X-Message-Number: 32690
Date: Fri, 2 Jul 2010 19:34:10 -0700 (PDT)
From: 
Subject: wish list: heart lung machine for cryonics


[Below I pasted part of the article on "Cardiopulmonary bypass" from  Wikipedia,
and then made one addition. See if you can spot the addition.]

http://en.wikipedia.org/wiki/Heart_lung_machine

Uses of cardiopulmonary bypass

Cardiopulmonary bypass is commonly used in heart surgery because of the 
difficulty of operating on the beating heart. Operations requiring the opening 
of the chambers of the heart require the use of CPB to support the circulation 
during that period.

CPB can be used for the induction of total body hypothermia, a state in which 
the body can be maintained for up to 45 minutes without perfusion (blood flow). 
If blood flow is stopped at normal body temperature, permanent brain damage 
normally occurs in three to four minutes - death may follow shortly afterward.

Extracorporeal membrane oxygenation (ECMO) is a simplified form of CPB sometimes
used as life-support for newborns with serious birth defects, or to oxygenate 
and maintain recipients for organ transplantation until new organs can be found.

CPB mechanically circulates and oxygenates blood for the body while bypassing 
the heart and lungs. It uses a heart-lung machine to maintain perfusion to other
body organs and tissues while the surgeon works in a bloodless surgical field. 
The surgeon places a cannula in right atrium, vena cava, or femoral vein to 
withdraw blood from the body. The cannula is connected to tubing filled with 
isotonic crystalloid solution. Venous blood that is removed from the body by the
cannula is filtered, cooled or warmed, oxygenated, and then returned to the 
body. The cannula used to return oxygenated blood is usually inserted in the 
ascending aorta, but it may be inserted in the femoral artery. The patient is 
administered heparin to prevent clotting, and protamine sulfate is given after 
to reverse effects of heparin. During the procedure, hypothermia is maintained; 
body temperature is usually kept at 28 C to 32 C (82.4-89.6 F). The blood is 
cooled during CPB and returned to the body. The cooled blood slows the body's 
basal metabolic rate, decreasing its demand for oxygen. Cooled blood usually has
a higher viscosity, but the crystalloid solution used to prime the bypass 
tubing dilutes the blood.

Surgical procedures in which cardiopulmonary bypass is used
Coronary artery bypass surgery

Cardiac valve repair and/or replacement (aortic valve, mitral valve, tricuspid 
valve, pulmonic valve)

Repair of large septal defects (atrial septal defect, ventricular septal defect,
atrioventricular septal defect)

Repair and/or palliation of congenital heart defects (Tetralogy of Fallot, 
transposition of the great vessels)

Transplantation (heart transplantation, lung transplantation, heart-lung 
transplantation)
Repair of some large aneurysms (aortic aneurysms, cerebral aneurysms)
Pulmonary thromboendarterectomy
Pulmonary thrombectomy
Cryonics procedures

Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=32690