Discovery #2 (1947): Thrombophlebitis and Pulmonary Embolism Prevention

There was a major happening in place a I neared the end of my year’s surgical residency. One of my obligations, on top of the basic demands on this surgical resident was to control the anticoagulants in patients with thrombophlebitis and others where a pulmonary embolism, usually fatal, was a risk. I had to administer IV Heparin three times a day after checking bleeding and clotting times before each injection. It was a real labor required in at least 10% of our 110 surgical patients. So, as I always seemed to be trying to wrestle with THE PROBLEM, it was logical for me to think like the engineer who loved his hydraulics course to assume that clotting was most likely with slow flow, often to the point of stasis( no flow). Thus that if we could speed the flow, the danger of clotting could be lessened. Bernoulli’s Theorem, as I had Iearned in hydraulics class, states that the velocity of flow is markedly increased even with a small decrease in vessel diameter. Thus, I expected that it would require very little calf pressure to narrow the veins and accomplish this.

With Dr. Smithwick’s OK, I enlisted two coworkers, another resident and an experienced researcher in the vascular field of hypertension. We were given inflatable puttees to place uniform pressure on the calves below the knees as used by airmen. First, in order to track the speed of flow we injected a blue dye used for measurement of blood volumes, known as Evans Blue, into the antecubital veins on top of the foot foot. With another needle in the major deep femoral vein as it reached the groin,. We measured the time required between injection and recovery. This was the “circulation time”.

Our first test disclosed that with the application of a reasonable pressure the speed of flow was doubled. And then, using an intravenous radiopaque dye we could identify all of the veins in the leg on an XRay filmg as they shrunk with the compression, and thus speeded the flow. The original theory became fact!

Bauer and Black then gave us compressive socks (later known as SupHose), and these were used on the wards in a control series, resulting in a drop of these complications of at least 50%. This was a major break through, still immensely valuable today.

Sedentary airline passengers in tight seating are at risk for vascular stasis, and embolism has proved fatal. I am anticipating that the same is likely to result with the immobility the computer can make likely. Lessons learned from surgical experience make it common sense that the possibility of embolism must be considered, whether in flight or at the computer.

Prevention is possible by a combination of the tight stockings and the simplest of foot exercises alone to further speed the flow.

As the last part of this study began with the trial of the compression socks, I left for San Francisco and my urology residency, although I had planned to continue in the footsteps of my mentor, Reginald Smithwick. Many surgical cures of the most severe forms of hypertension were being accomplished, but as he warned me, in our very own hospital, Robert Wilkins and others were discovering medicines that could cure. And I didn’t require convincing because, asked to try the drug Vertavis in my research lab, I had to take great care not to put my patient into shock, so potent was this drug. It was clear that our special surgery would soon no longer be necessary.

Thus the dye was cast, and urology now beckoned, always lurking because of my admiration of Oakland urologist “Uncle Bert”. And added to this was the mentoring of Thomas Addis and the stimulation of trouble shooting the still little understood fluid-electrolyte balance realm where I believed the kidney was as yet unappreciated. And I had been chosen to work with the preeminent urologist in the world, Dr. Frank Hinman at home in San Francisco.

But, now the surprise! My associates in this enterprise were careful to put the boss’s name on the revolutionary report, but somehow neglected to include the inventor-discoveror who in San Francisco was still working with flow as a urologist. I now required a catheter to be effective. I suppose I should have been upset, but on the other hand, the job was done. And I had and would always have the satisfaction of having been “useful” in making this DISCOVERY.

ANALYSIS.. What made this-”advance” possible? The PROBLEM was obvious. The chance of an embolus causing a death was at least 50% and the morbidity of inflammatory thrombophlebitis alone was immensely complicated by the thereauputic requirements.

So what in the way of personal experience and education had to be in place to make this advance come about?

  1. An engineering discipline, providing a background and fascination with the characteristics of flow studied in Hydraulics as a starter.
  2. A growing interest in the nervous system, particularly in the sympathetic nervous system actions seeming to be set in motion by “fear” and leading to various vaso-constrictions, this both arterial and venous and encouraging blood stasis and

The Solution

There are choices. However, common sense would suggest that the elimination of vascular stasis and its tendency to allow clotting had to be the first choice, thus the speed of flow takes priority, and how could this be accomplished. My engineering familiarity with Bernoulli and his flow dynamics where the speed of flow is proportional to the diameter of the vessel to the third power made it clear that a small decrease in cross section of veins would make a tremendous difference in speed of flow. And our venograms clearly demonstrated this, to the degree that flow velocity was immediately doubled.

EFECTIVITY? The calf pressure dressings proved the hypothesis as the incidence of venous problems and emboli were halved. The acceptance of this reality met no resistance, and to this day the method is in general practice. Rating? 100

Gifts from Inheritance
Gifts from Inheritance, page 2
Gifts from Inheritance, page 3
The Open Mind
The Transition..? Metamorphosis.
The Process of Getting There
1947....Discovery #1....A Beginning
Discovery #2 (1947): Thrombophlebitis and Pulmonary Embolism Prevention