To Evaluate Reduction of Pain in Wounds Treatment Previously Applying Lidocaine Topical Solution vs Placebo

Comparador activo: Lidocaine solution ("A")

Two sterile gauzes will be dampen with the content of the second syringe (the content of the first syringe is always 20 ml of saline solution and it is the first sterile gauzes administrated always) that will contain 20ml of 0.5% lidocaine dilution when the wound treatment process is assigned to the letter "A". The nurse has a third syringe exactly like this second syringe to apply if necessary (process still painful to the patient).

Droga: Lidocaine solution ("A")

Each of 26 patients will be evaluated during 6 consecutive wound treatments. The nurse will receive 3 syringes for each procedure, the syringe 1 always contains saline solution (blinded to the patient and to the nurse) to register the basal pain; the other two syringes are identical (number 2 and 3) and contain the study drug: lidocaine solution or saline solution.

The investigators randomise the patients depending on the administration sequence (ABABAB or BABABA). When the procedure is "A", the nurse will receive the syringes number 2 and 3 containing lidocaine solution to apply (blinded to the nurse, the patient and the doctor).

Note: The investigators consider important apply both treatments (lidocaine solution and saline solution) alternatively to avoid the bias that could might fall a cause of wound evolution (to heal or to get worse). And it is important that the same patient receives both treatments to decrease the subjective component in pain perception.

Comparador de placebos: Saline solution ("B")

Two sterile gauzes will be dampen with the content of the second syringe (the content of the first syringe is always 20 ml of saline solution and it is the first sterile gauzes administrated always) that will contain 20ml of saline solution when the wound treatment process is assigned to the letter "B". The nurse has a third syringe exactly like this second syringe to apply if necessary (process still painful to the patient). In this case, the three syringes supplied to the nurse, have saline solution.

Droga: Saline solution ("B")

Each of 26 patients will be evaluated during 6 consecutive wound treatments. The nurse will receive 3 syringes for each procedure, the syringe 1 always contains saline solution (blinded to the patient and to the nurse) to register the basal pain; the other two syringes are identical (number 2 and 3) and contain the study drug: lidocaine solution or saline solution.

The investigators randomise the patients depending on the administration sequence (ABABAB or BABABA). When the procedure is "B", the nurse will receive the syringes number 2 and 3 containing saline solution to apply (blinded to the nurse, the patient and the doctor).

Note: The investigators consider important apply both treatments (lidocaine solution and saline solution) alternatively to avoid the bias that could might fall a cause of wound evolution (to heal or to get worse). And it is important that the same patient receives both treatments to decrease the subjective component in pain perception.

Register the VNS punctuation during wound treatments to demonstrate pain reduction (less VNS punctuation) when lidocaine solution has been administrated comparing to placebo.

The doctor asks to the patient about the punctuation on the VNS before touching the wound and when the wound treatment starts, it is, 10 minutes later than the dampen gauzes (with the syringe 1 content) has been applied on the wound and the VNS punctuation is registered. The nurse does the same procedure with the syringe 2 content and the VNS punctuation is registered. The syringe 3 content is only applied if the procedure is still painful, and the VNS punctuation is also registered.

This process is done during 6 consecutive wound treatments for each patient. The time frame is up to 19 days because it depends on the need of treatment of each patient: every 24, 48 or 72 hours.

At the end of the study, the investigators, will compare the punctuation registered when lidocaine solution has been administrated with the procedures realized when placebo solution was administrated, to demonstrate if the procedure is less painful (less VNS punctuation) when lidocaine solution was applied.

Register if systemic analgesics are required after the third syringe content application and compare if it decreases when lidocaine solution has been applied comparing to placebo.

If the wound treatment is still painful after application the dampen gauzes with the third syringe content, each patient has prescribed a systemic analgesic to decrease the pain. It does not matter which analgesic, the only condition is that it can not be modified during the period of inclusion into the study, it is 6 consecutive wound treatments. The time frame is up to 19 days because it depends on the need of treatment of each patient: every 24, 48 or 72 hours.

The need of the systemic analgesic to decrease the pain, in spite of the topical solution contained in the three syringes, it is registered for each wound treatment. At the end of the study, the investigators, will assess the requirements of systemic analgesics and if it exists any relation with lidocaine solution or placebo solution.

Register the efficacy (decrease VNS punctuation) of systemic analgesics when it has been required during the wound treatment.

If the wound treatment is still painful after application the dampen gauzes with the third syringe content, each patient has prescribed a systemic analgesic to decrease the pain. It does not matter which analgesic, the only condition is that it can not be modified during the period of inclusion into the study, it is 6 consecutive wound treatments. The time frame is up to 19 days because it depends on the need of treatment of each patient: every 24, 48 or 72 hours.

The VNS punctuation before and after systemic analgesic administration is registered. At the end of the study, the investigators will assess the efficacy (decrease VNS punctuation) of systemic analgesic comparing the VNS punctuation registered before and after the administration.

Register the requirements of systemic analgesics at 60 minutes after each procedure and compare if it decreases when lidocaine solution has been applied comparing to placebo.

At Bellvitge University Hospital, the treatment prescription and administration has an electronic registration so, the investigators have the timing of administration registered at the computer.

The investigators will compare if the need of systemic analgesics decrease (need of administration or not need of administration) at 60 minutes after the procedure when lidocaine solution has been applied during the procedure comparing when placebo has been administrated.

Register the number of doses of rescue systemic analgesics during the next 24 hours after each procedure and compare if it decreases when lidocaine solution has been applied comparing to placebo.

All the patients have prescribed a fixed systemic analgesia and rescue systemic analgesia (only administrated if the patient has pain). At Bellvitge University Hospital, the treatment prescription and administration has an electronic registration so, the investigators have the drug, the dose, the route of administration (all this invariable during the patient is included into the study) and the timing registered at the computer.

The investigators will compare if the needs (number of doses) of rescue systemic analgesics decrease during the next 24 hours when lidocaine solution has been applied during the procedure comparing when placebo has been administrated.

Register the number of applications that it is necessary to decrease the pain (less punctuation in VNS) during the wound treatment procedure (it is: 1 or 2 applications).

The content of the syringes 1 and 2 will be always applied (the number 1 contains always saline solution to register the basal pain, and the syringe 2 is the study drug: lidocaine solution or saline solution, according to the random list) and the VNS punctuation is registered after both applications. If the procedure is still painful after the content of the syringe 2 application, the content of the syringe 3 is applied (it is always the same study drug that contents the syringe 2 for each procedure) and it is registered as well as the VNS punctuation given by the patient.

At the end of the study, the investigators will determine how many times it has been necessary to apply the third syringe to reduce the pain (less punctuation given in the VNS) and, doing this, determinate if it is necessary one or two applications of the study drug to reduce the pain.

Register if any side effects is detected.

Registering if any side effect (local or systemic) appears during the procedures and comparing if any relation exists with lidocaine solution.

Seven days after the sixth procedure has been done, the investigators will contact with the patient to take care that any side effects has been detected.