Ignite Creation Date:
2024-10-25 @ 8:03 PM
Last Modification Date:
2024-10-26 @ 3:35 PM
Study NCT ID:
NCT06510348
Status:
NOT_YET_RECRUITING
Last Update Posted:
None
First Post:
2024-07-14
Brief Title:
Achieving nuTritional Target in criticAlly Ill patieNts With iMpairEd gastroiNtesTinal Dysfunction
Sponsor:
None
Organization:
None
Study Overview
Official Title:
Achieving nuTritional Target in criticAlly Ill patieNts With iMpairEd gastroiNtesTinal Dysfunction
Status:
NOT_YET_RECRUITING
Status Verified Date:
2024-07
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
No
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
ATTAINMENT
Brief Summary:
Clear study hypothesis research question
It has already been proven that a prolonged negative energy balance during intensive care stay is an independent risk factor for mortality Although it was thought that achivieng optimal delivery of calories will prevent nutritional deficits in critically ill patients published randomized controlled trials failed to confirm this hypothesis
Combinging enteral and parenteral support may be an efficent strategy to reach nutritional target in critically ill patients According to the current guidelines the use of suplemental parenteral nutrition SPN should be considered when energy targets are not achieved by enteral EN route however no clear data regarding timing amount and composition is specified Moreover based on recente published data overfeeding should also be avoided considering the negative impact on outcome
Nutritional support for critically ill patients was focused more on preventing caloric and protein deficits and no great emphasis was placed on the efficiency of intestinal absorption Gastrointestinal dysfunction is a prevalent reported complication that may contribute to falling short of meeting nutritional goals This encompasses a wide spectrum of symptoms such as impaired gastric emptying ileus or impaired intestinal absorbtion exposing patients to feeding intolerance malnutrition and worse outcomes No standard definition and monitoring techniques are so far available for the diagnostic of feeding intolerance Although increased gastric residual volume GRV is the most used parameter for highlighting feeding intolerance a controversy regarding the adequate threshold of GRV persists Acetaminophen absorption test has been previously proposed as a diagnostic tool to asses impaired gastric emptying and intestinal absorbtion
Besides intestinal absorbtion efficient utilization of macronutients should also be assessed considering that critically ill patients have varying metabolic conditions and may not be able to metabolically handle adminsitered substrates As a result body composition analysis should be taken into account in order to obtain a dynamic quantification especially of the mucle mass compartiments
Therefore the following low-interventional study is designed to investigate the hypothesis regarding energy and protein intake achievement in critically ill patients with diagnosed impaired gastrointestinal dysfunction to whom tailored nutritional support is administered
Taking into account that we aim to identify patients with early-phase gastrointestinal dysfunction impaired gastric emptying and reduced intestinal absorbtion diagnosed using ultrasound gastric residual volume and byacetaminiphen absorbtion test will serve as defining factors Patients will be randomized to receive nutritional support either according to the EN protocol or enteral trophic feed SPN protocol
Differences in rectus femoris thickness measured on admission on day 10 and 15 variation of lean body mass measured by bioelectrical impedance on admission on day 10 and 15 and differences between groups in muscle function using handgrip dynamometer will also be evaluated in both groups
It has already been proven that a prolonged negative energy balance during intensive care stay is an independent risk factor for mortality Although it was thought that achivieng optimal delivery of calories will prevent nutritional deficits in critically ill patients published randomized controlled trials failed to confirm this hypothesis
Combinging enteral and parenteral support may be an efficent strategy to reach nutritional target in critically ill patients According to the current guidelines the use of suplemental parenteral nutrition SPN should be considered when energy targets are not achieved by enteral EN route however no clear data regarding timing amount and composition is specified Moreover based on recente published data overfeeding should also be avoided considering the negative impact on outcome
Nutritional support for critically ill patients was focused more on preventing caloric and protein deficits and no great emphasis was placed on the efficiency of intestinal absorption Gastrointestinal dysfunction is a prevalent reported complication that may contribute to falling short of meeting nutritional goals This encompasses a wide spectrum of symptoms such as impaired gastric emptying ileus or impaired intestinal absorbtion exposing patients to feeding intolerance malnutrition and worse outcomes No standard definition and monitoring techniques are so far available for the diagnostic of feeding intolerance Although increased gastric residual volume GRV is the most used parameter for highlighting feeding intolerance a controversy regarding the adequate threshold of GRV persists Acetaminophen absorption test has been previously proposed as a diagnostic tool to asses impaired gastric emptying and intestinal absorbtion
Besides intestinal absorbtion efficient utilization of macronutients should also be assessed considering that critically ill patients have varying metabolic conditions and may not be able to metabolically handle adminsitered substrates As a result body composition analysis should be taken into account in order to obtain a dynamic quantification especially of the mucle mass compartiments
Therefore the following low-interventional study is designed to investigate the hypothesis regarding energy and protein intake achievement in critically ill patients with diagnosed impaired gastrointestinal dysfunction to whom tailored nutritional support is administered
Taking into account that we aim to identify patients with early-phase gastrointestinal dysfunction impaired gastric emptying and reduced intestinal absorbtion diagnosed using ultrasound gastric residual volume and byacetaminiphen absorbtion test will serve as defining factors Patients will be randomized to receive nutritional support either according to the EN protocol or enteral trophic feed SPN protocol
Differences in rectus femoris thickness measured on admission on day 10 and 15 variation of lean body mass measured by bioelectrical impedance on admission on day 10 and 15 and differences between groups in muscle function using handgrip dynamometer will also be evaluated in both groups
Detailed Description:
Rationale and clinical significance of the hypothesis
It has already been stated that nutritional support represents a crucial component in the care of critically ill patients High metabolic demand encountered for critically ill patients may cause significant energy deficits responsible for increased risk of infection prolonged mechanical ventilation and ICU stay Aditionally providing nutritional support in ICU patients is often deeemd challenging as enteral feeding intolerance devolps secondary to gastrointestinal dysfunction Although some authors opinioned that reducing energy targets might be beneficial several studies proved that permissive underfeeding has no positive impact on outcome Morover reduction of energy target recommendation was associated with a scondary decrease of protein supplementation
Apart from disscussing nutritional intake great emphasis should be placed on nutritional uptake as an increased percentage of critically ill patients fail to reach nutritional targets often due to gastrointestinal dysfunction
Gastrointestinal dyfunction may be defined by a variety of functional impairements affecting motility absorbtion microbiome composition or perfusion but still at this momement there is a lack of recommendation regarding monitoring methods6 At the bedside assesement of gastrointestinal dysfunction often relies on measuring GRV However gastric emptying rate proved to be poorly correlated with GRV This monitoring technique may also result in a decresed amount of nutrients delivery Since ultrasound has became a popular diagnostic tool also in the ICU several studies indicated that ultrasonographic measurement of gastric antral cross-sectional area has a good correlation with both aspirated GRV and gastric volume measured by computerised tomography Considering that paracetamol has little to no absorption in the stomach and is completely absorbed at the intestinal level paracetamol absorption test PAT has been proposed as a simple indirect method for evaluating gastric emptying As the pharmacokinetic studies have established that gastric emptying is a rate-limiting step for paracetamol absorbtion studies where PAT was used validated a significant correlation with scintigraphy results
The combination of reduced tolerance to enteral feeding at the initiation of nutritional support along with the initiation of nutritional support within 48 hours has been proven to be responsible for a progressively significant and intractable energy deficit It has been found that continuing enteral feeding under these circumstances is ineffective in resolving this energy debt which is proportional with an increased risk of nosocomial infections
Using SPN for patients who cannot tolerate EN proved to be safe and was associated with improved cumulative energy balance decreased rate of infections and significant cost reduction Although SPN is proposed both by ESPEN and ASPEN guideline as an efficient alternative when energy and protein target are not achieve by oral or enteral route recent data revealed that SPN use is rather limited14 The primary concern regarding SPN use is the risk of overfeeding However utilizing the appropriate concept of SPN and measuring energy needs by indirect calorimetry may overcome administering feeds in an unphysiological manner
Besides intake and uptake muscle capacity to respond to nutritional protein should also be taken into account Several different tools have been proposed for body composition analysis of critically ill patients Ultrasound with different protocols has also been used to assess muscle mass even in ICU patients with greater fluid shifts16 Studies have indicated that a significant reduction in muscle mass may be identified by both rectus femoris cross-sectional area and quadriceps muscle layer thickness measurements Bioelectrical impedance analysis is another non-invasive low-cost technique used for body composition assesment Despite reported limitations related with frequent overhydration states in critically ill patients this method can still provide reliable data if the appropriate timing for examination is chosen Nevertheless bioelectrical impedance analysis-derived phase angle proved to be a trustworthy parameter not only for evaluating fat-free mass but also mortality Functional parameters such as handgrip strengts measurements should be also included when effectivness of nutritional support is evaluated However it is important to acknowledge barriers to collecting functional outcome data particularly when critically ill patients are studied
Study design
1 Study type This single-center controlled randomized pragmatic trial will be conducted in the 34-bed general intensive care of Clinical Emergency Hospital of Bucharest a tertiary-care university affiliated hospital
Participating site data
Department of Anaesthesia and Intensive Care from the Clinical Emergency Hospital of Bucharest disposes in total of 86 intensive care beds
Considering that there is no globally validated single definition that can be used to objectify this gastrointestinal dysfunction real prevalence of this dysfunction is not quantified It has been reported that one-third of all enterally fed mechanically ventilated critically ill patients are presenting enteral feed intolerance but many more patients may have subclinical gastrointestinal dysmotility the estimated percentage could reach as high as 80 Taking into account the annual rate of admission in our unit it is feasible to complete the inclusion process by July 2025 1 year and 8 months
Nevertheless maintaining this study as monocentric will provide better control over potential confounding factors and reduce heterogeneity Furthermore it will enhance internal validity and streamline coordination efforts
Ethics
Study protocol together with a a model of informed consent were submitted to the Clinical Emergency Hospital of Bucharest Ethics Committee and the final approval has been obtained on 18052023
Taking into account that the included patients are not able to provide informed consent at the time of recruitment on ICU admission a Power of Attorney or a Legal tutor will act as Consultee and will be asked to consentdecline participation to the study on legal behalf of the patient If patients have Advance Decision Plan including participation in research studies the Plan will be respected and recruitment pursuedabandoned accordingly After regaining capacity all patients will be asked to provide Informed Consent for using their personal data and will be given the possibility to
Provide Informed Consent for the acute data and follow-up Deny research participation and request destruction of acute data collected
2 Description of the study population inclusion and exclusion criteria
All adults 18 years old are eligible for inclusion if it will be expected to require mechanical ventilation for more than four days have a controlled shock state hemodynamic and tissue perfusion goals are reached and impaired intestinal absorbtion defiend by both ultrasound measurement of gastric residual volume and paracetamol absorbtion test Exclusion criteria are patients on non-invasive mechanichal ventilation contraindication for EN for 48 h after admission patients with gastrointestinal surgical intervention within 3 months history of malabsorption inflammatory bowel disease short bowel syndrom anorexia nervosa gastrointestinal bleeding cirrhosis traumatic brain injury subarahnoidal hemorrhage neoplasia post cardiac arrest patients patients on chronic therapy with corticosteroids and pregnant women
e Methods and techniques
Randomisation
Selected patients for inclusion will be allocated in one of the two groups after stratified randomisation
The patient population can be stratified into three groups based on their admission type which includes General Surgery Multiple Trauma and Internal Medicine To perform stratified randomization three separate randomization lists would be required - one for each stratum These lists could be generated using techniques such as block randomization Depending on the stratum a patient belongs to the corresponding randomization list would be utilized to allocate the patient to one of the nutritional protocol being compared
Nutritional protocol
Nutritional targets are based on ESPEN guidelines recommendation calories administration based on indirect calorimetry study proteins 13 gkgday From the first day of ICU admission indirect calorimetry will be performed daily in order to evaluate energy requirements For both groups enteral nutritional support will be started after 48 hours since admission or after controlled shock state will be confirmed Enteral nutrition will be incrementally escalated using a ramped fashioned approach with the goal of reaching 25 to 50 of the energy target determined by indirect calorimetry by day 2 Subsequently on days 3 and 4 the target will be gradually raised to 75 Enteral nutrition will be administered continuously
On the fourth day the patient will undergo a gastric residual volume measurement and a paracetamol absorption test If gastrointestinal dysfunction is detected the patient will be assigned to a study group based on the randomization protocol
In the EN group enteral nutrition intake will progressively be increased according to the gastrointestinal tolerance evaluated based on ultrasound guided gastric residual volume measurement until the target of 100 is attained following admission to the ICU
The SPN group will gradually initiate supplemental parenteral nutrition in order to achieve the target of 80 by the fifth day Trophic feed will be administered to cover the remaining 20 of the targeted nutrition intake Figure 1 depicts a graphical illustration of the nutritional protocol
Products
EN formula for EN group and trophic feeds polymeric fibre-enriched formulas - Fresubin Original Fibre 15 proteins 30 lipids 52 carbohydrates Fibre 3 PN formula for SPN group SMOFKABIVEN EXTRA NITROGEN 16 gN - 1518 ml - 10 amino acids 20 lipid emulsion SMOFlipid 20 42 glucose and electrolytes
Ultrasound guided gastric residual volume measurement
Gastric ultrasound assessment will be performed by two independent observers in supine position Both sets of measurements will be performed after a minimum of six hours of fasting Antral cross-sectional area ACSA area will be calculated by using antero-posterior and cranio-caudal antral diameters measured from serosa to serosa and the formula of the area of an elipse 4 Furthermore the gastric volume will be calculated according to the model proposed by Perlas et al Gastric Volume ml 2763 016 x weight kg 124 x BMI - 0013 x time since last meal in hours x antral cross-sectional area in cm²
A gastric residual volume above 200 ml will be considered positive for impaired gastric motility
Paracetamol absorbtion test
In order to evaluate paracetamol absorbtion area under the plasma concentration curve was chosen to be calculated at 240 mins AUC240 by using the trapezoidal method In order to be able to obtain AUC240 five different measurements will be carried out at predetermined intervals namely at the baseline before paracetamol administration at 30 minutes 60 minutes 120 minutes and 240 minutes Paracetamol 15 mgkg disolved in 10 ml aqueous solution followed by 20 ml of water will be adminsitered
Afterwards Enzyme Multiplied Immunoassay Technique EMIT will be used to detect paracetamol level
Principle of technique The technique involves conjugating an enzyme with a small target molecule specific to the analyte being tested in this case acetaminophen Binding of a specific target antibody inhibits the enzymatic activity The enzyme glucose-6-phosphate dehydrogenase is bound to the antigen for acetaminophen which oxidizes glucose-6-phosphate to gluconolactone-6-phosphate and reduces NAD to NADH If a free target molecule such as acetaminophen is present in the plasma inhibition is weakened by competition for the antibody leading to restoration of enzymatic activity and intensity of the signal proportional to the concentration of the free target molecule Enzymatic activity is measured by spectroscopic analysis of the amount of NADH produced which correlates directly to the amount of acetaminophen in the specimen Blood samples will be collected from patients in vacutainer tubes with sodium citrate or EDTA anticoagulant under vacuum to facilitate plasma separation and prevent hemolysis
Bioelectrical impedance analysis BIA
We will use the InBody BWA 20 BIA machine to perform BIA measurements The following measurements will be collected for analysis impedance phase angle resistance reactance WaistHip Ratio body cellular mass lean body mass and fat-free mass index
Measurement of rectus femoris cross sectional area
B-mode ultrasonography utilizing an 8 MHz 56 cm linear transducer array will be employed to measure the Cross-sectional area of the rectus femoris RFCSA employing a previously described technique The transducer will be positioned perpendicularly to the long axis of the thigh on its superior aspect specifically three-fifths of the way from the anterior superior iliac spine to the superior patellar border
It has already been stated that nutritional support represents a crucial component in the care of critically ill patients High metabolic demand encountered for critically ill patients may cause significant energy deficits responsible for increased risk of infection prolonged mechanical ventilation and ICU stay Aditionally providing nutritional support in ICU patients is often deeemd challenging as enteral feeding intolerance devolps secondary to gastrointestinal dysfunction Although some authors opinioned that reducing energy targets might be beneficial several studies proved that permissive underfeeding has no positive impact on outcome Morover reduction of energy target recommendation was associated with a scondary decrease of protein supplementation
Apart from disscussing nutritional intake great emphasis should be placed on nutritional uptake as an increased percentage of critically ill patients fail to reach nutritional targets often due to gastrointestinal dysfunction
Gastrointestinal dyfunction may be defined by a variety of functional impairements affecting motility absorbtion microbiome composition or perfusion but still at this momement there is a lack of recommendation regarding monitoring methods6 At the bedside assesement of gastrointestinal dysfunction often relies on measuring GRV However gastric emptying rate proved to be poorly correlated with GRV This monitoring technique may also result in a decresed amount of nutrients delivery Since ultrasound has became a popular diagnostic tool also in the ICU several studies indicated that ultrasonographic measurement of gastric antral cross-sectional area has a good correlation with both aspirated GRV and gastric volume measured by computerised tomography Considering that paracetamol has little to no absorption in the stomach and is completely absorbed at the intestinal level paracetamol absorption test PAT has been proposed as a simple indirect method for evaluating gastric emptying As the pharmacokinetic studies have established that gastric emptying is a rate-limiting step for paracetamol absorbtion studies where PAT was used validated a significant correlation with scintigraphy results
The combination of reduced tolerance to enteral feeding at the initiation of nutritional support along with the initiation of nutritional support within 48 hours has been proven to be responsible for a progressively significant and intractable energy deficit It has been found that continuing enteral feeding under these circumstances is ineffective in resolving this energy debt which is proportional with an increased risk of nosocomial infections
Using SPN for patients who cannot tolerate EN proved to be safe and was associated with improved cumulative energy balance decreased rate of infections and significant cost reduction Although SPN is proposed both by ESPEN and ASPEN guideline as an efficient alternative when energy and protein target are not achieve by oral or enteral route recent data revealed that SPN use is rather limited14 The primary concern regarding SPN use is the risk of overfeeding However utilizing the appropriate concept of SPN and measuring energy needs by indirect calorimetry may overcome administering feeds in an unphysiological manner
Besides intake and uptake muscle capacity to respond to nutritional protein should also be taken into account Several different tools have been proposed for body composition analysis of critically ill patients Ultrasound with different protocols has also been used to assess muscle mass even in ICU patients with greater fluid shifts16 Studies have indicated that a significant reduction in muscle mass may be identified by both rectus femoris cross-sectional area and quadriceps muscle layer thickness measurements Bioelectrical impedance analysis is another non-invasive low-cost technique used for body composition assesment Despite reported limitations related with frequent overhydration states in critically ill patients this method can still provide reliable data if the appropriate timing for examination is chosen Nevertheless bioelectrical impedance analysis-derived phase angle proved to be a trustworthy parameter not only for evaluating fat-free mass but also mortality Functional parameters such as handgrip strengts measurements should be also included when effectivness of nutritional support is evaluated However it is important to acknowledge barriers to collecting functional outcome data particularly when critically ill patients are studied
Study design
1 Study type This single-center controlled randomized pragmatic trial will be conducted in the 34-bed general intensive care of Clinical Emergency Hospital of Bucharest a tertiary-care university affiliated hospital
Participating site data
Department of Anaesthesia and Intensive Care from the Clinical Emergency Hospital of Bucharest disposes in total of 86 intensive care beds
Considering that there is no globally validated single definition that can be used to objectify this gastrointestinal dysfunction real prevalence of this dysfunction is not quantified It has been reported that one-third of all enterally fed mechanically ventilated critically ill patients are presenting enteral feed intolerance but many more patients may have subclinical gastrointestinal dysmotility the estimated percentage could reach as high as 80 Taking into account the annual rate of admission in our unit it is feasible to complete the inclusion process by July 2025 1 year and 8 months
Nevertheless maintaining this study as monocentric will provide better control over potential confounding factors and reduce heterogeneity Furthermore it will enhance internal validity and streamline coordination efforts
Ethics
Study protocol together with a a model of informed consent were submitted to the Clinical Emergency Hospital of Bucharest Ethics Committee and the final approval has been obtained on 18052023
Taking into account that the included patients are not able to provide informed consent at the time of recruitment on ICU admission a Power of Attorney or a Legal tutor will act as Consultee and will be asked to consentdecline participation to the study on legal behalf of the patient If patients have Advance Decision Plan including participation in research studies the Plan will be respected and recruitment pursuedabandoned accordingly After regaining capacity all patients will be asked to provide Informed Consent for using their personal data and will be given the possibility to
Provide Informed Consent for the acute data and follow-up Deny research participation and request destruction of acute data collected
2 Description of the study population inclusion and exclusion criteria
All adults 18 years old are eligible for inclusion if it will be expected to require mechanical ventilation for more than four days have a controlled shock state hemodynamic and tissue perfusion goals are reached and impaired intestinal absorbtion defiend by both ultrasound measurement of gastric residual volume and paracetamol absorbtion test Exclusion criteria are patients on non-invasive mechanichal ventilation contraindication for EN for 48 h after admission patients with gastrointestinal surgical intervention within 3 months history of malabsorption inflammatory bowel disease short bowel syndrom anorexia nervosa gastrointestinal bleeding cirrhosis traumatic brain injury subarahnoidal hemorrhage neoplasia post cardiac arrest patients patients on chronic therapy with corticosteroids and pregnant women
e Methods and techniques
Randomisation
Selected patients for inclusion will be allocated in one of the two groups after stratified randomisation
The patient population can be stratified into three groups based on their admission type which includes General Surgery Multiple Trauma and Internal Medicine To perform stratified randomization three separate randomization lists would be required - one for each stratum These lists could be generated using techniques such as block randomization Depending on the stratum a patient belongs to the corresponding randomization list would be utilized to allocate the patient to one of the nutritional protocol being compared
Nutritional protocol
Nutritional targets are based on ESPEN guidelines recommendation calories administration based on indirect calorimetry study proteins 13 gkgday From the first day of ICU admission indirect calorimetry will be performed daily in order to evaluate energy requirements For both groups enteral nutritional support will be started after 48 hours since admission or after controlled shock state will be confirmed Enteral nutrition will be incrementally escalated using a ramped fashioned approach with the goal of reaching 25 to 50 of the energy target determined by indirect calorimetry by day 2 Subsequently on days 3 and 4 the target will be gradually raised to 75 Enteral nutrition will be administered continuously
On the fourth day the patient will undergo a gastric residual volume measurement and a paracetamol absorption test If gastrointestinal dysfunction is detected the patient will be assigned to a study group based on the randomization protocol
In the EN group enteral nutrition intake will progressively be increased according to the gastrointestinal tolerance evaluated based on ultrasound guided gastric residual volume measurement until the target of 100 is attained following admission to the ICU
The SPN group will gradually initiate supplemental parenteral nutrition in order to achieve the target of 80 by the fifth day Trophic feed will be administered to cover the remaining 20 of the targeted nutrition intake Figure 1 depicts a graphical illustration of the nutritional protocol
Products
EN formula for EN group and trophic feeds polymeric fibre-enriched formulas - Fresubin Original Fibre 15 proteins 30 lipids 52 carbohydrates Fibre 3 PN formula for SPN group SMOFKABIVEN EXTRA NITROGEN 16 gN - 1518 ml - 10 amino acids 20 lipid emulsion SMOFlipid 20 42 glucose and electrolytes
Ultrasound guided gastric residual volume measurement
Gastric ultrasound assessment will be performed by two independent observers in supine position Both sets of measurements will be performed after a minimum of six hours of fasting Antral cross-sectional area ACSA area will be calculated by using antero-posterior and cranio-caudal antral diameters measured from serosa to serosa and the formula of the area of an elipse 4 Furthermore the gastric volume will be calculated according to the model proposed by Perlas et al Gastric Volume ml 2763 016 x weight kg 124 x BMI - 0013 x time since last meal in hours x antral cross-sectional area in cm²
A gastric residual volume above 200 ml will be considered positive for impaired gastric motility
Paracetamol absorbtion test
In order to evaluate paracetamol absorbtion area under the plasma concentration curve was chosen to be calculated at 240 mins AUC240 by using the trapezoidal method In order to be able to obtain AUC240 five different measurements will be carried out at predetermined intervals namely at the baseline before paracetamol administration at 30 minutes 60 minutes 120 minutes and 240 minutes Paracetamol 15 mgkg disolved in 10 ml aqueous solution followed by 20 ml of water will be adminsitered
Afterwards Enzyme Multiplied Immunoassay Technique EMIT will be used to detect paracetamol level
Principle of technique The technique involves conjugating an enzyme with a small target molecule specific to the analyte being tested in this case acetaminophen Binding of a specific target antibody inhibits the enzymatic activity The enzyme glucose-6-phosphate dehydrogenase is bound to the antigen for acetaminophen which oxidizes glucose-6-phosphate to gluconolactone-6-phosphate and reduces NAD to NADH If a free target molecule such as acetaminophen is present in the plasma inhibition is weakened by competition for the antibody leading to restoration of enzymatic activity and intensity of the signal proportional to the concentration of the free target molecule Enzymatic activity is measured by spectroscopic analysis of the amount of NADH produced which correlates directly to the amount of acetaminophen in the specimen Blood samples will be collected from patients in vacutainer tubes with sodium citrate or EDTA anticoagulant under vacuum to facilitate plasma separation and prevent hemolysis
Bioelectrical impedance analysis BIA
We will use the InBody BWA 20 BIA machine to perform BIA measurements The following measurements will be collected for analysis impedance phase angle resistance reactance WaistHip Ratio body cellular mass lean body mass and fat-free mass index
Measurement of rectus femoris cross sectional area
B-mode ultrasonography utilizing an 8 MHz 56 cm linear transducer array will be employed to measure the Cross-sectional area of the rectus femoris RFCSA employing a previously described technique The transducer will be positioned perpendicularly to the long axis of the thigh on its superior aspect specifically three-fifths of the way from the anterior superior iliac spine to the superior patellar border
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
None
Is a FDA Regulated Device?:
None
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None