en.wikipedia.org/wiki/Cardiopulmonary_bypass
4 corrections found
The machine pumps the blood by using an oxygenator, allowing red blood cells to pick up oxygen, as well as allowing carbon dioxide levels to decrease.
An oxygenator does gas exchange, but it does not pump blood. In cardiopulmonary bypass, the pump circulates blood and the oxygenator adds oxygen/removes carbon dioxide.
Full reasoning
This sentence conflates two different CPB components.
A cardiopulmonary bypass circuit uses separate components for circulation and gas exchange:
- The pump acts as the heart by circulating blood.
- The oxygenator acts as the lungs by adding oxygen and removing carbon dioxide.
Authoritative educational material from Cleveland Clinic states that the oxygenator "acts as your lungs" and that the pump "acts as your heart." Nationwide Children's likewise explains that blood is "pumped into an artificial lung (oxygenator), which adds oxygen and removes carbon dioxide," and then the oxygenated blood is pumped back to the aorta.
So the article's wording is incorrect because blood is not pumped by using an oxygenator; rather, blood is pumped through an oxygenator by the pump.
2 sources
- What is Cardiopulmonary Bypass? | Cleveland Clinic
Oxygenator. The oxygenator acts as your lungs. It adds oxygen to your blood... Pump. The pump acts as your heart. It sends oxygen-rich blood from the machine back to your body.
- What is Cardiopulmonary Bypass? | Nationwide Children's Hospital
the blood is drained from the veins into the heart-lung machine while the blood is pumped into an artificial lung (oxygenator), which adds oxygen and removes carbon dioxide. The oxygenated blood is pumped back to the aorta
antibodies against heparin are formed
In HIT/HITT, the antibodies are not directed against heparin alone. They typically target complexes of platelet factor 4 (PF4) and heparin.
Full reasoning
This is a mechanistic error.
Heparin-induced thrombocytopenia (HIT) is classically caused by platelet-activating antibodies against complexes of platelet factor 4 (PF4) and heparin, not antibodies against heparin by itself.
The American Society of Hematology guideline states that HIT is mediated by antibodies that target complexes of platelet factor 4 and heparin. This understanding is also reflected in foundational mechanistic studies showing that HIT antibodies react with PF4-heparin complexes.
That distinction matters clinically because the antigenic target in HIT is the PF4-heparin complex (or closely related PF4/polyanion complexes), not isolated heparin alone.
2 sources
- American Society of Hematology 2018 guidelines for management of venous thromboembolism: heparin-induced thrombocytopenia
Heparin-induced thrombocytopenia (HIT) is an adverse drug reaction mediated by platelet-activating antibodies that target complexes of platelet factor 4 and heparin.
- Antibodies from patients with heparin-induced thrombocytopenia/thrombosis are specific for platelet factor 4 complexed with heparin or bound to endothelial cells
plasma from each of 12 patients with HITP contained high titer antibodies that reacted with immobilized complexes of heparin and platelet factor 4
For retrograde cardioplegia, an incision is made on the posterior (back) surface of the heart through the right ventricle. The cannula is placed in this incision, passed through the tricuspid valve, and into the coronary sinus.
Retrograde cardioplegia is typically delivered to the coronary sinus via the right atrium/right atriotomy, not through an incision in the right ventricle.
Full reasoning
This describes the retrograde cardioplegia route incorrectly.
Standard descriptions of retrograde cardioplegia place the catheter into the coronary sinus via the right atrium (right atriotomy). A StatPearls review states: "The cardioplegia catheter is inserted via atriotomy in the right atrium into the coronary sinus." The AATS cardiopulmonary bypass primer likewise explains that cardioplegia may be delivered "retrograde via the coronary sinus."
Because the normal route is right atrium → coronary sinus, the article's statement that the surgeon makes an incision "through the right ventricle" and then passes the cannula "through the tricuspid valve" into the coronary sinus is anatomically wrong.
2 sources
- Cardiopulmonary Bypass Fundamentals | The American Association for Thoracic Surgery
Cardioplegia may be delivered anterograde via the aortic root/coronary ostia or retrograde via the coronary sinus.
- Cardioplegia - StatPearls - NCBI Bookshelf
The cardioplegia catheter is inserted via atriotomy in the right atrium into the coronary sinus, and flow is administered in a retrograde fashion.
This rewarming method of using CPB is successful if the core temperature of the patient is above 16 °C.
Successful extracorporeal rewarming has been reported below 16 °C. Published reviews describe survival after rewarming at 13.7 °C in adults and 11.8 °C in children.
Full reasoning
This temperature cutoff is stated too strictly and is contradicted by published survival data.
Reviews of extracorporeal life support/rewarming in accidental hypothermia report successful neurologically intact survival below 16 °C. One review states that the lowest recorded temperature with neurologically intact survival after ECLS rewarming was 11.8 °C in a pediatric survivor and 13.7 °C in an adult survivor. Another review likewise notes that successful resuscitation and rewarming have been achieved at 13.7 °C in accidental hypothermia.
So CPB/ECLS rewarming is not limited to patients above 16 °C as this sentence implies.
2 sources
- Extracorporeal Life Support in Accidental Hypothermia with Cardiac Arrest—A Narrative Review
The lowest recorded temperature with neurologically intact survival following ECLS rewarming from accidental hypothermia in a pediatric survivor is 11.8°C, while the lowest in an adult survivor is 13.7°C.
- Accidental hypothermia–an update
The lowest temperature from which successful resuscitation and rewarming has been achieved is currently 13.7 °C for accidental hypothermia