Abstract: Epidurals are the most diffused loco-regional techniques for the relief of operative, postoperative, and chronic pain and are used for about 50% of deliveries. Currently, doctors still identify epidural space relying on subjective perception, by using ¿blind¿ manual techniques that are associated with failure rates up to 7%. In the last years, many systems aimed at assisting and guiding the placement of epidural needles have been proposed. In this study, a novel sensorized medical needle, based on the judicious integration of a fiber Bragg grating sensor inside the epidural needle lumen, will be tested. The device, by providing continuous and real-time measurements of the pressure experienced by the needle tip during its advancement, is able to effectively detect the needle passage from one tissue to the other. Due to the promising results obtained with phantom (CIRS Model 034 Lumbar Training Phantom ) it has been decided to validate this theory in-vivo. The scope of the study is to find out the wavelength associated with the correct insertion of a needle in the epidural space. Six young pigs are needed and due to the availability of 7 vertebral spaces (L1-S1) and the possibility of 6 different insertion points (median, paramedian dx, paramedian sx, all repeated twice), 6 pigs will allow 252 insertions. The procedures will be repeated with different intensities and wavelengths in order for random errors to be eliminated and obtain a more accurate result. A computerized system elaborates the signals of the fibres and will produce a spectrogram of the different wavelengths refracted that will be recorded and then compared. The outcomes of the procedures will be separated in two categories:
* Correct epidural and catheter position
* Incorrect epidural and catheter position
Once these two set of results have been split up, their respective spectrograms can be compared and analysed to determine if the wavelengths of successful procedures are similar.
Possible relapses within the human public health
Benefits for the patients will be:
- Smaller incidence of complications as accidental puncture of the Dura Mater
- Failure of the technique for bad positioning or removal of the epidural catheter
- Greater safety in the drugs administration
- Optimization of the postoperative pain management
- Possibility to record the layout
- Reduction of the hospitalization days and associated costs
Only in Italy more than 1 million of epidural anaesthesia/year for surgical interventions and 600.000 analgesia for natural birth-child or C sections are done
In USA 1,6 million epidural analgesia are done for birth and 8,4 million for other interventions.
The failure percentage of epidural technique manually performed is around 20-30%. The main reasons for epidural anesthesia/analgesia failures are due to incorrect catheter positioning (up to 35% of failures) and wrong epidural space identification (0,4-7%). The accidental puncture of the dura mater determines often a great discomfort and an additional hospitalization of 5-7 days. The identification of a low cost device that succeeds in individualizing the epidural space, would reduce the risk of bad positioning and therefore allow:
- A reduction of the risk to submit the patient to a useless risky technique
- Improvement of the quality of the analgesia
Greater safety in the correct location of the catheters means a better safety in the administration of the drugs and in obtaining the auspicious results.
- optimization of the management of post operative pain in non responsive patients to intravenous drugs
- chance to record the layout related to the access in the epidural space and the catheter positioning
Impact on the economic industrial sector:
reduction of the hospitalization days of the patient owed to the failure of the manual technique. Such circumstance is associated to direct cost of hospitalization - and indirect due to infections related costs.
The industrial impact to spread an automated technique can be derived by the fact that in USA the epidurals market is greater than 1 million dollars per year. The costs of this automated system is negligible and comparable to the actual manual technique.