PERFUSION TECH Flashcards
developed an approach to continuously titrate coagulation with Heparin
BARTLETT AND DRINKER
ROUTE OF BLOOD
(OXYGENATED)
- P.V.
- L.A.
- L.V.
- A
- C.A.
- provides a bloodless field for cardiac surgery.
- It incorporates an extracorporeal circuit to provide physiological support in which venous blood is drained to a reservoir, oxygenated and sent back to the body using a pump.
CPB
Calculations are performed to determine necessary blood flow and if blood or other products are needed. The pump can then be primed and the sizes of the cannulae determined. Drug doses in the prime can also be determined.
PRE-BYPASS
- includes two rollers positioned on a rotating arm, which compress a length of tubing to produce forward flow.
- This action can produce haemolysis and tubing debris, the incidence of which increases with time.
- Hence, the use for longer procedures is discouraged.
ROLLER PUMP
can be crystalloid (cold) or blood-based (warm or cold); can be given continuously or intermittently. Potassiumbased solutions are commonly used
CARDIOPLEGIA
The deairing of CPB circuit is done by priming solutions, consisting of a mixture of crystalloids and colloids. Priming causes haemodilution which improves flows during hypothermia. Heparin 3–4 units/ml is added to the prime.
PRIMING
single-stage cannulae are used during most openheart surgeries, where two cannulae are inserted into the superior and inferior vena cava and joined by a Y-piece.
VENOUS CANNULAE
Blood level in the reservoir should be monitored to prevent air (?).
embolism
revolutionized the artificial lung with the development of synthesis of silicone rubber
KAMMERMEYER
ROUTE OF BLOOD
(DEOXYGENATED)
- S&I. V.N.
- R.A.
- R.V.
- P.T.
- P.A.
have a limited volume capacity, but offer a smaller area of blood contact with artificial surfaces. This produces less inflammatory activation, better sterility and reduces post-operative transfusion. They, however, require a separate circuit for processing suctioned blood.
CLOSE RESERVOIR
Blood viscosity (?) with hypothermia and allows maintenance of a higher perfusion pressure despite (?). However, hypothermia reversibly inhibits the (?) and (?).
- INCREASES
- HAEMODILUTION
- CLOTTING FACTORS
- PLATELETS
a method of myocardial protection where the heart is perfused with a solution to cause electromechanical arrest which reduces myocardial oxygen consumption.
CARDIOPLEGIA
- The main objective is to provide systemic perfusion and gas exchange allowing the heart and/or lungs to rest and recover or to bridge a patient to a different modality of support or to transplantation.
- This technology involves redirecting the blood flow from the patient’s body through cannulas and connecting tubing to a gas exchange membrane and then returning the blood by means of a pump back to the patient’s circulation.
ECMO
- consist of hollow microporous polypropylene fibres (100–200 μm internal diameter). Blood flows outside the fibre while gases pass inside the fibre, thus separating the blood and gas phases. They have lesser propensity for air embolism and give greater accuracy in blood gas control. Newer designs have an integrated filter to manage emboli, thus making additional arterial filters unnecessary.
- A heat exchanger is integrated and placed proximal to it to reduce the release of gaseous emboli due to alterations in the temperature of saturated blood
OXYGENATOR
(?) is used as a surrogate marker of organ perfusion and should be maintained between 50 and 70 mmHg. Hypertensive patients and those at risk for stroke require higher flows and (?) to maintain organ perfusion. Cerebral oximetry, evoked potentials and transcranial Doppler can be used to assess the adequacy of cerebral blood flow.
PERFUSION PRESSURE
(?) can occur due to cross clamping of the aorta in spite of cardioplegia.
Subclinical myocardial injury
are used for most closed-heart procedures, where a single cannula is inserted into the right atrium. Drainage occurs through gravity. Vacuum applied to the reservoir allows the use of smaller cannulae and tubing, thus decreasing the circuit volume.
DUAL-STAGE CANNULAE
the process where extracorporeal support is gradually withdrawn as the heart takes over the circulation.
WEANING
reported the first successful cardiac ECMO run of 36 hours in a 2 year old infant with cardiac failure
BARTLETT, GAZZANIGA ET AL.
(?) can be maintained by inhalational route or total intravenous (?) can be given.
ANAESTHESIA
can be associated with bleeding, cannula malposition causing selective cerebral perfusion, plaque dislodgement and dissection
ARTERIAL CANNULATION
development of a roller pump in the 1930’s led to the first successful extracorporeal assist in 1953
DR. JOHN GIBBON
(?) employ artificial blood pumps to propel open-heart surgery patients’ blood through their body tissue, replacing the function of the heart while the cardiac surgeon operates.
PERFUSIONIST
can be associated with bleeding, cannula malposition/air lock causing an inadequate return, leading to cerebral and splanchnic congestion. Massive air embolism is due to pumping from an empty reservoir.
VENOUS CANNULATION
- Central venous pressure (CVP) should be (?).
- High CVP indicates a (?) venous return
- LOW
- POOR
They collect the blood drained from the heart. Open (?) are more commonly used. They allow passive removal of entrained venous air along with the option of applying vacuum to assist drainage. They integrate a separate cardiotomy, and defoaming circuit to process suctioned blood. When they are used, a safe level of blood is maintained to avoid air entry into the arterial circuit.
(OPEN) RESERVOIR
is used after completion of the surgical repair before protamine administration, with blood removed from the arterial line and returned to the venous line after passing through the haemofilter. It was first described by Naik et al. in 1991.
MODIFIED ULTRAFILTRATION
a skilled, allied health professional, trained and educated specifically as a member of an open-heart, surgical team responsible for the selection, setup, and operation of a mechanical device commonly referred to as the heart-lung machine
PERFUSIONIST
a broader term used synonymously, both include various modalities of temporary mechanical cardiopulmonary assistance used to support patients with severe heart and/or lung failure which is unresponsive to optimal conventional care.
ECMO (EXTRACORPOREAL MEMBRANE OXYGENATION)
The spectrum of cerebral injury ranges from (?)
cognitive dysfunction to stroke
venous blood is drained through gravity into a reservoir. The pump moves blood from the reservoir to the oxygenator through a heat exchanger, before returning it to the arterial circulation. Additional components include suckers (to remove blood from surgical field), vents (to decompress the heart), haemofilters (for ultrafiltration) and cardioplegia system
CPB
The use of hypothermia requires a period of (?). Rapid rewarming and hyperthermia are associated with (?). Nasopharyngeal temperature should not exceed (?), although authors accept temperature range of 35.5°C–36.5°C.
- REWARMING
- CEREBRAL INJURY
- 37°C
The (?) of heart contractions change to meet the metabolic needs of the tissues, which vary depending on such conditions as rest, exercise, and changes in body position
rate and force
is frequently used during CPB for its presumed organ protective effects.
HYPETHERMIA
Glucose is maintained between (?) mg/dL.
120 and 180
is a combination of oxygenated blood and crystalloid in a ratio ranging from 1:1 to 8:1. Substances such as bicarbonate, mannitol, magnesium, calcium, adenosine, procaine, glucose and glutamate may be added.
BLOOD CARDIOPLEGIA
The (?) separates the pulmonary and systemic circulations and ensures better oxygenation of the blood flowing to the tissues.
heart
The term “perfusion” is derived from the French verb ‘perfuse’ meaning to ‘(?)’
pour over or through
(?) can be present due to the effects of CPB.
Acute respiratory distress syndrome
- consists of impellers/stacked cones within housing.
- When rotated rapidly, negative pressure is created at one inlet, and positive pressure at the other, thus propelling the blood forward.
- may improve platelet preservation, renal function and neurological outcomes in longer cases.
CENTRIFUGAL PUMP
capable of combining sterile tubing and artificial organs to build an ECC to meet the needs of several physician specialists to treat patients with specific operable diseases.
PERFUSIONIST
connect the patient to the circuit and hence to the CPB machine. They are made of polyvinylchloride (PVC) and are wire reinforced to prevent obstruction due to kinking.
CANNULAE
can cause acute kidney injury (AKI). Risk factors are prolonged bypass time, sepsis and diabetes.
INFLAMMATORY RESPONSE AND HYPOTENSION
during and after CPB removes inflammatory mediators and excess fluid thereby producing haemoconcentration.
ULTRAFILTRATION
During arterial cannulation, systolic pressure should be 90–100 mm Hg to reduce the risk of aortic dissection. The aortic cannulation is done first to provide volume resuscitation in case of hypotension associated with venous cannulation. Once the aortic cannula is connected to the tubing, line pressure is checked to rule out dissection. After venous cannulation, venous clamp is gradually released to establish full CPB and then ventilation is discontinued
INITIATION
(?) of the heart generate blood pressure, which is responsible for moving blood through the blood vessels.
Contractions
uses a haemofilter inserted into the bypass circuit.
CONVENTIONAL ULTRAFILTRATION
- These are generally made of PVC, due to PVC’s durability and acceptable haemolysis rate. Plasticisers like di(2-ethylhexyl) phthalate which are added to impart flexibility are potentially toxic and shown to leach from.
- Newer plasticisers such as dioctyl adipate have less leaching and are under investigation
TUBING
causes qualitative and quantitative platelet dysfunction
CPB
The (?) of the heart ensure a one-way flow of blood through the heart and blood vessels.
valves
