about heart lung machine

1. Principles of
Cardiopulmonary bypass
“Heart Lung Machine”
Ida Simanjuntak
Perfusionist Staff
National Cardiovascular Center Harapan Kita
Agustus 2012

2. How it’s work ?

4. Definition
Cardiopulmonary bypass(CPB) is a form
of extracorporeal circulation
It temporarily takes over the function of
the heart and lungs during surgery,
maintaining the circulation of blood and
the oxygen content of the body

5. Tujuan Umum Cardio Pulmonary By Pass
1. Mempertahankan sirkulasi dan respirasi yang adekuat
dengan mengalirkan darah ke suatu sirkuit
extracorporal yang berfungsi sebagai jantung dan
paru.
2. Menciptakan lapangan operasi yang bersih dari darah.
Dengan cara mengalirkan darah keluar jantung dan
menghisap darah yang masuk ke jantung, sehingga
dokter bedah dapat melakukan koreksi pembedahan/
operasi dengan bebas. ( Jon W. Austin, 1986).

6. Componen of Heart
Lung Machine
Pumps
Cannula
Reservoir
Oxygenator
Heat Exchanger
Arterial Filter
Accessory pump & devices

7. PUMP
Roller Pump Centrifugal pump

8. Roller versus centrifugal pump
Roller pump Centrifugal pump
Description Nearly occlusive Non occlusive
After load independent After load sensitive
Advantages Low prime volume Portable, position insensitive
Low cost Safe positive and negative pressure
No potential for backflow Adapts to venous return
Shallow sine-wave pulse Superior for right or left heart bypass
Preferred for long-term bypass
Protects against massive air embolism
Disadvantages Excessive positive and negative pressure Large priming volume
Spallation Requires flow meter
Tubing rupture, hemolysis Potential passive backward flow
Potential for massive air embolism Higher cost
Necessary occlusion adjustments

9. Aorta Canullas

10. Vena Cannulas
VENOUS CANNULAS AND CANNULATION
 Three basic approaches for central venous cannulation
are used: bicaval, single atrial, or cavoatrial ("two stage")
 At times, venous cannulation is accomplished via the
femoral or iliac vein. This either open or percutaneous
cannulation is used for emergency closed
cardiopulmonary assist, for support of particularly ill
patients,reoperations.
Single Canul /Two Stage Double Canul
( SVC, IVC Canul )

13. Femoral Cannula
Aortic: single outlet hole
Venous: multiple inlet holes

14. Level Detector (SAFETY)

15. Different ports and Manifold

16. BUBBLE DETECTOR
can efficiently detect air embolisms between 10 and 250 μm in
diameter, as well as simultaneously monitoring for micro bubbles

17. FILTERS

18. PRINCIPLES OF VENOUS DRAINAGE
Venous blood usually enters the circuit by gravity or
siphonage into a venous reservoir placed 40 to 70
cm below the level of the heart.
“AUGMENTED OR ASSISTED VENOUS RETURN”

19. 19

20. CARDIOPLEGIA
Antegrade cardioplegia is delivered through a small
cannula in the aortic root or via handheld cannulas directly
into the coronary ostia when the aortic valve is exposed.
Pressure Antegrade
150-200 mmHg (Perfusion)
50-100 mmHg (Monitor)
Antegrade Cannula

21. Retrograde cardioplegia is delivered through a cuffed
catheter inserted blindly into the coronary sinus. Proper
placement of the retrograde catheter is critical, but not
difficult, and is verified by palpation, TEE, color of the
aspirated blood, or pressure waveform of a catheter
pressure sensor. Complications of retrograde
cardioplegia include rupture or perforation of the sinus,
hematoma, and rupture of the catheter cuff
Retrograde
Pressure Retrograde Cannula
100-150 mmHg (Perfusion)
30-50 mmHg (Monitor)

23. (A) Aortic root vent,
which can also be
Vent Cannula
used to administer
cardioplegic solution
after the ascending
aorta is clamped.
(B) A catheter placed
in the right superior
pulmonary vein/left
atrial junction can be
passed through the
mitral valve into the
left ventricle.
(C) Direct venting of
the left ventricle at the
apex.
(D) Venting the main
pulmonary artery,
which decompresses
the left atrium
because pulmonary
veins lack valves.

24. Oxygenator
Oxygenation
Two types of oxygenators are in current use: the bubble
oxygenator and the more widely used mem- brane
oxygenator.
Both types usually have an integral heat exchanger to
control the temperature of the blood
Membrane oxygenator with integral venous reservoir

25. Oxygenator
 Studies have shown that membrane oxygenators are less traumatic
to blood components (e.g., platelets) and cause less blood loss and
protein denaturization than bubble oxygenators (van Oeveren et al.
1985; Hill et al. 1985). Membrane oxygenators also provide sepa-
rate control of oxygen and carbon dioxide, which is more difficult to
obtain with bubble oxygenators. The indirect blood/gas interface
also reduces the occurrence of microemboli (Toner et al. 1997).
 Furthermore, mem- brane oxygenators require lower priming
volumes and eliminate the need for defoaming devices or antifoam
agents. However, despite the current preference for membrane
oxygenators over bubble oxygenators, the effect of oxygenator type
on clinical outcome is not completely certain. Although there is
evidence that membrane oxygenators can reduce cerebral injury
dur- ing cardiopulmonary bypass (Toner et al. 1997

26. HEMOFILTRATION
Untukmengurangi
Hemodelusi
Filtrasi Cairan,
faktor inflamasi,
hiperkalemia atau
azotemia
Diintegrasikan
dengan sirkuit
secara hati2 dan
bebas Bubble

29. Pre-Bypass
1.Begins with the posting of the operating schedule
Perfusionist must assemble specific information about
the scheduled procedure
Specific information about the scheduled procedure :
Surgeon, patient’s data, diagnoses, procedure, time
of operation
2. .Review of the patient’s hospital chart
Information is recorded on the perfusion record

30. 3.Selection of the disposable equipment and perfusion circuit
using existing protocols
4.Assembly of the cardiopulmonary bypass circuit
5. Calculation of BSA, BV, cardiac indeks and blood flow
6. Size of cannulae
7. Drug dose l and laboratories
8. Predicted hemoglobin and hematocrits
9. Setting up the HLM & oxygenator
10. Priming the oxygenator
11. Initiating CPB
12. Saffety device on
13. Ice

32. Dr Gibbon’s early heart/lung
machine
Gibbon JH et al. Arch Surg 1937; 34:

33. Priming
Filling the CPB circuit with blood or blood
substitutes after CO2 Flushing
Result in hemodilution

34. Hemodilution
 Pt’s Blood Volume
Predicted Hct
 Pre-CPB IV + CPB prime volume
Target: < 30% at BT below 30℃
 < 25% when BT below 25℃
 not below 20%

35. Hindari Hct intra CPB < 18 % Hct
Untuk memastikan Hct ketika inisiasi CPB:
 Hctint = initial Hct on CPB
 EBV = estimated patient blood volume
 Hct = preoperative Hct
Jika diperlukan penambahan RBC maka bisa dikalkulasi dengan :
 PBV = patient’s blood volume
 ECCV = extracorporeal circuit volume
 CPBHct = desired Hct on CPB
 PtHct = patient’s pre CPB Hct

36. Initiating CPB
 “Lines down”  connects between table lines & pump
lines (in a sterile manner)  Debubble
 Surgeon : “Heparin in”
 Anesthesiologist give heparin  ACT check.
 “Speed up (speedy)”  fast circulating the priming
solutions, make sure no bubble exist.
 “Stop”  debubbling stopped, venous lines clamped.
Surgeons prepare to do cannulation
 ACT > 300 sec  Pump suckers on

37. right debubbling ???

38.  Insert drugs and manitol
 Resirculated of the priming solution
 Oksigen on
 Before cannulation of the aortic cannula, surgeon
will ask the perfusionist to roll forward, to fill in the
tubing with priming solution and to make sure no
bubble exist.
 Reply : “Forward”..
 After the aortic cannula is unclamp, surgeon :
“Open to you”.
 Reply : “Open/Ok”, check the pressure fluctuation
on the pressure module of the pump.
 Inform surgeon. Feel for pulsation the arterial line
tubing
 ACT > 480 ready to on bypass

40. Continous Monitoring During CPB
 Reservoir level
 Blood flow at proper rate/flow rate
 Pressure line/arterial line pressure
 Blood pressure/patient’s arterial pressure 50-90
mmHg
 Oxigen saturation
 Temperature appropriate
 ECG
 Venous oksigen saturation 65%-75%

41. Monitoring Blood pressure
MAP: in mild to moderate hypothermia
 normal adult: 60-70 mmHg
 adult with CAD, DM, and old age: > 60mmHg
 infants: > 60mmHg
CVP: approximate 0 mmHg

42. Pump Flow Rate
In the normal body temperature
 adult: 2.2~2.8 L /m2 ． min
 infant: 2.6~3.2 L /m2 ． min
In hypothermia
 adult: 1.6~2.2 L /m2 ． min
 Infant: 2.0~2.4 L /m2 ． min
Adjust according MAP and SvO2

43. Monitoring pressure
Causes of aortic cannula high line pressure
1. Kink in arterial cannula or line
2. Cannula improperly positioned
3. Clamp too near cannula
4. Cannula to small
5. Arterial systemic blood pressure very high
6. Aortic disection
7. Blockage in arterial filter

44. Monitoring Venous Drain
Causes of Poor Venous return

45. Intermittent Monitoring During
CPB
 blood gas
 Urine output minimal 0,5-1 ml/kgBB/jam
 electrolit
 ACT > 480 sec

46. Monitoring Devices
Monitoring secara
kontinue : SVO2,
Suhu vena, Hct
ACT > 480 sec
Cek ACT dan AGD
setiap 30 – 60 menit
jika stabil

47. Monitoring Blood Gas
 Coagulation Status and Laboratory Data
 Menggunakan ACT untuk evaluasi status
koagulasi
 Hb 7,0 – 9,0 gr%
 Ht 20 – 30 %
 pO2 arterial AGD : 140-180 mmHg
 pCO2 arterial AGD : 31 – 45 mmHg
 BE (-2,5) – (+ 2,5)

48. Monitoring Urine Output
 Urinary volume and renal function
 Dipengaruhi waktu bypass dan gagal ginjal
sebelumnya
 Volume urine 0,5-1 mL/kg/jam
 Oligouria / normal + hiperkalemia,
hemoglobinemia, hemodilusi berlebihan =
indikasi diuretik

49. Causes of Urine Production
1. Kinked or disconnected Foley catheter or tubing
2. Catheter with tip obstructed by gel
3. Decreased blood pressure
4. Low pump flows
5. Fluid moving to interstitial space
Corrective Action
1. Straighten or connect tubing
2. Push on bladder
3. Give vasopressor
4. Increase flows
5. Use mannitol or lasix

50. Hypothermia
 Advantages:
decrease metabolic rate, oxygen
requirement
decrease rate of degradative reactions,
increase tolerance to ischemia
reduces K+ necessary for cardiac arrest
inhibits intracellular Ca2+ accumulation

51. Hypothermia
 Monitoring:
Core temperature: nasopharyngeal or
tympanic membrane probes reflect brain
temperature
Shell temperature: rectal probe or skeletal
muscle needle sensor reflect relatively
pooly perfused tissues of most of the
body’s mass

52. Temperature Cardiac Index FIO2 Gas/Blood Flow Ratio
37 C 2,4 L 0,80 1:1
34 C 2,2 L 0,70 0,8 : 1
30 C 2,0 L 0,65 0,7 : 1
28 C 1,8 L 0,60 0,6 : 1
22 C 1,6 L 0,50 0,5 : 1

53. Termination of CPB
 Preparing for Separation (Rewarming)
 Hipotermia sedang (25-30°C) digunakan untuk
memperlambat rewarming. Hipotermia berat (16-
25°C) + circulatory arrest : operasi defek
kongenital atau rekonstruksi arkus aorta
 Kriteria rewarm : naso 37°C, bladder/rectal 35°C
atau jempol kaki 30°C
 Rewarm yang inadekuat mengakibatkan penurunan
suhu pasien 2-3°C pasca CPB sampai tiba di ICU 
mengigil, ↑VO2, gangguan irama jantung, ↑ PVR

54. Termination of CPB
LAMPS
 Laboratory data
 pH, pCO2 darah arteri
 Acidosis  depressant fungsi myocardial, gangguan obat inotropic
 SvO2, Ht, ACT, konsentrasi heparin
 Na, K, Ca,
 HyperK >6 mEq/L (gangguan konduksi, AV blok)
 HypoK (gangguan irama ventrikel dan atrial)
 HypoCa akibat hemodilusi, albumin atau produk darah (+sitrat) 
CaCl2 3-5 mg/kg (memperbaiki kontraksi miocardial dan PVR)
 Glucosa darah  insulin 10-20 unit iv + glukosa prn

55. Termination of CPB
 Anastesia/Machine
 Analgesia – supplemental opioid
 Amnesia – benzodiazepine
 Muscle relaxant – prn
 Airway and functional oxygen delivery system
 Anastesia machine on, Adequate oxygen supply
 Breathing circuit intact, ETT connected
 Ventilator functional, Ability to ventilate both lungs
confirmed
 Vaporizers off (10 menit sebelum terminasi CPB) untuk
mengurangi efek depresi sirkulasi dan menghindari
depresi myocardial saat dilepas bypass

56. Termination of CPB
 Monitors
 Invasive BP monitors – zeroed & calibrated
 Arterial catheter – radial, femoral, aortic
 PAC, CVC (right atrial), left atrial catheter
 ECG
 Kecepatan, irama, konduksi, iskemia (review semua lead)
 Bladder catheter – urine output
 Pulse oxymeter
 Capnometer/mass spectrometer
 Safety monitor – oxygen analyzer, circuit pressure alarm,
spirometer
 TEE
 Temperature (37°C nasofaringeal, 35°C rectal/bladder)

57. Termination of CPB
 Patient/Pump
 The Heart
Cardiac function – contractility, size
Rhythm, ventricular filling, air removed, vent
removed
 The Lungs
Inflation/deflation, compliance
 The Field
bleeding
Oxygenation – blood color
Movement – sign of inadequate anasthesia

58. Termination of CPB
 Support
 Pharmacologic
 Inotropes
 Vasodilators
 Vasoconstrictiors
 Antidysrhythmics
 Electrical
 Atrial/Ventricular Pacing
 Mechanical
 Intraaortic Balloon Counterpulsation
 Left and/or right ventricular assist device

60. Termination of CPB
 Separation Technique
 CPB : (v. cavae  oxygenator  aorta)
 Partial bypass : (v. cavae  oxygenator +
RV/lungs/LV  common return to aorta)
 Off CPB : (v. cavae  heart/lungs  aorta)

61. After Termination of CPB
 Setelah kanul aorta dilepas, sisa perfusate bisa
diproses kedalam kantung intravena sterile untuk
kebutuhan transfusi nantinya. Atau dengan alat cell
salvage sehingga darah dicuci dahulu sebelum
ditransfusi
 Pemberian protamine pada beberapa pasien
mengakibatkan penurunan hemodinamik sementara.
Perfusionis harus terus mengobservasi hemodinamik
pasien dan menjaga sirkuit CPB tetap dapat digunakan

62. Daftar Pustaka
 http://www.cts.usc.edu/zglossary-heartlungmachine.html
 http://www.surgeryencyclopedia.com/Fi-La/Heart-Lung-Machines.html
 Lippincott Williams & Wilkins 2007 Cardiopulmonary Bypass :
Principles and Practice
 Cardiopulmonary Bypass: Principles and Management: Edited by
Kenneth M. Taylor. 1998, Baltimore
 On Bypass ,Advanced Perfusion Techniques Series: Current
Cardiac Surgery Mongero, Linda B.; Beck, James R. (Eds.) 2008,
XII, 576 p. 173 illus.

63. THANK YOU...