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Date of event is unknown.It was inadvertently reported reported as (b)(6) 1980.A review of the device history records (dhr) for reported lot number 816323x indicates product and specification requirements were met with no non-conforming product identified relating to this customer report.Product cannot be released unless it passes all quality and conformance requirements.In-process procedures are also in place to prevent nonconforming product in the manufacturing process.This ensures components and finished products meet all quality inspection standards.These controls include, but are not limited to: material verification/certification processes, dimensional specifications, statistical samplings, periodic audits, process inspections, machine maintenance/operation and personnel training and certification.All process parameters, product, raw materials, and sub-assembly components met the required acceptance criteria to completely satisfy the manufacturing requirements per the product specification.No adverse conditions, special circumstances, or events were documented that may have led to the gel delamination and/or skin irritation.In addition, the dhr¿s were reviewed for hydrogel body subassembly that were used in product 22550r, lot 816323x.The dhr¿s for the hydrogel body sub-assemblies met all acceptance criteria.Raw material records were reviewed as well and all acceptance criteria were met.The uv dosage outputs for curing the hydrogel bodies were within the proper range.The conductive silver/silver chloride ink and gel batch mix sheets were also reviewed.All components and mix time were within tolerance.During the production of hydrogel bodies, four corner peel testing is performed to simulate the removal of the electrode release liner by a clinician prior to delivering therapy (corners of gel body are lifted from the liner to evaluate for release of gel from the substrate).The production lot numbers for hydrogel body sub-assembly did exhibit some minor aesthetic delamination and had no functional delamination.In the relation to the gel peeling off when the backing was removed from the electrodes, this is called delamination.This type of event is commonly referred to gel delamination.Gel delamination occurs when the gel-to-release liner bond strength is greater than the cohesive strength of the gel or greater than the gel-to-substrate bond strength.Such an inequity in bond strength can cause the gel to peel from the substrate and/or tear.Delamination is categorized as follows: an aesthetic delamination is characterized by a permanent separation of the hydrogel from the substrate, exposing the underlying carbon vinyl with little (i.E.Area less than 1/8 inch x 1/8 inch) or no hydrogel remains on the release liner.Also, no silver/silver chloride ink is exposed.Aesthetic delamination defects will not significantly affect electrode function, but may displease the clinician.Functional delamination is a permanent separation of the hydrogel from the substrate such that the silver/silver chloride ink remains exposed.Additionally, per the defibrillation electrodes design, there shall be no less than 55% hydrogel remaining on the adult electrode when the release liner is removed from the electrode.There shall be no less than 78% hydrogel remaining on the adult electrode, when the area of separation includes the area of underlying conductive mat.With loss of the hydrogel no more than the percentages as defined above the electrodes retain functionally essential performance; however the reduction in the hydrogel area with the silver/silver chloride ink being exposed may cause an increase in current density across the remaining gel area.This increases the potential for skin irritation and burns.No pictures of the burns/redness were provided with the complaint; as a result an evaluation could not performed to determine if the burn (skin irritation) was typical of what a patient might experience using a defibrillation electrode product in a defibrillation procedure.Four (4) samples were received from the customer for evaluation.The samples consisted of the defibrillator electrodes contained within open pouches.The labels on the pouches indicated lot number 816323x.All four pads were either folded over onto itself or two pads were stuck together.It was observed that there was some hair (1-2¿ in length and substantial on several of the pads) along the edge and in the gel of both of the pads of all four sets of electrodes.The defibrillator electrode sets were visually evaluated for defects.No delamination was observed on any of the pads once unmated from each other.All components were present and the defibrillator electrode sets were constructed per the product specifications.The printed silver pattern on the conductive gel bodies met the acceptance criteria.The connector wire sets were inspected for compromised insulation, no defects were observed.The electrode set gel was somewhat dried out on all sets as they were not contained within sealed pouches.Production retains (5 sets) were also evaluated for gel delamination.No delamination was observed.Based on the complaint description and the investigation, gel delamination described by the customer could not be confirmed as related to manufacturing process.The following potential root causes related to manufacturing were evaluated and could not be confirmed.If the gel is insufficiently cured (the strength of the bond between the gel and the substrate was too weak) or there was insufficient silicone on the mylar liner (the strength of the bond between the gel and the plastic liner was too strong) delamination can occur, however none of the production records or incoming inspection records indicate this occurred.Another potential root cause related to manufacturing is that the silver ink re-mixing was not adequately performed during the sub-assembly printing process.If the silver ink is not adequately it may not properly dry which could result in gel not properly adhering to the silver printed substrate.This may contribute to gel delamination.Silver mixtures can become separated over time because they are suspensions; this is visually detectable prior to use.If re-mixing is required the machine operator documents this process occurred and that the silver mixture met the required acceptance criteria.A review of the production records indicated that silver re-mixing was not required.Additionally, gel delamination is possible if the defib electrodes are not properly stored.As indicated on the product packaging proper storage and usage of the electrodes is critical to the performance of the gel.The electrodes should be stored in their sealed protective pouch in a cool, dry place and out of direct sunlight.Do not open package until ready for use.Do not bend, fold, or puncture the packaging.Improper storage conditions and/or handling of the product may compromise gel properties prior to the expiration.The environmental and handling condition in which the product was stored was not provided with the complaint.In relation to the reported skin irritation and superficial burns it is important to note that these electrodes provide a reduced skin irritation, but do not eliminate skin irritation.Erythemas, burns, and even blisters while not desirable, are not an uncommon consequence of defibrillation/cardioversion.Defibrillation/cardioversion requires high intensity electrical energy to be delivered to the body through the skin, which generates heat at the contact site.Repeated shocks of escalating energy, often required for a successful defibrillation/cardioversion, will exacerbate the undesirable side effects of therapy.It should be noted that conductive printed gradient design reduces the probability and extent of irritation resulting from defibrillation, but it does not eliminate it.Care should be taken to properly prepare the patient skin prior to electrode application and special consideration should be given to the electrodes and wires while working around a patient or moving a patient so that the electrodes are not damaged.To help the electrode make good skin contact and to help reduce contact impedance the product labeling instructions and warnings should be followed: remove excess hair (it was noted that the customer returned sample had a substantial amount of hair on the pads).Clean and dry skin sites.Do not use alcohol or tincture of benzoin.Position electrodes per the figures provided on the packaging.If possible, do not place electrodes on broken skin.Smooth the electrode from the center outward to the edges with fingertips to ensure that there are no air pockets between the gel and the patient's skin.Electrodes are not repositionable.Replace with new electrodes if repositioning is required.This will ensure optimal adhesion and minimize potential patient skin burns.Remove the electrodes from the patient by slowly peeling pad from the patient¿s skin.Do not discharge hand-held paddles through these electrodes.Do not open package until immediately prior to use.Do not use if electrode or pouch is damaged.Important: replace the electrode pads after 24 hours on skin or 50 defibrillation shocks.Use separate ecg electrodes when performing noninvasive pacing.It is important that the operator be thoroughly familiar with the electrode operating instructions and warnings prior to use.Failure to comply with the product instructions for use or warnings may increase the likelihood of a patient exhibiting skin irritation.Another potential root cause is patient skin sensitivity to the gel or adhesive foam component of the electrode.Biocompatibility studies are performed on the adhesive foam and gels according to the guidelines defined in the iso standards.Each gel and electrode manufactured in the facility must pass cytotoxicity, primary skin irritation and skin sensitization testing before it is distributed for commercial sale.Each hydrogel offered for sale have passed all three tests to ensure the highest quality medical hydrogels available.The complete reports are available upon request.In addition, all hydrogels manufactured as this facility must comply with iso standards.Skin reaction such as those experienced by the patient could be the result of an acute sensitization response to the material components that make up the electrode.All materials have been deemed safe and effective for use per the iso standards.The results of the manufacturing facility investigation were unable to attribute any potential root causes associated with the manufacture of product which would have contributed to the susceptibility of skin irritation or gel delamination.Based upon the investigative details and the root cause evaluation, no further corrective or preventative actions will be taken at this time in relation to the customer described event.The reported customer complaint was not confirmed.A root cause could not be determined.This complaint will be used for trending purposes.
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