I assume you are speaking of the number of epidurals performed by a physician and not the number of epidurals a patient may receive 🙂
It sounds like an article based an older model of radiation exposure that imputed safe radiation margins. However, the truth is, there is no safe yearly or lifetime dose of radiation exposure. Radiation has a cumulative effect on tissues. But higher exposures for short times have more of a tissue effect than low dose exposures for longer periods of time. Physician exposure varies wildly depending on technique, where exposure is measured, etc. For instance physicians using live fluoroscopy with the hands in the field are exposed to hundreds of times the exposure of a doctor that takes a step back between spot exposures. Use of magnification, use of C-arms with a nominal radiation output that is higher than others, use of I/I extended far above the patient, lack of personal radiation shielding, lack of collimation, use of a large image intensifier vs a smaller image intensifier, failure to use low dose or pulsed mode, etc. are all variables that increase physician exposure significantly.
There is no magic safe number of epidurals to prevent radiation damage, but there is good technique to minimize radiation exposure.
