Palpating pulses in the foot is part of the routine evaluation for blood flow. But what does it really mean in the diabetic foot? If pulses are palpable, does it mean that circulation is adequate? I have seen cases of poor wound healing and progressive gangrene in the presence of palpable pedal pulse.

  • Comments (10)
  • Our vascular lab techs do a similar thing. We just tell them something like 'it's the documentation, fool' and they go back and do the tests.

    I'm dying to try out the SPY thingy we have. It's supposed to be able to quantify microvascular perfusion.

    Dave Gottlieb, DPM personal opinions only

  • Neil - I like your example.
    I will tell you right or wrong as a resident any amputation surgery got a "vascular consult or concurrence" .
    The vascular doc would come in the room and feel for pulses if he found them he would scream what the hell are you calling me for, if they weren't felt then further work up would be done.
    In fact, even younger vascular docs that I encounter have a similar disposition. I think there attitude is do your thing if it doesn't work call me.
    Although, I don't agree with their assessment, I don't recall them ever being wrong.
  • The vascular surgeon at the wound center MANY years ago taught me the following: Take a garden hose and stretch it out on the driveway. Connect it to the inflow at one end and with the other end closed at the nozzle. Now have someone step on the hose near the inflow supply end and you "palpate" the hose near the closed end nozzle. You will feel a "pulse" as the water in the hose moves back and forth.  But, is any water being delivered OUT of the hose? None.

    The lesson is: a pulse  (anywhere) does NOT guarantee tissue perfusion. Especially with arterial calcifications and possible microvascular disease as well. And, for us podiatrists, in the pedal periphery, this may be especially true.

    Got it?

  • Podiatrically speaking, as a biomechanically oriented practitioner, I believe that closed chain repetitive microtrauma (RMT) precurses focal ischaemia and immunosuppression at areas where loads and tissue stress are challenged thousands of times each day for a lifetime, especially in the face of neuropathy from any source.

    I theorize that biomechanical intervention in those that are predictably foot type challenged would go a long way to allow tissues to co-exist with a diminished microcirculation.

    As Foot Centering continues to expand into new applications such as this one, I am more and more convinced that a foot typing and a vaulted orthotic with n=1 casting and prescribing are important lifelong adjuncts to combating the never ending destructive force of gravity here on Earth.

    Dennis

  • Ryan Fitzgerald, DPM,FACFAS, wrote:
    I very much agree with the previous statements. It is important to remember that diabetes manefests as both a microvascular and macrovascular disease. As a member of the limb salvage team on the vascular surgery service, I routinely manage patients with distal ischemia and palpable pulses. Ischemia is a supply and demand issue. While there may be supply, generally, speaking, it may not be adequate to address increaing demands (such as wound healing).

    Ryan, I don't think there is often an adequate supply there.....those calcified arteries are not giving up much and the peripheral focal micro circulatory deficits leave islands of ischemia that are desert-like. So, not only does the digital ulcer, say, need O2, as you said it needs EXTRA O2 to accomplish the challenge of healing.

    So often patients maintain a limb or digit with the sparest of blood supply but you put an extra stress on it, and it needs a "flood" and it is only getting a trickle.
  • I very much agree with the previous statements. It is important to remember that diabetes manefests as both a microvascular and macrovascular disease. As a member of the limb salvage team on the vascular surgery service, I routinely manage patients with distal ischemia and palpable pulses. Ischemia is a supply and demand issue.  While there may be supply, generally, speaking, it may not be adequate to address increaing demands (such as wound healing). 

  • For several years now, I no longer am lulled into a secure feeling with palpable pulses and warm feet. Many times after pleading with the vascular people to do an angiogram, significant occlusion, especially in the SFA, is found. I also beleive that many patients with minimal flow can be fine, until there is a break in the skin. The metabolic demands of intact skin is less than that of wounded skin, which is often the precipitator of the degenration to gangrene.

  • Interesting concerns which we encounter weekly if not daily with our heavily diabetic, obese, tobacco using patient population. Years ago I used to use the photocellphlethysmograph to evaluate small vessel flow. Currently Capillary Refill time is the surrogate used for this in clinic. I don't have access to TCO2 but we do have something called SPY. It uses an IV dye which flouresces. I personally haven't used it but others here do before they perform a TMA to determine where sufficient flow exists for healing. It seems to work.

    I know that there is another similar device out there. They both use UV light and measure the intensity of the flourescence. Someone has managed to come up with an algorithm which gives a number to the intensity. That then is used to determine what will or won't heal.

    Interesting stuff. And to answer the topic question, no, palpable pulses are not really a sign of good microvascular flow in the diabetic foot.

    Dave Gottlieb, DPM personal opinions only

  • The issue at hand deals with micro vs. macro-circulation. Thepresence of palpable pulses is a good indicator of patentmacro-circulation but I agree with Dr. Roger's that evaluation of themicro-circulation via TcPO2 and SPP is necessary when dealing withhealing surgical or chronic wounds in patients with diabetes.

    The key is to remember the presence of palpable pulses does notnecessarily mean that there is enough local blood supply to heal alower extremity ulceration.
  • I've listened to Gary Gibbons, MD (vascular surgeon, the Deaconess, Boston) on multiple occasions state that diabetic patients with a threatened limb require maximal flow to heal. I believe we have all seen patients like Dr. Liu describes. In a patient that presents with a new wound to my center, we always obtain non-invasive measures macrovascular flow (ABI, TBI, segmental pressures, PVR). I am surprised how often they don't correlate with the presence or absence of pulses. We often obtain microvascular measures as well (OxyVu, but TcPO2, SPP are adequate too). It is also surprising seeing the discordance between macro and micro vascular studies.

    Also, remember about 8% of healthy patients have a non palpable DP pulse, and anatomical studies have shown the DP artery to be absent 2% of the time.