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Anesthesia and analgesia 07/2012; 115(4):772-5. · 3.08 Impact Factor
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ABSTRACT: Although the traditional surgical approach for left hypoplastic heart syndrome is to perform staged, palliative procedures as a single ventricle lesion, certain anatomical subsets of patients are candidates for a 2-ventricle repair either as a primary or as a staged procedure. The pulmonary blood flow (Q(P))/systemic blood flow (Q(S)) range necessary to optimize systemic oxygen delivery (DO(2)) and systemic venous oxygen saturation has been delineated for patients undergoing conventional interventions as a single ventricle physiology where the left ventricle is assumed to make no contribution to systemic cardiac output. However, in the transitional circulations created during staging to a 2-ventricle repair, the left ventricle does contribute to cardiac output. The Q(P)/Q(S) at which systemic DO(2) and systemic venous oxygen saturation are optimized in the latter circulations has not yet been evaluated. Using computer modeling, we investigated parameters to optimize systemic oxygen delivery.
We designed model circulations after both modified stage I operation and modified bidirectional Glenn shunt with Sano shunt, which are transitional circulations created during staging to a 2-ventricle repair. Mathematical equations were derived to describe DO(2) in both models. Using a computer and an Excel spreadsheet, we used the equations to examine the relationships between DO(2) and arterial oxygen saturation (Sao(2)), venous oxygen saturation (SvO(2)), SaO(2) - SvO(2), Q(P)/Q(S), and the oxygen excess factor SaO(2)/(SaO(2) - SvO(2)).
In both circulations, SaO(2) or SvO(2) alone does not accurately predict DO(2) or Q(P)/Q(S). The relationships between these variables are further altered by the degree of systemic cardiac output supplied by the left ventricle. To the contrary, DO(2) demonstrates the linear relationship with the oxygen excess factor Sao(2)/(Sao(2) - Svo(2)) irrespective of the degree of systemic cardiac output supplied by the left ventricle.
Commonly obtained clinical values such as SaO(2) and SvO(2) alone are not accurate assessments of DO(2) or Q(P)/Q(S). Therefore, these cannot be used in isolation to guide perioperative therapy.
Anesthesia and analgesia 06/2012; 115(3):618-26. · 3.08 Impact Factor
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Journal of cardiothoracic and vascular anesthesia 01/2012; · 1.06 Impact Factor
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ABSTRACT: Congenital supravalvular aortic stenosis (SVAS) is a rare form of left ventricular outflow tract (LVOT) obstruction that often
is associated with peripheral pulmonary artery stenoses (approximately 40% of patients). Congenital SVAS is an elastin arteriopathy
and is most commonly associated with Williams–Beuren syndrome. Williams–Beuren syndrome, commonly referred to as Williams
syndrome (WS), is characterized by the presence of SVAS and peripheral pulmonary artery stenoses in association with mental
retardation and distinctive elfin facies.
05/2011: pages 379-394;
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ABSTRACT: Minimally invasive endoscopic strip craniectomy (ESC) is a relatively new surgical technique for treating craniosynostosis in early infancy. In this study we reviewed our anesthesia experience with ESC. The hypothesis was that infants with low body weight and syndromes would have a higher risk of perioperative blood transfusion and that those with respiratory complications are more likely to be admitted to the intensive care unit (ICU).
We retrospectively reviewed patient charts and anesthesia records of the first 100 consecutive infants who underwent ESC between May 2004 and December 2008 and follow-up evaluations until December 2009. Outcomes included (a) perioperative blood transfusion, (b) venous air embolism (VAE), (c) ICU admission, and (d) reoperation with craniofacial reconstruction procedures. Multivariable logistic regression was used to determine significant factors of patient outcomes.
Infants ranging from 4 to 34 weeks of age (weight: 3.2 to 10.1 kg), presented for 87 single and 13 multiple ESC. Four infants had a craniofacial syndrome. The mean surgical time was 48 minutes (range: 26 to 86 minutes). Ninety-two infants had a median estimated blood loss of 23 mL (interquartile ranges [IQR]: 15 to 30 mL). Eight infants who required blood transfusion received a median amount of 17.2 mL/kg (IQR: 10.1 to 21.2 mL/kg). Body weight ≤5 kg (P = 0.04), sagittal ESC (P < 0.01), syndromic craniosynostosis (P < 0.01), and earlier date of surgery in the series (P < 0.01) were factors associated with blood transfusion. VAE was detected in 2 infants with no changes in clinical outcome. Eight infants were admitted to the ICU. Factors associated with ICU admission were blood transfusion (P < 0.001) and respiratory complications (P < 0.001). Eighty-two infants were discharged on postoperative day 1 (range: 1 to 3 days). Six infants underwent subsequent fronto-orbital advancement and 1 cranial vault reconstruction. Multiple-suture craniosynostosis (P < 0.01), associated syndromes (P = 0.03), and ICU admission after ESC (P = 0.04) were predictive of reoperation.
Twenty percent of infants undergoing ESC had 1 or more of the following: need for blood transfusion, VAE, respiratory complications, and ICU admission. Multivariable analysis confirmed that patients with lower body weight, those with earlier date of surgery in the series, those undergoing sagittal ESC, and those with syndromic craniosynostosis had a higher rate of blood transfusion. ICU admissions often occurred in infants requiring transfusion and those with respiratory complications. Infants with multiple-suture craniosynostosis were more likely to require subsequent craniofacial reconstruction procedures.
Anesthesia and analgesia 02/2011; 112(2):407-14. · 3.08 Impact Factor
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ABSTRACT: Near-infrared spectroscopy monitoring of cerebral oxygen saturation (rSo(2)) has become routine in many centers, but no studies have reported the relationship of intraoperative near-infrared spectroscopy to long-term neurodevelopmental outcomes after cardiac surgery.
Of 104 infants undergoing biventricular repair without aortic arch reconstruction, 89 (86%) returned for neurodevelopmental testing at 1 year of age. The primary near-infrared spectroscopy variable was the integrated rSo(2) (area under the curve) for rSo(2) <or=45%; secondary variables were the average and minimum rSo(2) by perfusion phase and at specific time points. Psychomotor and mental development indexes of the Bayley scales, head circumference, neurological examination, and abnormalities on brain magnetic resonance imaging did not differ between subjects according to a threshold level for rSo(2) of 45%. Lower Psychomotor Development Index scores were modestly associated with lower average (r=0.23, P=0.03) and minimum (r=0.22, P=0.04) rSo(2) during the 60-minute period after cardiopulmonary bypass but not with other perfusion phases. Hemosiderin foci on brain magnetic resonance imaging were associated with lower average rSo(2) from postinduction to 60 minutes post cardiopulmonary bypass (71+/-10% versus 78+/-6%, P=0.01) and with lower average rSO(2) during the rewarming phase (72+/-12% versus 83+/-9%, P=.003) and during the 60-minute period following cardiopulmonary bypass (65+/-11% versus 75+/-10%, P=0.009). In regression analyses that adjusted for age <or=30 days, Psychomotor Development Index score (P=0.02) and brain hemosiderin (P=0.04) remained significantly associated with rSo(2) during the 60-minute period following cardiopulmonary bypass.
Perioperative periods of diminished cerebral oxygen delivery, as indicated by rSo(2), are associated with 1-year Psychomotor Development Index and brain magnetic resonance imaging abnormalities among infants undergoing reparative heart surgery. Clinical Trial Registration- URL: http://clinicaltrials.gov. Unique identifier: NCT00006183.
Circulation 07/2010; 122(3):245-54. · 14.74 Impact Factor
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KEIRA P. MASON MD,
DAVID ZURAKOWSKI PhD,
STEVEN ZGLESZEWSKI MD,
RANDY PRESCILLA MD,
PAULETTE J. FONTAINE BS,
JAMES A. DINARDO MD,
KEIRA P. MASON,
DAVID ZURAKOWSKI,
STEVEN ZGLESZEWSKI,
RANDY PRESCILLA,
PAULETTE J. FONTAINE, JAMES A. DINARDO
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ABSTRACT: This study reviewed the hypertensive response of a large population of children to high-dose dexmedetomidine sedation with the aim of determining the incidence and predictors of hypertension.Background: When dexmedetomidine is used to provide sedation for children, fluctuations in blood pressure have been described in case reports. We report the incidence and predictors of hypertension in a large series of children who received dexmedetomidine.Methods/Materials: At our institution, a computerized database holds patient demographics, sedation outcomes, adverse events, and hemodynamic data for all children who receive dexmedetomidine sedation for radiological imaging studies. After Institutional Review Board approval, this database was reviewed.Results: Three thousand five hundred twenty-two (3522) children received dexmedetomidine sedation between May 1, 2007 and December 31, 2008 for magnetic resonance imaging studies. Median age was 3.6 years (interquartile range: 1.8–5.9). A total of 172 patients (4.9%) developed hypertension, with a higher incidence in the younger age group (0–3 years) when compared to the older age groups (3–18 years) (P < 0.05). Multivariable logistic regression modeling confirmed that younger age (Wald test = 43.5 of 5 degrees of freedom, P < 0.001) and more than one bolus (Wald test = 22.7, P < 0.001) were highly significant predictors of the occurrence of hypertension.Conclusion: When high-dose dexmedetomidine is used for pediatric sedation for MR imaging, the incidence of hypertension is low. Hypertension is most likely to occur in children <1 year of age during the continuous infusion, after they have received more than one bolus of dexmedetomidine.
Pediatric Anesthesia 05/2010; 20(6):516 - 523. · 2.10 Impact Factor
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ABSTRACT: This study reviewed the hypertensive response of a large population of children to high-dose dexmedetomidine sedation with the aim of determining the incidence and predictors of hypertension.
When dexmedetomidine is used to provide sedation for children, fluctuations in blood pressure have been described in case reports. We report the incidence and predictors of hypertension in a large series of children who received dexmedetomidine.
At our institution, a computerized database holds patient demographics, sedation outcomes, adverse events, and hemodynamic data for all children who receive dexmedetomidine sedation for radiological imaging studies. After Institutional Review Board approval, this database was reviewed.
Three thousand five hundred twenty-two (3522) children received dexmedetomidine sedation between May 1, 2007 and December 31, 2008 for magnetic resonance imaging studies. Median age was 3.6 years (interquartile range: 1.8-5.9). A total of 172 patients (4.9%) developed hypertension, with a higher incidence in the younger age group (0-3 years) when compared to the older age groups (3-18 years) (P < 0.05). Multivariable logistic regression modeling confirmed that younger age (Wald test = 43.5 of 5 degrees of freedom, P < 0.001) and more than one bolus (Wald test = 22.7, P < 0.001) were highly significant predictors of the occurrence of hypertension.
When high-dose dexmedetomidine is used for pediatric sedation for MR imaging, the incidence of hypertension is low. Hypertension is most likely to occur in children <1 year of age during the continuous infusion, after they have received more than one bolus of dexmedetomidine.
Pediatric Anesthesia 04/2010; 20(6):516-23. · 2.10 Impact Factor
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ABSTRACT: The purpose of our study was to examine the reliability of nurse reports of adverse events related to procedural sedation in children. A descriptive, correlational design was used to analyze for inter-rater agreement between prospective adverse event reporting and that identified on independent review of the medical record. All sedation documentation at a pediatric hospital over one calendar year was reviewed, and inter-rater reliability of reporting was analyzed using K statistics. Five thousand forty-five sedation documentation records were reviewed. An adverse event rate of 6.52% was identified: 1.92% of adverse events were serious, and 4.60% were minor. Although overall agreement between nurse reports and independent review was greater than 99%, subanalysis suggested greater agreement for serious events than for minor ones (K values: 0.85 vs 0.49, P < .01). The results of our study revealed that minor adverse events associated with procedural sedation were under-reported, despite clear perianesthesia documentation in the medical record that an event had occurred. Improved education for perianesthesia nurses regarding the importance of monitoring both for serious and minor adverse events will help to identify opportunities to improve sedation protocols.
Journal of perianesthesia nursing: official journal of the American Society of PeriAnesthesia Nurses / American Society of PeriAnesthesia Nurses 10/2009; 24(5):300-6.
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ABSTRACT: Despite a relatively universally applicable knowledge base and skill set, training and experience in pediatric cardiac anesthesia in currently organized basic anesthesia and Adult Cardiothoracic Anesthesia fellowship programs are very limited and not uniformly available. Experience during Pediatric Anesthesia fellowship training is uniformly available but of limited duration and varying intensity. We present a schema, developed by a working group of the Congenital Cardiac Anesthesia Society, for training in pediatric cardiac anesthesia that pediatric cardiac anesthesia educators internationally should consider as a template to be modified as necessary.
Anesthesia & Analgesia 09/2009; 110(4):1121-5. · 3.29 Impact Factor
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ABSTRACT: Despite aggressive measures to miniaturize the cardiopulmonary bypass (CPB) circuit in neonates and infants, the CPB prime volume is often at least as large as the patients' blood volume. We conducted an observational study to characterize the hemostatic consequences of a CPB prime consisting of either non-fresh or reconstituted whole blood.
Hematocrit, fibrinogen, platelet count, plasminogen, anti-thrombin III (AT-III), and factors (F) II, V, VII, IX, and X of 30 neonates and infants undergoing cardiac surgery with CPB utilizing either a non-fresh or reconstituted whole blood prime were prospectively evaluated at eight time points. Following protamine administration, microvascular bleeding was treated by protocol.
The hemostatic composition of the CPB prime was the same following the use of either non-fresh or reconstituted whole blood. The CPB prime platelet count (mean +/- SD) was 5.87 +/- 2.84 x 10(3) microl(-1) when compared to a preoperative platelet count of 298 +/- 142 x 10(3) microl(-1) (P < 0.0001). Twenty patients received 17.3 +/- 9.2 ml x kg(-1) (0.86 +/- 0.46 units x kg(-1)) of platelets with significant improvement in platelet count. Nine patients received 16.7 +/- 13.4 ml x kg(-1) (0.84 +/- 0.67 units x kg(-1)) of cryoprecipitate with significant improvements in FVIII and fibrinogen.
Non-fresh or reconstituted whole blood as a component of a small volume CPB prime in neonates and infants induces clinically significant dilutional thrombocytopenia in conjunction with less significant reductions in fibrinogen, FII, FV, FVII, FVIII, FIX, FX, plasminogen, and AT-III.
Pediatric Anesthesia 09/2009; 19(9):854-61. · 2.10 Impact Factor
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ABSTRACT: The risk for thrombosis is increased after the Fontan operation. It is unknown whether children with univentricular heart disease have an intrinsic coagulation anomaly or acquire a defect in coagulation during the course of the staged repair. This prospective, longitudinal study evaluated changes in coagulation profiles in a cohort of patients with hypoplastic left heart syndrome from stage I palliation through completion of the Fontan operation.
Thirty-seven patients with hypoplastic left heart syndrome were enrolled prospectively, and the concentration of factors II, V, VII, VIII, IX, X, proteins C and S, fibrinogen, antithrombin, serum albumin, and liver enzymes were measured before stage I palliation (mean age 4 +/- 2 days), before bidirectional Glenn (mean age 5.9 +/- 1.8 months), before the Fontan procedure (mean age 27.1 +/- 6.6 months), and after the Fontan procedure (mean age 49 +/- 17.6 months). Healthy children were used as age-matched controls for coagulation factors. Demographic, hemodynamic variables, and elapsed time after the Fontan procedure were evaluated as possible predictors of coagulation abnormalities.
Significantly lower levels of both procoagulation and anticoagulation factors were demonstrated through to completion of the Fontan procedure. After the Fontan procedure, there was a significantly higher factor VIII level (P < .005) but no correlation with hemodynamic variables or liver function.
This longitudinal study in patients with identical cardiac disease and staged surgical procedures confirms the increase in factor VIII level after the Fontan procedure. This is an acquired defect, and although the cause remains to be determined, monitoring factor VIII levels after the Fontan operation could indicate a subset of patients at risk for thrombosis.
The Journal of thoracic and cardiovascular surgery 05/2009; 137(4):934-41. · 3.41 Impact Factor
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ABSTRACT: Milrinone is a phosphodiesterase III inhibitor that increases intracellular cyclic adenosine monophosphate resulting in improved ventricular function and vasodilation. Increased intracellular levels of cyclic adenosine monophosphate also inhibit adenosine diphosphate (ADP) and arachidonic acid (AA)-induced platelet aggregation. We hypothesized that inhibition of ADP and AA-induced platelet activation by therapeutic blood concentrations of milrinone could be quantified using TEG Platelet Mapping.
Blood was taken from 15 healthy adults who had not been taking antiplatelet medications. Milrinone was added to whole blood in three clinically relevant concentrations (30, 100, and 300 ng/mL). Conventional thromboelastography (TEG) and TEG Platelet Mapping were performed on whole blood without milrinone and at each of these three concentrations.
Increased blood concentrations of milrinone were associated with increased inhibition of ADP and AA-induced platelet activation (P < 0.0001). Milrinone at a blood concentration of 300 ng/mL markedly impaired the platelet activation response to ADP and AA.
Therapeutic blood concentrations of milrinone exhibit a significant inhibitory effect on ADP and AA-induced platelet activation as determined by TEG Platelet Mapping, without affecting the conventional kaolin-activated TEG. We suggest that TEG Platelet Mapping results be interpreted with caution in patients being treated with milrinone, and other drugs that modify platelet cyclic nucleotide concentrations.
Anesthesia and analgesia 05/2009; 108(5):1425-9. · 3.08 Impact Factor
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ABSTRACT: At our institution, high-dose i.v. dexmedetomidine is used to provide sedation for pediatric patients undergoing nonpainful radiological imaging studies. Some of these patients exhibit marked bradycardia (more than 20% deviation from the lowest age-adjusted normal values) while maintaining an arterial blood pressure within an acceptable normal range. We report on three cases wherein treatment of dexmedetomidine-induced bradycardia with i.v. glycopyrrolate (5.0 microg/kg) not only resulting in resolution of bradycardia but also resulting in an exaggerated increase of arterial blood pressure.
Anesthesia and analgesia 04/2009; 108(3):906-8. · 3.08 Impact Factor
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ABSTRACT: We examined changes in cerebral oxygen saturation during infant heart surgery and its relationship to anatomic diagnosis and early outcome.
Regional cerebral oxygen saturation (rSO(2)) was measured by near-infrared spectroscopy in 104 infants undergoing biventricular repair without aortic arch obstruction as part of a randomized trial of hemodilution to a hematocrit of 25% vs 35%.
Before cardiopulmonary bypass (CPB), infants with tetralogy of Fallot had higher rSO(2) values compared to those with D-transposition of the great arteries (D-TGA) or ventricular septal defect (P < 0.001). During CPB cooling, low flow, and at the termination of CPB, D-TGA subjects had the highest rSO(2) values (P < 0.001). There were no significant associations between intraoperative rSO(2) and early postoperative outcomes after adjustment for diagnosis. In 39 D-TGA subjects with > or =5 min of deep hypothermic circulatory arrest (DHCA), there was no correlation between the rSO(2) (91% +/- 6%) or hematocrit (29.2% +/- 5.5%) at the onset of arrest and the rate of decline in rSO(2) during arrest.
Intraoperative rSO(2) varies according to anatomic diagnosis but accounts for very little of the variance in early outcome. As measured by frontal near-infrared spectroscopy, higher levels of hematocrit and current perfusion techniques appear to provide an adequate oxygen reservoir prior to relatively short periods of DHCA.
Anesthesia and analgesia 04/2009; 108(4):1122-31. · 3.08 Impact Factor
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ABSTRACT: Patients with congenital supravalvular aortic stenosis and associated peripheral pulmonary artery stenoses, the majority of whom have Williams-Beuren syndrome, are inherently at risk for development of myocardial ischemia. This is particularly true in the setting of procedural sedation and anesthesia. The biventricular hypertrophy that accompanies these lesions increases myocardial oxygen consumption and compromises oxygen delivery. In addition, these patients often have direct, multifactorial compromise of coronary blood flow. In this article, we review both the pathophysiology of congenital supravalvular aortic stenosis and the literature regarding sudden death in association with sedation and anesthesia. Recommendations as to preoperative assessment and management of these patients are made based on the best available evidence.
Anesthesia and analgesia 01/2009; 107(6):1848-54. · 3.08 Impact Factor
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Anesthesia and analgesia 12/2008; 107(5):1509-11. · 3.08 Impact Factor
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ABSTRACT: The incidence and implications of anti-heparin-platelet factor 4 (PF4) antibody seroconversion in the pediatric cardiac surgical population remain largely unexplored. We sought to prospectively characterize the incidence of seroconversion in two populations: neonates undergoing primary cardiac surgery and children undergoing reoperative cardiac surgery with a history of unfractionated heparin (UFH) exposure.
One hundred and thirty-five consecutive patients were studied: Neonatal = 60 neonates, first time cardiac surgery. Reoperative (ReOp) = 75 children, reoperative cardiac surgery. Preoperative and postoperative day (POD) 5 and 10 blood samples were used to determine the presence of PF4 immunoglobulin (Ig)G, IgA, and IgM antibodies with enzyme-linked immunosorbent assay.
No anti-heparin/PF4 antibodies were detected preoperatively in either group. On POD 5, antibodies were present in 1 of 60 (1.7%) Neonatal; and in 12 of 75 (16%) ReOp; P = 0.006. On POD 10, antibodies were present in 1 of 60 (1.7%) Neonatal; and in 39 of 75 (52%) ReOp; P < 0.001. Seroconversion in ReOp patients on POD 10 was significantly associated (P = 0.03) with previous UFH exposures. Heparin-induced thrombocytopenia (HIT) was not diagnosed in any Neonatal patients. One ReOp patient (1.3%) seroconverted and developed HIT without thrombosis or skin lesions.
HIT is a rare occurrence in pediatric cardiac surgical patients. The incidence of anti-heparin-PF4 antibody seroconversion in children undergoing reoperation is approximately 50% at 10 days postoperatively, a finding similar to that reported in adult cardiac surgical patients. Both age and previous UFH exposure correlate with this rate of seroconversion. In contrast, the rate of seroconversion in neonates undergoing first time surgery is substantially lower.
Anesthesia and analgesia 08/2008; 107(2):371-8. · 3.08 Impact Factor
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ABSTRACT: This large-scale retrospective review evaluates the sedation profile of dexmedetomidine. Aim: To determine the hemodynamic responses, efficacy and adverse events associated with the use of high dose dexmedetomidine as the sole sedative for magnetic resonance imaging (MRI) studies.
Dexmedetomidine has been used at our institution since 2005 to provide sedation for pediatric radiological imaging studies. Over time, an effective protocol utilizing high dose dexmedetomidine as the sole sedative agent has evolved.
As part of the ongoing Quality Assurance process, data on all sedations are reviewed monthly and protocols modified as needed. Data were analyzed from all 747 consecutive patients who received dexmedetomidine for MRI sedation from April 2005 to April 2007.
Since 2005, the 10-min loading dose of our dexmedetomidine protocol increased from 2 to 3 microg.kg(-1), and the infusion rate increased from 1 to 1.5 to 2 microg.kg(-1).h(-1). The current sedation protocol progressively increased the rate of successful sedation (able to complete the imaging study) when using dexmedetomidine alone from 91.8% to 97.6% (P = 0.009), reducing the requirement for adjuvant pentobarbital in the event of sedation failure with dexmedetomidine alone and decreased the mean recovery time by 10 min (P < 0.001). Although dexmedetomidine sedation was associated with a 16% incidence of bradycardia, all concomitant mean arterial blood pressures were within 20% of age-adjusted normal range and oxygen saturations were 95% or higher.
Dexmedetomidine in high doses provides adequate sedation for pediatric MRI studies. While use of high dose dexmedetomidine is associated with decreases in heart rate and blood pressure outside the established 'awake' norms, this deviation is generally within 20% of norms, and is not associated with adverse sequelae. Dexmedetomidine is useful as the sole sedative for pediatric MRI.
Pediatric Anesthesia 05/2008; 18(5):403-11. · 2.10 Impact Factor
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International Anesthesiology Clinics 02/2008; 46(2):137-55.
