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Barrett JS, Hirankarn S, Holford N, Hammer GB, Drover DR, Cohane CA, Anderson B, Dombrowski E, Reece T, Zajicek A, Schulman SR. A hemodynamic model to guide blood pressure control during deliberate hypotension with sodium nitroprusside in children. Front Pharmacol 2015; 6:151. [PMID: 26283961 PMCID: PMC4516882 DOI: 10.3389/fphar.2015.00151] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 07/09/2015] [Indexed: 12/01/2022] Open
Abstract
Sodium nitroprusside (SNP) has been widely used to control blood pressure in infants and children. The goals of this analysis were to develop models that describe the hemodynamic response to SNP dosing in pediatric patients; examine sources of variation in dose-response, defining age, and size dependencies; and determine vulnerable populations or patient subtypes that may elicit dosing modifications. A multi-center, randomized, double-blinded, parallel-group, dose-ranging, effect-controlled study, followed by an open-label dose titration of an intravenous infusion of SNP was undertaken in 203 pediatric subjects, who required deliberate hypotension or controlled normotension during anesthesia. A total of 3464 MAP measurements collected from 202 patients during the study's blinded phase, including baseline measurements up to 6 min prior to the blinded were available for analysis. A population K-PD model was developed with a one-compartment model assumed for SNP. Size differences in CL and V of the effect compartment were described using theory-based allometry. An inhibitory sigmoidal Emax model was used to describe the effect of SNP. A power function of age was used to describe age-related differences in baseline MAP. A mixture model of two groups with low and high EC50 was used to explain variability in MAP response. Change in MAP was characterized by a linear disease progression slope during the blinded phase. In the final population model, CL and V increased with weight, and baseline MAP increased with age. The effect compartment half-life of SNP was 13.4 min. The infusion rate producing 50% of Emax (ER50) at steady state for high EC50, was 0.34 μg/kg/min and for low EC50 0.103 μg/kg/min. The K-PD model well-describes initial dosing of SNP under controlled circumstances; model-based dosing guidance agrees with current practice. An initial titration strategy supported via algorithm-based feedback should improve maintenance of target MAP.
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Affiliation(s)
- Jeffrey S Barrett
- Clinical Pharmacology and Therapeutics Division, The Children's Hospital of Philadelphia and Department of Pediatrics, University of Pennsylvania Medical School Philadelphia, PA, USA
| | - Sarapee Hirankarn
- Clinical Pharmacology and Therapeutics Division, The Children's Hospital of Philadelphia and Department of Pediatrics, University of Pennsylvania Medical School Philadelphia, PA, USA
| | - Nick Holford
- Department of Pharmacology and Clinical Pharmacology and Anesthesia, University of Auckland Auckland, New Zealand ; Department of Anesthesia, University of Auckland Auckland, New Zealand
| | - Gregory B Hammer
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine Stanford, CA, USA
| | - David R Drover
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine Stanford, CA, USA
| | - Carol A Cohane
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine Stanford, CA, USA
| | - Brian Anderson
- Department of Anesthesia, University of Auckland Auckland, New Zealand
| | - Erin Dombrowski
- Clinical Pharmacology and Therapeutics Division, The Children's Hospital of Philadelphia and Department of Pediatrics, University of Pennsylvania Medical School Philadelphia, PA, USA
| | - Tammy Reece
- Duke Clinical Research Institute, Duke University Medical Center Durham, NC, USA
| | - Anne Zajicek
- The Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health Bethesda, MD, USA
| | - Scott R Schulman
- Duke Clinical Research Institute, Duke University Medical Center Durham, NC, USA
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Drover DR, Hammer GB, Barrett JS, Cohane CA, Reece T, Zajicek A, Schulman SR. Evaluation of sodium nitroprusside for controlled hypotension in children during surgery. Front Pharmacol 2015. [PMID: 26217225 PMCID: PMC4491614 DOI: 10.3389/fphar.2015.00136] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
PURPOSE (1) To define the onset and offset of the blood-pressure-lowering effects of sodium nitroprusside (SNP) for use in developing instructions for dose titration in children undergoing a surgical or medical procedure, and (2) to assess the safety of SNP administration in pediatric patients requiring controlled reduction of blood pressure. METHODS We conducted a randomized, double-blind, parallel-group, dose-ranging, effect-controlled, multicenter study of intravenous (IV) infusions of SNP in pediatric patients <17 years, who required controlled hypotension for at least 2 h while undergoing a surgical or medical procedure. A blinded SNP dose of 0.3, 1, 2, or 3 μg/kg/min was infused for 30 min, followed by open-label administration for at least 90 min. Both infusions were titrated to effect. RESULTS The final intent-to-treat group comprised 203 patients. Significant reductions in mean arterial pressure (MAP) from baseline were observed for all four doses at 20 and 25 min after the start of infusion (p ≤ 0.009 and p ≤ 0.010 for each time, respectively). Overall, 98.5% of the patients achieved the target MAP; 72.9% first achieved the target MAP during the blinded infusion. The mean infusion rate at target MAP was 1.07 μg/kg/min. CONCLUSION We determined that 0.3 μg/kg/m is a reasonable starting dose for SNP in pediatric patients requiring controlled hypotension. The infusion rate can then be increased to achieve the desired reduction in blood pressure. On the basis of our results, we found an average infusion rate of 1 μg/kg/min might be appropriate. Of note, no cyanide toxicity was reported, and no measureable cyanide levels were detected in any blood samples obtained during the study. http://clinicaltrials.gov/show/NCT00135668.
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Affiliation(s)
- David R Drover
- Department of Anesthesia, Perioperative and Pain Medicine, Stanford University School of Medicine Stanford, CA, USA
| | - Gregory B Hammer
- Department of Anesthesia, Perioperative and Pain Medicine, Stanford University School of Medicine Stanford, CA, USA
| | - Jeffrey S Barrett
- Clinical Pharmacology and Therapeutics Division, The Children's Hospital of Philadelphia and Department of Pediatrics, University of Pennsylvania Medical School Philadelphia, PA, USA
| | - Carol A Cohane
- Department of Anesthesia, Perioperative and Pain Medicine, Stanford University School of Medicine Stanford, CA, USA
| | - Tammy Reece
- Duke Clinical Research Institute, Duke University Medical Center Durham, NC, USA
| | - Anne Zajicek
- The Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health Bethesda, MD, USA
| | - Scott R Schulman
- Department of Anesthesia and Perioperative Care, University of California, San Francisco San Francisco, CA, USA
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Hammer GB, Connolly SG, Schulman SR, Lewandowski A, Cohane C, Reece TL, Anand R, Mitchell J, Drover DR. Sodium nitroprusside is not associated with metabolic acidosis during intraoperative infusion in children. BMC Anesthesiol 2013; 13:9. [PMID: 23631460 PMCID: PMC3648371 DOI: 10.1186/1471-2253-13-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 04/16/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Sodium nitroprusside (SNP) is a potent vasodilator that has been used to induce deliberate hypotension in children during surgery involving significant blood loss, including craniofacial and spinal fusion procedures. SNP metabolism liberates cyanide, which may cause interference with cellular energy metabolism, leading to metabolic acidosis and central nervous system injury. We performed a retrospective, case-control study to determine whether the short-term intra-operative use of SNP for deliberate hypotension is associated with metabolic acidosis in children undergoing surgical procedures for craniofacial or spinal anomalies. Cyanide and thiocyanate concentrations were also recorded in patients who received SNP. METHODS Data from 166 children undergoing craniofacial and spinal fusion surgery between 2005 and 2010 at Lucile Packard Children's Hospital (LPCH) at Stanford were analyzed. Records from 60 patients who received SNP (SNP group) as part of a multicenter, randomized, double-blind study were compared with records from 106 eligible patients who had blood pressure reduction using anesthetic agents and did not receive SNP (control group). Metabolic acidosis was defined as serum bicarbonate (HCO3) < 18.5 mEq/L. Whole blood CN, plasma thiocyanate and urinary thiocyanate concentrations were measured in patients in the SNP group. Differences in metabolic acidosis rates between the SNP and control groups were assessed through a test of noninferiority in the rate for the SNP group with a noninferiority threshold of 0.2. A z-test was used to test the null hypothesis. The alternative hypothesis was that the difference in these rates was less than 0.2. The same noninferiority threshold of 0.2 was also used to perform separate, secondary tests for noninferiority in the proportion of patients with HCO3 levels below 18.5 mEq/L and the proportion of patients who required HCO3 administration. RESULTS Fewer patients in the SNP group experienced metabolic acidosis compared to the control group (31.7% vs. 36.8%, respectively; p < .001). No whole blood CN levels above the lower limit of quantification were detected in any of the 51 patients with validated CN data. Plasma and urinary thiocyanate levels were also low. CONCLUSIONS Our findings suggest that SNP, when used for short-term deliberate hypotension, does not cause an increased incidence of metabolic acidosis compared with the use of anesthetic agents alone. TRIAL REGISTRATION TRIAL REGISTRATION NUMBER NCT00135668.
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Affiliation(s)
- Gregory B Hammer
- Department of Anesthesia, Stanford University School of Medicine, Stanford, USA.
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Abstract
Hypertensive crisis is a relatively rare event and is associated with significant morbidity and mortality in adults and pediatric patients alike. Rapid, safe, and effective treatment is imperative to alleviate immediate presenting clinical symptoms, prevent devastating morbidity, preserve long-term quality of life, and prevent mortality. Many medications in the hypertensive crisis arsenal have been used for nearly half a century. Nearly all treatment options have been utilized in children for decades, yet reliable data and sound clinical literature remain elusive. Every agent considered to be a first-line, second-line, or adjunctive option has yet to be evaluated in a randomized controlled trial in pediatric patients. With a paucity of clinical data to form evidence-based decisions, the clinician must rely entirely on the extrapolation from adult data and small retrospective studies, case series, and case reports of medication use in pediatric patients. Although more research in the treatment of pediatric hypertensive crisis is desperately needed, current practice demands a sharp knowledge of the pediatric clinical literature and pharmacology in this area as an essential tool to consistently improve patient outcomes with respect to morbidity and mortality.
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Affiliation(s)
- Christopher A Thomas
- Department of Pharmacy, Riley Hospital for Children - Indiana University Health, Indianapolis, IN 46202, USA.
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Baek JG, Jeong HL, Park JS, Seo JH, Park ES, Lim JY, Park CH, Woo HO, Youn HS, Yeom JS. Successful treatment by exchange transfusion of a young infant with sodium nitroprusside poisoning. KOREAN JOURNAL OF PEDIATRICS 2010; 53:805-8. [PMID: 21189979 PMCID: PMC3004497 DOI: 10.3345/kjp.2010.53.8.805] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Revised: 04/19/2010] [Accepted: 05/25/2010] [Indexed: 11/27/2022]
Abstract
Although sodium nitroprusside (SNP) is often used in pediatric intensive care units, cyanide toxicity can occur after SNP treatment. To treat SNP-induced cyanide poisoning, antidotes such as amyl nitrite, sodium nitrite, sodium thiosulfate, and hydroxycobalamin should be administered immediately after diagnosis. Here, we report the first case of a very young infant whose SNP-induced cyanide poisoning was successfully treated by exchange transfusion. The success of this alternative method may be related to the fact that exchange transfusion not only removes the cyanide from the blood but also activates detoxification systems by supplying sulfur-rich plasma. Moreover, exchange transfusion replaces cyanide-contaminated erythrocytes with fresh erythrocytes, thereby improving the blood's oxygen carrying capacity more rapidly than antidote therapy. Therefore, we believe that exchange transfusion might be an effective therapeutic modality for critical cases of cyanide poisoning.
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Affiliation(s)
- Jong Geun Baek
- Department of Pediatrics, Gyeongsang National University School of Medicine, Jinju, Korea
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Sani M, Gadacha W, Sebaï H, Boughattas NA, Attia MB. 12-hour phase-shift of mice kidney rhodanese (thiosulfate sulfurtransferase) activity in the first two months of life. BIOL RHYTHM RES 2008. [DOI: 10.1080/09291010701424812] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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López-Herce J, Borrego R, Bustinza A, Carrillo A. Elevated carboxyhemoglobin associated with sodium nitroprusside treatment. Intensive Care Med 2005; 31:1235-8. [PMID: 16041521 DOI: 10.1007/s00134-005-2718-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2005] [Accepted: 06/21/2005] [Indexed: 12/01/2022]
Abstract
OBJECTIVE To report four cases of carboxyhemoglobinemia associated with high doses of sodium nitroprusside after cardiac transplant in children. PATIENTS Four children in the pediatric care unit of a university hospital aged 6 months-4 years. Carboxyhemoglonemia developed at levels of 5.5-7.7% in patients receiving high doses of sodium nitroprusside (7-16 microg/kg per minute and no other medication that could caused elevated carboxyhemoglobin). One patient died, and three recovered with no sequelae after discontinuation of sodium nitroprusside. CONCLUSIONS High doses of sodium nitroprusside can induce carboxyhemoglobinemia in children after heart transplant, probably by inducing hemeoxygenase, with no other secondary effects.
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Affiliation(s)
- Jesús López-Herce
- Pediatric Critical Care Unit, Gregorio Marañón University Hospital, Dr. Castelo 47, 28009 Madrid, Spain.
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