.0). Fasting blood samples were collected before surgery and repeated after 5 days and after 2 months. IGF-I and IGFBP-1 were determined in serum by RIA. Body composition was determined by dual energy X-ray absorptiometry (DXA).

RESULTS

Compared with placebo we found a relative increase in IGF-I bioavailability post-operatively after a carbohydrate-rich drink given shortly before surgery. There were no significant longterm differences in the changes in fat or lean body mass between groups, but, in a subgroup with late scheduled surgery, there was a tendency to a difference (p=0.08) of fat loss after 2 months, with less fat loss in those who received another carbohydrate drink close to surgery. The pre-operative intake of a 200-200 x 2 ml carbohydrate drink was well tolerated and safe. There were no adverse events such as pulmonary aspiration before, during or after operation.

CONCLUSIONS

A carbohydrate- rich drink given shortly before surgery increases IGF-I bioavailability post-operatively in patients undergoing a THR, but has no significant effects on body composition after 2 months in physically active people. We suggest that, if the operation is postponed for more than four hours on the same day, an additional carbohydrate drink should be given.

Carbohydrate supplementation before operation retains intestinal barrier function and lowers bacterial translocation in a rat model of major abdominal surgery

BACKGROUND

Overnight fasting of rats augments the susceptibility of the small intestine to ischemia-reperfusion damage. Feeding before surgery may improve injuries to distant organs that were induced by ischemia-reperfusion. The present study tested the hypothesis that one of the food constituents, namely carbohydrates, may be responsible for the protective effect of preoperative feeding on postoperative organ dysfunction.

METHODS

Male Wistar rats were fed ad libitum for 5 d and had either free access to water or free access to a carbohydrate drink and water. Then they were fasted for 16 h and access remained to either water or a carbohydrate drink and water. Following this, the arteria mesenterica superior was clamped for 60 min followed by 180 min of reperfusion. Subsequently, the intestinal permeability of stripped ileum was determined by measuring the mucosal to serosal flux in Ussing chambers. For assessment of bacterial content, organs were aseptically removed and assessed for bacterial content by culture under anaerobic conditions.

RESULTS

Preoperative supplementation with carbohydrates resulted in a better maintenance of intestinal barrier function when compared with water supplemented animals. Moreover, carbohydrate supplementation resulted in a reduction in the ischemiareperfusion-induced increase in bacterial content of the liver, kidney, and mesenteric lymph nodes.

CONCLUSIONS

Preoperative intake of carbohydrates by rats retains both the intestinal barrier function and prevents translocation of bacteria to distant organs.

The resistance to changing guidelines – what are the challenges and how to meet them

Bridging the gap between scientific evidence and its practical application is of the utmost importance in improving the quality of care and increasing patient safety. Guidelines based on evidenced-based medicine (EBM) have led to improved performances and better outcomes. However, even though scientific data are available, resistance to adopting evidence-based guidelines is still enormous. Significant barriers hinder the introduction of best medical practice into the daily clinical routine. The barriers to implementing change are complex, multifunctional, and influenced on many levels by various interests both inside and outside the health-care system. Political, organizational, financial, cultural and scientific interests are regarded as being as important as the perception of patients and health workers. Strategies need to be planned which take account of the multidimensional character of quality of care and incorporate it at the various levels. The conclusion, therefore, is that we need to combine methods and tools to tailor our interventions to the patient's needs.

Effect of "preoperative" oral carbohydrate treatment on insulin action--a randomised cross-over unblinded study in healthy subjects

BACKGROUND AND AIMS

Preoperative intake of a clear carbohydrate-rich drink reduces insulin resistance after surgery. In this study, we evaluated whether this could be related to increased insulin sensitivity at the onset of surgery. Furthermore, we aimed to establish the optimal dose-regimen.

METHODS

Six healthy volunteers underwent hyperinsulinaemic (0.8 mU/kg/min), normoglycaemic (4.5 mmol/l) clamps and indirect calorimetry on four occasions in a crossover-randomised order; after overnight fasting (CC), after a single evening dose (800 ml) of the drink (LC), after a single morning dose (400 ml, CL) and after intake of the drink in the evening and in the morning before the clamp (LL). Data are presented as mean+/-SD. Statistical analysis was performed using the Student's t-test and ANOVA.

RESULTS

Insulin sensitivity was higher in CL and LL (9.2+/-1.5 and 9.3+/-1.9 mg/kg/min, respectively) compared to CC and LC (6.1+/-1.6 and 6.6+/-1.9 mg/kg/min, P<0.01 vs. CL and LL).

CONCLUSIONS

A carbohydrate-rich drink enhances insulin action 3 h later by approximately 50%. Enhanced insulin action to normal postprandial day-time level at the time of onset of anaesthesia or surgery is likely to, at least partly, explain the effects on postoperative insulin resistance.

Current practice of preoperative fasting: a nationwide survey in Japanese anesthesia-teaching hospitals

PURPOSE

We conducted a nationwide survey to investigate the current practice of the preoperative fasting period in Japanese anesthesia-teaching hospitals. Acceptance of the clinical practice guideline published by the American Society of Anesthesiologists (ASA) was also surveyed.

METHODS

A written type of questionnaire was mailed to 795 teaching hospitals.

RESULTS

The response rate of the questionnaires was 57%. Most (>90%) of the respondents had been applying a longer fasting period than the ASA-recommended minimum period specifically in adults; the median duration of fasting was 12-13 h for solids and 6-9 h for liquids. Children or infants were allowed a more liberalized fasting period, frequently being permitted an oral intake of clear fluids up to 3 h before anesthesia. The incidence of pulmonary aspiration was 1/12,500 general anesthesia cases, and application of the ASA guideline appeared not to affect the incidence. Japanese anesthesiologists were still reluctant to depart from their traditional long fasting periods, as most of them could find little benefit in reducing the fasting periods.

CONCLUSION

The long preoperative fasting period is still common practice in Japanese anesthesia-teaching hospitals. A national guideline for a preoperative fasting policy is worth exploring to change the current practice.

Preoperative fasting: an outdated concept?

Recent studies have shown that fasting during the preoperative period for elective surgery induces a metabolic state that seems unfavorable for patients. Results from animal studies indicate that rapid depletion of liver glycogen before surgery leads to mobilization of muscle glycogen after surgery, in turn leading to reduced muscle strength. Depletion of liver glycogen also influences the function of the mononuclear phagocytic system (MPS), which is located predominantly in the liver. The MPS is essential in restricting endotoxin, which may translocate from the gut. In addition, surgery per se puts a substantial physical strain on the patient, and fasting may adversely affect the metabolic response to surgery. This paper presents experimental and clinical data that, when combined together, prove that fasting before surgery has adverse consequences for the patient.

Pre-operative fasting guidelines: an update

Liberal pre-operative fasting routines have been implemented in most countries. In general, clear fluids are allowed up to 2 h before anaesthesia, and light meals up to 6 h. The same recommendations apply for children and pregnant women not in labour. In children <6 months, most recommendations now allow breast- or formula milk feeding up to 4 h before anaesthesia. Recently, the concept of pre-operative oral nutrition using a special carbohydrate-rich beverage has also gained support and been shown not to increase gastric fluid volume or acidity. Based on the available literature, our Task Force has produced new consensus-based Scandinavian guidelines for pre-operative fasting. What is still not clear is to what extent the new liberal fasting routines should apply to patients with functional dyspepsia or systematic diseases such as diabetes mellitus. Other still controversial areas include the need for and effect of fasting in emergency patients, women in labour and in association with procedures done under 'deep sedation'. We think more research on the effect of various fasting regimes in subpopulations of patients is needed before we can move one step further towards completely evidence-based pre-operative fasting guidelines.

Enhanced recovery after surgery: a consensus review of clinical care for patients undergoing colonic resection

BACKGROUND & AIMS

Clinical care of patients undergoing colonic surgery differs between hospitals and countries. In addition, there is considerable variation in rates of recovery and length of hospital stay following major abdominal surgery. There is a need to develop a consensus on key elements of perioperative care for inclusion in enhanced recovery programmes so that these can be widely adopted and refined further in future clinical trials.

METHODS

Medline database was searched for all clinical studies/trials relating to enhanced recovery after colorectal resection. Relevant papers from the reference lists of these articles and from the authors' personal collections were also reviewed. A combination of evidence-based and consensus methodology was used to develop the resulting enhanced recovery after surgery (ERAS) clinical care protocol.

RESULTS AND CONCLUSIONS

Within traditional perioperative practice there is considerable evidence supporting a range of manoeuvres which, in isolation, may improve individual aspects of recovery after colonic surgery. The present manuscript reviews these issues in detail. There is also growing evidence that an integrated multimodal approach to perioperative care can result in an overall enhancement of recovery. However, effects on major morbidity and mortality remain to be determined. A protocol is presented which is in current use by the ERAS Group and may provide a standard of care against which either current or future novel elements of an enhanced recovery approach can be tested for their effect on outcome.

Randomized clinical trial of the effects of oral preoperative carbohydrates on postoperative nausea and vomiting after laparoscopic cholecystectomy

Background

A carbohydrate-rich drink (CHO) has been shown to reduce preoperative discomfort. It was hypothesized that it may also reduce postoperative nausea and vomiting (PONV).

Methods

Patients undergoing elective laparoscopic cholecystectomy under inhalational anaesthesia (127 women and 45 men; mean(s.d.) 48(15) years) were randomized to either preoperative fasting, intake of CHO (50 kcal/100 ml, 290 mOsm/kg) or placebo. The non-fasting groups were double-blinded; patients ingested 800 ml of liquid on the evening before surgery and 400 ml 2 h before anaesthesia. Nausea and pain scores on a visual analogue scale (VAS) and episodes of PONV were recorded up to 24 h after surgery.

Results

The incidence of PONV was lower in the CHO than in the fasted group between 12 and 24 h after surgery (P = 0·039). Nausea scores in the fasted and placebo groups were higher after operation than before admission to hospital (P = 0·018 and P &lt; 0·001 respectively), whereas there was no significant change in the CHO group. No intergroup differences in VAS scores were seen. The use of anaesthetics, opioids, antiemetics and intravenous fluids was similar in all groups.

Conclusion

CHO may have a beneficial effect on PONV 12–24 h after laparoscopic cholecystectomy.

The administration of an oral carbohydrate-containing fluid prior to major elective upper-gastrointestinal surgery preserves skeletal muscle mass postoperatively—a randomised clinical trial

AIM

Recent evidence suggests that the provision of energy-containing fluids is safe and may impact positively on markers of recovery. The aims of this study were to assess the tolerance of preoperative carbohydrate fluid administration and to determine its effect on postoperative metabolic and clinical responses.

METHODS

Patients admitted to the Royal Infirmary of Edinburgh for major, elective abdominal surgery were recruited to this double-blind, randomised study and received either a placebo drink or carbohydrate (12.6g/100ml) drink (CHOD). Patients consumed 800 ml of their drink on the evening before surgery and 400 ml on the day of surgery 2-3 h before the induction of anaesthesia. Nutritional status was determined using body mass index (BMI) and upper arm anthropometry; all measurements were taken preoperatively, postoperatively and at discharge. Blood glucose and insulin concentrations were also measured preoperatively and on the first post operative day. Length of hospital stay (LOS) and postoperative complications were recorded.

RESULTS

Seventy-two patients were recruited and 65 (34 male:31 female) completed this study. Thirty-four patients were randomised to receive the placebo drink (control group) and 31 patients to receive the carbohydrate drink (CHOD group). Groups were well-matched in terms of gender and age. There were no differences between the two groups at baseline for BMI (control: -25.1+/-1.7 kg/m2; CHOD -25.2+/-1.2 kg/m2), upper arm anthropometry or surgical procedure. At discharge loss of muscle mass (arm muscle circumference) was significantly greater in the control group when compared with the CHOD group (control: -1.1+/-0.15 cm; CHOD: -0.5+/-0.16 cm; P<0.05). Baseline insulin (control: 20.7+/-4.9 mU/l; CHOD: 24.6+/-6.2 mU/l) and glucose (control: 6.0+/-1.4 mmol/l; CHOD 5.7+/-1.4 mmol/l) were comparable in the two groups and did not differ postoperatively. No complications were recorded as a result of preoperative fluid consumption. Postoperative morbidity occurred in six patients from each group. Median LOS in the control group was 10 days (IQR=6), and 8 days (IQR=4) in the CHOD group.

CONCLUSION

Preoperative consumption of carbohydrate-containing fluids is safe. Provision of a carbohydrate energy source prior to surgery may attenuate depletion of muscle mass after surgery. Further studies are required to determine if this preservation of muscle mass is reflected in improved function and reduced rehabilitation time.

Dose minimization study of single-dose epidural morphine in patients undergoing hip surgery under regional anesthesia with bupivacaine

BACKGROUND

In order to decrease the rate of adverse effects, we aimed to identify the lowest analgesic dose of epidural morphine administered to patients undergoing hip surgery.

METHODS

Forty-five ASA I-II children undergoing surgical correction of hip dysplasia under caudal or epidural anesthesia with bupivacaine were randomized to receive epidural morphine 11.2, 15 or 20 microg.kg(-1) (groups 1, 2 and 3, respectively; 15 patients per group) immediately after completion of surgery. Postoperative pain control, sedation, motor block, urinary retention, pruritus and vomiting were evaluated.

RESULTS

In the recovery room, 46.7% of patients from group 1, 33.3% from group 2, and 93.3% from group 3 were sleeping but were easy to arouse (x(2) = 12.2; P < 0.005). The rest of the patients from each respective group were completely asleep. The cardiovascular and respiratory parameters were within normal limits. The ability to move the legs returned approximately 1 h after surgery in all three groups. Seven patients (46.7%) from group 1, nine (60%) from group 2, and 13 patients (86.7%) from group 3 vomited (x(2) = 5.4; P = 0.06). One patient receiving 20 microg.kg(-1) morphine experienced urinary retention. One patient receiving 15 microg.kg(-1) morphine suffered from pruritus. The duration of analgesia was similar, 12-14 h, in all three groups.

CONCLUSIONS

In patients undergoing hip surgery under regional anesthesia with bupivacaine, epidural morphine at a dose of 11.2 microg.kg(-1) administered immediately after completion of the procedure resulted in adequate pain relief for more than 12 h. Explanation of the high rate of patients vomiting (>45%) remains to be elucidated.

Strategies for prophylaxis and treatment for aspiration

The absolute incidence of aspiration is difficult to define because of its relatively low occurrence and difficulty in diagnosis. The gastric volume predisposing to aspiration is larger than 30 ml. Fasting times for fluids have reduced; however, a large meal may require 9 hours of preoperative fasting. Preoperative carbohydrate-enriched beverages may attenuate postoperative catabolism. Aspiration occurs most frequently during induction and laryngoscopy. Awake fibre-optic intubation may be a suitable alternative in high-risk cases for aspiration. The role of cricoid pressure in anaesthesia needs re-evaluation as radiological and clinical evidence suggest that it may be ineffective and may impede intubation and ventilation. Chemoprophylaxis does not reduce the severity of aspiration pneumonitis as gastric bile is unaffected by these agents and induces a worse pneumonitis than gastric acid. Patients may be discharged home 2 hours after aspirating provided they are clinically unaffected and have postoperative surveillance.

Preoperative assessment

Although anaesthetic and surgical procedures should be individualised for every patient, in practice many preoperative protocols and routines are used generally. In this article, we aim to emphasise: why preoperative assessment is important; how it should be done, and by whom; what can be expected; and the importance of test selection based on patients' needs and on scientific evidence of effectiveness. We outline the roles of preoperative medical assessment in otherwise healthy patients. Clinical history, preoperative questionnaires, physical examination, routine tests, individual risk-assessment, and fasting policies are investigated by review of published work. Cost of routine preoperative assessment, the anaesthetist's legal responsibility, and patients'views in the preoperative process are also considered. A thorough clinical preoperative assessment of the patient is more important than routine preoperative tests, which should be requested only when justified by clinical indications. Moreover, this practice eliminates unnecessary cost without compromising the safety and quality of care. Education and training of medical doctors should be more scientifically guided, emphasising the relevance of effectiveness, and cost-effectiveness in clinical decision-making and complemented by audit.

Preoperative fasting

BACKGROUND AND METHODS

To avoid pulmonary aspiration, fasting after midnight has become standard in elective surgery, but recent studies have found no scientific support for this practice. Several anaesthesia societies now recommend a 2-h preoperative fast for clear fluids and a 6-h fast for solids in most elective patients. The literature supporting such fasting recommendations was reviewed.

RESULTS

The recommendations are safe and improve well-being before operation, mainly by reducing thirst. A carbohydrate-rich beverage given before anaesthesia and surgery alters metabolism from the overnight fasted to the fed state. This reduces the catabolic response (insulin resistance) after operation, which may have implications for postoperative recovery.

CONCLUSION

Most patients having elective operations can be allowed a free intake of clear fluids up to 2 h before anaesthesia. Preoperative carbohydrates reduce postoperative insulin resistance.

Effects of preoperative oral carbohydrates and peptides on postoperative endocrine response, mobilization, nutrition and muscle function in abdominal surgery

BACKGROUND

Surgery is succeeded by long-lasting state of relative peripheral insulin resistance, which is reduced by giving glucose infusion or oral carbohydrate-rich drinks immediate before operating instead of fasting. The aim of the present study was to investigate whether oral carbohydrate or carbohydrate with peptide drinks preoperatively instead of fasting would improve postoperative voluntary muscle strength, nutritional intake and ambulation, decrease postoperative fatigue, anxiety and discomfort, and reduce the endocrine response to surgery.

METHODS

Forty-eight patients were included and randomized into three groups to receive 2 x 400 ml of carbohydrate-rich drinks or to fast overnight and allowed only water. Voluntary grip and quadriceps strength, body composition, pulmonary function, VAS-score of eight parameters of wellbeing, muscle biopsies and insulin, glucagon, IGF-1 and free fatty acids were measured before and after the operation. The basic postoperative regimen for all groups were immediate oral nutrition and early enforced mobilization.

RESULTS

Significant postoperative decrease in glycogen synthase activity in the muscle biopsies was reduced in the intervention groups, and in combination, the intervention groups had a less reduced quadriceps strength after one week (-10% vs. -16%, NS) and one month (-5% vs. -13%, P < 0.05). Minor changes in the endocrine response to surgery were found without differences between the groups, and there were no differences between the groups in ambulation time, nutritional intake or subjective measures of wellbeing.

Compensatory fluid administration for preoperative dehydration--does it improve outcome?

BACKGROUND

Preoperative fasting may lead to a fluid deficit of about 1 litre, which may contribute to perioperative discomfort and morbidity. We therefore examined the association between perioperatively administered fluids aiming to correct dehydration and clinical outcome.

METHODS

Review of randomized, controlled, clinical trials evaluating clinical outcome, in which fluid versus no fluid was administered pre- or intraoperatively, attempting to correct preoperative fluid deficits. Data were obtained from a Medline search (1966-2001), and references cited in original papers. Seventeen trials met the inclusion criteria.

RESULTS

Based on the amount of fluid administered, we divided the studies into two groups. In nine studies, fluid administration was <1 litre, and in eight studies > or =1 litre of fluid was administered. Administration of low-dose fluid reduced preoperative thirst, but the limited data do not allow conclusions on postoperative outcome such as nausea, vomiting, headache and pain. Administration of > or =1 litre fluid generally reduced postoperative drowsiness and dizziness, while the effects on postoperative nausea, vomiting and thirst has not been clarified.

CONCLUSION

Fluid administration to compensate preoperative dehydration improves symptoms related to dehydration. Based on the available data, administration of about 1 litre fluid pre- or intraoperatively in patients having fasted for minor surgical procedures seems rational.

Respiratory complications associated with anesthesia

Adverse pulmonary outcomes that follow anesthesia and surgery are often attributed to anesthesia care. PPCs are a significant concern for anesthesia caregivers because they use drugs and techniques that temporarily decrease lung volume, impair airway reflexes, limit immune function, and depress secretion mobilization. A significant component of perioperative risk derives from the surgical site, postoperative pain, and effects of pharmacologic pain management. Rapidly evolving surgical and anesthesia techniques and the introduction of newer pharmaceutical agents make it difficult to identify best practice from retrospective experience reported in the perioperative literature. Prospective studies that deal with specific patient populations, incomparable patient groups or techniques, and unique practice bias have limited validity of claims regarding several promising approaches to perioperative risk reduction. In the absence of clear scientific principles, a perioperative pulmonary risk management strategy for the early part of this century is based on the consensus practice of informed clinicians (Box 4).

Modulation of post-operative insulin resistance by pre-operative carbohydrate loading

Insulin resistance develops as a response to virtually all types of surgical stress. There is an increasing body of evidence that suggests that insulin resistance in surgical stress is not beneficial for outcome. A recent large study in intensive-care patients showed that aggressive treatment of insulin resistance using intravenous insulin reduced mortality and morbidity substantially. Similarly, in burn patients, intensive insulin and glucose treatment has been shown to improve N economy and enhance skin-graft healing. In surgical patients insulin resistance has been characterized in some detail, and has been shown to have many similarities with metabolic changes seen in patients with type 2 diabetes. This finding may be important since insulin resistance has been shown to be one independent factor that influences length of stay. When patients about to undergo elective surgery have been treated with glucose intravenously or a carbohydrate-rich drink instead of overnight fasting, insulin resistance was reduced by about half. A small meta-analysis showed that when post-operative insulin resistance was reduced by pre-operative carbohydrates, length of hospital stay was shortened. Overnight intravenous glucose at high doses improved post-operative N economy. This type of treatment has also been shown repeatedly to reduce cardiac complications after open-heart surgery. Furthermore, if the carbohydrates are given as a drink pre-operatively, pre-operative thirst, hunger and anxiety are markedly reduced. In summary, preventing or treating insulin resistance in surgical stress influences outcome. Fasting overnight is not an optimal way to prepare patients for elective surgery. Instead, pre-operative carbohydrates have clinical benefits.

Attitudes of Mexican anesthesiologists to indicate preoperative fasting periods: A cross-sectional survey

BACKGROUND: In Mexico, guidelines for fasting periods, or any audits on this topic are unavailable, and therefore the attitudes of anesthesiologists for recommending preoperative fasting periods are unknown. MATERIAL AND METHODS: The study was a cross-sectional survey of anesthesiologists subscribed to the Annual Updated Course, organized by the Sociedad Mexicana de Anestesiologia in 2000. The response rate was 31.4%. RESULTS: Most respondents were general anesthesiologists, with 5 or more years experience in a clinical post, were working in both public and private hospitals, and were performing anesthetic procedures on both pediatric and adult patients and in both ambulatory and hospitalized patients. Approximately 23% of the respondents considered natural fruit juices to be clear liquids. For a pediatric patient ingesting breast milk 1 h before undergoing a surgical procedure, 45% thought that surgery should be delayed for 3h, followed by those delaying the surgical procedure for 6 to 8 h. Our results show that more than 50% of the anesthesiologists had better defined attitudes for fasting milk and clear liquids in patients of 6 month or under than for older children and adults. However, due to the poor definition or pre-operative fasting, using clear liquids, in all other patient groups, several patients are allowed to go without oral clear liquids administration for prolonged periods. CONCLUSION: Preoperative fasting periods recommended by Mexican anesthesiologists differ from international guidelines.

A carbohydrate-rich drink reduces preoperative discomfort in elective surgery patients

We studied the effects of different preoperative oral fluid protocols on preoperative discomfort, residual gastric fluid volumes, and gastric acidity. Two-hundred-fifty-two elective abdominal surgery patients (ASA physical status I-II) were randomized to preparation with a 12.5% carbohydrate drink (CHO), placebo (flavored water), or overnight fasting. The CHO and Placebo groups were double-blinded and were given 800 mL to drink on the evening before and 400 mL on the morning of surgery. Visual analog scales were used to score 11 different discomfort variables. CHO did not increase gastric fluid volumes or affect acidity, and there were no adverse events. The visual analog scale scores in a control situation were not different between groups. During the waiting period before surgery, the CHO-treated group was less hungry and less anxious than both the other groups (P < or = 0.05). CHO reduced thirst as effectively as placebo (P < 0.0001 versus Fasted). Trend analysis showed consistently decreasing thirst, hunger, anxiety, malaise, and unfitness in the CHO group (P < 0.05). The Placebo group experienced decreasing unfitness and malaise, whereas nausea, tiredness, and inability to concentrate increased (P < 0.05). In the Fasted group, hunger, thirst, tiredness, weakness, and inability to concentrate increased (P < 0.05). In conclusion, CHO significantly reduces preoperative discomfort without adversely affecting gastric contents.

IMPLICATIONS

Discomfort during the period of waiting before elective surgery can be reduced if patients are prepared with a carbohydrate-rich drink, compared with preoperative oral intake of water or overnight fasting. Visual analog scales can provide useful information about preoperative discomfort in elective surgery patients.