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Robert A Peterfreund - One of the best experts on this subject based on the ideXlab platform.
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Infusion System architecture impacts the ability of intensive care nurses to maintain hemodynamic stability in a living swine simulator
Anesthesiology, 2016Co-Authors: Matthew J Pezone, Mikhail Y Maslov, Robert A Peterfreund, Radhika R Govindaswamy, Mark A LovichAbstract:Background:The authors have previously shown that drug Infusion Systems with large common volumes exhibit long delays in reaching steady-state drug delivery and pharmacodynamic effects compared with smaller common-volume Systems. The authors hypothesized that such delays can impede the pharmacologic
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Infusion System carrier flow perturbations and dead volume large effects on drug delivery in vitro and hemodynamic responses in a swine model
Anesthesia & Analgesia, 2015Co-Authors: Mark A Lovich, Matthew G Wakim, Mikhail Y Maslov, Matthew J Pezone, Michael R Murray, Robert A PeterfreundAbstract:BACKGROUND:We have previously shown that, at constant carrier flow, drug Infusion Systems with large dead-volumes (V) slow the time to steady-state drug delivery in vitro and pharmacodynamic effect in vivo compared to those with smaller V. In this study, we tested whether clinically relevant alterat
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drug Infusion System manifold dead volume impacts the delivery response time to changes in infused medication doses in vitro and also in vivo in anesthetized swine
Anesthesia & Analgesia, 2013Co-Authors: Mark A Lovich, Matthew G Wakim, Mikhail Y Maslov, Matthew J Pezone, Hisashi Tsukada, Michael Parker, Robert A PeterfreundAbstract:BACKGROUND: IV Infusion Systems can be configured with manifolds connecting multiple drug Infusion lines to transcutaneous catheters. Prior in vitro studies suggest that there may be significant lag times for drug delivery to reflect changes in Infusion rates set at the pump, especially with low drug and carrier flows and larger Infusion System dead-volumes. Drug manifolds allow multiple Infusions to connect to a single catheter port but add dead-volume. We hypothesized that the time course of physiological responses to drug Infusion in vivo reflects the impact of dead-volume on drug delivery. METHODS: The kinetic response to starting and stopping epinephrine Infusion ([3 mL/h] with constant carrier flow [10 mL/h]) was compared for high- and low-dead-volume manifolds in vitro and in vivo. A manifold consisting of 4 sequential stopcocks with drug entering at the most upstream port was contrasted with a novel design comprising a tube with separate coaxial channels meeting at the downstream connector to the catheter, which virtually eliminates the manifold contribution to the dead-volume. The time to 50% (T50) and 90% (T90) increase or decrease in drug delivery in vitro or contractile response in a swine model in vivo were calculated for initiation and cessation of drug Infusion. RESULTS: The time to steady state after initiation and cessation of drug Infusion both in vitro and in vivo was much less with the coaxial low-dead-volume manifold than with the high-volume design. Drug delivery after initiation in vitro reached 50% and 90% of steady state in 1.4 ± 0.12 and 2.2 ± 0.42 minutes with the low-dead-volume manifold and in 7.1 ± 0.58 and 9.8 ± 1.6 minutes with the high-dead-volume manifold, respectively. The contractility in vivo reached 50% and 90% of the full response after drug initiation in 4.3 ± 1.3 and 9.9 ± 3.9 minutes with the low-dead-volume manifold and 11 ± 1.2 and 17 ± 2.6 minutes with the high-dead-volume manifold, respectively. Drug delivery in vitro decreased by 50% and 90% after drug cessation in 1.9 ± 0.17 and 3.5 ± 0.61 minutes with the low-dead-volume manifold and 10.0 ± 1.0 and 17.0 ± 2.8 minutes with the high-dead-volume manifold, respectively. The contractility in vivo decreased by 50% and 90% with drug cessation in 4.1 ± 1.1 and 14 ± 5.2 with the low-dead-volume manifold and 12 ± 2.7 and 23 ± 5.6 minutes with the high-dead-volume manifold, respectively. CONCLUSIONS: The architecture of the manifold impacts the in vivo biologic response, and the drug delivery rate, to changes in drug Infusion rate set at the pump.
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quantitative analysis of continuous intravenous Infusions in pediatric anesthesia safety implications of dead volume flow rates and fluid delivery
Pediatric Anesthesia, 2011Co-Authors: Mark A Lovich, Robert A PeterfreundAbstract:Summary Objective: Quantitative characterization of continuous pediatric drug Infusions. Background: The dynamics of drug delivery by continuous Infusion to pediatric patients have not been Systematically examined. This study extends previously described analytic models to propofol and remifentanil delivery, focusing on infants and toddlers. We postulated that Infusion System dead volume, and drug and carrier flow rates, significantly influence drug delivery. Methods: We studied effects of patient weight, Infusion System dead volume, drug and carrier flow rates, along with drug stock concentration and dose, on propofol and remifentanil delivery to the circulation. We calculated the drug mass available for inadvertent bolus in the dead volume, the volume of fluid supplied by drug Infusions, and model-based estimates of the range of lag times to achieve a targeted steady-state rate of drug delivery. Results: The drug mass in the dead volume at steady state increased with dead volume size and drug dose. For infants, this drug mass could exceed 100% of commonly used loading doses. Predicted lag times to steady state depend on patient size, fluid flow rates, and the mixing behavior of the drug entering the main fluid pathway. Neonates have the longest lag times to achieve steady state. Fluid quantities delivered by drug Infusions increase with drug flow rate and can represent a large fraction of estimated maintenance fluid requirements. Fluid delivery increases if stock drug concentrations are diluted. These relationships were qualitatively similar for propofol and remifentanil. Conclusions: Traditional studies focus on drug disposition once a drug enters the circulation. Our analysis shows the potential importance of factors influencing drug delivery to the patient’s circulation, focusing on propofol and remifentanil administration to small patients. The drug mass available for inadvertent bolus residing in the reservoir of the dead volume at steady state may be large and clinically relevant. Lag times to achieve steady-state delivery are long, depending on the Infusion System’s architecture and fluid flow rates. By themselves, drug Infusions can deliver significant fluid loads to children. These observations have practical and perhaps safety implications for Infusions of drugs commonly administered to infants and children.
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an analysis of drug delivery dynamics via a pediatric central venous Infusion System quantification of delays in achieving intended doses
Anesthesia & Analgesia, 2009Co-Authors: Karsten Bartels, David R Moss, Robert A PeterfreundAbstract:BACKGROUND:Pediatric patients frequently receive continuous Infusions of drugs via central venous catheters in the intensive care unit and the operating room. This study characterized drug delivery profiles in a quantitative laboratory model of a standard pediatric central venous Infusion System.MET
Mark A Lovich - One of the best experts on this subject based on the ideXlab platform.
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Infusion System architecture impacts the ability of intensive care nurses to maintain hemodynamic stability in a living swine simulator
Anesthesiology, 2016Co-Authors: Matthew J Pezone, Mikhail Y Maslov, Robert A Peterfreund, Radhika R Govindaswamy, Mark A LovichAbstract:Background:The authors have previously shown that drug Infusion Systems with large common volumes exhibit long delays in reaching steady-state drug delivery and pharmacodynamic effects compared with smaller common-volume Systems. The authors hypothesized that such delays can impede the pharmacologic
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Infusion System carrier flow perturbations and dead volume large effects on drug delivery in vitro and hemodynamic responses in a swine model
Anesthesia & Analgesia, 2015Co-Authors: Mark A Lovich, Matthew G Wakim, Mikhail Y Maslov, Matthew J Pezone, Michael R Murray, Robert A PeterfreundAbstract:BACKGROUND:We have previously shown that, at constant carrier flow, drug Infusion Systems with large dead-volumes (V) slow the time to steady-state drug delivery in vitro and pharmacodynamic effect in vivo compared to those with smaller V. In this study, we tested whether clinically relevant alterat
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drug Infusion System manifold dead volume impacts the delivery response time to changes in infused medication doses in vitro and also in vivo in anesthetized swine
Anesthesia & Analgesia, 2013Co-Authors: Mark A Lovich, Matthew G Wakim, Mikhail Y Maslov, Matthew J Pezone, Hisashi Tsukada, Michael Parker, Robert A PeterfreundAbstract:BACKGROUND: IV Infusion Systems can be configured with manifolds connecting multiple drug Infusion lines to transcutaneous catheters. Prior in vitro studies suggest that there may be significant lag times for drug delivery to reflect changes in Infusion rates set at the pump, especially with low drug and carrier flows and larger Infusion System dead-volumes. Drug manifolds allow multiple Infusions to connect to a single catheter port but add dead-volume. We hypothesized that the time course of physiological responses to drug Infusion in vivo reflects the impact of dead-volume on drug delivery. METHODS: The kinetic response to starting and stopping epinephrine Infusion ([3 mL/h] with constant carrier flow [10 mL/h]) was compared for high- and low-dead-volume manifolds in vitro and in vivo. A manifold consisting of 4 sequential stopcocks with drug entering at the most upstream port was contrasted with a novel design comprising a tube with separate coaxial channels meeting at the downstream connector to the catheter, which virtually eliminates the manifold contribution to the dead-volume. The time to 50% (T50) and 90% (T90) increase or decrease in drug delivery in vitro or contractile response in a swine model in vivo were calculated for initiation and cessation of drug Infusion. RESULTS: The time to steady state after initiation and cessation of drug Infusion both in vitro and in vivo was much less with the coaxial low-dead-volume manifold than with the high-volume design. Drug delivery after initiation in vitro reached 50% and 90% of steady state in 1.4 ± 0.12 and 2.2 ± 0.42 minutes with the low-dead-volume manifold and in 7.1 ± 0.58 and 9.8 ± 1.6 minutes with the high-dead-volume manifold, respectively. The contractility in vivo reached 50% and 90% of the full response after drug initiation in 4.3 ± 1.3 and 9.9 ± 3.9 minutes with the low-dead-volume manifold and 11 ± 1.2 and 17 ± 2.6 minutes with the high-dead-volume manifold, respectively. Drug delivery in vitro decreased by 50% and 90% after drug cessation in 1.9 ± 0.17 and 3.5 ± 0.61 minutes with the low-dead-volume manifold and 10.0 ± 1.0 and 17.0 ± 2.8 minutes with the high-dead-volume manifold, respectively. The contractility in vivo decreased by 50% and 90% with drug cessation in 4.1 ± 1.1 and 14 ± 5.2 with the low-dead-volume manifold and 12 ± 2.7 and 23 ± 5.6 minutes with the high-dead-volume manifold, respectively. CONCLUSIONS: The architecture of the manifold impacts the in vivo biologic response, and the drug delivery rate, to changes in drug Infusion rate set at the pump.
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quantitative analysis of continuous intravenous Infusions in pediatric anesthesia safety implications of dead volume flow rates and fluid delivery
Pediatric Anesthesia, 2011Co-Authors: Mark A Lovich, Robert A PeterfreundAbstract:Summary Objective: Quantitative characterization of continuous pediatric drug Infusions. Background: The dynamics of drug delivery by continuous Infusion to pediatric patients have not been Systematically examined. This study extends previously described analytic models to propofol and remifentanil delivery, focusing on infants and toddlers. We postulated that Infusion System dead volume, and drug and carrier flow rates, significantly influence drug delivery. Methods: We studied effects of patient weight, Infusion System dead volume, drug and carrier flow rates, along with drug stock concentration and dose, on propofol and remifentanil delivery to the circulation. We calculated the drug mass available for inadvertent bolus in the dead volume, the volume of fluid supplied by drug Infusions, and model-based estimates of the range of lag times to achieve a targeted steady-state rate of drug delivery. Results: The drug mass in the dead volume at steady state increased with dead volume size and drug dose. For infants, this drug mass could exceed 100% of commonly used loading doses. Predicted lag times to steady state depend on patient size, fluid flow rates, and the mixing behavior of the drug entering the main fluid pathway. Neonates have the longest lag times to achieve steady state. Fluid quantities delivered by drug Infusions increase with drug flow rate and can represent a large fraction of estimated maintenance fluid requirements. Fluid delivery increases if stock drug concentrations are diluted. These relationships were qualitatively similar for propofol and remifentanil. Conclusions: Traditional studies focus on drug disposition once a drug enters the circulation. Our analysis shows the potential importance of factors influencing drug delivery to the patient’s circulation, focusing on propofol and remifentanil administration to small patients. The drug mass available for inadvertent bolus residing in the reservoir of the dead volume at steady state may be large and clinically relevant. Lag times to achieve steady-state delivery are long, depending on the Infusion System’s architecture and fluid flow rates. By themselves, drug Infusions can deliver significant fluid loads to children. These observations have practical and perhaps safety implications for Infusions of drugs commonly administered to infants and children.
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the delivery of drugs to patients by continuous intravenous Infusion modeling predicts potential dose fluctuations depending on flow rates and Infusion System dead volume
Anesthesia & Analgesia, 2006Co-Authors: Mark A Lovich, Ellen M Kinnealley, Nathanial M Sims, Robert A PeterfreundAbstract:IV drug Infusion has the potential for dosing errors, which arise from complex interactions between carrier flows and the Infusion set dead volume. We computed the steady-state mass of drug stored in the Infusion set dead volume, using phenylephrine as a model compound. The mass of drug in the dead volume increases with stock drug concentration and desired dose but decreases with carrier flow rate. We also modeled the dynamic perturbations in drug delivery when a carrier is abruptly stopped. Rapid initial carrier flow rates lead to greater depression in drug delivery rate after carrier flow ceases. Rapid drug Infusion rates lead to faster restoration of desired drug delivery. Finally, the time to reach a new steady-state after a change in drug delivery or carrier rate was computed. This time is longest for large stock-drug concentrations, larger dead volumes, and slower final carrier rates. These computations illustrate that (a) the dead volume may contain a large mass of drug available for inadvertent bolus, (b) cessation of carrier flow can profoundly reduce drug delivery, and (c) after a change in carrier flow or drug dosing, a significant lag is possible before drug delivery achieves steady state. Although computed for phenylephrine, the concepts are generic and valid for any drug administered by IV Infusion.
L. H. Cohn - One of the best experts on this subject based on the ideXlab platform.
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A modified collection and rapid Infusion System for shed whole blood autotransfusion during aortic aneurysm surgery.
The journal of extra-corporeal technology, 1995Co-Authors: Rene J. Dekkers, R. J. Rizzo, Desmond J. Fitzgerald, L. H. CohnAbstract:We describe our experience in 10 patients (5 males) undergoing resection of a descending thoracic aortic aneurysm or a thoracoabdominal aortic aneurysm in which a modified shed whole blood collection and autotransfusion System was used. This modification allows several options for the processing and autotransfusion of shed blood : use of the cell saving device or the ultrafiltration of collected blood, and the autotransfusion of unprocessed shed whole blood. Either low dose heparin or sodium citrate was used for anticoagulation. All 10 patients underwent autotransfusion and volume resuscitation with the modified rapid Infusion device. Total autotransfusion ranged from 1400 ml to 7843 ml. Ultrafiltration volumes ranged from 600 ml to 1100 ml. There were no intraoperative deaths and no patient reoperations for bleeding. Arterial blood gases, potassium, and platelet counts were all within the normal laboratory ranges. This modification enables the clinician to process poor quality shed blood and reinfuse whole blood, in an attempt to decrease the need for homologous blood products.
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shed whole blood autotransfusion during aortic aneurysm operation with a modified collection Infusion System
The Annals of Thoracic Surgery, 1995Co-Authors: Rene J. Dekkers, R. J. Rizzo, Desmond J. Fitzgerald, Simon C Body, L. H. CohnAbstract:We describe a modified shed whole blood collection and autotransfusion System that allows several options for the processing and autotransfusion of shed blood: use of the Cell Saver (Haemonetics, Braintree, MA) or the ultrafiltration of collected blood, and the autotransfusion of unprocessed shed whole blood. The System has proved useful for transfusion in the setting of thoracic aortic operations, and we describe here our experience in 5 patients undergoing resection of a descending thoracic aortic aneurysm in whom this System was used.
Matthew J Pezone - One of the best experts on this subject based on the ideXlab platform.
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Infusion System architecture impacts the ability of intensive care nurses to maintain hemodynamic stability in a living swine simulator
Anesthesiology, 2016Co-Authors: Matthew J Pezone, Mikhail Y Maslov, Robert A Peterfreund, Radhika R Govindaswamy, Mark A LovichAbstract:Background:The authors have previously shown that drug Infusion Systems with large common volumes exhibit long delays in reaching steady-state drug delivery and pharmacodynamic effects compared with smaller common-volume Systems. The authors hypothesized that such delays can impede the pharmacologic
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Infusion System carrier flow perturbations and dead volume large effects on drug delivery in vitro and hemodynamic responses in a swine model
Anesthesia & Analgesia, 2015Co-Authors: Mark A Lovich, Matthew G Wakim, Mikhail Y Maslov, Matthew J Pezone, Michael R Murray, Robert A PeterfreundAbstract:BACKGROUND:We have previously shown that, at constant carrier flow, drug Infusion Systems with large dead-volumes (V) slow the time to steady-state drug delivery in vitro and pharmacodynamic effect in vivo compared to those with smaller V. In this study, we tested whether clinically relevant alterat
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drug Infusion System manifold dead volume impacts the delivery response time to changes in infused medication doses in vitro and also in vivo in anesthetized swine
Anesthesia & Analgesia, 2013Co-Authors: Mark A Lovich, Matthew G Wakim, Mikhail Y Maslov, Matthew J Pezone, Hisashi Tsukada, Michael Parker, Robert A PeterfreundAbstract:BACKGROUND: IV Infusion Systems can be configured with manifolds connecting multiple drug Infusion lines to transcutaneous catheters. Prior in vitro studies suggest that there may be significant lag times for drug delivery to reflect changes in Infusion rates set at the pump, especially with low drug and carrier flows and larger Infusion System dead-volumes. Drug manifolds allow multiple Infusions to connect to a single catheter port but add dead-volume. We hypothesized that the time course of physiological responses to drug Infusion in vivo reflects the impact of dead-volume on drug delivery. METHODS: The kinetic response to starting and stopping epinephrine Infusion ([3 mL/h] with constant carrier flow [10 mL/h]) was compared for high- and low-dead-volume manifolds in vitro and in vivo. A manifold consisting of 4 sequential stopcocks with drug entering at the most upstream port was contrasted with a novel design comprising a tube with separate coaxial channels meeting at the downstream connector to the catheter, which virtually eliminates the manifold contribution to the dead-volume. The time to 50% (T50) and 90% (T90) increase or decrease in drug delivery in vitro or contractile response in a swine model in vivo were calculated for initiation and cessation of drug Infusion. RESULTS: The time to steady state after initiation and cessation of drug Infusion both in vitro and in vivo was much less with the coaxial low-dead-volume manifold than with the high-volume design. Drug delivery after initiation in vitro reached 50% and 90% of steady state in 1.4 ± 0.12 and 2.2 ± 0.42 minutes with the low-dead-volume manifold and in 7.1 ± 0.58 and 9.8 ± 1.6 minutes with the high-dead-volume manifold, respectively. The contractility in vivo reached 50% and 90% of the full response after drug initiation in 4.3 ± 1.3 and 9.9 ± 3.9 minutes with the low-dead-volume manifold and 11 ± 1.2 and 17 ± 2.6 minutes with the high-dead-volume manifold, respectively. Drug delivery in vitro decreased by 50% and 90% after drug cessation in 1.9 ± 0.17 and 3.5 ± 0.61 minutes with the low-dead-volume manifold and 10.0 ± 1.0 and 17.0 ± 2.8 minutes with the high-dead-volume manifold, respectively. The contractility in vivo decreased by 50% and 90% with drug cessation in 4.1 ± 1.1 and 14 ± 5.2 with the low-dead-volume manifold and 12 ± 2.7 and 23 ± 5.6 minutes with the high-dead-volume manifold, respectively. CONCLUSIONS: The architecture of the manifold impacts the in vivo biologic response, and the drug delivery rate, to changes in drug Infusion rate set at the pump.
Mikhail Y Maslov - One of the best experts on this subject based on the ideXlab platform.
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Infusion System architecture impacts the ability of intensive care nurses to maintain hemodynamic stability in a living swine simulator
Anesthesiology, 2016Co-Authors: Matthew J Pezone, Mikhail Y Maslov, Robert A Peterfreund, Radhika R Govindaswamy, Mark A LovichAbstract:Background:The authors have previously shown that drug Infusion Systems with large common volumes exhibit long delays in reaching steady-state drug delivery and pharmacodynamic effects compared with smaller common-volume Systems. The authors hypothesized that such delays can impede the pharmacologic
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Infusion System carrier flow perturbations and dead volume large effects on drug delivery in vitro and hemodynamic responses in a swine model
Anesthesia & Analgesia, 2015Co-Authors: Mark A Lovich, Matthew G Wakim, Mikhail Y Maslov, Matthew J Pezone, Michael R Murray, Robert A PeterfreundAbstract:BACKGROUND:We have previously shown that, at constant carrier flow, drug Infusion Systems with large dead-volumes (V) slow the time to steady-state drug delivery in vitro and pharmacodynamic effect in vivo compared to those with smaller V. In this study, we tested whether clinically relevant alterat
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drug Infusion System manifold dead volume impacts the delivery response time to changes in infused medication doses in vitro and also in vivo in anesthetized swine
Anesthesia & Analgesia, 2013Co-Authors: Mark A Lovich, Matthew G Wakim, Mikhail Y Maslov, Matthew J Pezone, Hisashi Tsukada, Michael Parker, Robert A PeterfreundAbstract:BACKGROUND: IV Infusion Systems can be configured with manifolds connecting multiple drug Infusion lines to transcutaneous catheters. Prior in vitro studies suggest that there may be significant lag times for drug delivery to reflect changes in Infusion rates set at the pump, especially with low drug and carrier flows and larger Infusion System dead-volumes. Drug manifolds allow multiple Infusions to connect to a single catheter port but add dead-volume. We hypothesized that the time course of physiological responses to drug Infusion in vivo reflects the impact of dead-volume on drug delivery. METHODS: The kinetic response to starting and stopping epinephrine Infusion ([3 mL/h] with constant carrier flow [10 mL/h]) was compared for high- and low-dead-volume manifolds in vitro and in vivo. A manifold consisting of 4 sequential stopcocks with drug entering at the most upstream port was contrasted with a novel design comprising a tube with separate coaxial channels meeting at the downstream connector to the catheter, which virtually eliminates the manifold contribution to the dead-volume. The time to 50% (T50) and 90% (T90) increase or decrease in drug delivery in vitro or contractile response in a swine model in vivo were calculated for initiation and cessation of drug Infusion. RESULTS: The time to steady state after initiation and cessation of drug Infusion both in vitro and in vivo was much less with the coaxial low-dead-volume manifold than with the high-volume design. Drug delivery after initiation in vitro reached 50% and 90% of steady state in 1.4 ± 0.12 and 2.2 ± 0.42 minutes with the low-dead-volume manifold and in 7.1 ± 0.58 and 9.8 ± 1.6 minutes with the high-dead-volume manifold, respectively. The contractility in vivo reached 50% and 90% of the full response after drug initiation in 4.3 ± 1.3 and 9.9 ± 3.9 minutes with the low-dead-volume manifold and 11 ± 1.2 and 17 ± 2.6 minutes with the high-dead-volume manifold, respectively. Drug delivery in vitro decreased by 50% and 90% after drug cessation in 1.9 ± 0.17 and 3.5 ± 0.61 minutes with the low-dead-volume manifold and 10.0 ± 1.0 and 17.0 ± 2.8 minutes with the high-dead-volume manifold, respectively. The contractility in vivo decreased by 50% and 90% with drug cessation in 4.1 ± 1.1 and 14 ± 5.2 with the low-dead-volume manifold and 12 ± 2.7 and 23 ± 5.6 minutes with the high-dead-volume manifold, respectively. CONCLUSIONS: The architecture of the manifold impacts the in vivo biologic response, and the drug delivery rate, to changes in drug Infusion rate set at the pump.