as told to Wendy O'Brien by Tim Savage Cardiothoracic Surgeon, 1955 - 1988
Prescription of a cold bath has featured occasionally in the therapeutic armamentarium
of the physician in the past. It was a favoured treatment in medieval Jordan's
Bethlehem Hospital for the Insane (BEDLAM) in the days of Hogarth who painted those haunting
pictures of the dreadful life of the poor in his time. King George III of
England was subjected to this treatment during his bouts of insanity (due to the familial
disease PORPHYRIA), with marked lack of success. Some people of note have
attributed their good health and longevity to the habit of a cold bath each morning
- no doubt bearable and good in the tropics - and I recall at boarding school having to
take a cold shower each morning, supervised by a sadistic prefect. I cannot
say that it ever did me any good. Fortunately modern medicine abandoned this
torture, but curiously a "cold bath" was destined to play a part in the development of
intra-cardiac surgery in Wellington Hospital.
The use of the
"atrial well" technique when a "well" or wide rubber tube was stitched to the right atrium
forming a "well". When the atrium was opened in the base of the "well" blood rose
only a few cm's into the well as the pressure in the atrium is only a few cm's as seen in the
neck veins. It was then possible to stitch, by feel, a defect in the atrial septum.
However before the bypass pump became a safe technique and before such a pump became available
to us in Wellington we opted for a direct technique for these lesions using hypothermia.
It was long known from observation of people who had suffered exposure to severe cold temperatures
accidentally that such people could withstand hypoxic insult to the brain for longer periods than
at ordinary temperatures. At normal body temperature loss of oxygenated blood circulation to the
brain will cause irreparable damage after two minutes.
During the Nazi occupation of Europe (1940 - 1944) the infamous Dr MENGELES at Auschwitz conducted
his inhumane hypothermia experiments on children in the concentration camps and in his teutonic way
meticulously recorded all his findings and so it was known that at a body temperature of 31 degrees C the
brain could stand up to 10 minutes of oxygen deprivation without permanent damage. Such time would
allow repair of some congenital intra-cardiac defects notably secundum atrial septal defects and some
cases of pulmonary artery valve stenosis. After the war when all this dreadful experimental work became
known from the Nazi archives it was considered inappropriate to use such information, but a London
thoracic surgeon, Russell Brock (later Sir Russell) persuaded the governments that such information
was useful to humanity and using it for humanitarian purposes would mean that those unfortunate children
had not died entirely in vain. J.A.B (James Baird) and I both worked for Sir Russell during our London
experience. He was an inspirational teacher and we decided to pursue the hypothermia path till the
heart-lung bypass pump was a reality for us.
By the mid 1960's we had collected, from the cardiologists, a number of secundum ASDs and decided to press on. In order that the entire operating team was absolutely familiar and happy with the procedure (we had practiced together for weeks in the dog-lab) it was decided to do the whole procedure on a dog in the cardiac operating theatre. The selected candidate was anaesthetised in the dog-lab then taken, well covered, on a trolley to the theatre and the whole operation was successfully carried out. We were now ready.
To accommodate an adult human being we needed a suitable bath for cooling - an old fashioned metal claw-foot
tub was acquired from the hospital surplus stores. I think it originally came from the old Victorian fever
hospital (up the hill) which had recently been upgraded (showers not baths). The tub was mounted on a
specially made flat trolley with good casters and this was wheeled into the theatre on the selected day.
The first patient, a large young man, was anaesthetised, thermometer probe placed in the oesophagus and
rectum, and he was the lifted into the bath which was then filled with cold water and ice. Cooling was
a slow business, considerable amounts of ice needed to be added and the water stirred (not shaken) continuously.
With a large man several hours was necessary for the cooling process - most of the morning. It was known from
Mengeles' detached figures that when the oesophageal temperature reached approximately 34 degrees C and no further
cooling was carried out, then without further cooling the body temperature would drift on down to 31 degrees before
natural unaided warming would start. At this point the patient was lifted out onto the operating table, dried
off, and the legs and lower torso wrapped in warming blankets through which warm water could be circulated
when further warming was necessary.
The chest was now opened, this taking about 20mins and so when the heart was exposed this temperature had
drifted down to 31 degrees. Sling tourniquets round the inflow veins to the right atrium (SVC & IVC) were now
tightened and when the heart was empty of blood the aorta and pulmonary artery was cross-clamped. The heart
rate was now very slow - approximately 30 beats per minute. The right atrium was now opened and the secundum
defect was clearly visible. There was now 10 minutes available to close the defect. To ensure we did not
pass the danger limit, using a stopwatch the anaesthetist called the time. It was possible to close most
secundum defects well within 10 minutes - 2 or 3 interrupted sutures and that was all that was necessary.
If after about 6 minutes it looked as if more time would be needed it was possible to re-establish circulation
by loosening the venous tourniquets allowing the heart to fill with blood, and, unclamping aorta and pulmonary
artery, and putting a clamp across the atrial incision. After allowing several minutes or recirculation, another
10 minute spell of stopping the circulation would be available. To be certain we were always within our time
limits we would always re-establish circulation of 8 minutes, and I recall that only once did we need to use
a second period of circulation stoppage. To establish recirculation the venous tourniquet were slowly released
to allow the heart chambers to fill with blood and to exclude all air bubbles that could be the source of air
embolism. The incision in the right atrium could now be clamped and the incision closed with a running stitch
after all air had been allowed to bubble out. Warm water was now circulated in the warming blankets. The chest
was now closed after appropriate drainage tubes had been placed in the open pericardium and pleural cavity.
It was very important during the procedure not to allow the body temperature to fall much below 31 degrees as below
this, if ventricular fibrillation developed, it would be very difficult to reverse, certainly at 26 degrees or below.
We always kept well above this limit. Warm water was kept circulating in the blankets till body temperature of
36 degrees was reached and this often took up to two hours. The patient was not allowed to rouse until this temperature
was reached. Post operative course was, on the whole, trouble free.
Of course once the heart-lung bypass pump was available it became the method of choice and so the team went back
to the dog-lab to get the team proficient in the technique, and the rest, as they say, is history.
Thousands of
cardiac problems both acquired and congenital have been corrected with this safe technique.