Sadaf T. Bhutta MBBS
Disclosures No financial disclosures No off label drug or equipment use
Sedation and Anesthesia To breathe or not to breathe……that is the question!
Current Clinical practice MRI predominantly used for diagnosis and follow up of congenital heart diseases due to following reasons: No ionizing radiation Less invasive than cardiac catheterization Good spatial and temporal resolution Morphology AND function
Current Clinical practice Need for deep sedation or general anesthesia
Prolonged image acquisition time Need for high quality and motion free images Sequences requiring breath‐holds in patients who cannot voluntarily hold breath
At the cost of….“…administration of anesthesia in MRI suite possesses inherent risks that might be the same or even higher than those in the OR.”“…there is almost a 2‐fold increased risk in mortality associated with non‐OR versus OR anesthetics at ourInstitution”
Michael Girshin, MD, Victoria Shapiro, MD, Amanda Rhee, MD, Sanford Ginsberg, MD,and Mario A. Inchiosa, Jr, PhD. Increased Risk of General Anesthesia for High‐Risk Patients Undergoing Magnetic Resonance Imaging. J Comput Assist Tomogr 2009;33: 312Y315
Cardiac MR imaging Practice Advisory on Anesthetic Care for Magnetic Resonance Imaging Report defined anesthetic care in cardiac imaging as high risk .
Anesthesiology 2009; 110:459–79
General Anesthesia “Use of GA and examinations on hospitalized patients are independent risk factors for adverse events with the most acutely ill patients at highest risk.”
The highest rate of adverse events was noted in inpatients under GA (10.4%, p < 0.001)
Dorfman AL, Odegard KC, Powell AJ, Laussen PC, Geva T. Risk factors for adverse events during cardiovascular magnetic resonance in congenital heart disease. J cardiovasc Magn Reson. 2007;9(5):793‐8.
General Anesthesia “…mortality rate after anesthesia‐related cardiac arrests was 28%. The only factors predictive of mortality after cardiac arrest were ASA physical status and emergency surgery.”
Mortality from cardiac arrest increases by 50% in children with aortic stenosis or cardiomyopathy
Anesthesia related cardiac arrest in children: Update from the pediatric perioperative cardiac arrest registry. Sanjay M. Bhananker, Chandra Ramamoorthy, Jeremy M. Geiduschek, Karen L. Posner, PhD Karen B. Domino, Charles M. Haberkern, John S. Campos, Jeffrey P. Morray. Anesth Analg 2007;105:344 –50
Neurological effects Behavior and learning disabilities are well established in rats and primate models. General anesthetics are thought to induce apoptosis through γ‐aminobutyric acid (GABA) receptor agonism and N‐methyl‐D‐aspartate (NMDA) receptor antagonism during critical neurodevelopment that leads to disruption of mitochondrial membrane permeability leading to neuronal apoptosis.
Hays SR, Deshpande JK (2011) Newly postulated neurodevelopmental risks of pediatric anesthesia. Curr Neurol Neurosci Rep 11:205–210
Is it worth it? The improved resolution gained by breath holds (read: general anesthesia) outweighs the risks of cardiac arrests from deep stages of anesthesia and the hemodynamic alterations incurred by the mechanisms used to create a breath hold
Problem? CMR still the standard of care for imaging and functional evaluation
Usual scan times range from 30‐60 mins. Anesthesia/deep sedation needed for pediatric patients
Solutions? “Feed and sleep method” in infants less than 6 months of age undergoing CMR
Limitations
Jonathan Windram & Lars Grosse‐Wortmann & Masoud Shariat & Mary‐Louise Greer & Mark W. Crawford & Shi‐Joon Yoo. Pediatr Radiol (2012) 42:183–187
Solutions? “Combined cardiac and respiratory triggering, enabled by a blood pool contrast agent, improves delineation of most anatomical structures in pediatric cardiovascular MRA”
Shreyas S. Vasanawala, Frandics P. Chan & Beverley Newman & Marcus T. Alley. Combined respiratory and cardiac triggering improves blood pool contrast‐enhanced pediatric cardiovascular MRI. Pediatr Radiol(2011) 41:1536–1544
Is CT a solution? Newer scanners and software have allowed for diagnostic cardiac examinations well below the dose at which an increase in cancer risk is currently detectable
Greenberg SB, Bhutta S, Braswell L et al (2011) Computedtomography angiography in children with cardiovascular disease: low dose techniques and image quality. Int J Cardiovasc Imaging. 2012 Jan; 28(1): 163‐70. Paul JF, Rohnean A, Elfassy E et al (2011) Radiation dose forthoracic and coronary step‐and‐shoot CT using a 128‐slice dualsourcemachine in infants and small children with congenital heart disease. Pediatr Radiol 41:244–249
CT radiation risk Radiation epidemiology branch (REB), a commission of National Cancer Institute of UK is conducting a retrospective study of 200,000 children and adolescents from 1985‐2002, and subsequent development of cancer
http://dceg.cancer.gov/reb/research/ionizing/medical/4
Solutions? A low dose CT scan might be less risky than an MRI performed under general anesthesia.
Further development and applications of newer software like de‐noising, iterative reconstruction and volume scanning in our daily practice.
Improve MRI protocols to decrease scan time, need for breath holds and subsequently deep sedation and anesthesia.
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