Complex localized pain syndrome (CRPS) of the extremities is one of the more difficult problems in the pain clinic. At the Pain Center of the University Surgical Hospital Heidelberg, Germany, the application of guanethidine for intravenous local norepinephrinergic nerve blocks for CRPS has shown significant results. The key to this technique is to prevent the drug from entering the body circulation causing cardiovascular disturbances and to control tourniquet pain.
Operating according to a process they produced themselves, the authors saw that after implementing local intravenous guanethidine infiltration therapy, all 15 patients developed significant flushing of the treated limb, and the skin temperature of the affected limb could be 7 to 10 degrees Celsius higher than that of the healthy limb 30 min after treatment. None of the cases showed clinically significant changes in heart rate and blood pressure during the observation period.
The procedure was as follows.
1, The patient was in sitting position (slightly lying back), monitored ECG and continuous cuff blood pressure.
2, Two soft cannula needle intravenous channels were left in place (treatment area of the affected limb + healthy limb)
3.The skin temperature of the affected limb is tested
4.Placement of double wide tourniquet (double wide cuff, Figure 1) at the proximal end of the treatment area of the affected limb
5.Esmarch`s bandage was applied to expel blood (Figure 2,3)
6.Intravenous injection of gastrofacial 10mg/2ml + morphine 2mg on the healthy side
7.Double wide tourniquet of the affected limb with proximal band inflation 300~350mmHg
8.Measure the pulse volume wave of the affected limb (toe) to confirm the absence of circulation
9, the affected limb intravenous injection of 1% mepivacaine hydrochloride 5ml
10.Wait 5min, double wide tourniquet distal band inflation 300~350mmHg, proximal band deflation
11.Intravenous injection of dexamethasone 4mg in the affected limb
12.Intravenous injection of guanethidine (Guanethidine Monosulphate, Sovereign Medical product) 15~20mg/20ml for the affected limb
13.Massage the affected limb and observe for 25min, during which the affected limb was continuously injected with 30ml of saline intravenously
14.Open the tourniquet–5min and then inflate it–5min and then deflate it–5min and then inflate it–5min and then deflate it
15.If the patient feels pain in the limb during the above process, increase the amount of morphine injection by 2mg through the intravenous channel of the healthy limb until the pain is basically controlled.
16, skin temperature test, record, rest until no dizziness feeling when leaving the hospital.
In this procedure, some patients can effectively control the whole tourniquet pain with 2mg of intravenous morphine, while some patients need to increase the dosage to 10mg, averaging about 4~6mg. It takes about 120min~150min from the beginning of treatment to the patient’s discharge. 3~4 days between treatments, and gradually increase to 6~10 days after two weeks, a course of 10~20 times. The vast majority of CRPS patients have satisfactory near- and mid-term outcomes, but there is a lack of statistical data on long-term outcomes.