***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: Context Perioperative oral carbohydrate intake is beneficial to general surgery patients . Total hip arthroplasty is a common surgical procedure , and even a moderate improvement in patient outcome could have a significant effect on the re sources needed for these patients . However , few studies have focused on the effects of carbohydrate intake on orthopaedic patients . Objective The purpose of this study was to investigate if perioperative oral carbohydrate intake alters the postoperative course for patients undergoing total hip arthroplasty . The primary hypothesis was that pain scores would be lower in patients treated with carbohydrate . Design A r and omised , double-blind , controlled trial . Setting This study was carried out between September 2009 and April 2011 at a district Swedish hospital that specialises in orthopaedic surgery . Patients Sixty ASA physical status I – III patients scheduled for elective total hip arthroplasty were included . Exclusion criteria were obesity , diabetes , prior hip surgery to the same hip , ongoing infection , immunological deficiency or age less than 50 or more than 80 years . Interventions Patients were given 400 ml of either an oral 12.5 % carbohydrate solution or a placebo beverage ( flavoured water ) 1.5 h before and 2 h after surgery . Main outcome measures Visual analogue scales were used to score six discomfort parameters . Results Immediately prior to surgery , the carbohydrate-treated patients were less hungry ( median score 9.5 vs. 22 mm ) and experienced less nausea ( 0 vs. 1.5 mm ) ( P < 0.05 ) . Postoperatively , patients in the carbohydrate group experienced less pain at 12 , 16 and 20 h ( median scores 20 , 30 and 34 vs. 7 , 5 and 0 mm ; P < 0.05 ) . Conclusion This study shows that there is limited benefit from administering oral carbohydatre prior to total hip arthroplasty UNLABELLED Infusions of carbohydrates before surgery reduce  postoperative insulin resistance . We in-vestigated the effects of a carbohydrate drink , given shortly before surgery , on postoperative metabolism . METHOD Insulin sensitivity , glucose turnover ( [ 6,6 , 2H2]-D-glucose ) and substrate utilization were measured using hyperinsulinemic normoglycemic clamps and indirect calorimetry in two matched groups of patients before and after elective colorectal surgery . The drink group ( n = 7 ) received 800 ml of an isoosmolar carbohydrate rich beverage the evening before the operation ( 100 g carbohydrates ) , as well as another 400 ml ( 50 g carbohydrates ) 2 h before the initiation of anesthesia . The fasted group ( n = 7 ) was operated after an overnight fast . RESULTS After surgery , energy expenditure increased in both groups . Endogenous glucose production was higher after surgery and the difference was significant during low insulin infusion rates in both groups ( P < 0.05 ) . The supressibility of endogenous glucose production by the two step insulin infusion was similar pre- and postoperatively in both groups . At the high insulin infusion rate postoperatively , whole body glucose disposal was more reduced in the fasted group ( -49 + /- 6 % vs -26 + /- 8 % , P < 0.05 vs drink ) . Furthermore , during high insulin infusion rates , glucose oxidation decreased postoperatively only in the fasted group ( P < 0 . 05 ) and postoperative levels of fat oxidation were greater in the fasted group ( P < 0.05 vs drink ) . Only minor postoperative changes in cortisol and glucagon were found and no differences were found between the treatment groups . CONCLUSIONS Patients given a carbohydrate drink shortly before elective colorectal surgery displayed less reduced insulin sensitivity after surgery as compared to patients who were operated after an overnight fast Background : Patients at nutritional risk reveal an increased morbidity . Fast-track ( FT ) programs in colonic surgery have shown reduced complications and hospital stay . We aim ed to assess the effect of FT programs on patients at nutritional risk . Methods : In a r and omized trial ( NCT00556790 ) , we compared complications after open colonic surgery with either a FT program or st and ard care ( SC ) . A subgroup analysis was performed in 67 patients for whom a prospect i ve nutritional risk score ( NRS ) was available . Results : The SC and FT groups did not differ regarding patient characteristics or prevalence of NRS ≧3 ( SC 8/31 , FT 7/36 , p = 0.569 ) . Patients with SC had more complications ( 14/31 vs. 8/36 , p = 0.044 ) and a longer hospital stay ( 9 vs. 5 days , p < 0.0001 ) . No major complication occurred in patients with an NRS <3 . Patients at nutritional risk had a high complication rate regardless of SC or FT ( 6/8 and 5/7 , respectively , p = 1.000 ) . Median hospital stay was shorter in FT ( 7 ( range 5–30 ) days ) versus SC patients ( 14.5 ( range 8–30 ) days , p = 0.164 ) . Conclusions : Patients with a NRS ≧3 have an increased postoperative morbidity  even within a FT program . They should be identified by nutritional screening and might benefit from nutritional supplements The effect of preoperative glucose infusion on preoperative alterations in hepatic glycogen content , the activity of key hepatic glucoregulatory enzymes ( fructose 1,6-diphosphatase [ FDPase ] ) , pyruvate kinase ( PK ) , hormonal developments , and plasma levels of free fatty acids ( FFA ) were investigated in 16 patients undergoing open cholecystectomy .  Patients were r and omized to receive ( group G ) or not receive ( group C ) overnight glucose infusion ( 5 mg.kg-1.d-1 ) preoperatively . Infusion of glucose overnight result ed in preoperative elevations of insulin and c-peptide ( P < 0.05 ) and lower plasma levels of FFA , while the same glucose levels were found in both groups , 4.6 mmol/L. During and after surgery , only minor changes in the plasma levels of insulin , c-peptide , catecholamines , glucagon , cortisol , growth hormone , and FFA were found , with minimal differences between groups . The hepatic glycogen content was 65 % higher in group G and a significant reduction was confirmed only in this group of patients during surgery . The higher glycogen content was associated with a higher FDPase activity ratio ( P < 0.05 ) , which remained unchanged during surgery . In contrast , a significant ( P < 0.05 ) increase in the activity of this enzyme was found in group C. The PK activity ratio did not differ between groups and remained unchanged during surgery . The finding of enhanced FDPase activity suggests that the indirect route ( via gluconeogenesis ) represents an important contributor to the increased glycogen formation during glucose infusion . Additionally , surgery in the overnight fasted patient induces enzymatic changes favoring gluconeogenesis . Lastly , preoperative high-dose glucose infusion has only minor effects on the endocrine response , plasma levels of FFA , and glycogen depletion during elective open cholecystectomy INTRODUCTION In this study , the recently liberalised national guidelines for preoperative fasting were evaluated from the view point of the patients and according to their clinical usability . PATIENTS AND METHODS Patients undergoing elective laparoscopic gynaecological surgery were r and omised into two groups . Patients in the long-time NPO-group ( LTNPO-group ) had nothing per mouth after midnight whereas patients in the short-time NPO-group ( STNPO-group ) did not receive any oral nutrition after midnight but were allowed an unlimited intake of Pfrimmer Nutricia preOP up to 2 hours before scheduled surgery . Patients were asked to assess the incidence of 12 symptoms of perioperative discomfort prior to and 4 - 6 hours after surgery using a st and ardised question naire . Gastric fluid volume , vital signs during the induction period of anaesthesia and the actual duration of fasting were registered and compared . RESULTS 42 patients were included into the study ( LTNPO-group : n = 23 , STNPO-group : n = 19 ) . The actual duration of fasting for solid nutritition was 11.3 h in the LTNPO-group and 10.9 h in the STNPO-group , respectively . The time of fasting for fluids was in the STNPO-group significantly shorter ( 4.5 h ) compared to the LTNPO-group ( 11.3 h ) . The patients of the STNPO-group reported preoperatively a significant lower incidence of " feeling cold " and pre- and postoperatively of " thirst / having a dry mouth " . No significant differences were reported between the groups with respect to heart rate , blood pressure , gastric volume , need of vasopressors and infusion requirements . DISCUSSION The liberation of the national guidelines for preoperative fluid administration with unlimited intake of a carbohydrate drink offers the benefit of a significantly lower incidence of the preoperative item " feeling cold " and of the pre- and postoperative item " thirst / having a dry mouth " . However , in daily clinical practice the length of fasting for fluids was conspicuously longer than that postulated by the new recommendations ZusammenfassungHINTERGRUND UND ZIEL DER STUDIE : In letzter Zeit mehren sich die Hinweise , dass präoperatives Fasten , wie es seit mehreren Jahrzehnten klinische Praxis ist , von ungünstigen Folgen begleitet sein könnte . I m Gegenteil könnte eine st and ardisierte präoperative Nahrungsaufnahme sogar von Vorteil sein . Tatsächlich stellt eine solche Nahrungsaufnahme eine Komponente des ERAS ( " enhanced recovery after surgery " ) Konzeptes dar . Wir erhoben daher in einer r and omisierten kontrollierten Studie bei chirurgischen Patienten mit kolorektalen Erkrankungen die Wirkung einer präoperativen oralen oder intravenösen Gabe von Kohlehydraten , Elektrolyten und Wasser auf verschiedene biochemische , psychosomatische und echokardiographische und muskuläre Parameter in der perioperativen Phase i m Vergleich zu präoperativ nüchternen Patienten . Außerdem untersuchten wir die Nebenwirkungsfreiheit einer peroralen Nahrungsaufnahme kurz vor der Operation . PATIENTEN UND METHOD EN : Insgesamt wurden 221 elektive chirurgische Patienten mit einer kolorektalen Erkrankung in diese an zwei Zentren durchgeführte , r and omisierte , prospektive und verblindete klinische Studie aufgenommen . Die Patienten wurden in 3 Gruppen eingeteilt : A : Patienten , die ab Mitternacht vor der Operation fasteten ( Kontrollgruppe ) ; B : Patienten , denen Glukose , Magnesium und Kalium intravenös verabreicht wurde ; C : Patienten , die präoperativ oral ein speziell zusammengesetztes Nahrungssupplement einnahmen . ERGEBNISSE : Klinisch war der perioperative Allgemeinzust and der Patienten der Gruppen B und C signifikant besser als der der Kontrollgruppe . Der psychosomatische Zust and war am besten bei den Patienten der Gruppe C ( p < 0,029 ) . Der Anstieg des Insulin-Resistenz-Index ( QUICKI ) von vor der Operation zu postoperativ war in Gruppe A signifikant ( p < 0,05 ) . Die systolische und diastolische Linksventrikelfunktion besserte sich in Gruppe C signifikant i m Vergleich zu Gruppe A ( p < 0,04 ) – auch die Auswurffraktion war postoperativ signifikant höher ( p < 0,03 ) . Das gastrale Residualvolumen betrug 5 ml , der pH des Magensafts lag in allen Gruppen bei 3,5–5 ohne statistisch signifikanten Unterschied zwischen den Gruppen . Die Komplikationsrate , sowie die Dauer des stationären Aufenthaltes unterschied sich ebenfalls nicht zwischen den Gruppen . SCHLUSSFOLGERUNGEN : Präoperatives Fasten bringt für chirurgische Patienten keinen Vorteil . I m Gegenteil könnte die Einnahme einer entsprechenden aus Wasser , Elektrolyten und Kohlehydraten zusammengesetzten Nahrung den Patienten einen gewissen Schutz gegen das Operationstrauma bieten – vor allem in Bezug auf den Stoffwechsel , aber auch auf die Funktion des Herzens und auf den psychosomatischen Zust and . Die kurz vor der Operation erfolgte perorale Einnahme erhöhte das gastrale Residualvolumen nicht und war auch sonst mit keinem Risiko verbunden . Summary 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 st and ardized preoperative intake of nutrients might be advantageous ; this is a component of the enhanced recovery after surgery ( ERAS ) concept . Thus , in a r and omized controlled trial we compared preoperative fasting with preoperative preparation with either oral or intravenous intake of carbohydrates , minerals and water .  
    Output:
    
Preoperative carbohydrate treatment was associated with a small reduction in length of hospital stay when compared with placebo or fasting in adult patients undergoing elective surgery .
It was found that preoperative carbohydrate treatment did not increase or decrease postoperative complication rates when compared with placebo or fasting .