Anesthesiology; Blood Circulation; Cardiovascular System; Headache; Heart Failure; Hypertension; Ischemia; Microcirculation; Neuromuscular Diseases; Pain; Perfusion; Reperfusion; Hypovolemia
I am presently undertaking several major areas of research.
- I am seeking to get a better insight into regulation of blood flow at the level of the capillaries and tissues, with an emphasis on assessing how this is controlled by the autonomic nervous system.
- Detecting when somebody is dehydrated or is losing blood before the change in volume status can cause significant harm to the body.
- New means of monitoring body temperature through a surface temperature monitor.
- Developing a common score for assessing the local impact of disorders, the systemic impact of disorders, and the impact of challenges such as surgery.
Specialized Terms: Anesthesiology; Cardiovascular System; Congestive Heart Failure; Headaches; Heart; Hypertension; Ischemia; Neuromuscular Disorders; Pain; Perfusion Or Reperfusion; Circulation; Circulatory Disorders; Endothelial Dysfunction; Healthcare Worker Safety; Hypovolemia; Microcirculation; Needle Safety; Needlesticks; Neuromuscular System; Neuromuscular Disorders
Extensive Research Description
1. Using a multi-dimensional computerized data acquisition system, we are integrating input from arterioles and capillaries (laser Doppler flowmetry), arteries and veins (plethysmography), with continuous monitors of blood pressure and heart rate to gain insight into two major areas of cardiovascular physiology: a) the regulation of microvascular perfusion, with a focus on autonomically-mediated autoregulatory processes; b) the assessment of the cardiovascular responses to volume loss intraoperatively and in healthy volunteers (withdrawal and reinfusion of two units of blood; simulated hypovolemia with the use of lower body negative pressure). These studies involve time-domain and spectral-domain analytical techniques in collaborative efforts with Cardiology, Emergency Medicine, Pulmonary Medicine, and Physiology at Yale and the J.B. Pierce Foundation as well as with Chairman of Biomedical Engineering at another institution. The work has led to intellectual property that has been transferred to Yale University School of Medicine.
2. As Co-Director of the BTT Interdisciplinary Research Group, I am the senior investigator on a series of multidisciplinary, multicenter studies monitoring brain and core temperature noninvasively. In collaboration with Dr. Marc Abreu, the discoverer of the brain thermal tunnel (BTT) and inventor of related technology, I h ave been determining the ability to continuously monitor core and, more specifically, brain temperature, with a noninvasive surface sensor applied beneath the medial brow ridge. Our initial studies have focused on whether BTT is an accurate measure of brain temperature and a reliable detector of brain/core discordance. We thereby haveidentified (and quantified) changes in brain temperature during anesthesia and throughout the perioperative period. For example, we identified otherwise unseen brain hyperthermia (with the potential for neuronal injury) during recovery from cardiopulmonary bypass surgery. In the emergency setting, we documented otherwise undetected ipsilateral hypothermia during incipient ischemic stroke, leading to likely application of BTT as a harbinger of brain loss. Monitoring via the BTT has enabled us to delineate changes during sleep, including delta and REM sleep and abnormalities thereof. We similarly have isolated changes in brain temperature during seizures, craniotomy, mental effort, ischemic stroke and exercise. Preliminary evidence suggests that monitoring BTT may enable us to more effectively identify incipient heat stroke. Such monitoring thus provides previously unattainable insight into brain thermodynamics in health and disease, constituting a hinge moment for brain as well as core thermometry -- and hence patient safety. Upon publication of our initial manuscripts (in prep), I anticipate that BTT will become required monitoring during major surgery and prove to be invaluable in myriad other hospital and nonhospital settings. The sensitivity of monitoring via the BTT to temperature channels at the level of the hypothalamus (body’s thermostat) may make it particularly valuable in detecting prodromal phases of a disorder (such as the flu) as well as active and recovery phases.
3. I have introduced a new way for uniform scoring of bodily systems and the disorders affecting them and integrating this with the anticipated risks associated with anesthesia and surgery. I am exploring ways of adapting my new method of assessment to improve the utility and workability of the electronic health record.
Integrated assessment and consultation for the preoperative patient
Silverman DG. Rosenbaum SH. Integrated assessment and consultation for the preoperative patient. Medical Clinics of North America. 93(5):963-977, 2009 Sep.
Modeling Perioperative Risk – Can Numbers Speak Louder Than Words?
Holt NF, Silverman DG: Modeling Perioperative Risk – Can Numbers Speak Louder Than Words? In: Rosenbaum SH (editor). Anesthesiology Clinics of NA 24:427-459, 2006
The relationship between the photoplethysmographic waveform and systemic vascular resistance
Awad AA. Haddadin AS. Tantawy H. Badr TM. Stout RG. Silverman DG. Shelley KH. The relationship between the photoplethysmographic waveform and systemic vascular resistance. Journal of Clinical Monitoring & Computing. 21(6):365-72, 2007 Dec.
Comparing the effect of arginine vasopressin on ear and finger photoplethysmography
Jablonka DH, Awad AA, Stout RG, Silverman DG, Shelley KH: Comparing the effect of arginine vasopressin on ear and finger photoplethysmography. Journal of Clinical Anesthesia 20:90-93, 2008
Distinction between atropine-sensitive control of microvascular and cardiac oscillatory activity
Silverman DG, Stout RG: Distinction between atropine-sensitive control of microvascular and cardiac oscillatory activity. Microvasc Res 63:196-208, 2002
Peripheral assessment of phenylephrine-induced vasoconstriction by laser Doppler flowmetry and its potential relevance to homeostatic mechanisms
Silverman DG, Jotkowitz AB, Freemer M, Gutter V, O'Connor TZ, Braverman IM: Peripheral assessment of phenylephrine-induced vasoconstriction by laser Doppler flowmetry and
Full List of PubMed Publications
- Tuckel P, Milczarski W, Silverman DG: Injuries Caused by Falls From Playground Equipment in the United States. Clin Pediatr (Phila). 2017 Sep 1; 2017 Sep 1. PMID: 28969430
- Alian AA, Atteya G, Gaal D, Golembeski T, Smith BG, Dai F, Silverman DG, Shelley K: Ventilation-Induced Modulation of Pulse Oximeter Waveforms: A Method for the Assessment of Early Changes in Intravascular Volume During Spinal Fusion Surgery in Pediatric Patients. Anesth Analg. 2016 Aug. PMID: 27284998
- Zhu R, Atteya G, Shelley KH, Silverman DG, Alian AA: Analysis of plethysmographic waveform changes induced by beach chair positioning under general anesthesia. J Clin Monit Comput. 2014 Dec; 2014 Jan 14. PMID: 24420341
- Schuster KM, Jenq GY, Thung SF, Hersh DC, Nunes J, Silverman DG, Horwitz LI: Electronic handoff instruments: a truly multidisciplinary tool? J Am Med Inform Assoc. 2014 Oct; 2014 Feb 19. PMID: 24553477
- Alian AA, Galante NJ, Stachenfeld NS, Silverman DG, Shelley KH: Impact of lower body negative pressure induced hypovolemia on peripheral venous pressure waveform parameters in healthy volunteers. Physiol Meas. 2014 Jul; 2014 Jun 5. PMID: 24901895
- Odonkor CA, Schonberger RB, Dai F, Shelley KH, Silverman DG, Barash PG: New utility for an old tool: can a simple gait speed test predict ambulatory surgical discharge outcomes? Am J Phys Med Rehabil. 2013 Oct. PMID: 24051992
- Dai F, Silverman DG, Chelly JE, Li J, Belfer I, Qin L: Integration of pain score and morphine consumption in analgesic clinical studies. J Pain. 2013 Aug; 2013 Jun 3. PMID: 23743256
- Horwitz LI, Schuster KM, Thung SF, Hersh DC, Fisher RL, Shah N, Cushing W, Nunes J, Silverman DG, Jenq GY: An institution-wide handoff task force to standardise and improve physician handoffs. BMJ Qual Saf. 2012 Oct; 2012 May 23. PMID: 22626740
- Alian AA, Galante NJ, Stachenfeld NS, Silverman DG, Shelley KH: Impact of central hypovolemia on photoplethysmographic waveform parameters in healthy volunteers part 2: frequency domain analysis. J Clin Monit Comput. 2011 Dec; 2011 Nov 6. PMID: 22057245
- Alian AA, Galante NJ, Stachenfeld NS, Silverman DG, Shelley KH: Impact of central hypovolemia on photoplethysmographic waveform parameters in healthy volunteers. Part 1: time domain analysis. J Clin Monit Comput. 2011 Dec; 2011 Nov 4. PMID: 22051898
- Moore CL, Tham ET, Samuels KJ, McNamara RL, Galante NJ, Stachenfeld N, Shelley K, Dziura J, Silverman DG: Tissue Doppler of early mitral filling correlates with simulated volume loss in healthy subjects. Acad Emerg Med. 2010 Nov. PMID: 21175513
- Walton ZD, Kyriacou PA, Silverman DG, Shelley KH: Measuring venous oxygenation using the photoplethysmograph waveform. J Clin Monit Comput. 2010 Aug; 2010 Jul 20. PMID: 20644985
- Silverman DG, Rosenbaum SH: Integrated assessment and consultation for the preoperative patient. Anesthesiol Clin. 2009 Dec. PMID: 19942170
- Silverman DG, Rosenbaum SH: Integrated assessment and consultation for the preoperative patient. Med Clin North Am. 2009 Sep. PMID: 19665614
- Akhtar S, Assaad S, Amin M, Holt NF, Barash PG, Silverman DG: Preoperative beta-blocker use: impact of national guidelines on clinical practice. J Clin Anesth. 2008 Mar. PMID: 18410867
- Jablonka DH, Awad AA, Stout RG, Silverman DG, Shelley KH: Comparing the effect of arginine vasopressin on ear and finger photoplethysmography. J Clin Anesth. 2008 Mar. PMID: 18410861
- Awad AA, Haddadin AS, Tantawy H, Badr TM, Stout RG, Silverman DG, Shelley KH: The relationship between the photoplethysmographic waveform and systemic vascular resistance. J Clin Monit Comput. 2007 Dec; 2007 Oct 17. PMID: 17940842
- Gesquiere MJ, Awad AA, Silverman DG, Stout RG, Jablonka DH, Silverman TJ, Shelley KH: Impact of withdrawal of 450 ml of blood on respiration-induced oscillations of the ear plethysmographic waveform. J Clin Monit Comput. 2007 Oct; 2007 Aug 16. PMID: 17701386
- Tantawy H, Silverman TJ, Silverman DG, Akhtar S: Survey of anesthesiologists as to the value of prior ECG in a patient with nonspecific ST-T wave changes. Conn Med. 2007 Sep. PMID: 17902381
- Holt NF, Silverman DG, Prasad R, Dziura J, Ruskin KJ: Preanesthesia clinics, information management, and operating room delays: results of a survey of practicing anesthesiologists. Anesth Analg. 2007 Mar. PMID: 17312219
- Holt NF, Silverman DG: Modeling perioperative risk: can numbers speak louder than words? Anesthesiol Clin. 2006 Sep. PMID: 17240601
- Shelley KH, Jablonka DH, Awad AA, Stout RG, Rezkanna H, Silverman DG: What is the best site for measuring the effect of ventilation on the pulse oximeter waveform? Anesth Analg. 2006 Aug. PMID: 16861419
- Awad AA, Stout RG, Ghobashy MA, Rezkanna HA, Silverman DG, Shelley KH: Analysis of the ear pulse oximeter waveform. J Clin Monit Comput. 2006 Jun; 2006 Apr 13. PMID: 16612551
- Shelley KH, Awad AA, Stout RG, Silverman DG: The use of joint time frequency analysis to quantify the effect of ventilation on the pulse oximeter waveform. J Clin Monit Comput. 2006 Apr; 2006 Jun 1. PMID: 16779621
- Schonberger RB, Worden WS, Shahmohammadi K, Menn K, Silverman TJ, Stout RG, Shelley KH, Silverman DG: Topical non-iontophoretic application of acetylcholine and nitroglycerin via a translucent patch: a new means for assessing microvascular reactivity. Yale J Biol Med. 2006 Mar. PMID: 17876370
- Akhtar S, Amin M, Tantawy H, Senior A, Barash PG, Silverman DG: Preoperative beta-blocker use: is titration to a heart rate of 60 beats per minute a consistently attainable goal? J Clin Anesth. 2005 May. PMID: 15896586
- Shelley KH, Tamai D, Jablonka D, Gesquiere M, Stout RG, Silverman DG: The effect of venous pulsation on the forehead pulse oximeter wave form as a possible source of error in Spo2 calculation. Anesth Analg. 2005 Mar. PMID: 15728063
- Stout RG, Shine TS, Silverman DG, Brull SJ: Recovery of neuromuscular function after a combination of mivacurium and rocuronium. Yale J Biol Med. 2004 Sep. PMID: 15989744
- Akhtar S, Silverman DG: Assessment and management of patients with ischemic heart disease. Crit Care Med. 2004 Apr. PMID: 15064671
- Halaszynski TM, Juda R, Silverman DG: Optimizing postoperative outcomes with efficient preoperative assessment and management. Crit Care Med. 2004 Apr. PMID: 15064666
- Silverman DG, Halaszynski T, Sinatra R, Luther M, Rinder CS: Rofecoxib does not compromise platelet aggregation during anesthesia and surgery. Can J Anaesth. 2003 Dec. PMID: 14656777
- Hartmannsgruber MW, Atanassoff PG, Budde A, Brull SJ, Kain ZN, Silverman DG: Intradermal sufentanil does not improve lidocaine-induced local anesthesia. Can J Anaesth. 2003 Feb. PMID: 12560306
- Silverman DG, Stout RG: Distinction between atropine-sensitive control of microvascular and cardiac oscillatory activity. Microvasc Res. 2002 Mar. PMID: 11866543