Papers by Ricardo Peverini
Is the Concomitant Use of High Frequency Oscillatory Ventilation (HFOV) and High Frequency Jet Ventilation (HFJV) Feasible?
Pediatric Transplantation, 1999
Before I dedicate the rest of my blog entries to my work with CONTENTdm, I have one more exciting... more Before I dedicate the rest of my blog entries to my work with CONTENTdm, I have one more exciting piece of news regarding the manuscript collection I processed... the finding aid for MS-118 Wikoff has been digitized and is now available on the Special Collections website! Here's the link! The photo to the right serves as the cover page to my completed finding aid. The three images in the center of my finding aid are photocopies of the three articles Mr. Wikoff published in the Gettysburg magazine based on the alumni letters that comprise the manuscript collection.
Pediatric Critical Care Medicine, Sep 1, 2004
Background: Concern exists that extracorporeal membrane oxygenation (ECMO) may decrease cerebral ... more Background: Concern exists that extracorporeal membrane oxygenation (ECMO) may decrease cerebral blood flow (CBF), impair cerebral autoregulation, and thereby increase the risk of neurologic injury. Objective: This study was undertaken in newborn lambs to compare the effects of initiation of venoarterial and venovenous ECMO on CBF and cerebral oxygen delivery as measured by laser-Doppler flowmetry. This study also evaluates the effects of carotid artery and jugular vein ligation on CBF. Design: CBF, arterial blood pressure, sagittal sinus pressure, heart rate, cardiac output, arterial blood gases, and hemoglobin saturation were measured. After anesthesia, instrumentation, and a 1-2 hr stabilization period, values were recorded during a 30-min control period, and the carotid artery or jugular vein was cannulated. The animals were then studied during venoarterial or venovenous ECMO for 1 hr. Main Results: Carotid ligation resulted in a transient decrease in right cortex CBF that resolved within 60 secs. Next, during a 60-min period of venoarterial ECMO (flow rate of 100 mL•min ؊1 •kg ؊1 , n ؍ 11), cerebral resistance to flow increased, CBF decreased 25%, and cerebral oxygen delivery decreased by 30%. Native cardiac output and PaCO 2 remained constant. Pulsatility in the lingual artery, representing the pulsatility of arterial flow to the brain, decreased throughout venoarterial ECMO. In contrast, in those lambs receiving ECMO in the venovenous mode (n ؍ 7), resistance to flow, CBF, cerebral oxygen delivery, and pulsatility did not change. Conclusions: There was no sustained decrease in CBF after ligation of either the carotid artery or jugular vein. Venoarterial but not venovenous ECMO induced decreases of CBF that could not be attributed to changes in blood gases or blood pressure but that may relate to diminished pulsatility in cerebral resistance vessels or to differences in levels of circulating vasoactive compounds.
Pharmacodynamics of heparin and platelet infusions in extracorporeal membrane oxygenation ecmo
Clinical Pharmacology & Therapeutics, Jun 25, 1992
Anticoagulation therapy advisor: a decision-support system for heparin therapy during ECMO
PubMed, 1992
We present a case study describing our development of a mathematical model to control a clinical ... more We present a case study describing our development of a mathematical model to control a clinical parameter in a patient--in this case, the degree of anticoagulation during extracorporeal membrane oxygenation (ECMO) support. During ECMO therapy, an anticoagulant agent (heparin) is administered to prevent thrombosis. Under- or over-coagulation can have grave consequences. To improve control of anticoagulation, we developed a pharmacokinetic-pharmacodynamic (PK-PD) model that predicts activated clotting times (ACT) using the NONMEM program. We then integrated this model into a decision-support system, and validated it with an independent data set. The population model had a mean absolute error of prediction for ACT values of 33.5 seconds, with a mean bias in estimation of -14.3 seconds. Individualization of model-parameter estimates using nonlinear regression improved the absolute error prediction to 25.5 seconds, and lowered the mean bias to -3.1 seconds. The PK-PD model is coupled with software for heuristic interpretation of model results to provide a complete environment for the management of anticoagulation.
Artificial Organs, Nov 1, 1999
Currently there is a lack of consensus on guidelines in the clinical application of extracorporea... more Currently there is a lack of consensus on guidelines in the clinical application of extracorporeal membrane oxygenation (ECMO) in neonatal and pediatric cardiac transplantation patients. In this context, given the limited data presently available through the Extracorporeal Life Support Organization (ELSO) Registry, we conducted a preliminary survey to specifically evaluate the practice of using ECMO as a bridge to cardiac transplantation or as posttransplantation therapy for failure to wean from cardiopulmonary bypass or graft failure. We received responses to our questionnaire from 95 of 118 (81%) centers located in the U.S.A. and abroad. Of the 95 centers that responded, 36 were performing neonatal/pediatric cardiac transplants, with 29 centers reporting the concomitant use of ECMO to support cardiac transplant patients. There was wide variability in the responses from the 29 centers to a selected list of relative ECMO contraindications. However, only 7 centers had specific ECMO entry criteria for cardiac transplant patients. Fifteen of the 29
Pediatric Dermatology, May 1, 2008
Netherton syndrome is a rare genodermatosis characterized by ichthyosiform scaling, hair shaft ab... more Netherton syndrome is a rare genodermatosis characterized by ichthyosiform scaling, hair shaft abnormalities, and atopic features. Affected infants typically have delayed growth and development, immune abnormalities with recurrent infections, and intermittent aminoaciduria. We report a 23-day-old girl who presented with severe primary pulmonary hypertension, exfoliative erythroderma, and trichorrhexis invaginata. Genetic studies confirmed a premature termination mutation R350X in exon 12 of SPINK5. This mutation further supports the genotypic-phenotypic prediction that severe sequela result from premature termination mutations. To our knowledge, this is the first instance of Netherton syndrome associated with primary pulmonary hypertension to be reported. Further postulated is a possible link between excessive desquamation of fetal skin and respiratory failure in a neonate with Netherton syndrome.
IEEE Transactions on Biomedical Engineering, 1982
A new microscope system that is designed to provide images for a computer has been built and test... more A new microscope system that is designed to provide images for a computer has been built and tested. This system differs from previous computerized microscopes in that the fundamental design parameters have been tuned to the computer as the receiver of the image instead of the human visual system. This solid-state automated microscope system (SSAM) simultaneously provides wide-field (2 mm), high-resolution (0.5 M), high signal-to-noise images (>53 dB) at data rates of 5 X 106 pixels/s. Various methods have been developed and used to test the design specifications of the system against the actual performance. I. HISTORICAL BACKGROUND MsAN'S first microscope was almost certainly a drop of water. Acting as a hemispherical lens on the surface of a leaf or the back of a hand, it provided magnification on the order' of 1.3 X. As early as the end of the 16th century Hans and Zaccharis Janssen of Middelburg, The Netherlands constructed the first compound (multiple lens) microscope. While Galileo is considered to be the first scientific user of a microscope [1], it was the work of van Leeuwenhoek in Leiden, Hooke in London, and Malpighi in Italy that demonstrated the usefulness and, indeed, necessity of the microscope for biological and medical studies. Van Leeuwenhoek, with an appointment as a custodian in the City Hall of Delft, used his spare time to construct over 500 simple (one-lens) microscopes. The lenses of these microscopes were exquisitely made and provided magnifications up to 200X. With these microscopes, first devised to examine drapery fabrics, van Leeuwenhoek described protozoa, bacteria, and human sperm [2]-[4]. Thus, the use of the microscope as a high-technology scientific instrument goes back at least 350 years.
Nonsurgical retrieval of embolized umbilical catheters in premature infants
Journal of perinatology : official journal of the California Perinatal Association
ABSTRACT
Anticoagulation therapy advisor: a decision-support system for heparin therapy during ECMO
Proceedings / the ... Annual Symposium on Computer Application [sic] in Medical Care. Symposium on Computer Applications in Medical Care, 1992
We present a case study describing our development of a mathematical model to control a clinical ... more We present a case study describing our development of a mathematical model to control a clinical parameter in a patient--in this case, the degree of anticoagulation during extracorporeal membrane oxygenation (ECMO) support. During ECMO therapy, an anticoagulant agent (heparin) is administered to prevent thrombosis. Under- or over-coagulation can have grave consequences. To improve control of anticoagulation, we developed a pharmacokinetic-pharmacodynamic (PK-PD) model that predicts activated clotting times (ACT) using the NONMEM program. We then integrated this model into a decision-support system, and validated it with an independent data set. The population model had a mean absolute error of prediction for ACT values of 33.5 seconds, with a mean bias in estimation of -14.3 seconds. Individualization of model-parameter estimates using nonlinear regression improved the absolute error prediction to 25.5 seconds, and lowered the mean bias to -3.1 seconds. The PK-PD model is coupled wi...
Pharmacodynamics of heparin and platelet infusions in extracorporeal membrane oxygenation ecmo
Clinical Pharmacology & Therapeutics, 1992
A Multifaceted Waveform High Frequency Ventilator System
Pediatrics
The Difference between High Flow Nasal Cannula and Continuous Positive Airway Pressure
Pediatrics
Background: Nasal Continuous Positive Airway Pressure (NCPAP) has been the mainstay for non-invas... more Background: Nasal Continuous Positive Airway Pressure (NCPAP) has been the mainstay for non-invasive respiratory support for at risk neonates. Recent advances in High Flow Nasal Cannula (HFNC) usage including enhanced humidity and improved comfort factors have led to its widespread use, at times replacing NCPAP in many neonatal settings. Although ease of application cannot be matched by traditional CPAP devices, concerns about appropriate delivery of volume at a given pressure must be validated given that HFNC rarely exceeds 4 LPM. However, the NCPAP apparatus is often set at 8 …
Neonatal Diabetes Mellitus: The Impact of Molecular Diagnosis
NeoReviews, 2010
Neonatal hyperglycemia has multiple causes, some of which are common (sepsis, stress, phenytoin o... more Neonatal hyperglycemia has multiple causes, some of which are common (sepsis, stress, phenytoin or glucocorticoid administration) and others of which are more rare, including transient neonatal diabetes and mutations of sulfonylurea receptors, which require molecular diagnosis. Many infants identified with the latter condition may respond well to oral sulfonylurea medications. We describe an infant in whom molecular diagnosis permitted such therapy as well as a new diagnosis for the mother, who had been insulin-dependent for 17 years. In addition to aberrant expression of imprinted genes on chromosome 6q24 for transient neonatal diabetes, molecular diagnosis offers a rationale for oral hypoglycemic agents (off-label use) that may improve the lives of affected infants.
Journal of Perinatology, 2014
Maximum Pressure Propagation is Altered by the Presence of a Pop Off Valve
Pediatrics
Growth and neurodevelopmental outcome of infants undergoing heart transplantation
The Journal of heart and lung transplantation : the official publication of the International Society for Heart Transplantation
The purpose of this study was to examine the long-term growth and developmental outcome of infant... more The purpose of this study was to examine the long-term growth and developmental outcome of infants undergoing heart transplantation. We studied weight, length, and head circumference from birth to 12 months after surgery in 110 infant recipients less than 6 months of age. Forty-eight early transplant recipients (0 to 30 days) were compared with 62 late transplant recipients (31 to 180 days). Late transplant recipients showed less growth in all parameters at the time of transplant. However, by 6 months after transplantation, there were no differences between the two groups. Growth in 20 infants, now 3 to 7 years old, appears normal. Neurodevelopmental outcome was evaluated prospectively in 57 infants. Four months after transplantation, 11 infants (19%) had abnormal neurologic examinations, with generalized hypotonia (64%) being the most common finding. The Bayley Scale of Infant Development was administered to 48 of 57 infants. The Mental Developmental Index averaged 87 (+/- 21) and ...
Transplantation, 2008
resulting in graft injury which could be overcome in only some mice by complete NK cell deletion.... more resulting in graft injury which could be overcome in only some mice by complete NK cell deletion. The mannose receptor does not appear to play a role in the graft recognition. HTF grafts do not become tolerant after recovery from innate immune-injury. Recipient treatment can induce tolerance to new HTF grafts but not to innate immune injury.
Air transport in neonatal medicine
Seminars in Neonatology, 1999
... Am J Dis Child 138 (1984), pp. 967970. View Record in Scopus | Cited By in Scopus (11). 19. ... more ... Am J Dis Child 138 (1984), pp. 967970. View Record in Scopus | Cited By in Scopus (11). 19. JP Shenai, GE Johnson and RV Varney, Mechanical vibration in neonatal transport. Pediatrics 68 (1981), pp. 5559. 20. American ...
Pediatric Critical Care Medicine, 2004
Background: Concern exists that extracorporeal membrane oxygenation (ECMO) may decrease cerebral ... more Background: Concern exists that extracorporeal membrane oxygenation (ECMO) may decrease cerebral blood flow (CBF), impair cerebral autoregulation, and thereby increase the risk of neurologic injury. Objective: This study was undertaken in newborn lambs to compare the effects of initiation of venoarterial and venovenous ECMO on CBF and cerebral oxygen delivery as measured by laser-Doppler flowmetry. This study also evaluates the effects of carotid artery and jugular vein ligation on CBF. Design: CBF, arterial blood pressure, sagittal sinus pressure, heart rate, cardiac output, arterial blood gases, and hemoglobin saturation were measured. After anesthesia, instrumentation, and a 1-2 hr stabilization period, values were recorded during a 30-min control period, and the carotid artery or jugular vein was cannulated. The animals were then studied during venoarterial or venovenous ECMO for 1 hr. Main Results: Carotid ligation resulted in a transient decrease in right cortex CBF that resolved within 60 secs. Next, during a 60-min period of venoarterial ECMO (flow rate of 100 mL•min ؊1 •kg ؊1 , n ؍ 11), cerebral resistance to flow increased, CBF decreased 25%, and cerebral oxygen delivery decreased by 30%. Native cardiac output and PaCO 2 remained constant. Pulsatility in the lingual artery, representing the pulsatility of arterial flow to the brain, decreased throughout venoarterial ECMO. In contrast, in those lambs receiving ECMO in the venovenous mode (n ؍ 7), resistance to flow, CBF, cerebral oxygen delivery, and pulsatility did not change. Conclusions: There was no sustained decrease in CBF after ligation of either the carotid artery or jugular vein. Venoarterial but not venovenous ECMO induced decreases of CBF that could not be attributed to changes in blood gases or blood pressure but that may relate to diminished pulsatility in cerebral resistance vessels or to differences in levels of circulating vasoactive compounds.
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Papers by Ricardo Peverini