Cardiothoracic anesthesiology

Cardiothoracic anesthesiology is a subspeciality of the medical practice of anesthesiology devoted to the preoperative, intraoperative, and postoperative care of adultpatients undergoing cardiothoracic surgery and related invasive procedures.It is one of the most interesting and challenging careers in anesthesiology.

It deals with the anesthesia aspects of care related to surgical cases such as, but not limited to open heart surgery, lung surgery, and other operations of the human chest. [Barash, Cullen, Stolelting: Clinical Anesthesia, fifth edition 2006] [Stoelting RK, Miller RD: Basics of Anesthesia, 4th edition, 2000]

Most cardiac surgeries require a machine that take over the functions of the heart and lungs while the heart is repaired . The responsibility of cardiovascular and thoracic (CVT) anesthesiologist is to supervise "bypass" (or heart-lung) machine and to keep the patient "asleep", to monitor and to control the patients vital signs during the operation.

CVT Fellowship

After satisfactory completion of Accreditation Councilfor Graduate Medical Education (ACGME) accredited residency program in anesthesiology formal advanced training in cardiac, vascular, and thoracic anesthesia is available via a one year fellowship. [http://anesthesiology.med.miami.edu/x161.xml] [http://www.scahq.org/sca3/fellowships/]

This fellowship consists of at least 8 month of adult cardiothoracic anesthesiology, one month dedicated to transesophageal echocardiography,one month in surgical intensive care unit and one month in learning the principle of cardiopulmonary bypass (CPB)with perfusionist.

Fellows are trained to provide Anesthesia for Coronary Artery bypass Surgery (CABG) on CPB and on beating heart,valvular heart surgery, aortic surgeries, heart transplant, lung transplant, heart & lung transplant.Adequate exposure and experience provided in the management of adultpatients for cardiac pacemaker and automatic implantable cardiac defibrillatorplacement, surgical treatment of cardiac arrhythmias.The fellow willgain sufficient experience to independently manage intra-aortic ballooncounterpulsation and patients with ventricular assist devices.The Cardiac Catheterization Laboratory will enable the fellow to gain expertise in the care of patients undergoing invasive cardiologic and electrophysiologic therapies. [Michael G D Souza, Daniel M Thys; Textbook of cardiothoracic Anesthesiology,chapter 27 page 711]

Additional clinical experience within the full one-year fellowship will includeanesthetic management of adult patients undergoing thoracic and vascular surgery. Fellows are trained to manage all type of thoracic surgeries which include video assisted thoracoscopy (VAT [Jose Castro, Daniel M Thys; Textbook of cardiothoracic Anesthesiology,chapter 29, 30 page 761-816] ),Thoracotomy and aortic surgery.Fellows will achieve expertise in differnt techniques of lung isolation like Double-lumen endotracheal tube, bronchial blocker, Univent Tube under guidance of fiber optic broncoscophy [Joel A Kaplan Thoracic Anesthesia ]

Fellows are trained to achieve expertise in the advanced monitoring techniques including but not limited to invasive blood pressure, arterial blood gas analysis, pulmonary artery catheterisation, cardiac output monitoring, cerebral oximetry, jugular venous oxygen saturation, cerebral oximetry, Bispectral Index (BIS) [Acta Anaesthesia Scandinavia: 48;20;2004] , Transcranial dopper(TCD) [Journal of Vascular Surgery;26;579;1997] ,Near Infra Red Spectroscopy(NIRS) [ European Journal of Cardiothoracic Surgery; 13; 370;1998] . In addition fellows will achieve basic proficiency in intraoperative transesophageal echocardiography (TEE) at the completion of fellowship.

Fellow conferences are held once a week to discuss interesting cases and review selected topics relevant to cardiothoracic anesthesia & intraoperative TEE.

Fellows are trained to manage cardiothoracic cases in the postoperative care unit.

Research : The recent developements in cardiac surgery expanded the scope of research including neuroprotection [Joel A Kaplan ; Cardiac Anesthesia; Chapter 23, Thoracic Aorta; page 732-737] , myocardial protection [Stephen J Thomas; Manual of Cardiac Anesthsia, William A dell, chapter 15, page 387-396, 1984] , blood conservation strategies [Stephen J Thomas; Manual of Cardiac Anesthsia,Dennis W Coombs, chapter 16, page 397-418, 1984] , port access surgery in this young subspeciality. Fellows are offered the opportunity to participate in clinical research and encouraged to present at national or international conference after completion of a research project.

Ultrasound - TEE

Transoesophageal echocardiography (TEE) has rapidly become the most powerful monitoring technique and diagnostic tool for the management of cardiac surgical patients. The TEE machine uses ultrasound waves to acquire real time images of the heart during the operation. [Kaplan, Cardiac Anesthesia, third edition 1993 ] [Gallagher, Board Stiff TEE Transesophaegeal Edchocardiography, 2004 ]

Ultrasound principles [Andrey Denault, TEE multimedia manual; A perioperative trans disciplinary approach, 1st edition] :
Ultrasound frequencies are much higher than those perceptible to human ear. In human tissues ultrasound waves travels at the constant speed (C) of 1540 m/s. Spatial resolution is defined as the minimal distance between two objects necessary to distinguish them from each other. To achieve a better spatial resolution, the ultrasound wavelength should be shorter than the distance between two objects. Transducers :TEE transducers are made of piezoelectric crystals. These crystals convert alternating voltage into ultrasound and vice versa, act as an emitter and receiver.

Modes of TEE [Jan Poelart, TEE in anesthesia, 1st edition]

2D modeIn this mode images will be displayed in two dimension or cross sectional image of the heart. This is the mode most commonly used in TEE.

Doppler EffectA shift of frequency of sound waves occurs when the source of sound is in relative motion as compared to the stationary receiver. Fellows are encouraged to appear for NBE/SCA Examination of Special Competence in Perioperative Transesophageal Echocardiography (PTEeXAM) [http://www.echoboards.org/pte/exam.html]

Cardio-pulmonary Bypass (CPB)

The cardio-pulmonary bypass machine is a complex piece of equipment/circuit used in cardiac surgery.

It is used to take over the heart and lung function of the patient during surgery. It enables total cardiac standstill so the operative field is still. [Gravlee, Cardio pulmonary bypass principles & practice, 2nd edition]

The supervision of this Cardio pulmonary bypass machine is the responsibility of the anesthesiologist, in conjunction with the cardiac surgeon and perfusionist. [Pierrea Cas Thely, Cardio pulmonary bypass: Physiology, related complications and pharmacology] The cardiac anesthesiologists need to know about the components, function, operation and complications associated with the use of CPB.

Role of Cardiac Anesthesiologists in Non Cardiac Surgery

Cardiac anesthesiologists not only provide anesthesia care for cardiac surgery, they also have specific role in providing anesthesia care for patients with complex cardiac disease undergoing non cardiac surgery, evaluating the heart function during intraoperative hemodynamic instability/cardiac arrest with the help of TEE, placement of advanced hemodynamic monitoring techniques.

References

External links

* [http://www.scahq.org Society of Cardiovascular Anesthesiologists]
* [http://anesthesiology.med.miami.edu/x161.xml Cardiothoracic Anesthesia fellowship in University of Miami, Fl]
* [http://anesthesiology.med.miami.edu/x27.xml Division of Cardiothoracic Anesthesiology, Department of Anesthesiology, university of miami, FL]
* [http://www.scahq.org/sca3/fellowships/ Cardiothoracic & Vascular Anesthesia Fellowship Programs]
* [http://www.asahq.org/ American Society of anesthesiologists (ASA) Home Page]
* [http://www.jcardioanesthesia.com/ Journal of Cardiothoracic and Vascular Anesthesia (JCTVA)]
* [http://www.annals.in/ Annals of Cardiac Anaesthesia (ACA)]
* [http://www.echoboards.org/pte/exam.html NBE/SCA Examination of Special Competence in Perioperative Transesophageal Echocardiography (PTEeXAM)]
* [http://www.asahq.org/publicationsAndServices/tee.pdf ASA TEE Practice Guidelines ]
* [http://www.asahq.org/publicationsAndServices/pulm_artery.pdf ASA PAC Practice Guidelines]