X-Message-Number: 1114
From:  ()
Newsgroups: sci.cryonics
Subject: How to freeze a human
Date: 8 Aug 1992 08:22:58 GMT
Message-ID: <>

                        CRYONIC SUSPENSION PROTOCOL

We are frequently asked just what is done in a cryonic suspension. 
In this article we outline the major procedures used to place a
patient into cryonic suspension, as conducted by Trans Time, Inc.
There are four main steps:

     I)         Stabilize, cool, and transport the patient.
     II)        Perfuse the patient with cryoprotective solutions.
     III)       Lower the patient's temperature to ~79xC.
     IV)        Lower the patient's temperature to ~196xC.

                                  Step I

Follow these guidelines when the patient is pronounced dead:

     ~     Maintain blood flow and respiration of the patient (with
     ~     Cool the patient by surrounding with ice bags, especially
           the head.
     ~     Inject 500 IU/kg of heparin.
     ~     Use sterile technique if possible.

This procedure should be performed in conjunction with a physician,
nurse or paramedic.

1)   At the time of death maintain blood flow (using sternal
compression) and oxygenation (using a bag resuscitator or other
positive pressure device) to limit ischemic injury.  Administer the
oxygen through a face mask, or preferably an endotracheal tube.
Avoid mouth-to-mouth resuscitation, because of the danger of
infection. Do cardiopulmonary resuscitation manually until a
mechanical heart-lung resuscitator (with 100% O2) can be employed. 

Note: The chest compression rate affects hemodynamics, and it has
been recommended that one apply 120 compressions/minute and 12
breaths/minute (Circulation 74:63, 1986). CPR (cardiopulmonary
resuscitation) predisposes the patient to gastric insufflation due
to the unprotected airway. Thus while using CPR it is advisable to
intersperse abdominal compressions. It should be noted that chest
compressions may not be efficient enough to maintain adequate blood
flow. A thoracotomy can be performed to expose the heart, which can
be pumped manually.

2)   Establish venous cannulation in the forearm, employ a 3-way
stopcock and tape securely, before the time of death if possible,
for the administration of pharmacological agents. Keep the pathway
open until death using normal saline. Upon death, administer
heparin: 500 IU/kg.

3)   Place the patient on a cooling blanket, if available, and
circulate coolant. Surround the patient with Ziploc ice bags,
paying particular attention to cooling the head. Lower the body
temperature toward 0xC.

4)   Insert thermocouple probes in the esophagus and in the rectum,
and monitor temperature throughout the protocol.

5)   Tape the eyelids closed to prevent dehydration.

6)   Inject 300 mg Tagamet (cimetidine HCl), or administer 20 ml
Maalox through a gastric tube, to prevent HCl production by the
gastro-intestinal tract. 

7)   When suitable, use a Foley catheter to drain the bladder.

8)   While continuing to apply CPR, transport the patient to the
facility where the patient will be prepared for bypass, perfusion
and extracorporeal oxygenation. The sooner the patient is on bypass
the better, due to superior cooling and oxygenation.

                                 Step II

This perfusion step should be performed with the guidance of a
surgeon, perfusionist, and medical technician.

Expose and cannulate the carotid artery and jugular vein.  Secure
the cannulas and attach them to the tubing of the bypass circuit. 

Alternatively, one can use the femoral approach.  Expose and
cannulate the femoral vein and artery. Secure the cannulas and
attach them to the tubing of the bypass circuit. The cannula in the
femoral vein should be pushed up toward the right atrium of the

Arterial and venous pressure should be monitored throughout
perfusion to limit edema. Catheters should be inserted into the
radial vein and radial artery or a femoral artery. These catheters
should be coupled to pressure sensors. Monitor pH, O2, CO2, and
cryoprotectant concentration by using a refractometer.
The reservoir should initially contain ice-cold BioTime Dextend~
solution. Begin total body washout and replace the blood with 4 to
6 liters of BioTime Dextend solution (one blood volume or 5 L / 70
kg).  Discard the venous effluent into containers holding Clorox
bleach. Add cryoprotective agents to the basic blood substitute as
shown below. About one blood volume of each solution should be

           Solution             Concentration % (v/v)      Amount perfused

           BioTime Dextend      no cryoprotectant          4 to 6 L

           Dextend/Z cryo       1/4 Z cryo                 4 to 6 L

           Dextend/Z cryo       1/2 Z cryo                 4 to 6 L

           Dextend/Z cryo       3/4 Z cryo                 4 to 6 L

           BioTime Z cryo       full strength              4 to 6 L

After perfusion is complete, decannulate and suture the surgical

                                Step III

Place thermocouples on the skin surface, and in the esophagus and
rectum (if not already done). Cool the patient in an insulated
chest using dry ice. Monitor the patient's temperature and freeze
gradually. Temperature lowering should ideally between 0.01 and
0.1xC per minute, with slower preferred especially after the
patient has solidified.

                                Step IV

Place the patient in a container, and suspend the container above
the (low) level of liquid nitrogen in a dewar, to begin vapor phase
cooling to ~196xC. Cooling should continue slowly at about 0.01xC
per minute if possible. Rapid cooling may cause stress fractures.

Art Quaife, President
Trans Time, Inc.

Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=1114