Mechanical Ventilation Management And Congenital Cardiac Surgery

Altered resp. mechanics & positive press ventilation have significant influence on hemodynamic

Approach to ventilation should not be focused to achieve desired gas exchange, rather it should be influenced by cardiorespiratory interactions

Endotracheal Tube
Narrowest segment of airway, prior to puberty is below the cords, at level of cricoid cartilage
Generally uncuffed tubes have been recommended

If expecting a significant leak, or airway edema
Change ETT to a Larger size, or cuffed ETT
Cuffed ETT at the time of initial intubation and leave the cuff deflated

Endotracheal Tube
Nasal approach
ETT easier to secure,
Less likely to move in trachea
Less irritation, inflammation, and less likely to lead to stenosis
Comfortable, with less gagging

Cardiorespiratory interactions
Vary significantly between patients
Is not possible to provide specific ventilatory strategies for all patients
Mode of ventilation should be adjusted to each patient’s hemodynamic status to achieve adequate CO, and gas exchange
Thus frequent modifications to mode and pattern of ventilation maybe necessary during the recovery period
With attention to lung volume and airway pressure

Changes in lung volume have significant impact on PVR
PVR is lowest at FRC
Hypo, or hyperinflation may result in significant increase in PVR
Due to altered traction on alveolar septae and extra-alveolar vessels
Positive pressure ventilation influences preload and afterload on the heart

Afterload on pulmonary ventricle is increased during positive press. Breath
Due to changes in lung volume, and increase in mean intrathoracic press.
If this is significant or limited reserve
RV stroke vol. maybe reduced, and RVEDP maybe increased
Can lead to low CO state and signs of RV dysfunction
•Tricuspid regurgitation, hepatomegally, ascites, and pleural effusions

Afterload on the systemic ventricle is decreased during a positive press. breath, in contrast to RV
Due to a fall in ventricle transmural pressure
Thus patients with LV dysfunction and increased LVEDV/LVEDP
Can have impaired pulmonary mechanics
•Secondary to increased lung water, decreased lung compliance, and increased airway resistance
•Leading to increased work of breathing in neonates and infants resulting in poor feeding and failure to thrive
•Thus positive press ventilation can reduce the work of breathing and O2 demand in patients with LV dysfunction, and volume overload
During weaning, CPAP or press support maybe helpful in these patients

PEEP utilization has been controversial in congenital heart patients
Initially perceived not to have a positive impact on gas exchange, and be detrimental to hemodynamic, and lead to lung injury
However, PEEP increases FRC leading to lung recruitment, and redistributes lung water from alveolar septae to more compliant perihilar regions
These lead to improved gas exchange, and decreased PVR
PEEP should be used in all mechanically ventilated patients after congenital heart surgery
Excessive levels can be detrimental by increasing afterload on RV
3-5 cmH2O of PEEP will help maintain FRC, and redistribute lung water without negative impact on hemodynamic

Conclusion
Mode of ventilation should be adjusted to each patient’s hemodynamic status to achieve adequate CO, and gas exchange
Cardiorespiratory mechanics should be optimized throughout the perioperative period which includes prior to the operation, intraoperative, during transport, and in the Intensive Care Unit Kamal K. Pourmoghadam, MD, is a pediatric cardiac surgeon at The Heart Center at Arnold Palmer Hospital for Children. He is board certified in general surgery, cardiothoracic surgery and congenital cardiac surgery.

About Dr. Kamal K. Pourmoghadam

Kamal Pourmoghadam, MD, is a pediatric cardiac surgeon at The Heart Center at Arnold Palmer Hospital for Children. He is board certified in general surgery, cardiothoracic surgery and congenital cardiac surgery.

Dr. Pourmoghadam earned his bachelor’s degree from University of California, Berkeley, and his medical degree from Albany Medical College in New York. He trained for adult cardiac surgery at the University of Miami, Jackson Memorial Hospital in Miami, and for congenital cardiac surgery at the University of Washington, Seattle Children’s Hospital in Seattle.

Dr. Pourmoghadam is a professor of surgery at the University of Central Florida College of Medicine, practicing congenital cardiac surgery for over twenty years and has been active in clinical research. He has extensive experience in neonatal and infant cardiac surgery and has special interest in the repair of single ventricle physiology patients and research in univentricular hearts.
References:

Website: https://kamalpourmoghadam.com
Blog: https://drpourmoghadam.home.blog/
News: https://hippocratesguild.com/dr-kamal-pourmoghadam
News: https://medicogazette.com/dr-kamal-pourmoghadam#425f92ce-0ccc-4fe2-8c31-56cf497704f4
News: https://hype.news/dr-kamal-pourmoghadam/
News report about Dr. Pourmoghadam: http://www.tiogapublishing.com/features/the_marketplace/covington-tot-returns-home-to-pennsylvania-after-lengthy-oklahoma-hospital/article_04865c00-0ae5-11e1-aec8-001cc4c002e0.html
Linkedin: https://www.linkedin.com/in/kamal-pourmoghadam-9a796157/

Tetralogy of Fallot

Historical Background

First complete description of tetralogy of Fallot (TOF) credited to Etienne Fallot, published 1888
First surgical procedure, palliation, for TOF, Alfred Blalock & Vivien Thomas 1945, John Hopkins University
Numerous aortopulmonary shunts
First successful intracardiac repair, Dr. Lillehei & Varco at University of Minnesota, controlled cross circulation, 1954
First successful repair with cardiopulmonary bypass, Dr. Kirklin, 1955
First complete description of tetralogy of Fallot (TOF) credited to Etienne Fallot, published 1888
First surgical procedure, palliation, for TOF, Alfred Blalock & Vivien Thomas 1945, John Hopkins University
Numerous aortopulmonary shunts
First successful intracardiac repair, Dr. Lillehei & Varco at University of Minnesota, controlled cross circulation, 1954
First successful repair with cardiopulmonary bypass, Dr. Kirklin, 1955

Morphology

The classic “tetrad” of TOF
Ventricular Septal Defect
Aortic override
Right ventricular outflow tract obstruction
Right ventricular hypertrophy
Each results from anterior and leftward displacement of infundibular/conal septum with respect to the trabecular septum
Boundaries of the VSD
Anterior- Anterior limb of septal band
Posterior- Anteroseptal leaflet of TV
Inferior- Posterior limb of septal band
Superior- Conal septum
Pulmonary valve, bicuspid in 58% of patients
Rarely PV, smallest portion of RVOT
Pulmonary atresia, 7% of TOF patients
Multiple aortopulmonary collateral arteries (MAPCAs)
More likely to have peripheral pulmonary stenosis
Complete absence of pulmonary valve leaflets, 5% of TOF patients
Severe pulmonary insufficiency
Aneurysmal dilatation of MPA & PA branches
Compression of distal tracheobronchial tree
Origin of LAD from RCA, 3-5% of TOF patients
Dual distribution of LAD
Single right coronary, rare

Associated Defects

ASD
PDA
Complete atrioventricular canal defect
Multiple VSDs

Pathophysiology & Diagnosis

Initial manifestation depends on the degree of RVOT obstruction
Cyanosis is mild at birth, progressive with age
Cyanosis main physical finding in TOF
First heart sound is normal but second sound is often single
Inaudible pulmonary component
Systolic murmur results from RVOT obstruction
Murmur disappears during “tet spell”
Electrocardiographic characteristics consistent with right ventricular hypertrophy
Chest radiography
Heart size usually normal
Aortic arch is right-sided, 25%
“boot shaped” heart
Elevation of cardiac apex due to RV hypertrophy
Concave upper left heart border due to narrowing of MPA
Diagnosis
Established by echocardiography
Cardiac catheterization
Usually not necessary
Recommended
Concerns for coronary anatomy
Multiple VSDs
Determination of aortopulmonary collateral anatomy
Non-confluent pulmonary artery branches

Treatment
Medical Management
Progressive decrease in oxygen saturation usually due to fixed RVOT obstruction, does not respond to Med. Therapy
Hypoxemic spells may result from transient decrease in pulmonary blood flow
Medical Management Cont.
Sudden increase in RVOT obstruction & decrease in SVR
Results in sudden profound decrease in oxygen saturation
Dehydration
Anemia
Increased catecholamine levels
Acidosis
Decrease in SVR
Medical Management Cont.
Treatment
Oxygen
Sedation
Bicarbonate
Transfusion/volume resuscitation
Administration of α-agonist to increase SVR
Long-term β-blocker may decrease myocardial contractility & decrease frequency and severity of spells
Indications for surgery
Usually asymptomatic at birth
Operative intervention is undertaken, once oxygen saturation is 75 to 80%
Occurrence of hypoxemic spells generally considered indication for surgery
In most institutions elective repair is undertaken at 3 to 6 months of age
Single stage complete repair, majority
Staged repair, preferred by few especially when
Pulmonary atresia with marked hypoplasia of PA branches
Severe associated non-cardiac anomalies
Systemic to pulmonary artery shunts designed to increase pulmonary blood flow in cyanotic children
Blalock-Taussing Shunt, Alfred Blalock,1944
Potts Shunt, Willis Potts, 1946
Waterston Shunt, David Waterston, 1962
Cooley Shunt, Denton Cooley, 1966
Modified Blalock-Taussing Shunt, Marc DeLeval, 1976
Complete repair
Closure of VSD
Relief of RVOT Obstruction
Pulmonary valve sparing vs. transannular patch (estimated RV/LV < 0.7)
Hypoplastic PA branches, rare
Considered present, McGoon ratio < 1.2 (diameter RPA + LPA/diameter of Ao at level of diaphragm)
Nakata index of approximately 70
Pulmonary atresia with MAPCAs
Usually associated with diminutive PA branches
Abnormal arborization
Peripheral PA stenosis
Higher operative mortality and complexity
Complete vs. staged repair
TOF with absent pulmonary valve
Urgent repair with placement of competent pulmonary valve and PA Branch plication
Early mortality is 21.4%
Preoperative mechanical ventilation, poorer outcome
TOF with complete AV canal defect (CAVCD)
Occurs in 2% of patients with TOF
Most common in patients with Down’s syndrome
Anatomy is that of CAVCD
Anterior bridging leaflet is always undivided & unattached to crest of the septum (Rastelli type C)
VSD has a large outlet component
Difficult to repair through atrial approach
Due to marked override of Ao valve, exposure is impeded
Valve in the pulmonic position is unnecessary unless marked branch PA hypoplasia

Results
Early hospital mortality, 1 to 5% (3.7%)
Repair within first year of life, does not influence early outcome
Improvement in intraoperative technique
Avoidance of excessive RVOT muscle resection
CPB management
Refinement in postoperative care

Long-term survival from University of Alabama at Birmingham, postoperative
1 month-93%
1 year-92%
5 years-92%
20 years-87%

Effect of pulmonary valve insufficiency (PI)
Long standing PI appears to have certain deleterious effects on ventricular function & exercise capacity
Particularly true if additional lesions
Peripheral pulmonary stenosis
Residual VSD
In a series of 20 asymptomatic patients, 9 years post-op., significantly lower RV & LV EFs were found compared to a group with competent PV
When symptoms develop, PV insertion improves functional status & ventricular function

Effect of pulmonary valve insufficiency (PI) cont.
Indications for pulmonary valve replacement in absence of CHF & exercise intolerance is not well defined
Pulmonary valve replacement should be considered when there is
Poor ventricular function
Tricuspid valve insufficiency
Progressive RV dilatation
Effect of pulmonary valve insufficiency (PI) cont.
Early operation for asymptomatic RV dysfunction improves likelihood of full recovery of ventricular function & decreases prevalence of ventricular arrhythmias
Operative risk, 1.1%
Functional status post-op. was NYHA I for 90% of patients
10 year survival, 95%

Conclusion
The results of surgical repair of TOF have continued to steadily improve due to
Enhanced myocardial preservation techniques
More attentive RVOT reconstruction
Improved postoperative care
These refinements have decreased, but have not eliminated the long-term sequalae of pulmonary valve insufficiency, RV dysfunction, and ventricular arrhythmias
A more aggressive approach to implantation of a competent pulmonary valve, in TOF patients with progressive RV dilatation, TV insufficiency, or poor ventricular function improves the likelihood of full recovery of RV function & decreases the prevalence of ventricular arrhythmias.

About Dr. Kamal K. Pourmoghadam

Kamal Pourmoghadam, MD, is a pediatric cardiac surgeon at The Heart Center at Arnold Palmer Hospital for Children. He is board certified in general surgery, cardiothoracic surgery and congenital cardiac surgery.

Dr. Pourmoghadam earned his bachelor’s degree from University of California, Berkeley, and his medical degree from Albany Medical College in New York. He trained for adult cardiac surgery at the University of Miami, Jackson Memorial Hospital in Miami, and for congenital cardiac surgery at the University of Washington, Seattle Children’s Hospital in Seattle.

Dr. Pourmoghadam is a professor of surgery at the University of Central Florida College of Medicine, practicing congenital cardiac surgery for over twenty years and has been active in clinical research. He has extensive experience in neonatal and infant cardiac surgery and has special interest in the repair of single ventricle physiology patients and research in univentricular hearts.
References:

Website: https://kamalpourmoghadam.com
Blog: https://drpourmoghadam.home.blog/
News: https://hippocratesguild.com/dr-kamal-pourmoghadam
News: https://medicogazette.com/dr-kamal-pourmoghadam#425f92ce-0ccc-4fe2-8c31-56cf497704f4
News: https://hype.news/dr-kamal-pourmoghadam/
News report about Dr. Pourmoghadam: http://www.tiogapublishing.com/features/the_marketplace/covington-tot-returns-home-to-pennsylvania-after-lengthy-oklahoma-hospital/article_04865c00-0ae5-11e1-aec8-001cc4c002e0.html
Linkedin: https://www.linkedin.com/in/kamal-pourmoghadam-9a796157/

Surgical Evolution Towards Fontan

Dr. Kamal K. Pourmoghadam, Ppediatric Cardiac Surgeon

Surgical Evolution

Early Palliative Efforts
–Blalock-Taussig Shunt (1945)
–Pulmonary artery banding (1952)
Alternative to expectant Therapy
Not part of staged approach
Septation of the Heart
–First attempt at definitive repair for functional single ventricle
•Kirklin & Barratt-Boyes (1956)
•Sakakibara & colleagues (1972)
•Edie & Malm (1973)
•McGoon & Danielson (1977)
•Doty (1979)
–Very high mortality rate
–Frequent major complications
•Complete Heart Block (CHB)
•Residual ventricular septal defect (VSD)
•Atrioventricular (AV) valve incompetence
•Sudden Death
nSuperior Vena Cava to Pulmonary Artery Shunt (cavopulmonary shunt)
–Right ventricular exclusion
•Rodbard & Wagner (1949)
•Warden , De Wall and Varco (1955)
–Carlon & colleagues (1950)
•End-end anastomosis of proximal azygous to RPA, ligation proximal SVC
– Glenn and Patino (1954)
•“Unidirectional” Glenn shunt
Dogliotti (1961), Haller (1966) and Azzolina (1972)
–“Bidirectional” Glenn shunt
Advantages of cavopulmonary shunt
–Increased pulmonary blood flow without increased volume load
–Transpulmonary blood flow without subpulmonary ventricle

Fontan’s and Kreutzer’s Procedure.

Definitive treatment of tricuspid atresia
–Fontan (1968)
•First definitive successful physiologic repair
Patient selection criteria (Choussat and Fontan)
–Age ³ 4 years
–Sinus rhythm
–Normal systemic venous connection
–Normal right atrial volume
–Mean pulmonary artery pressure < 15mm Hg
–Pulmonary vascular resistance < 4 units/m2
–Ratio pulmonary artery/aortic diameter > 0.75, with normal size pulmonary branches
–Good ventricular function (ejection fraction ³ 0.60)
–No mitral valve incompetence
–No pulmonary distortion by previous shunt
Kreutzer and colleagues performed their first definitive repair of tricuspid atresia in 1971
–Similar physiologic endpoint as the Fontan
–Different technique
•Anastomosis of RA appendage/distal MPA
•No homograft valve at RA/IVC junction
•No Glenn Shunt
•Fenestrated
Modifications to incorporate the hypoplastic right ventricle
–Bowman and colleagues (1978)
–Bjork and colleagues (1979)
Results inconsistent
Evolution of the modifications of Fontan’s and Kreutzer’s procedures
–Application to other forms of functional single ventricle
–Homograft valve implantation no longer necessary
–Maintaining integrity of the pulmonary artery confluence

Modifications of Fontan’s and Kreutzer’s Procedure
deLeval and colleagues (1988)
–Introduction of total cavopulmonary connection (TCPC)
•SVC to RPA end-side anastomosis
•Construction of intra-atrial tunnel
•IVC flow to proximal divided SVC
•Proximal SVC to MPA anastomosis
deLeval and colleagues
–Interposition tube graft between the IVC and SVC orifices
Norwood and Danielson (personal communication)
–Utilization of an intra-atrial tube graft
Marcelletti and Colleagues
–Extracardiac total cavopulmonary connection
–Advantages
•Avoidance of any intra-atrial suture lines
•Shielding the right atrium from high central venous pressures
Marcelletti and Colleagues
–Technical modification for extracardiac total cavopulmonary connection
•The superior vena cava is divided and anastomosed to the ipsilateral branch pulmonary artery in an end-side fashion
•The inferior vena cava is transected at its junction with the right atrium
•The right atrial end is oversewn
•The flow of blood is directed from the inferior vena caval orifice to the underside of the ipsilateral branch pulmonary artery via a conduit

Staging Fontan’s Operation
Despite improvements significant morbidity and early mortality remained
–Elevated central venous pressures
–Persistent pleural & peritoneal effusions
–Tachycardia
–Hypotension
–Hemodynamic instability
Prediction of favorable outcome post Fontan operation was difficult
Donofrio, Jacobs, and Norwood (1995)
–Palliated state created a chronic volume load on the heart
–Fontan completion led to significant increase in the mass-volume ratio of the single ventricle
–Deleterious effects on early post operative hemodynamics
Predictors of unfavorable outcome post Fontan
–Older age
–Hypertrophied systemic ventricle
Pennigton and colleagues
–Fontan post BDG yielded lower operative mortality
Philosophy of staging Fontan’s operation

Norwood and colleagues
–The hemi-Fontan operation , 1989
–Advantages of hemi-Fontan
•Physiologic equivalent to BDG
•Augments central pulmonary arteries
•Enlarges superior cavopulmonary amalgamation
•Enlarges RA to SVC connection
•Maintains anatomic continuity of RA and SVC
•Results in improved flow dynamics after TCPC
Advantages of bidirectional Glenn anastomosis
–Technically simple
–Can accomplish without aortic cross clamp
–Can accomplish without cardiopulmonary bypass
–Natural precursor to extracardiac Fontan
Prior to staging Fontan
–Single ventricle pumps pulmonary & systemic cardiac output
–Chronic volume load
Hemi-Fontan or BDG reduce volume load
–Alter ventricular compliance
–Ventricular filing maintained
–Avoiding low cardiac output states
Concept of patient preparation
–Remove other sources of pulmonary blood flow
–Optimize branch pulmonary artery architecture
–Relieve systemic ventricle outflow obstruction
–Repair AV valve regurgitation
–Replacing earlier theoretical patient selection criteria
Fenestration of cavopulmonary pathway
–Achieve benefits seen by staging Fontan
–Decompresses systemic venous pathway
–Improved cardiac output
–Decreased systemic arterial saturation
–Originally performed by Kreutzer, 1971
Bridges and colleagues
–Adjustable snared ASD, 1988
Jacobs and colleagues
–Multiple small fenestrations

Surgical Methods
Preparatory staging operations
–Hemi-Fontan operation
–Bidirectional Glenn anastomosis
Completion Fontan operation
–Mass-volume ratio optimized
–Ventricular remodeling optimized
–12-24 months after first stage
–Generally 2 years for Intraatrial lateral tunnel
–Generally 3 years for extracardiac pathway
The Completion Fontan operation (lateral tunnel )
–Arterial BP, ABG monitored, avoid CVP lines
–Ascending aorta, RA cannulated for CPB
–Caval cannulas, snares avoided
–CPB 120-150 ml/KG/min, cooling to 18°C
The Completion Fontan operation (lateral tunnel )
–Aorta cross clamped, cardioplegia infused
–Oblique RA incision, avoid sulcus terminalis
–Homograft dam RA-SVC junction resected
–PTFE gusset used to fashion the lateral tunnel
The Completion Fontan operation (Cont. )
–Lateral tunnel is fenestrated
–Lateral tunnel completed as PTFE incorporated into atriotomy closure
–DHCA, 20 minutes
–Ventilation resumed during re-warming
–Pulmonary venous pressures monitored by transthoracic atrial lines
–Low dose inotropic support
–Single anterior chest tube
–Extubated 4-6 hours post operatively
–Meds, aspirin, ACE inhibitors, diuretics
–Average length of stay, 10 days
The Completion Fontan operation (extracardiac pathway)
–Hemodynamic monitoring
–IVC transected during DHCA
–PTFE conduit interposed between IVC & superior cavopulmonary amalgamation
–Patients with prior BDG shunts
•Conduit anastomosed end-side to RPA
–Patients with prior hemi-Fontan
•Superior end anastomosed to the superior cavopulmonary amalgamation through a cruciate incision
–Fenestration
•Side-side anastomosis between conduit & RA
•Interposition graft between conduit & RA

Results of Surgery
Mortality
–Improved early survival
•Technical modifications
•Improved postoperative care
•Survival, 75%-83% in the 1970’s
•Survival over 90% in the 1990’s
•Cetta and colleagues, 1996
–Decrease mortality from 16%-9%
•Gentles and colleagues, 1997
–Decreased early failure rate from 27.1% to 7.5%
•Survival over 93%, Mayer and colleagues, 2001
•Over 80 consecutive Fontans since 1997 with no deaths, author’s experience

Post Fontan Consideration
Functional status
–Exercise tolerance
–Early volume unloading improves long-term results
–Neurological Status
Thromboembolic events
–Incidence varies 3%-20%, reported as late as 16 years
–MPA cul-de-sac, source systemic emboli
–Hypercoagulable state
–No widely accepted anticoagulation strategy
–Author’s preference, one baby aspirin daily
Systemic ventricular outflow obstruction
–Frequent in functional single ventricle
–Preemptive strategy
Arrhythmias
–Supraventricular arrhythmias, high incidence
•Driscoll & colleagues, 1992
•Fishberger & colleagues, 1997
–Hypotheses
•Trauma to SA node, blood supply
•Long atrial incision, suture lines
•Elevated RA pressures
•Anatomical factors
–AV discordance
–Heterotaxy
Arrhythmias (cont.)
–Hemodynamic risk factors
–AV valve regurgitation
–Abnormal AV valve
–Preoperative supraventricular tachyarrhythmias
–Older age at operation
•Lower risk associated with TCPC
–Management
•Medical
•Permanent pacing
•Fontan conversion to TCPC
–Mavroudis and colleagues
•Fontan conversion to TCPC
•Atrial reduction
•Cox-Maze III modification
•Permanent pacing
Protein losing enteropathy
–Enteric losses of serum proteins, electrolytes
•Edema
•Immunodeficiency
•Fat malabsorption
•Hypercoagulopathy
•Incidence, 3.7%-13.4%
•Mortality, 50% at 5yrs, 80% at 10yrs
•Etiology, unclear, low cardiac output, low flow state
–Management
•Cardiac catheterization, hemodynamic evaluation
•Fenestration
•Pacing, sinus node dysfunction
•Medical
•Cardiac transplant

References:
Website: https://kamalpourmoghadam.com
Blog: https://drpourmoghadam.home.blog/
News: https://hippocratesguild.com/dr-kamal-pourmoghadam
News: https://medicogazette.com/dr-kamal-pourmoghadam#425f92ce-0ccc-4fe2-8c31-56cf497704f4
News: https://hype.news/dr-kamal-pourmoghadam/
News report about Dr. Pourmoghadam: http://www.tiogapublishing.com/features/the_marketplace/covington-tot-returns-home-to-pennsylvania-after-lengthy-oklahoma-hospital/article_04865c00-0ae5-11e1-aec8-001cc4c002e0.html
Linkedin: https://www.linkedin.com/in/kamal-pourmoghadam-9a796157/

Extracorporeal Membrane Oxygenation

Introduction

•ECMO uses venoarterial bypass with a membrane oxygenator
–Allows both hemodynamic and respiratory support
–Standard technique for pediatric extracorporeal life support (ECLS)

Equipment

•ECMO Support generally uses:
–Silicon membrane oxygenator
–Heat exchange
–Bladder
–Roller/centrifugal pump

Results

•ECMO Support generally uses:
–Silicon membrane oxygenator
–Heat exchange
–Bladder
–Roller/centrifugal pump

Candidates for ECMO

•ECMO has been traditionally analyzed by considering four separate subgroups
–Neonatal respiratory failure
–Pediatric respiratory failure
–Neonatal and pediatric cardiac failure
–Adult cardiorespiratory failure
•Indications for support, support strategy and outcomes differ drastically in each

Neonatal Respiratory Failure

•Indicators for ECMO in neonatal respiratory failure is based on degree of respiratory failure and response to conventional measures
•Oxygenation Index (OI) provides a useful measure for evaluation of these patients
OI = Mean Airway pressure x ([FiO2 x 100]/PaO2)
•OI >25 is associated with mortality of 50% when conventional modalities are used
•OI > 40 is associated with mortality of 80% when conventional modalities are used
•ECMO should be considered when OI > 25 accompanied with no clinical improvement, or when OI> 40
•Cannulation For Respiratory Failure
–Venous drainage through right internal jugular vein
•8-12F for neonates with side holes in RA
•Arterial cannulation through R common carotid artery
•Femoral cannula can be used as an adjunct or in children greater than 15 kg
–Alternatively many centers are gaining increasing experience with venovenous ECMO
•Significant conversion rate
•More feasible in larger children and adults
•Decannulation
–Many centers routinely ligate carotid artery and jugular vein
–Preference to repair
•Institutional
•Except in rare instances of local wound infection
–ECMO for Neonatal respiratory failure has declined
•Inhaled NO
–Approved by the FDA in December 1999
–High frequency oscillatory ventilation

Pediatric Respiratory Failure

•Small percentage of cases, 8.8%
•Survival to separation from ECLS, 62%
•Survival to discharge, 55%
•Etiologies for ECMO
–Pneumonia
–ARDS
–Acute respiratory failure, non-ARDS
–Other forms of sepsis
–Severe tracheal disease

Neonatal and Pediatric Cardiac Failure

•14.2% of cases
•Survival to separation from ECLS, 53%
•Survival to discharge, 39%
•Cannulation
–Cervical
–Often transthoracic, RA and AO
•May decompress the left side (LV vent)
–LA appendage
–RSPV/LA
–Atrial septostomy
•ECMO Support was evaluated for three groups (Walters et al.)
–Patients on ECMO preoperatively
–Patients unable to wean from CPB and converted to ECMO
–Patients who were cannulated postoperatively after an initial period of stability
•ECMO support (Walters et al.):
–Hospital survival for all patients, 58%
–Group 2 survival to discharge, 23.5%
–Group 3 survival to discharge, 69.4%
“ ECMO is most effective in salvaging pediatric cardiac surgical patients who demonstrate medically refractory hemodynamic deterioration at some interval after being successfully weaned from cardiopulmonary bypass.”
•ECMO has also been used as an adjunct to pediatric cardiac transplantation
–Used as a bridge to transplant
–Used as a facilitation of allograft in immediate postoperative period
–Used as a complement therapy for rejection
–60 % survival, 35 % lived more than 8 months
•Children with cardiac failure and biventricular hearts have a higher success rate than those with single ventricle physiology
–Previously many considered single ventricle physiology as a contraindication to ECMO
•2% of all cardiac ECMO were HLHS, 1996
•Recent improvement results
–This group has grown to 28% of all cases
•Management of systemic to pulmonary artery shunt
–Controversial
•Occlude
•Partial occlusion (Jacobs et al.)
•Open (Ungerleider et al.)

Adult Cardiorespiratory Failure
•3.8 % of all cases of adult respiratory and adult cardiac failure
•Results of adult ECMO not as good as those in neonatal and pediatric population
•Survival to separation from ECLS, 47%
•Survival to discharge, 43%
–Adult respiratory failure
•Survival to separation from ECLS, 52%
•Survival to discharge, 48 %
–Adult cardiac failure
•Survival to separation from ECLS, 37%
•Survival to discharge, 32 %

Weaning & Decannulation
•Performed under echo guidance to asses ventricular filling and function
•Flows are gradually turned down over several hours until flows of 25-40 ml/kg/min are reached
•Ventilator support and inotropic infusions are increased appropriately
•Arterial and venous cannulas are clamped
–Full anticoagulation is maintained
–Cannulas are intermittently flushed (every 15-20 minutes) as needed
•Until patient shows stability off ECMO
•Patient can be maintained off ECMO for 1-2 hours in this manner (intermittent flushing)
•In certain fragile patients with profound ventricular dysfunction, the weaning period can be extended over 48-72 hours, with gradual reduction in flow
–Fragile patients gradually accommodate to lower flows

Cardiopulmonary Support System
•Limitations of ECMO
–Prolonged set-up time (45-60 minutes)
–Large priming volume (450-800 ml)
–Increased postoperative blood loss
–Difficulty in transport
•Measures to counteract limitations
–Pre-priming the circuit
–Added risk of infection
–Cost
•ECMO used as rescue during acute cardiopulmonary failure
–Effectiveness depends on CPR duration
•CPR< 15 minutes, 100% survival
•CPR> 42 minutes, 55% survival
–Del Nido et al.
“ Success of resuscitation depends largely on the speed and recognition of the arrest event and the establishment of effective respiratory and circulatory support.”

Summary
•Proper ECLS systems must be matched to the individual needs of the patient, personal experience of clinicians / surgeons, and the attributes of the institution
•Future evolution in ECLS system for children will involve
–Decreasing anticoagulation requirements
–More biocompatibility with smaller circuit /support systems
–Eventual development of compatible implantable support devices

Complex Neonatal Repair In The Current Era

Hypoplastic Left Heart Syndrome:

Refers to constellation of cardiac anomalies
–Marked hypoplasia or absence of LV and severe hypoplasia of ascending aorta/aortic arch
–Systemic circulation is perfused by RV through PDA
–Mixing of systemic and pulmonary venous blood in the RA
Term was introduced by Noonan and Nadas in 1958
Occurs in 7-9% of neonates diagnosed with heart disease
Without surgery HLHS is fatal
–Accounts for 25% of cardiac deaths in the first week of life
Most are diagnosed due to tachypnea and cyanosis in the 1st 24 to 48 hours after birth
Diagnosed by echocardiogram
Once PDA closes
–Diminished systemic perfusion
Acidosis
Demise if untreated

Treatment
–Maintain ductal patency, PGE
–Maintain Oxygen saturation (75-85%)
Decreased pulmonary blood flow
May need sub-atmospheric oxygen (Nitrogen vs. CO2)
Avoid mechanical ventilation if possible
Inotropic Support
NPO
Anti-congestive therapy
–Diuretic

Surgical Management
–Augment ascending aorta
–Amalgamate aorta and pulmonary artery
–Enlarge atrial communication
–Provide reliable source of pulmonary blood flow
Blalock-Taussig Shunt
RV to PA shunt (Sano Shunt)

Conclusion
The perioperative care, surgical techniques and technology in repair of complex congenital cardiac defects in neonates and infants have evolved considerably over the past 40 years
These changes have allowed us to repair many defects which were considered lethal even in the 1980’s. As the mortality rate is decreasing for treatment of these complex congenital cardiac defects, surgeons are challenged to improve not only the survival of their patients, but also their quality of life.

How Cholesterol Is Bad for You and What Measures You Can Take to Reduce Its Negative Effects

Kamal Pourmoghadam, MD, Orlando, Florida

Cholesterol, a type of waxy substance found in every human body, is a natural byproduct of the liver. This fat can be found in every cell of a human body and helps the skin, brain, and other organs to function properly.

Cholesterol can also be artificially consumed from food items such as eggs, butter, cheese, meat, and milk. While the human body does need cholesterol in order to digest fat and produce hormones like estrogen and testosterone, and vitamin D, excessive cholesterol poses severe health risks.

Effects of Having High Cholesterol Levels

High cholesterol levels in the body develop fatty deposits in your blood vessels. These deposits gradually grow which stiffens the blood vessels. As a result, it becomes hard for the blood to flow in your arteries.

In some cases, high cholesterol is inherited as someone in your family may also have high cholesterol. However, most of the times, it is a result of an unhealthy lifestyle – poor diet, lack of exercise, smoking, and obesity. High Cholesterol eventually leads to the following life-threatening results:

1. Chest Pain
High cholesterol causes the accumulation of fat in unacceptable quantities and allows other deposits to build-up on the walls of your arteries. All of this reduces the smooth flow of blood in the body and causes severe chest pain.

2. Heart Attack
A blood clotting occurs when the cholesterol level is high. This, again, blocks your blood to flow and cause your arteries to break. This further prevents the blood flow to reach your heart and may cause a heart attack.

3. Heart Stroke
Heart strokes occur when a blood clot forms near the plaque or rupture. This prevents your blood to flow to your brain, ultimately leading to heart stroke.

How to Lower Your Cholesterol Level

Unfortunately, high cholesterol has no significant or apparent symptoms. The only way to identify if you have it is through a blood test. It is always smart to ask your doctor whether you should have a cholesterol test or not.

Usually, children and young adults, posing no risks for heart illnesses, are examined between the ages of 9 to 11 and then between the ages of 17 to 19. In case, your blood test results show spikes of high cholesterol level; your doctor will recommend certain medications to reduce your high cholesterol and some lifestyle changes to improve your cholesterol intensity.

1. Consume Foods Packed with Omega-3 Fatty Acids
Omega-3 fatty acids, typically found in fish and flaxseed, is incredibly important to your body and have plenty of health benefits.
However, the most significant benefit is that it improves heart health and thus reduces blood pressure. Eat food items rich in omega-3 fatty acids such as herring, salmon, fish, walnuts, flaxseeds, and mackerel.

2. Eliminate Saturated Fat from Your Diet
Saturated fat is primarily found in red meat and whole-fat dairy products. The regular or frequent consumption of saturated fats can increase your cholesterol level.
Hence, it becomes crucial to lowering the intake of saturated fats. This positive change in your diet will help reduce low-density lipoprotein (LDL) cholesterol which is notorious for being the “bad” cholesterol.

3. Regular Exercise
Lack of physical activity is a common cause behind high cholesterol which is why it is necessary to engage in exercises on a daily basis.

Doing simple forms of exercises like walking, jogging, running, or cycling regularly can help make your heart stronger and keep heart diseases at bay. If possible, you can engage in aerobic exercises as they are terrific at lowering high cholesterol levels. Furthermore, exercising daily is a powerful mean to boosts your HDL (good) cholesterol and lowers your LDL (bad) cholesterol. Make sure that you exercise 30 minutes or more every day in the morning or evening.

4. Avoid Eating Trans Fats
Trans fats are often listed down as “partially hydrogenated vegetable oil” on food items like margarine, cakes, cookies, chips, and biscuits. According to the Food and Drug Administration, trans fats increase the risk of cholesterol level which is why you should avoid eating foods that contain trans fats.

Incorporate these healthy measures into your daily life if you have high cholesterol and you will definitely experience positive effects in no time.

About Dr. Kamal K. Pourmoghadam

Preventing Heart Disease – Simple Tips for Maintaining a Healthy Heart

Heart Disease is the leading cause of death, globally. According to the Centers of Disease Control and Prevention, around 610,000 people die due to heart disease every year in the United States alone. This means that heart disease is the cause of 1 in every 4 deaths in the U.S.

What Causes Heart Disease?

While age and family history also contribute to determining your heart health, the World Health Organization has identified smoking, physical inactivity, unhealthy diet, and alcohol abuse as the key factors that can increase the risk of cardiovascular disease by contributing to hypertension, obesity, and increased blood glucose levels.

Is It Possible To Prevent Heart Disease?

While age and family history are beyond one’s control, maintaining a healthy lifestyle is considered as the best weapon to prevent and fight against heart problems.

According to the Harvard School of Public Health, the preventive measures can be divided into three categories. While all three types include the same elements, their starting times are different due to which they also have different effects.

1. Primordial Prevention

The ideal way to prevent heart disease is to begin taking precautionary measures in your life as soon as possible.
This includes adopting a healthy lifestyle to prevent obesity, high cholesterol, and hypertension, which then will eliminate the risks of the inflammation of arteries, endothelial dysfunction, and atherosclerosis.

2. Primary Prevention

These preventive measures are aimed at people who have already developed the risk factors for cardiovascular disease. Their main objective is to keep the risk factors under control in order to prevent the development of a heart disease.

Primary prevention includes making lifestyle changes as well as taking medication, if and when needed.

3. Secondary Prevention

This category includes the measures taken after a person has developed a heart disease, heart attack or stroke. In most cases, patients may have undergone a surgical procedure, like angioplasty or even a bypass surgery.
Secondary preventive measures include a combination of healthy diet, lifestyle changes, and medication.
While these measures cannot reverse heart health, they can greatly reduce the chances of a second heart attack by preventing the progression of heart disease.

Simple Ways to Prevent Heart Disease

In view of the risk factors identified by the World Health Organization, the following lifestyle changes can help prevent or greatly reduce the risk of heart problems:

* Start Exercising

Physical activity can help with maintaining a healthy weight as well as controlling blood pressure, blood glucose, and cholesterol levels, which then leads to improved heart health. As per the guidelines of the Department of Health and Human Services, you should aim for 30 minutes of moderate intensity exercise for at least 5 days a week to prevent heart problems as well as to improve your overall health.

* Maintain a Healthy Weight

Obesity is one of the major contributing factors to heart problems. Calculate your BMI and make sure to maintain your weight in the healthy range to prevent health issues, including the heart disease.

* Quit Smoking and Limit Your Alcohol Intake

Smoking cigarette and consuming excessive amounts of alcohol can increase your blood pressure. Alcohol intake is also linked to weight gain (by increasing your calorie intake). Both these factors affect your heart health and can increase the risk of a heart attack and stroke. Quit smoking and limit your alcohol intake to protect your heart.

* Keep an Eye on the Numbers

Your blood sugar, cholesterol, and blood pressure play a huge role in determining your heart health.
Higher levels of cholesterol and triglycerides can clog your arteries and cause a coronary heart disease, which then increases the risk of heart attack. Similarly, high blood pressure and glucose levels can also negatively affect your heart health. Get them checked regularly to make sure the levels aren’t high and take immediate measures to control them if they exceed the healthy range.

* Stress Management

Stress is a major factor that can cause heart disease. Stress not only increases blood pressure, but also leads to many unhealthy habits. Many people resort to drinking, smoking and overeating to cope with the daily stresses, all of which have a negative impact on the heart. Deal with your stress by opting for healthier choices, like listening to music, meditating, exercising, or doing yoga.

* Eat a Healthy Diet

We all know how important diet and nutrition is for our overall health. There are many foods known to promote heart health and reduce the risk of developing heart diseases, even if you have a genetic predisposition or family history for them. Begin your journey to a healthy heart by making simple dietary changes – stop eating fatty foods and junk. Also, limit the consumption of red meat to once or twice a month. Start eating more heart-healthy foods – they are known to promote heart health by keeping your blood pressure and cholesterol levels under control and prevent inflammation. A heart-healthy diet includes lots of raw vegetables and fruits, foods rich in omega-3 fatty acids, and whole grains. Some foods that prevent heart disease include leafy greens, fish, garlic, berries, dark chocolate, chia seeds, flaxseeds, almonds, and walnuts.

The Bottom Line

Preventing or reducing the chances of a heart disease isn’t as difficult as many of us think. Making small changes in our lifestyle and habits can offer great help to keep our hearts strong and healthy. Give up on your bad habits and opt for a healthy heart diet to prevent heart disease as well as improve your overall health.

About Dr. Kamal K. Pourmoghadam
Kamal Pourmoghadam, MD, is a pediatric cardiac surgeon at The Heart Center at Arnold Palmer Hospital for Children. He is board certified in general surgery, cardiothoracic surgery and congenital cardiac surgery.
Dr. Pourmoghadam earned his bachelor’s degree from University of California, Berkeley, and his medical degree from Albany Medical College in New York. He trained for adult cardiac surgery at the University of Miami, Jackson Memorial Hospital in Miami, and for congenital cardiac surgery at the University of Washington, Seattle Children’s Hospital in Seattle.
Dr. Pourmoghadam is a professor of surgery at the University of Central Florida College of Medicine, practicing congenital cardiac surgery for over twenty years and has been active in clinical research. He has extensive experience in neonatal and infant cardiac surgery and has special interest in the repair of single ventricle physiology patients and research in univentricular hearts.

Website: https://kamalpourmoghadam.com
Blog: https://drpourmoghadam.home.blog/
Blog: https://drpourmoghadamhome.wordpress.com
News: https://hippocratesguild.com/dr-kamal-pourmoghadam
News: https://medicogazette.com/dr-kamal-pourmoghadam#425f92ce-0ccc-4fe2-8c31-56cf497704f4
News report about Dr. Pourmoghadam: http://www.tiogapublishing.com/features/the_marketplace/covington-tot-returns-home-to-pennsylvania-after-lengthy-oklahoma-hospital/article_04865c00-0ae5-11e1-aec8-001cc4c002e0.html
Linkedin: https://www.linkedin.com/in/kamal-pourmoghadam-9a796157/

Dr. Kamal Pourmoghadam on Heart Health

Kamal K. Pourmoghadam, MD starts Blog about Heart Health and related Medical Issues

Experienced surgeon’s blog will focus on heart health, one of the most important public health issues. Heart disease is the leading cause of death in the U.S., accounting for almost 1 in every 4 deaths.

Doctor Kamal K. Pourmoghadam, board certified in general surgery, cardiothoracic surgery and congenital cardiac surgery, has started a Blog to provide easy-to-understand information how to keep your heart healthy, from childhood to old age. With the Blog articles, the public and patients can easily understand the underlying medical issues and treatments. The Blog is available at https://drpourmoghadam.home.blog/

In his Blog, Dr. Pourmoghadam will explain that heart disease actually describes several conditions, many of which relate to plaque buildup in the walls of the arteries. As the plaque builds, arteries narrow, thus making it more difficult for blood to flow. This increases the for a heart attack or stroke. However, there are many other types of heart issues, such as arrhythmias and angina, and ultimately heart failure.

Here are some key points, very briefly summarized. What can one do to prevent heart disease? By prevention and heeding the warning signs and symptoms of heart problems. Some of the following signs and symptoms may indicate heart issues:

Pain or discomfort in the upper body
Breathlessness
Chest pain or discomfort
Lightheadedness
Cold sweats

Preventive measures to protect the heart include lowering blood pressure and cholesterol. Also, certain lifestyle changes can reduce the risk of heart disease, including:

Regular exercise
Heart healthy diet (low in saturated fat, sugars, and salt, and includes fresh fruits and vegetables)
Not smoking
Carefully following the instructions for other medications you are taking
Stress management

Dr. Pourmoghadam explains that “in today’s medical practices, doctors and staff are often rushed and do not always have the time to answer in detail all questions that the patients have. When patients research online, such as on the website of the National Institutes of Health, they find highly complex answers that are very difficult to understand for a layperson. I hope I can fill that information gap with explanatory articles that anybody can understand.”

Dr. Pourmoghadam’s blog is available at https://drpourmoghadam.home.blog/

About Dr. Kamal K. Pourmoghadam

Photograph: CTVNEWS Canada, from the news article “Open-heart surgery patients warned of bacterial infection risk” at https://www.ctvnews.ca/health/open-heart-surgery-patients-warned-of-bacterial-infection-risk-1.3139511