The use of tens electrical stimulation to reduce the pain especially of postoperative nature is the main use of this technique.
The tens electrical stimulation principle is again based on “gate control theory” of Melzaek and Wall, viz: small fibres stimulation leads to transmission of nociceptive stimuli via substantia gelatinosa (SG) cells which act as controller of gate — the gate is opened for rostral transmission of these impulses. Large fiber input closes the “gate” and prevents this transmission, thus producing analgesia.
An electric pulse generator (a battery operated unit) with electrodes is used. A constant current of monophasic waveform, with 50—100 Hz frequency and 60—150 tsec duration is applied to the affected area for the period of 48—72 hours repeatedly. The patients who may be by tens electrical stimulation benefited are:
• These undergoing thoracotomy, upper abdominal surgery, LSCS, orthopaedic surgery
• Patients with chronic obstructive airway disorders
• Where opioids are not well indicated or tolerated.
• Other adjunctive methods not possible or failed.
The non-conventional methods have always been subject of controversy. The advocates of these methods claim miraculous effects which sometimes can’t stand up to the scientific evaluation and assessment methods.
The detractors of these methods claim that “outright shame” is the only description for them. Some of these modalities including tens electrical stimulation have withstood, test of time and many criticisms.
As a “pain therapist,” one has to use good judgement, clinical acumen, and pragmatic approach in practicing this tens electrical stimulation modalities of pain management.