Past Webinars

ASNM Webinars provide education for those in the IONM industry and those seeking to learn more about this evolving area of practice. Webinars are included as part of ASNM’s membership and are a worthwhile member benefit. Non-ASNM members can purchase individual webinars. Webinar sessions are presented in "real time” via the Internet. Participants view webinar materials online while listening to the concurrent audio portion of the presentation via their computer audio system.

All ASNM webinars are approved for one (1) credit hour of continuing education for ASNM-CEUs.

Only webinars that are marked are available for AMA PRA Category 1 Credit™ (CME). If a webinar has been up longer than a year we can no longer offer CME credit for them. Please keep this in mind.

Questions regarding ASNM’s webinar series?

Please e-mail [email protected] or call (331) 248–1699.

How to Access Webinars

Cost for all recorded webinars
Members: Complimentary
Non-members: $59

* IMPORTANT ACCESS INSTRUCTIONS *

*Please note that both members and non-members must complete the webinar purchase form below in order to gain access to on-demand webinars. After completing the form, a link titled "View Your On-Demand Webinars" will appear in the menu under Webinars. This link will take you to our On-Demand Learning Portal where you can access all of the webinars that you selected in the webinar purchase form. Your login information for the Learning Portal is the same as your login information for the ASNM website. In order to receive CME credit, you must watch the full webinar recording and complete the survey.

Purchase Webinars Here

How to Read and/or Design Comparative Studies in IONM
	OBJECTIVES 1. Designing cohort studies using casual modeling 2. 3 modes of analysis: RCT, propensity scoring, logistic regression 3. Flawed studies: sampling bias, poor covariate control PRESENTER: Stanley A. Skinner MC, FASNM, FACNS Allina Health Abbot Northwestern's Neuroscience Institute
Performing an Awake Craniotomy: 60 Hz or 250-500 Hz Technique?
	OBJECTIVES 1. Understand the role of Direct Electric Stimulation (DES) in language mapping 2. Detail DES: probe, parameters: cortical and subcortical effectiveness 3. Review patient functional outcomes PRESENTER: Dr. Silvia Mazzali-Verst, MD, PHD IOM Senior MD by Hospital Siriao Libanês, São Paulo IOM Fellowship Coordinator at Brain Spine Neurofisiologia Sirio Libanês Hopsital
Effects of General Anesthetics on Synaptic Transmission and Plasticity
	OBJECTIVES 1. Understand how general anesthetics modulate presynaptic neuronal activity 2. Understand the effects of general anesthetics on postsynaptic structure and signaling 3. Explore the functional outcomes of anesthetic-mediated effects on synaptic transmission and plasticity PRESENTER: Jimcy Platholi
Current Legal Issues in Neuromonitoring
	OBJECTIVES: 1. Discuss current regulatory environment 2. Review relevant legal developments applicable to IONM 3. Discuss common themes in litigation involving IONM PRESENTER: Janine Gregory Leads Legal and business operations functions for NuVasive Clinical Services. 15 years in IONM with prior law firm and in house experience.
Digital Signal Processing Intuition
	OBJECTIVES How to look at a signal and intuitively know how to optimize it. PRESENTER: Tom Epplin-Zapf, MS, MA, CNIM Tom Epplin-Zapf earned a B.S. in Biomedical Engineering with a focus in bioelectrics and an M.S. in Systems Science in Electrical Engineering from Washington University in St. Louis. Currently he is a Ph.D. candidate in Mathematical and Computational Science and a member of the Center for Neurodynamics at the University of Missouri, where he investigates learning neuroplastic networks, nonlinear and stochastic systems, and artificial intelligence. He serves as the Director of Clinical Quality and Education at SpecialtyCare.
Intraoperative Neurophysiology of Cranial Nerves III, IV, and VI.
	OBJECTIVES 1. Understand relevant orbital anatomy for extraocular muscle electrode placement. 2. Describes benefits and risks of deep intraorbital needle electrodes for recording extraocular muscle EMG. 3. Differentiate extraocular muscle EMG waveforms from other cranial muscles. PRESENTER: Matt Hoffman DO, PhD
Techniques for Spinal Cord Mapping
	OBJECTIVES 1. Learn about essentials regarding patient preop deficits 2. Explore effective spinal cord mapping techniques 3. Identify trends in post operative patient outcomes PRESENTER: Kent Rice, MS, REPT, DABNM, FASNM
tcMEP Troubleshooting: Is it a good time to optimize your motors?
	Speakers: Stephanie Schwartz, PA-S, CNIM and Emily Kale, BS, R.EPT, CNIM Available for (1) hour AMA PRA Category 1 Credit™ (CME) until August 31, 2022
Brain Motor Mapping: The History and Current Status
	Speaker: Dr. Mitchel Berger, MD, FACS, FAANS Available for (1) hour AMA PRA Category 1 Credit™ (CME) until June 23, 2022 Objectives Review brain mapping techniques. Explore past vs. present mapping applications. Discuss post-operative patient outcomes.
Probing Pedicle Screw Stimulation: Considerations for Thoracic Screw Placement
	Speaker: Dr. Jonathan Norton, PhD, FACNS Objectives Review the literature and experiential concepts distinguishing thoracic from lumbar screw testing. Discuss a regimen for effective assessment of Thoracic Screws Explore neural integrity findings from Thoracic Screw stimulation and post-operative patient outcomes.
Out on a Limb: Key IONM Concepts for Peripheral Orthopedic Surgery
	Speaker: Cheryl Wiggins, AuD, DABNM, CNIM Objectives Identify morbidity data related to peripheral orthopedic procedures. Describe: Relevant peripheral anatomy (both upper & lower extremity) Types of peripheral orthopedic procedures & critical stages Neural elements at risk Understand the benefit of IONM during select peripheral orthopedic procedures.
Surgical Treatment of Tethered Cords
	Speaker: Gregory Heuer, MD, PhD University of Pennsylvania Children's Hospital of Philadelphia Objectives Examine surgical treatment & at-risk structures for tethered cords cases. Review pre-surgical collaboration and IONM applications. Discuss post operative assessments and outcomes.
Brainstem Reflexes: New Prospects for Cranial Nerve Monitoring
	Speaker: Sedat Ulkatan, MD, DABNM, CNIM Objectives Learn emerging concepts for brainstem reflex monitoring Explore applications for cranial nerve preservation Review reflex functions for brainstem surveillance and neural integrity assessment
Impact of Anesthesia on the Diagnostic Process of IONM During Spine Procedures: An Interactive Review
	Speaker: Julie Trott, MS, CNIM, GCertED Neurophysiologist Director IONM Education Objectives Examine IONM cases, exploring different diagnostic and patient outcomes Relate case examples to published literature to compare and contrast results Case examples will illustrate how the anesthetics regimen can influence the interpretive process in neurophysiology and therapy alter the accuracy and impact of IONM
Intraoperative Sensory and Motor Mapping of the Human Huomunculus
	Speaker: Jeremy Bamford, PhD Clinical Assistant Professor Department of Neurosurgery, Tulane University School of Medicine Objectives This presentation will review the fundamental neuroscience behind the accurate mapping of the sensory and motor regions of the human homunculus. Focus will be given to common mistakes and controversies present in the published literature. When possible, intraoperative videos combining surgical views and intraoperative neurophysiological data will be used to visually illustrate the techniques discussed. Understand the neurophysiology that undergirds accurate mapping possible Understand the common mistakes and why they occur Understand the practical elements of how to guide a surgeon through the mapping of the homunculus
Town Hall Interactive MEP Webinar
	Speakers: Jeffrey Balzer, PhD, FASNM, DABNM Presentation: Advanced Principles of TcMEP: Where We Are in 2020 Alier Franco, PhD Presentation: MEPs in Infants and Toddlers Panelists: Jeffrey Balzer, PhD, FASNM, DABNM, Alier Franco, PhD, Laura Hemmer, MD, Faisal Jahangiri, MD, CNIM, DABNM, FASNM, FASET and Rich Vogel, PhD, DABNM, FASNM Objectives: This webinar was presented to give attendees the chance to ask questions. There are two presentations about MEPs, each presentation is 20 minutes each, and their is 1 hour and 20 minutes of questions from attendees. 5 different panelists' perspectives are provided.
How Much Confidence Should I Have in the Results of This Study?
	Speaker: Dr. Robert Holdefer Available for (1) hour AMA PRA Category 1 Credit™ (CME) until April 27, 2021 Objectives Why all evidence is not created equal. We have more confidence in the results of some studies compared to others. Sources of bias reduce our confidence in study results and effective tools for recognizing risk of bias. The differences between systematic reviews, practice guidelines, and good practice statements.
Techniques Review: D Wave Motor Potentials
	Speaker: Mr. Kent Rice, MS, CNIM, DABNM, FASNM Nuvasive Clinical Services Ann Arbor, MI Available for ONLY 1 CEU, CME not available for this webinar. Objectives Understand the anatomic and physiologic basis for the D-wave and rationale for its use. Understand the technique for successful setup and monitoring of the D-wave. Understand basic troubleshooting and interpretation of the D-wave.


The below past webinars are educational resources offering CEU's only. All include a robust Q and A session near the end of each webinar.
Surgeon Communication Relative to the Cortical Bulbar MEPS & Blink Reflex
	Speaker: Dr. Isabel Fernández-Conejero: Director of Intra-operative Neurophysiology, University Hospital of Bellvitge in Barcelona Objectives Cortical Bulbar MEPs & Blink Reflex- utility, meaning, recording techniques, what to communicate to the surgeon.

Neuroimaging to Identify at Risk Structures Augments Neuromonitoring

Speaker: Melanie Brown Fukui, MD

Diagnostic Radiology Specialist

Innovation Institute, Aurora Medical Group

Objectives

Neuroimaging techniques and findings relevant to the patient surgical work up. Journey through deciphering imaging of Neural structures to learn visual cues and landmarks that are strategic for identifying at risk structures

Illustrative Case Studies of IONM Strategies During Lumbar Surgeries Part 2 of 2
	Michael Riley, MS, CNIM President Peak Neurophysiology Group, LLC Chris Martin, R.EP.T. CNIM Neurophysiologist NeuroAlert Objectives: Panel Discussion: IONM Case Studies During Lumbar Surgical Approaches/Case Examples in the Literature Procedural Implementation – includes Modifications if... Data Review and Surgical Interventions
Review of IONM Strategies Relative to Lumbar Surgical Approaches Part 1 of 2
	Michael Riley, MS, CNIM President Peak Neurophysiology Group, LLC Chris Martin, R.EP.T. CNIM Neurophysiologist NeuroAlert Objectives: Differentiate among the several surgical approaches for lumbar surgery and identify the procedure type based on standard acronyms Demonstrate understanding of the surgical steps of each approach type discussed, and the concomitant neurologic risks associated with the steps Plan and execute an appropriate intraoperative monitoring plan in order to avoid/mitigate the above-mentioned risks and provide comprehensive neurophysiologic coverage for the patient
The Changing Face of Carotid Endarterectomy Surgeries: A Comprehensive Neuromonitoring Review
	Jefrey Balzer, PhD Associate Professor Director, Clinical Services, Center for Clinical Neurophysiology Director, Cerebral Blood Flow Laboratory The participant will understand: How carotid disease is treated surgically and endovascularly Appropriate monitoring modalities How to effectively communicate change during carotid surgery Efficacy of individual IOM modalities for predicting significant change during the procedures Efficacy of individual IOM modalities for predicting post-operative and long-term stroke risk in these patients
The Role of Electrophysiology During Dorsal Root Entry Zone Microcoagulation to Treat Neuropathic Pain in Spinal Cord Injury
	David Barnkow, AuD, DABNM, CNIM, CCC/A Surgical Neurophysiologist Medsurant Health The participant will understand: The mechanism of Central Pain after Spinal Cord injury (SCI) That pain can present At-Level and Below-Level of the SCI That dorsal-column and sympathetic nervous system have different somatotopic maps
The Surgeon Perspective: IONM in Spinal Cord Tumors
	Francesco Sala, MD, FRCP(C), ABCN Assistant Professor of Neurosurgery Department of Neurosurgical Sciences and Movement, University of Verona Objectives: Understand the most relevant clinical aspects of intramedullary spinal cord tumors (ISCT) (signs and symptoms, MRI features, pathology) Describe the various steps of the surgery and the related IONM modalities Understand the role of different mapping and monitoring IONM techniques (SSEP, muscle MEPs, D-wave, sensory and motor mapping) Identify warning signals in IONM and suggest to the surgeon the related corrective measures Predict neurological outcome after ISCT surgery
Transcranial Electric Stimulation Motor Evoked Potential Monitoring Update
	David B. MacDonald M.D., FRCP(C) ABCN Section of Neurophysiology Department of Neurosciences King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia Experiential evidence for optimizing TcMEP data will be covered. Propel your knowledge and understanding of TcMEP practice recommendations. 1. Explain the Underlying Physiology For TcMEP’s 2. Optimize TcMEP Stimulation 3. Minimize Adverse Effects of TcMEP Stimulation 4. Apply Proper Warning Criteria for TcMEP Responses
Essentials of Intraoperative Auditory Brainstem Response Monitoring
	Lawrence Wierzbowski AuD, DABNM, FASNM President, Avatrode, LLC IONM Consulting and Education Since the first published description of the auditory brainstem response (ABR) by Jewett and Williston in 1971, there have been hundreds of published works on both clinical and perioperative ABR applications. Intraoperatively, the eighth cranial nerve is in jeopardy of being injured during microvascular decompression surgery. Auditory function preservation is enhanced by ABR monitoring during resection of small vestibular schwannomas. Surgical manipulation of the brainstem during excision of large cerebellar pontine angle tumors has been monitored by ABR to detect any deleterious effect to the brainstem auditory pathways that might occur. Interpretation criteria for the auditory brainstem response is available from several published guidelines that are based on the literature mentioned above but what are the "other" factors we encounter daily in the operating room that we need to consider as well.
Neuromonitoring during SCS Placement: Physiological Basis
	Jay Shils, PhD, DABNM, FASNM, FACNS Director, IONM Associate Professor, Anesthesiology, Rush University Medical Center This lecture will describe, in detail, the common IONM methodologies that are used during the placement of SCS leads as well as the physiology behind those methods. Common methods include the use of antidromic activation of the alpha-motor neurons via stimulation of the dorsal columns and the use of dorsal column collisions to lateralize the placement of leads. With new stimulation patterns the utilization of these techniques may be more important given standard awake lateralization cannot be used due to lack of standard clinical markers. Additionally, the physiology behind any IONM technique is critical to understand to both know the benefits and limitations of each technique.
Intraoperative Neuromonitoring for Neuromodulation Procedures
	Steven M. Falowski, MD, FAANS Director, Functional Neurosurgery St. Lukes University Health Network The use of IONM for neuromodulation is not only used as a modality for safety, but is also used as a confirmation of lead placement with spinal cord stimulators. It is this factor that is most important given the need to have a marker of proper lead position in an asleep patient. Newer protocols have also determined methods of lead placement with DRG stimulators. Newer research has examined the spinal and cortical responses of various programming waveforms, and has given an ability to have human spinal recording data.
Minimizing Confounding Variables and IONM Conflicts
	Christopher Pace, PhD, CNIM Chief Clinical Officer, Neuro Alert Monitoring Services Director, Center for Electroneurodiagnostics IONM is a helpful tool employed during spine surgery to reduce the risk of injury to delicate spinal cord and nerve pathways. IONM can, furthermore, be used to evaluate the integrity of bony structures into which metal implants have been placed (i.e. pedicle screw testing) and, also, to identify and localize neural structures. We may not always appreciate (take for granted) how many variables we are evaluating, and how much information we are integrating in order to provide the highest quality and value of IONM data. This presentation is intended to give an overview of IONM for major spine procedures and, through general discussion and case studies, to expand on this basic understanding. It will explore how specific technical, physiologic, anesthetic, surgical and communication variables (-based issues) impact IONM.
A “Bright” Future for FVEP’s? + “Insider” Tips for Brainstem Mapping
	David Houlden, PhD Associate Professor, Faculty of Medicine University of Ottawa Describe anatomy and methods for direct brainstem and spinal stimulation Describe limitations of stimulation and recording techniques during brainstem surgery Demonstrate the utility of brainstem and direct spinal stimulation with case studies Present Rationale and Factors that confound Flash Visual Evoked Potentials (FVEP) recordings Detail the relationship between FVEP changes and outcomes
A Comprehensive Guide to Corticospinal Tract Mapping and Monitoring
	Charles Yingling, PhD, CNIM, DABNM, FASNM, FACNS Chief Executive Officer Golden Gate Neuromonitoring Understand the anatomy and physiology of SEP polarity reversal as a method for identifying the central sulcus Understand when transcranial vs direct cortical MEP stimulation should be employed Understand the correct parameters and indications for short vs long train stimulation Know current procedures for avoiding damage to subcortical motor tracts Know safe access methods for resection of intrinsic spinal cord tumors
IONM and Current Trends in Pediatric Surgeries
	George Jallo, MD Director Johns Hopkins All Children's Institute for Brain Protection Sciences Understand the most common pediatric neurosurgical conditions Determine what is the best for intraoperative monitoring Discuss the need to alert the surgeon in cases Understand communication for intraoperative team
Neuromonitoring in the Interventional Radiology Suite
	James A. Watt, Jr. VP of Neuromonitoring Services Comprehensive Neuromonitoring Services This presentation will review the relevant cortical and spinal anatomy, published literature, types of arteriovenous malformations, mapping techniques and case examples. We will also discuss things to think about when monitoring in the IR suite.
Navigating Legal Issues in Neuromonitoring
	Eric D. Fader Counsel Day Pitney LLP There is considerable confusion and disagreement regarding many of the legal and regulatory requirements pertaining to IONM. The laws of different states and the federal government differ and are constantly changing, and IONM providers must also navigate insurance carriers’ and hospitals’ requirements, and relationships with their own or outsourced personnel, in order to bill and get paid for their services while complying with applicable law. State licensure and delegation issues, and what constitutes the “practice of medicine” in a given state, can vary considerably, and contractual dealings with customers, employees and contractors, and billing and IT service providers can also be complex. This webinar will discuss some common legal issues facing IONM providers and, where possible, offer possible solutions.
Utility of Spontaneous EMG, SSEPs, and MEPS to Monitor the Functional Integrity of Spinal Nerve Roots and Plexuses
	W. Bryan Wilent, PhD, DABNM Vice President of Education and Training Sentient Medical Systems During most orthopedic procedures SSEPs and MEPs are utilized primarily to assess conduction of the spinal cord pathways, but they obviously monitor the entire pathway, from peripheral nerve to brain or from brain to muscle, and can detect a functional compromise in specific nerve roots or plexuses. The usage of these modalities for monitoring peripheral function is debatable, however, because their utility is procedure/patient specific and the sensitivity and specificity is technique dependent; therefore, the IONM team should be aware when peripheral structures are most at risk and optimize the IONM accordingly
IONM Considerations in Endonasal Skull Base Surgery
	Adam T. Doan, DC, DABNM Director of Clinical Services Safe Passage Neuromonitoring Minimally invasive intracranial surgery continues to gain popularity, as advances in visualization, instrumentation and anatomical understanding allows the endoscope to be used to approach the skull base. The endonasal endoscopic route to the skull base can now be used to gain access from the crista galli to the odontoid process. It behooves the neuromonitoring team to appreciate the different neurovascular structures that may be encountered, in order to devise a specific multimodality strategy unique to the patient and the surgery. Knowing the rationale and limitations of the plan optimizes the information collected and communicated.
Variables in Pedicle Screw Monitoring
	Lawrence R. Wierzbowski, AuD, DABNM, FASNM Neurophysiologist Neurological Monitoring Services It is important to take anatomical, neurophysiological, surgical technique, surgical instrument conductivity and many other variables into consideration when recording triggered and free running electromyographic (EMG) signals in the operating room during spinal fusion with pedicle screw instrumentation. During the electrical evaluation of either the pedicle hole or the subsequent pedicle screw a "threshold" stimulation is commonly employed using the minimum amount of current to provoke an observable and repeatable compound muscle action potential (CMAP). Interpretation and alarm criteria for pedicle screw integrity using stimulated electromyography is usually based on the several published guidelines but are there "other" factors that we need to consider as well?
Troubleshooting Intraoperative Neurophysiologic Monitoring Data
	Kent Rice, MS, REPT, CNIM, DABNM, FASNM Director of Education and Training Biotronic Neuro Network Strategies for evaluating, identifying and resolving common noise patterns observed during IONM. Review a variety of recording and signal processing related technical problems including their identifying characteristics. Troubleshooting intraoperative neurophysiologic monitoring data.
The Use of SEP and MEP Monitoring During Cerebral AneurysmSurgery to Predict Brain Ischemia
	Lanjun Guo, MD, MS, DABNM University of California - San Francisco The participants will be able to understand the two main causes of brain ischemia during aneurysm surgery. Describe the roles of using SEPs and MEPs during cerebral aneurysm clipping procedures. Identify brain cortical and subcortical ischemia using SEPs and MEPs during the operation.
Communication in IONM, Let's Talk
	Joseph J. Moreira, MD Neurologist Intraoperative Monitoring Associates Review of the essential components of the legal document known as chat Fully appreciate the medicolegal ramifications and benefits of a proper line of communication between the neurosurgeon and technician Have both sides of the monitoring team understand each other’s limitations and pitfalls
Surgical Repair of the Brachial Plexus: A Surgeon’s Perspective of IONM
	Lynda Jun-San Yang, MD, PhD Clinical Associate Professor, Neurological Surgery Understand the indications for brachial plexus surgery Understand the role of IOM in brachial plexus surgery Understand the strategies for nerve reconstruction of the brachial plexus.
Neuromonitoring Challenges in the Pediatric Population
	Anthony Sestokas, PhD, DABNM, FASNM Chief Clinical Officer, Neuromonitoring SpecialtyCare Highlight aspects of nervous system development that produce neuromonitoring challenges in pediatric patients Identify strategies for overcoming neuromonitoring challenges secondary to nervous system development. Review anesthesia management strategies to optimize neuromonitoring in pediatric patients.
Neurosurgical Anesthesiology and Intraoperative Neurophysiological Monitoring: Uniqueness, Controversies, and Case Presentations
	Laura Hemmer, MD Assistant Professor, Northwestern University Feinberg School of Medicine Emphasize value of teamwork and communication between OR teams before and during the surgical procedure. Describe how different anesthetics impact evoked potentials & some controversies on use of different regimes. Discuss frequent anesthetic intraoperative maneuvers’ during neurosurgery and their impact on neuromonitoring.
Neurophysiological Monitoring During Endovascular Procedures
	Jeffery Balzer, PhD, D.ABNM, FASNM Associate Professor of Neurological Surgery, Neuroscience and Acute and Tertiary Care Nursing Associate Director of the Center for Clinical Neurophysiology Director of Cerebral Blood Flow Laboratory University of Pittsburgh Medical Center Understand which procedures pose neurophysiological risk Understand how application of IOM reduces these risks Understand which modalities are applicable to each procedure
Neuromonitoring During Spine Instrumentation and Deformity Correction Procedures
	Jay Shils, PhD, D.ABNM, FASNM Director of IONM The Lahey Hospital and Health System Associate Professor in Neurosurgery Tufts University Medical School Founding Partner Engineurix
Neuromonitoring Below the Belt
	Stanley Skinner, MD, FASNM, FACNS Neurophysiologist Allina Health
New Practice Guidelines in Facial Nerve Monitoring
	Jack Kartush, MD, FASNM Professor Emeritus Michigan Ear Institute Wayne State University Understand the increasing role that practice guidelines and checklists now play in clinical medicine and neurophysiological monitoring Understand the critical issues in intraoperative monitoring including a) which surgical procedures should be monitored, b) how they should be monitored, and c) who should monitor. Be able to list the critical steps in facial nerve monitoring.
Instrumentation Basics from the Amplifier to the Skin: Methods to Minimize Artifact and Risk for Electrical Surgical Unit and MRI Burns
	Brett Netherton, MS, FASNM, CNIM Managing Director Signal Gear How do you minimize artifact in your recordings? How do you avoid injuring your patient with your electrode attachments?
Blood Supply of the Spinal Cord
	Leo Happel, PhD Professor, Neurology, Neurosurgery, Physiology, and Neuroscience LSU Health Science Center Present a comparison of functional and classic anatomy Emphasize the DYNAMIC aspect of spinal cord circulation Relate functional anatomy to surgical procedures on the spine
Current Status of Perioperative Multimodality Neuromonitoringfor Cardiovascular Surgery
	Harvey L. Edmonds Jr., PhD, ScD Research Professor Emeritus Department of Anesthesiology & Perioperative Medicine University of Louisville School of Medicine Identify the causes and means of detecting potentially injurious physiologic imbalance affecting the nervous system of cardiovascular surgery patients in the perioperative environment. Identify the treatment options available to correct these physiologic imbalances.