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1.  Cardioprotective efficacy depends critically on pharmacological dose, duration of ischaemia, health status of animals and choice of anaesthetic regimen: a case study with folic acid 
Acute, high-dose folic acid (FA) administration has recently been shown to possess unprecedented effective cardioprotection against ischaemia/reperfusion (I/R) injury. Here we explore the translation potential of FA as treatment modality for cardiac I/R.
Dependency of FA protection on dose, ischaemia duration, and eNOS was examined in an isolated mouse heart I/R model, whereas dependency on animal health status and anaesthesia was examined in an in vivo rat model of regional cardiac I/R.
50 μM FA provided maximal reduction (by 95%) of I/R-induced cell death following 25 min ischaemia in isolated wild-type hearts, with protection associated with increased coupled eNOS protein. No protection was observed with 35 min I or in eNOS−/− hearts. Acute intravenous administration of FA during a 25 min ischaemic period reduced infarct size by 45% in in vivo pentobarbital-anaesthetised young, healthy rats. FA did not reduce infarct size in aged or pre-diabetic rats, although it did preserve hemodynamics in the pre-diabetic rats. Finally, using a clinically-relevant anaesthetic regimen of fentanyl-propofol anaesthesia, FA treatment was ineffective in young, aged and pre-diabetic animals.
The protective potential of an initially promising cardioprotective treatment of high dose FA against cardiac I/R infarction, is critically dependent on experimental conditions with relevance to the clinical condition. Our data indicates the necessity of expanded pre-clinical testing of cardioprotective interventions before embarking on clinical testing, in order to prevent too many “lost-in-translation” drugs and unnecessary clinical studies.
PMCID: PMC4265322  PMID: 25432364
Ischaemia/reperfusion; Translational science; eNOS; Infarct; Cardioprotection; Aged; Diabetic; Anaesthesia; Propofol; Pentobarbital
2.  Intravenous S-Ketamine Does Not Inhibit Alveolar Fluid Clearance in a Septic Rat Model 
PLoS ONE  2014;9(11):e112622.
We previously demonstrated that intratracheally administered S-ketamine inhibits alveolar fluid clearance (AFC), whereas an intravenous (IV) bolus injection had no effect. The aim of the present study was to characterize whether continuous IV infusion of S-ketamine, yielding clinically relevant plasma concentrations, inhibits AFC and whether its effect is enhanced in acute lung injury (ALI) which might favor the appearance of IV S-ketamine at the alveolar surface. AFC was measured in fluid-instilled rat lungs. S-ketamine was administered IV over 6 h (loading dose: 20 mg/kg, followed by 20 mg/kg/h), or intratracheally by addition to the instillate (75 µg/ml). ALI was induced by IV lipopolysaccharide (LPS; 7 mg/kg). Interleukin (IL)-6 and cytokine-induced neutrophil chemoattractant (CINC)-3 were measured by ELISA in plasma and bronchoalveolar lavage fluid. Isolated rat alveolar type-II cells were exposed to S-ketamine (75 µg/ml) and/or LPS (1 mg/ml) for 6 h, and transepithelial ion transport was measured as short circuit current (ISC). AFC was 27±5% (mean±SD) over 60 min in control rats and was unaffected by IV S-ketamine. Tracheal S-ketamine reduced AFC to 18±9%. In LPS-treated rats, AFC decreased to 16±6%. This effect was not enhanced by IV S-ketamine. LPS increased IL-6 and CINC-3 in plasma and bronchoalveolar lavage fluid. In alveolar type-II cells, S-ketamine reduced ISC by 37% via a decrease in amiloride-inhibitable sodium transport. Continuous administration of IV S-ketamine does not affect rat AFC even in endotoxin-induced ALI. Tracheal application with direct exposure of alveolar epithelial cells to S-ketamine decreases AFC by inhibition of amiloride-inhibitable sodium transport.
PMCID: PMC4227727  PMID: 25386677
3.  Study protocol of a randomised controlled trial comparing perioperative intravenous insulin, GIK or GLP-1 treatment in diabetes–PILGRIM trial 
BMC Anesthesiology  2014;14(1):91.
Diabetes mellitus (DM) is associated with poor outcome after surgery. The prevalence of DM in hospitalised patients is up to 40%, meaning that the anaesthesiologist will encounter a patient with DM in the operating room on a daily basis. Despite an abundance of published glucose lowering protocols and the known negative outcomes associated with perioperative hyperglycaemia in DM, there is no evidence regarding the optimal intraoperative glucose lowering treatment. In addition, protocol adherence is usually low and protocol targets are not simply met.
Recently, incretins have been introduced to lower blood glucose. The main hormone of the incretin system is glucagon-like peptide–1 (GLP-1). GLP-1 increases insulin and decreases glucagon secretion in a glucose-dependent manner, resulting in glucose lowering action with a low incidence of hypoglycaemia.
We set out to determine the optimal intraoperative treatment algorithm to lower glucose in patients with DM type 2 undergoing non-cardiac surgery, comparing intraoperative glucose-insulin-potassium infusion (GIK), insulin bolus regimen (BR) and GPL-1 (liragludite, LG) treatment.
This is a multicentre randomised open label trial in patients with DM type 2 undergoing non-cardiac surgery. Patients are randomly assigned to one of three study arms; intraoperative glucose-insulin-potassium infusion (GIK), intraoperative sliding-scale insulin boluses (BR) or GPL-1 pre-treatment with liraglutide (LG). Capillary glucose will be measured every hour. If necessary, in all study arms glucose will be adjusted with an intravenous bolus of insulin. Researchers, care givers and patients will not be blinded for the assigned treatment. The main outcome measure is the difference in median glucose between the three study arms at 1 hour postoperatively. We will include 315 patients, which gives us a 90% power to detect a 1 mmol l−1 difference in glucose between the study arms.
The PILGRIM trial started in January 2014 and will provide relevant information on the perioperative use of GLP-1 agonists and the optimal intraoperative treatment algorithm in patients with diabetes mellitus type 2.
Trial registration, NCT02036372
PMCID: PMC4240889  PMID: 25419179
Diabetes mellitus type 2; Perioperative management; GLP-1 agonist
Circulation research  2013;112(2):e8-13.
We have shown that partial dissociation of HKII from mitochondria in the intact heart using low dose (200 nM) TAT-HKII prevents the cardioprotective effects of ischemic preconditioning (IPC) whereas high-dose (10 μM) TAT-HKII administration results in rapid myocardial dysfunction, mitochondrial depolarization and disintegration. In this issue of Circulation Research, Pasdois et al argue that the deleterious effects of TAT-HKII administration on cardiac function are likely due to vasoconstriction and ensuing ischemia.
To investigate whether altered vascular function and ensuing ischemia recapitulate the deleterious effects of TAT-HKII in intact myocardium.
Methods and Results
Using a variety of complementary techniques, including mitochondrial membrane potential (ΔΨm) imaging, high-resolution optical action potential (AP) mapping, analysis of lactate production, NADH epifluorescence, lactate dehydrogenase (LDH) release, and electron microscopy, we provide direct evidence that refutes the notion that acute myocardial dysfunction by high-dose TAT-HKII peptide administration is a consequence of impaired vascular function. Moreover, we demonstrate that low-dose TAT-HKII treatment, which abrogates the protective effects of IPC, is not associated with ischemia or ischemic-injury.
Our findings challenge the notion that the effects of TAT-HKII are attributable to impaired vascular function and ensuing ischemia; thereby, lending further credence to the role of mitochondria bound HKII as a critical regulator of cardiac function, ischemia-reperfusion (IR) injury, and cardioprotection by IPC.
PMCID: PMC3596767  PMID: 23329797
TAT peptide; hexokinase; vasoconstriction; ischemia; mitochondrial membrane potential
5.  Safety and effectiveness using dexmedetomidine versus propofol TCI sedation during oesophagus interventions: a randomized trial 
BMC Gastroenterology  2013;13:176.
Endoscopic treatment of early neoplastic lesions in oesophagus has evolved as a valid and less invasive alternative to surgical resection. These endoscopic interventions are minimal invasive treatment options usually done with sedation on an outpatient basis. The aim of this trial is to determine the safety and effectiveness of dexmedetomidine sedation compared to the standard used propofol TCI sedation during endoscopic oesophageal interventions.
The study will be performed as a randomized controlled trial. The first 64 consenting patients will be randomized to either the propofol or the dexmedetomidine group. Following endoscopy patients and gastroenterologists have to fill in questionnaires (PSSI, CSSI) (see abbreviations) about their sedation experiences. Additionally, patients have to accomplish the Trieger test before and after the procedure. Patient monitoring includes time adapted HR, SO2, ECG, NIBP, exCO2, NICO, sweat conductance measurement, OAA/S, and the Aldrete score. Effectiveness of sedation, classified by satisfaction levels and pain and sedation score measured by questionnaires is the primary outcome parameter. Respiratory and hemodynamic complications are surrogate parameters for the secondary outcome parameter “safety”.
The acceptance level among patients after propofol sedation is high. Dexmedetomidine is a relatively new representative for procedural sedation. Has this new form of conscious sedation the potential to be safer and more effective for patients and endoscopists than propofol during endoscopic oesophageal interventions?
Trial registration
This trial is registered in the ISRCTN Register (ISRCTN 68599804). It will be conducted in accordance with the protocol and in compliance with the moral, ethical, and scientific principles governing clinical research as set out in the Declaration of Helsinki (1989) and Good Clinical Practice (GCP). The Departments of Anesthesiology and Gastroenterology & Hepatology of the Academic Medical Center of Amsterdam are responsible for the design and conduct of the trial.
PMCID: PMC3922843  PMID: 24377675
Procedural sedation; Dexmedetomidine; Endoscopic oesophageal intervention
6.  The PanAM study: a multi-center, double-blinded, randomized, non-inferiority study of paracetamol versus non-steroidal anti-inflammatory drugs in treating acute musculoskeletal trauma 
Acute musculoskeletal trauma, including strains, sprains or contusions, occur frequently. Pain management is a crucial component of treatment. However, there is no convincing evidence which drug is superior in managing pain in these patients. The aim of the PanAM Study is to compare analgesic efficacy of three strategies of pain management: paracetamol, diclofenac, or a combination of both in patients with acute musculoskeletal trauma.
The PanAM Study is a multi-center, double blind randomized controlled trial with non-inferiority design. Included are adult patients presenting to an academic, urban Emergency Department or to a General Practice with acute, blunt, traumatic limb injury. In total, 547 patients will be included using a predefined list of exclusion criteria, to be allocated by randomization to treatment with paracetamol + placebo diclofenac, diclofenac + placebo paracetamol or paracetamol + diclofenac. The hypothesis is that paracetamol will not be inferior to treatment with diclofenac, or the combination of both. Primary outcome will be between-group differences in decrease in pain, measured with Numerical Rating Scales at baseline and at 90 minutes after study drug administration. Secondary outcomes are Numerical Rating Scales at 30 and 60 minutes and measured frequently during three consecutive days after discharge; occurrence of adverse effects; patient satisfaction and an analysis of quality of life and cost-effectiveness. Recruitment started July 2013 and is expected to last a year.
With this multi-center randomized clinical trial we will investigate whether treatment with paracetamol alone is not inferior to diclofenac alone or a combination of both drugs in adult patients with acute musculoskeletal trauma. The main relevance of the trial is to demonstrate the benefits and risks of three commonly used treatment regimens for musculoskeletal trauma. Data that lead to the prevention of severe Non-Steroidal Anti-Inflammatory Drugs-related adverse effects might be gathered.
Trial registration
Dutch Trial Register ( NTR3982.
EudraCT database ( 201300038111.
PMCID: PMC4225513  PMID: 24256450
Wounds and injuries; Strains and sprains; Contusions; Analgesia; Pain; Paracetamol/acetaminophen; Anti-inflammatory agents; Non-steroidal; Costs and cost analysis
7.  NMDA Receptor Antagonist Ketamine Impairs Feature Integration in Visual Perception 
PLoS ONE  2013;8(11):e79326.
Recurrent interactions between neurons in the visual cortex are crucial for the integration of image elements into coherent objects, such as in figure-ground segregation of textured images. Blocking N-methyl-D-aspartate (NMDA) receptors in monkeys can abolish neural signals related to figure-ground segregation and feature integration. However, it is unknown whether this also affects perceptual integration itself. Therefore, we tested whether ketamine, a non-competitive NMDA receptor antagonist, reduces feature integration in humans. We administered a subanesthetic dose of ketamine to healthy subjects who performed a texture discrimination task in a placebo-controlled double blind within-subject design. We found that ketamine significantly impaired performance on the texture discrimination task compared to the placebo condition, while performance on a control fixation task was much less impaired. This effect is not merely due to task difficulty or a difference in sedation levels. We are the first to show a behavioral effect on feature integration by manipulating the NMDA receptor in humans.
PMCID: PMC3815103  PMID: 24223927
8.  Re-evaluating currently available data and suggestions for planning randomised controlled studies regarding the use of hydroxyethyl starch in critically ill patients - a multidisciplinary statement 
Critical Care  2013;17(4):R166.
Hydroxyethyl starch (HES) is a commonly used colloid in critically ill patients. However, its safety has been questioned in recent studies and meta-analyses.
We re-evaluated prospective randomised controlled trials (RCT) from four meta-analyses published in 2013 that compared the effect of HES with crystalloids in critically ill patients, focusing on the adherence to 'presumably correct indication'. Regarding the definition of 'presumably correct indication', studies were checked for the following six criteria (maximum six points): short time interval from shock to randomisation (<6 h), restricted use for initial volume resuscitation, use of any consistent algorithm for haemodynamic stabilisation, reproducible indicators of hypovolaemia, maximum dose of HES, and exclusion of patients with pre-existing renal failure or renal replacement therapy.
Duration of fluid administration ranged from 90 min up to a maximum of 90 days. Four studies considered follow-up until 90-day mortality, three studies 28-/30-day mortality, whereas four studies reported only early mortality. Included studies showed a large heterogeneity of the indication score ranging between 1 and 4 points with a median (25%; 75% quartile) of 4 (2; 4).
The most important question, whether or not HES may be harmful when it is limited to immediate haemodynamic stabilisation, cannot be answered yet in the absence of any study sufficiently addressing this question. In order to overcome the limitations of most of the previous studies, we now suggest an algorithm emphasising the strict indication of HES. Additionally, we give a list of suggestions that should be adequately considered in any prospective RCT in the field of acute volume resuscitation in critically ill patients.
PMCID: PMC4056523  PMID: 23890518
9.  A multi-centre randomised double-blind placebo-controlled trial to evaluate the value of a single bolus intravenous alfentanil in CT colonography 
BMC Gastroenterology  2013;13:94.
Pain is common during colonic insufflation required for CT colonography. We therefore evaluate whether a single intravenous alfentanil bolus has a clinically relevant analgesic effect compared with placebo in patients undergoing CT colonography.
A prospective multi-centre randomised double-blind placebo-controlled trial was performed in patients scheduled for elective CT colonography. Patients were randomised to receive either a bolus of 7.5 μg/kg alfentanil (n = 45) or placebo (n = 45). The primary outcome was the difference in maximum pain during colonic insufflation on an 11-point numeric rating scale. We defined a clinically relevant effect as a maximum pain reduction of at least 1.3 points. Secondary outcomes included total pain and burden of CT colonography (5-point scale), the most burdensome aspect and side effects. Our primary outcome was tested using a one-sided independent samples t-test.
Maximum pain scores during insufflation were lower with alfentanil as compared with placebo, 5.3 versus 3.0 (P < 0.001). Total CT colonography pain and burden were also lower with alfentanil (2.0 vs. 1.6; P = 0.014 and 2.1 vs. 1.7; P = 0.007, respectively). With alfentanil fewer patients rated the insufflation as most burdensome aspect (56.1% vs. 18.6%; P = 0.001). Episodes with desaturations < 90% SpO2 were more common with alfentanil (8.1% vs. 44.4%; P < 0.001, but no clinically relevant desaturations occurred.
A low-dose intravenous alfentanil bolus provides a clinically relevant reduction of maximum pain during CT colonography and may improve the CT colonography acceptance, especially for patients with a low pain threshold.
Trial registration
Dutch Trial Register: NTR2902
PMCID: PMC3671205  PMID: 23706123
Randomised controlled trial; Colonography; Computed tomographic; Alfentanil; Analgesics; Opioid; Patient satisfaction
10.  Results of the introduction of a minimally invasive esophagectomy program in a tertiary referral center 
Journal of Thoracic Disease  2012;4(5):467-473.
Esophagectomy is accompanied by a high postoperative complication rate. Minimally invasive esophageal surgery appears to be a promising technique that might be associated with a lower pulmonary morbidity rate. The objective of this study was to describe the implementation of minimally invasive esophageal surgery in a tertiary referral center and to compare the results of our first series of minimally invasive esophagectomies (MIE) to conventional open esophagectomies.
MIE was implemented after several procedures had been proctored by a surgeon with extensive experience with MIE. Preoperative characteristics and the postoperative course of patients who underwent a transthoracic esophagectomy were prospectively registered. Morbidity and overall hospital stay were compared between minimally invasive and open resections performed in the same period.
A total of 90 consecutive esophageal cancer patients underwent a transthoracic resection, 41 patients by means of a minimally invasive approach. Preoperative characteristics were comparable for both groups. The duration of surgery was longer in the MIE group (6.0 vs. 5.2 hours, P<0.001) and median blood loss was lower [100 vs. 500 mL (P<0.001)]. There was only a trend towards a shorter hospital stay in the MIE group (11 vs. 13 days, P=0.072), pulmonary complications occurred in 20% of patients in the MIE group vs. 31% in the open group (P=0.229). The overall complication rate was 51% in the MIE group vs. 63% in the open group, P=0.249.
Implementation of MIE in our center was successful and it appears to be a safe technique for patients with potentially curable esophageal carcinoma.
PMCID: PMC3461068  PMID: 23050110
Esophageal cancer; surgical technical; complications; thoracoscopy
11.  Effects of helium and air inhalation on the innate and early adaptive immune system in healthy volunteers ex vivo 
Helium inhalation protects myocardium, brain and endothelium against ischemia/reperfusion injury in animals and humans, when applied according to specific “conditioning” protocols. Before widespread use of this “conditioning” agent in clinical practice, negative side effects have to be ruled out. We investigated the effect of prolonged helium inhalation on the responsiveness of the human immune response in whole blood ex vivo.
Male healthy volunteers inhaled 30 minutes heliox (79%He/21%O2) or air in a cross over design, with two weeks between measurements. Blood was withdrawn at T0 (baseline), T1 (25 min inhalation) and T2-T5 (1, 2, 6, 24 h after inhalation) and incubated with lipopolysaccharide (LPS), lipoteichoic acid (LTA), T-cell stimuli anti-CD3/ anti-CD28 (TCS) or RPMI (as control) for 2, 4 and 24 hours or not incubated (0 h). An additional group of six volunteers inhaled 60 minutes of heliox or air, followed by blood incubation with LPS and RPMI. Tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), interferon-γ (IFN-γ) and interleukin-2 (IL-2) was analyzed by cytometric bead array. Statistical analysis was performed by the Wilcoxon test for matched samples.
Incubation with LPS, LTA or TCS significantly increased TNF-α, IL-1β, IL-6, IL-8, IFN-γ and IL-2 in comparison to incubation with RPMI alone. Thirty min of helium inhalation did not influence the amounts of TNF-α, IL-1β, IL-6, IL-8, IFN-γ and IL-2 in comparison to air. Sixty min of helium inhalation did not affect cytokine production after LPS stimulation.
We conclude that 79% helium inhalation does not affect the responsiveness of the human immune system in healthy volunteers.
Trial registration
Dutch Trial Register: NTR2152
PMCID: PMC3495766  PMID: 23006534
Noble gas; Side effects; Cell-mediated immunity; Ischemia-reperfusion injury; Whole blood stimulation
12.  Deletion of the Innate Immune NLRP3 Receptor Abolishes Cardiac Ischemic Preconditioning and Is Associated with Decreased Il-6/STAT3 Signaling 
PLoS ONE  2012;7(7):e40643.
Recent studies indicate that the innate immune system is not only triggered by exogenous pathogens and pollutants, but also by endogenous danger signals released during ischemia and necrosis. As triggers for the innate immune NLRP3 inflammasome protein complex appear to overlap with those for cardiac ischemia-reperfusion (I/R) and ischemic preconditioning (IPC), we explored the possibility that the NLRP3 inflammasome is involved in IPC and acute I/R injury of the heart.
Principal Findings
Baseline cardiac performance and acute I/R injury were investigated in isolated, Langendorff-perfused hearts from wild-type (WT), ASC−/− and NLRP3−/− mice. Deletion of NLRP3 inflammasome components ASC−/− or NLRP3−/− did not affect baseline performance. The deletions exacerbated I/R-induced mechanical dysfunction, but were without effect on I/R-induced cell death. When subjected to IPC, WT and ASC−/− hearts were protected against I/R injury (improved function and less cell death). However, IPC did not protect NLRP3−/− hearts against I/R injury. NLRP3−/− hearts had significantly decreased cardiac IL-6 levels with a trend towards lower IL-1β levels at end reperfusion, suggesting abrogation of IPC through diminished IL-6 and/or IL-1β signaling. Subsequent experiments showed that neutralising IL-6 using an antibody against IL-6 abrogated IPC in WT hearts. However, inhibition of the IL-1r receptor with the IL-1 receptor inhibitor Anakinra (100 mg/L) did not abrogate IPC in WT hearts. Analysis of survival kinases after IPC demonstrated decreased STAT3 expression in NLRP3−/− hearts when compared to WT hearts.
The data suggest that the innate immune NLRP3 protein, in an NLRP3-inflammasome-independent fashion, is an integral component of IPC in the isolated heart, possibly through an IL-6/STAT3 dependent mechanism.
PMCID: PMC3407219  PMID: 22848390
14.  A multicenter, randomized controlled trial of immediate total-body CT scanning in trauma patients (REACT-2) 
Computed tomography (CT) scanning has become essential in the early diagnostic phase of trauma care because of its high diagnostic accuracy. The introduction of multi-slice CT scanners and infrastructural improvements made total-body CT scanning technically feasible and its usage is currently becoming common practice in several trauma centers. However, literature provides limited evidence whether immediate total-body CT leads to better clinical outcome then conventional radiographic imaging supplemented with selective CT scanning in trauma patients. The aim of the REACT-2 trial is to determine the value of immediate total-body CT scanning in trauma patients.
The REACT-2 trial is an international, multicenter randomized clinical trial. All participating trauma centers have a multi-slice CT scanner located in the trauma room or at the Emergency Department (ED). All adult, non-pregnant, severely injured trauma patients according to predefined criteria will be included. Patients in whom direct scanning will hamper necessary cardiopulmonary resuscitation or who require an immediate operation because of imminent death (both as judged by the trauma team leader) are excluded. Randomization will be computer assisted. The intervention group will receive a contrast-enhanced total-body CT scan (head to pelvis) during the primary survey. The control group will be evaluated according to local conventional trauma imaging protocols (based on ATLS guidelines) supplemented with selective CT scanning. Primary outcome will be in-hospital mortality. Secondary outcomes are differences in mortality and morbidity during the first year post trauma, several trauma work-up time intervals, radiation exposure, general health and quality of life at 6 and 12 months post trauma and cost-effectiveness.
The REACT-2 trial is a multicenter randomized clinical trial that will provide evidence on the value of immediate total-body CT scanning during the primary survey of severely injured trauma patients. If immediate total-body CT scanning is found to be the best imaging strategy in severely injured trauma patients it could replace conventional imaging supplemented with CT in this specific group.
Trial Registration (NCT01523626).
PMCID: PMC3361475  PMID: 22458247
15.  Reduction in Hexokinase II Levels Results in Decreased Cardiac Function and Altered Remodeling after Ischemia-Reperfusion Injury 
Circulation research  2010;108(1):60-69.
Cardiomyocytes switch substrate utilization from fatty acid to glucose under ischemic conditions, however, it is unknown how perturbations in glycolytic enzymes affect cardiac response to ischemia-reperfusion (I/R). Hexokinase (HK) II is a HK isoform that is expressed in the heart and it can bind to the mitochondrial outer membrane.
We sought to define how HKII and its binding to mitochondria play a role in cardiac response and remodeling after I/R.
Methods and Results
We first showed that HKII levels and its binding to mitochondria are reduced 2 days after I/R. We then subjected the hearts of wild type and heterozygote HKII knockout (HKII+/−) mice to I/R by coronary ligation. At baseline, HKII+/− mice have normal cardiac function, however, they display lower systolic function after I/R compared to wild type animals. The mechanism appears to be through an increase in cardiomyocyte death and fibrosis and a reduction in angiogenesis, the latter is through a decrease in HIF-dependent pathway signaling in cardiomyocytes. HKII mitochondrial binding is also critical for cardiomyocyte survival, as its displacement in tissue culture with a synthetic peptide increases cell death. Our results also suggest that HKII may be important for the remodeling of the viable cardiac tissue as its modulation in vitro alters cellular energy levels, O2 consumption and contractility.
These results suggest that reduction in HKII levels causes altered remodeling of the heart in I/R by increasing cell death and fibrosis and reducing angiogenesis, and that mitochondrial binding is needed for protection of cardiomyocytes.
PMCID: PMC3017633  PMID: 21071708
Hexokinase; Ischemia-reperfusion; Mitochondria; Vascular endothelial growth factor (VEGF); Apoptosis
16.  A randomized double-blind placebo-controlled trial to evaluate the value of a single bolus intravenous alfentanil in CT colonography 
BMC Gastroenterology  2011;11:128.
Although CT colonography is a less invasive alternative for colonoscopy for the detection of colorectal polyps and cancer, procedural pain is common. In several studies, CT colonography pain and burden is higher than in colonoscopy. Apart from discomfort, anxiety and its related stress-induced peri- procedural side effects, this may influence the adherence for CT colonography as a possible screening tool for colorectal cancer. We hypothesize that a single bolus intravenous alfentanil will give a clinically relevant reduction in maximum pain defined as at least 1.3 point reduction on an 11-point numeric rating scale (NRS).
A randomized double-blind placebo-controlled trial in which patients scheduled for elective CT colonography in a single tertiary centre are eligible for inclusion. The first 90 consenting patient will be block-randomized to either the alfentanil group or the placebo group. Before bowel insufflation, the alfentanil group receives a single bolus intravenous alfentanil 7.5 μg/kg dissolved in 0.9% NaCl, while the placebo group receives an intravenous bolus injection of pure 0.9% NaCl. For both groups an equal amount of fluid per kilogram (75 μL/kg) is injected. The primary outcome is the difference in maximum pain on an 11-point NRS. Secondary outcomes include: pain and burden of different CT colonography aspects, side effects, procedural time and recovery time. For the primary outcome an independent samples t-test is performed and a P value < 0.05 is considered statistically significant.
This study will provide evidence whether a single bolus intravenous alfentanil gives a clinically relevant reduction in maximum pain during CT colonography.
Trial registration
Netherlands Trial Register (NTR): NTR2902
This trial will be conducted in accordance with the protocol and in compliance with the moral, ethical, and scientific principles governing clinical research as set out in the Declaration of Helsinki (1989) and Good Clinical Practice (GCP). The department of radiology of the Academic Medical Center of Amsterdam is responsible for the design and conduct of the trial.
PMCID: PMC3339326  PMID: 22111658
17.  Effect of remote ischemic conditioning on atrial fibrillation and outcome after coronary artery bypass grafting (RICO-trial) 
BMC Anesthesiology  2011;11:11.
Pre- and postconditioning describe mechanisms whereby short ischemic periods protect an organ against a longer period of ischemia. Interestingly, short ischemic periods of a limb, in itself harmless, may increase the ischemia tolerance of remote organs, e.g. the heart (remote conditioning, RC). Although several studies have shown reduced biomarker release by RC, a reduction of complications and improvement of patient outcome still has to be demonstrated. Atrial fibrillation (AF) is one of the most common complications after coronary artery bypass graft surgery (CABG), affecting 27-46% of patients. It is associated with increased mortality, adverse cardiovascular events, and prolonged in-hospital stay. We hypothesize that remote ischemic pre- and/or post-conditioning reduce the incidence of AF following CABG, and improve patient outcome.
This study is a randomized, controlled, patient and investigator blinded multicenter trial. Elective CABG patients are randomized to one of the following four groups: 1) control, 2) remote ischemic preconditioning, 3) remote ischemic postconditioning, or 4) remote ischemic pre- and postconditioning. Remote conditioning is applied at the arm by 3 cycles of 5 minutes of ischemia and reperfusion. Primary endpoint is the incidence AF in the first 72 hours after surgery, detected using a Holter-monitor. Secondary endpoints include length-of-stay on the intensive care unit and in-hospital, and the occurrence of major adverse cardiovascular events at 30 days, 3 months and 1 year.
Based on an expected incidence in the control group of 27%, 195 patients per group are needed to detect with 80% power a reduction by 45% following either pre- or postconditioning, while allowing for a 10% dropout and at an alpha of 0.05. With the combined intervention expected to be stronger, we need 75 patients in this group to detect a reduction in incidence of AF of 60%.
The RICO-trial (the effect of Remote Ischemic Conditioning on atrial fibrillation and Outcome) is a randomized controlled multicenter trial, designed to investigate whether remote ischemic pre- and/or post-conditioning of the arm reduce the incidence of AF following CABG surgery.
Trial registration under NCT01107184.
PMCID: PMC3119027  PMID: 21605453
18.  Rationale and study design of PROVHILO - a worldwide multicenter randomized controlled trial on protective ventilation during general anesthesia for open abdominal surgery 
Trials  2011;12:111.
Post-operative pulmonary complications add to the morbidity and mortality of surgical patients, in particular after general anesthesia >2 hours for abdominal surgery. Whether a protective mechanical ventilation strategy with higher levels of positive end-expiratory pressure (PEEP) and repeated recruitment maneuvers; the "open lung strategy", protects against post-operative pulmonary complications is uncertain. The present study aims at comparing a protective mechanical ventilation strategy with a conventional mechanical ventilation strategy during general anesthesia for abdominal non-laparoscopic surgery.
The PROtective Ventilation using HIgh versus LOw positive end-expiratory pressure ("PROVHILO") trial is a worldwide investigator-initiated multicenter randomized controlled two-arm study. Nine hundred patients scheduled for non-laparoscopic abdominal surgery at high or intermediate risk for post-operative pulmonary complications are randomized to mechanical ventilation with the level of PEEP at 12 cmH2O with recruitment maneuvers (the lung-protective strategy) or mechanical ventilation with the level of PEEP at maximum 2 cmH2O without recruitment maneuvers (the conventional strategy). The primary endpoint is any post-operative pulmonary complication.
The PROVHILO trial is the first randomized controlled trial powered to investigate whether an open lung mechanical ventilation strategy in short-term mechanical ventilation prevents against postoperative pulmonary complications.
Trial registration
PMCID: PMC3104489  PMID: 21548927
19.  Morphine induces preconditioning via activation of mitochondrial KCa channels 
Canadian Journal of Anaesthesia  2010;57(8):767-773.
Mitochondrial calcium sensitive potassium (mKCa) channels are involved in cardioprotection induced by ischemic preconditioning. In the present study we investigated whether morphine-induced preconditioning also involves activation of mKCa channels.
Isolated rat hearts (six groups; each n = 8) underwent global ischemia for 30 min followed by a 60-min reperfusion. Control animals were not further treated. Morphine preconditioning (MPC) was initiated by two five-minute cycles of morphine 1 μM infusion with one five-minute washout and one final ten-minute washout period before ischemia. The mKCa blocker, paxilline 1 μM, was administered, with and without morphine administration (MPC + Pax and Pax). As a positive control, we added an ischemic preconditioning group (IPC) alone and combined with paxilline (IPC + Pax). At the end of reperfusion, infarct sizes were determined by triphenyltetrazoliumchloride staining.
Infarct size was (mean ± SD) 45 ± 9% of the area at risk in the Control group. The infarct size was less in the morphine or ischemic preconditioning groups (MPC: 23 ± 8%, IPC: 20 ± 5%; each P < 0.05 vs Control). Infarct size reduction was abolished by paxilline (MPC + Pax: 37 ± 7%, P < 0.05 vs MPC and IPC + Pax: 36 ± 6%, P < 0.05 vs IPC), whereas paxilline alone had no effect (Pax: 46 ± 7%, not significantly different from Control).
Cardioprotection by morphine-induced preconditioning is mediated by activation of mKCa channels.
PMCID: PMC2899019  PMID: 20461490
Morphine; Preconditioning; mKCa; Infarct size
20.  Partial hexokinase II knockout results in acute ischemia–reperfusion damage in skeletal muscle of male, but not female, mice 
Pflugers Archiv   2010;459(5):705-712.
Cellular studies have demonstrated a protective role of mitochondrial hexokinase against oxidative insults. It is unknown whether HK protective effects translate to the in vivo condition. In the present study, we hypothesize that HK affects acute ischemia–reperfusion injury in skeletal muscle of the intact animal. Male and female heterozygote knockout HKII (HK+/-), heterozygote overexpressed HKII (HKtg), and their wild-type (WT) C57Bl/6 littermates mice were examined. In anesthetized animals, the left gastrocnemius medialis (GM) muscle was connected to a force transducer and continuously stimulated (1-Hz twitches) during 60 min ischemia and 90 min reperfusion. Cell survival (%LDH) was defined by the amount of cytosolic lactate dehydrogenase (LDH) activity still present in the reperfused GM relative to the contralateral (non-ischemic) GM. Mitochondrial HK activity was 72.6 ± 7.5, 15.7 ± 1.7, and 8.8 ± 0.9 mU/mg protein in male mice, and 72.7 ± 3.7, 11.2 ± 1.4, and 5.9 ± 1.1 mU/mg in female mice for HKtg, WT, and HK+/-, respectively. Tetanic force recovery amounted to 33 ± 7% for male and 17 ± 4% for female mice and was similar for HKtg, WT, and HK+/-. However, cell survival was decreased (p = 0.014) in male HK+/- (82 ± 4%LDH) as compared with WT (98 ± 5%LDH) and HKtg (97 ± 4%LDH). No effects of HKII on cell survival was observed in female mice (92 ± 2% LDH). In conclusion, in this mild model of acute in vivo ischemia–reperfusion injury, a partial knockout of HKII was associated with increased cell death in male mice. The data suggest for the first time that HKII mediates skeletal muscle ischemia–reperfusion injury in the intact male animal.
PMCID: PMC2842566  PMID: 20182739
Mitochondria; Cell death; Ischemia; Muscle; Muscle ischemia
21.  Perioperative strategy in colonic surgery; LAparoscopy and/or FAst track multimodal management versus standard care (LAFA trial) 
BMC Surgery  2006;6:16.
Recent developments in large bowel surgery are the introduction of laparoscopic surgery and the implementation of multimodal fast track recovery programs. Both focus on a faster recovery and shorter hospital stay.
The randomized controlled multicenter LAFA-trial (LAparoscopy and/or FAst track multimodal management versus standard care) was conceived to determine whether laparoscopic surgery, fast track perioperative care or a combination of both is to be preferred over open surgery with standard care in patients having segmental colectomy for malignant disease.
The LAFA-trial is a double blinded, multicenter trial with a 2 × 2 balanced factorial design. Patients eligible for segmental colectomy for malignant colorectal disease i.e. right and left colectomy and anterior resection will be randomized to either open or laparoscopic colectomy, and to either standard care or the fast track program. This factorial design produces four treatment groups; open colectomy with standard care (a), open colectomy with fast track program (b), laparoscopic colectomy with standard care (c), and laparoscopic surgery with fast track program (d). Primary outcome parameter is postoperative hospital length of stay including readmission within 30 days. Secondary outcome parameters are quality of life two and four weeks after surgery, overall hospital costs, morbidity, patient satisfaction and readmission rate.
Based on a mean postoperative hospital stay of 9 +/- 2.5 days a group size of 400 patients (100 each arm) can reliably detect a minimum difference of 1 day between the four arms (alfa = 0.95, beta = 0.8). With 100 patients in each arm a difference of 10% in subscales of the Short Form 36 (SF-36) questionnaire and social functioning can be detected.
The LAFA-trial is a randomized controlled multicenter trial that will provide evidence on the merits of fast track perioperative care and laparoscopic colorectal surgery in patients having segmental colectomy for malignant disease.
PMCID: PMC1693570  PMID: 17134506

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