MAUDE data represents reports of adverse events involving medical devices. This maude entry was filed with the FDA on 2015-10-21 for TOF WATCH manufactured by Organon Ireland Limited Swords.
[29297810]
Not returned to manufacturer.
Patient Sequence No: 1, Text Type: N, H10
[29297811]
Literature report: koekkoek, w. A. C. Et al, electrical bums caused by a train-of-four monitor, netherlands journal of critical care 2015-09-01: 22(4):21-22. Information has been received from a published literature article titled as above. A (b)(6) caucasian female was admitted to our icu because of acute respiratory failure due to severe pneumococcal pneumonia. She was intubated and mechanically ventilated. Due to progressive respiratory deterioration culminating in arterial hypoxaemia and hypercapnia, the patient was turned into the prone position to improve oxygenation. The patient was sedated to a richmond agitation and sedation score of -4, neuromuscular blocking agents (nmbas) were started within two hours of the diagnosis of acute respiratory distress syndrome (ards), as this treatment might improve mortality and decrease the duration of mechanical ventilation and complications related to barotraumas in ards patients when started early and continued for 48 hours. To assess the depth of neuromuscular blockade and ensure proper medication dosing, a train-of-four (tof) monitor was used. The model was neuromuscular transmission monitor (tof watch), the electrodes were attached to the skin on the internal surface of the wrist, along the course of the ulnar nerve. The contact area of the stimulating electrodes was 7 mm. The nerve was stimulated by four successive stimuli delivered at 2 hz with a current of 50 ma. With increasing degrees of block, the twitches in the tof progressively fade starting with the fourth and eventually disappear one by one. The ratio of the height of the fourth response to the first had been defined as the tof ratio. The optimum level of neuromuscular blockade was reached when 80-90% of receptors were blocked, this corresponds with 1 or 2 twitches on tof testing. When using continuous infusion of nmbas, tof monitoring was recommended for neuromuscular monitoring. A baseline measurement was started and thereafter performed every 15 minutes until adequate depth of muscle relaxation had been achieved, after which the measurement was performed every four hours. In the patient tof monitoring was used. However, 40 hours after the start of nmbas, second-degree burns were observed on the wrist with superficial skin necrosis. The tof monitor was immediately removed and neuromuscular blockade was discontinued. The patient had been ventilated in the prone position for 38 hours and had been turned into a supine position two hours before discontinuation of nmbas. Electrical burns of the skin caused by a peripheral nerve stimulator had been reported previously in one publication. However, in the past 40 years no additional cases had been reported even though various operating manuals of tof monitors warn for electrical burns in case of high-current intensity or tetanic stimulation. The burns on the wrist of the patient seemed to be caused by the repetitive electrical pulses sent by the tof monitor. Pressure sores seemed unlikely as the patient had been treated in prone position in an air fluidized bed with arms alongside the chest and abdomen with palms facing upwards. An allergic reaction was also unlikely as the same electrodes were used for heart rhythm monitoring. The reported current level was 50 ma and measurement was performed every four hours at a frequency of 2 hz according to the protocol. The causes of the electrical burns in the patient might be monitor malfunctioning with uncontrolled current intensity or a too rapid firing frequency. Another possible cause was high skin resistance due to dry skin or the presence of preliminary scar tissue at the contact area of the electrodes. As defined by joule's law, the higher the skin resistance the more heat was released in the skin which causes skin injury. However, the tof monitor's alarm for high skin resistance did not go off and no malfunctioning of the monitor was found on reexamination of the device. The wound was cleaned and the skin was viable, so no surgical exploration was needed. The burns were treated with sulfadiazine cream. The patient's skin healed completely within 12 weeks. Tof monitoring was frequently used in the icu to assess the depth of neuromuscular blockade. Electrical burns are a rare, but serious complication. The investigators therefore advise to regularly check the site of the tof monitor for burns and the tof monitor itself for malfunctioning by assessing the electrical pulse interval and the current intensity. Immediate discontinuation of tof monitoring was advised. This report concerns 1 patient and 1 device. The neuromuscular transmission monitor (tof watch) was not available for investigation. For neuromuscular transmission monitor (tof watch), the lot number was not available and the serial number is not available. For neuromuscular transmission monitor (tof watch), quality investigation status: although the device itself was unavailable and no batch/ lot no was reported a quality investigation was requested. The investigator considered the event of "second-degree burns were observed on the wrist with superficial skin necrosis" to be required intervention. Additional information has been requested. Literature report: koekkoek, w. A. C. Et al, electrical bums caused by a train-of-four monitor, netherlands journal of critical care 2015-09-01: 22(4):21-22. Information has been received from a published literature article titled as above. A (b)(6) caucasian female was admitted to our icu because of acute respiratory failure due to severe pneumococcal pneumonia. She was intubated and mechanically ventilated. Due to progressive respiratory deterioration culminating in arterial hypoxaemia and hypercapnia, the patient was turned into the prone position to improve oxygenation. The patient was sedated to a richmond agitation and sedation score of -4, neuromuscular blocking agents (nmbas) were started within two hours of the diagnosis of acute respiratory distress syndrome (ards), as this treatment might improve mortality and decrease the duration of mechanical ventilation and complications related to barotraumas in ards patients when started early and continued for 48 hours. To assess the depth of neuromuscular blockade and ensure proper medication dosing, a train-of-four (tof) monitor was used. The model was neuromuscular transmission monitor (tof watch), the electrodes were attached to the skin on the internal surface of the wrist, along the course of the ulnar nerve. The contact area of the stimulating electrodes was 7 mm. The nerve was stimulated by four successive stimuli delivered at 2 hz with a current of 50 ma. With increasing degrees of block, the twitches in the tof progressively fade starting with the fourth and eventually disappear one by one. The ratio of the height of the fourth response to the first had been defined as the tof ratio. The optimum level of neuromuscular blockade was reached when 80-90% of receptors were blocked, this corresponds with 1 or 2 twitches on tof testing. When using continuous infusion of nmbas, tof monitoring was recommended for neuromuscular monitoring. A baseline measurement was started and thereafter performed every 15 minutes until adequate depth of muscle relaxation had been achieved, after which the measurement was performed every four hours. In the patient tof monitoring was used. However, 40 hours after the start of nmbas, second-degree burns were observed on the wrist with superficial skin necrosis. The tof monitor was immediately removed and neuromuscular blockade was discontinued. The patient had been ventilated in the prone position for 38 hours and had been turned into a supine position two hours before discontinuation of nmbas. Electrical burns of the skin caused by a peripheral nerve stimulator had been reported previously in one publication. However, in the past 40 years no additional cases had been reported even though various operating manuals of tof monitors warn for electrical burns in case of high-current intensity or tetanic stimulation. The burns on the wrist of the patient seemed to be caused by the repetitive electrical pulses sent by the tof monitor. Pressure sores seemed unlikely as the patient had been treated in prone position in an air fluidized bed with arms alongside the chest and abdomen with palms facing upwards. An allergic reaction was also unlikely as the same electrodes were used for heart rhythm monitoring. The reported current level was 50 ma and measurement was performed every four hours at a frequency of 2 hz according to the protocol. The causes of the electrical burns in the patient might be monitor malfunctioning with uncontrolled current intensity or a too rapid firing frequency. Another possible cause was high skin resistance due to dry skin or the presence of preliminary scar tissue at the contact area of the electrodes. As defined by joule's law, the higher the skin resistance the more heat was released in the skin which causes skin injury. However, the tof monitor's alarm for high skin resistance did not go off and no malfunctioning of the monitor was found on reexamination of the device. The wound was cleaned and the skin was viable, so no surgical exploration was needed. The burns were treated with sulfadiazine cream. The patient's skin healed completely within 12 weeks. Tof monitoring was frequently used in the icu to assess the depth of neuromuscular blockade. Electrical burns are a rare, but serious complication. The investigators therefore advise to regularly check the site of the tof monitor for burns and the tof monitor itself for malfunctioning by assessing the electrical pulse interval and the current intensity. Immediate discontinuation of tof monitoring was advised. This report concerns 1 patient and 1 device. The neuromuscular transmission monitor (tof watch) was not available for investigation. For neuromuscular transmission monitor (tof watch), the lot number was not available and the serial number is not available. For neuromuscular transmission monitor (tof watch), quality investigation status: although the device itself was unavailable and no batch/ lot no was reported a quality investigation was requested. The investigator considered the event of "second-degree burns were observed on the wrist with superficial skin necrosis" to be required intervention. A copy of the published article is attached as further documentation of the patient's experience. Additional information has been requested.
Patient Sequence No: 1, Text Type: D, B5
[34165382]
Not returned to manufacturer.
Patient Sequence No: 1, Text Type: N, H10
[34165383]
Literature report: koekkoek, w. A. C. Et al, electrical bums caused by a train-of-four monitor, netherlands journal of critical care 2015-09-01: 22(4):21-22. Information has been received from a published literature article titled as above. A (b)(6)-year-old caucasian female was admitted to our icu because of acute respiratory failure due to severe pneumococcal pneumonia. She was intubated and mechanically ventilated. Due to progressive respiratory deterioration culminating in arterial hypoxaemia and hypercapnia, the patient was turned into the prone position to improve oxygenation. The patient was sedated to a richmond agitation and sedation score of -4, neuromuscular blocking agents (nmbas) were started within two hours of the diagnosis of acute respiratory distress syndrome (ards), as this treatment might improve mortality and decrease the duration of mechanical ventilation and complications related to barotraumas in ards patients when started early and continued for 48 hours. To assess the depth of neuromuscular blockade and ensure proper medication dosing, a train-of-four (tof) monitor was used. The model was neuromuscular transmission monitor (tof watch), the electrodes were attached to the skin on the internal surface of the wrist, along the course of the ulnar nerve. The contact area of the stimulating electrodes was 7 mm. The nerve was stimulated by four successive stimuli delivered at 2 hz with a current of 50 ma. With increasing degrees of block, the twitches in the tof progressively fade starting with the fourth and eventually disappear one by one. The ratio of the height of the fourth response to the first had been defined as the tof ratio. The optimum level of neuromuscular blockade was reached when 80-90% of receptors were blocked, this corresponds with 1 or 2 twitches on tof testing. When using continuous infusion of nmbas, tof monitoring was recommended for neuromuscular monitoring. A baseline measurement was started and thereafter performed every 15 minutes until adequate depth of muscle relaxation had been achieved, after which the measurement was performed every four hours. In the patient tof monitoring was used. However, 40 hours after the start of nmbas, second-degree burns were observed on the wrist with superficial skin necrosis. The tof monitor was immediately removed and neuromuscular blockade was discontinued. The patient had been ventilated in the prone position for 38 hours and had been turned into a supine position two hours before discontinuation of nmbas. Electrical burns of the skin caused by a peripheral nerve stimulator had been reported previously in one publication. However, in the past 40 years no additional cases had been reported even though various operating manuals of tof monitors warn for electrical burns in case of high-current intensity or tetanic stimulation. The burns on the wrist of the patient seemed to be caused by the repetitive electrical pulses sent by the tof monitor. Pressure sores seemed unlikely as the patient had been treated in prone position in an air fluidized bed with arms alongside the chest and abdomen with palms facing upwards. An allergic reaction was also unlikely as the same electrodes were used for heart rhythm monitoring. The reported current level was 50 ma and measurement was performed every four hours at a frequency of 2 hz according to the protocol. The causes of the electrical burns in the patient might be monitor malfunctioning with uncontrolled current intensity or a too rapid firing frequency. Another possible cause was high skin resistance due to dry skin or the presence of preliminary scar tissue at the contact area of the electrodes. As defined by joule's law, the higher the skin resistance the more heat was released in the skin which causes skin injury. However, the tof monitor's alarm for high skin resistance did not go off and no malfunctioning of the monitor was found on reexamination of the device. The wound was cleaned and the skin was viable, so no surgical exploration was needed. The burns were treated with sulfadiazine cream. The patient's skin healed completely within 12 weeks. Tof monitoring was frequently used in the icu to assess the depth of neuromuscular blockade. Electrical burns are a rare, but serious complication. The investigators therefore advise to regularly check the site of the tof monitor for burns and the tof monitor itself for malfunctioning by assessing the electrical pulse interval and the current intensity. Immediate discontinuation of tof monitoring was advised. This report concerns 1 patient and 1 device. The neuromuscular transmission monitor (tof watch) was not available for investigation. For neuromuscular transmission monitor (tof watch), the lot number was not available and the serial number is not available. For neuromuscular transmission monitor (tof watch), quality investigation status: although the device itself was unavailable and no batch/ lot no was reported a quality investigation was requested. The investigator considered the event of "second-degree burns were observed on the wrist with superficial skin necrosis" to be required intervention. Additional information has been requested. Literature report: koekkoek, w. A. C. Et al, electrical bums caused by a train-of-four monitor, netherlands journal of critical care 2015-09-01: 22(4):21-22. Information has been received from a published literature article titled as above. Final report: follow up information was received on 13-nov-2015 containing results of ae/qir investigation: the tof-guard was investigated by the manufacturer and the electrodes were found to be slightly corroded, but no root cause of the problem could be identified. It was not reported whether or not any high frequency (hf) surgical tools were used together with the tof-guard or whether high skin impedance was excluded in any way. Identified possible root cause: no possible single device related root-cause can be identified/concluded as the case sample is not available for detailed technical investigations. The conducted analysis and calculations supports this and even in the case of malfunctioning device it is seen highly unlikely that sufficient energy could be delivered from the tof-watch in order to create a second-degree burn. Pick-up of radiated hf energy from high frequency surgical equipment, short-wave or micro-wave therapy equipment (or similar) types of equipment by the tof-watch stimulation cables and this energy being routed on to the electrodes attached to the patient cannot be excluded as a potential source for the delivery of high energy levels that potentially could create a second-degree burn. Corrective actions i preventive actions: no biometer corrective actions will be initiated. The case description cannot be confirmed i verified by a physical device examination as no sample is available for investigation. Determination of potential possible device related root cause is only possible if a physical investigation of the case sample can be made. The conducted analysis does not point toward a possible device related problem. Additional information is not expected since all follow ups to complete the case were received.
Patient Sequence No: 1, Text Type: D, B5
| Report Number | 3002807818-2015-00001 |
| MDR Report Key | 5165783 |
| Date Received | 2015-10-21 |
| Date of Report | 2017-11-02 |
| Date Mfgr Received | 2015-11-13 |
| Date Added to Maude | 2015-10-21 |
| Event Key | 0 |
| Report Source Code | Manufacturer report |
| Manufacturer Link | Y |
| Number of Patients in Event | 0 |
| Adverse Event Flag | 3 |
| Product Problem Flag | 3 |
| Reprocessed and Reused Flag | 3 |
| Health Professional | 3 |
| Initial Report to FDA | 3 |
| Report to FDA | 3 |
| Event Location | 3 |
| Manufacturer Street | P.O. BOX 4 |
| Manufacturer City | WEST POINT PA 194860004 |
| Manufacturer Country | US |
| Manufacturer Postal | 194860004 |
| Manufacturer Phone | 2156527905 |
| Manufacturer G1 | MERCK HUMAN HEALTH DIVISION, MERCK & CO., INC. |
| Manufacturer Street | P.O. BOX 4 WEST POINT |
| Manufacturer City | PA 194860004 |
| Manufacturer Country | US |
| Manufacturer Postal Code | 194860004 |
| Single Use | 3 |
| Previous Use Code | 3 |
| Event Type | 3 |
| Type of Report | 3 |
| Brand Name | TOF WATCH |
| Generic Name | STIMULATOR, NERVE, PERIPHERAL, ELECTRIC (KOI) |
| Product Code | KOI |
| Date Received | 2015-10-21 |
| Operator | HEALTH PROFESSIONAL |
| Device Availability | N |
| Device Age | DA |
| Device Eval'ed by Mfgr | R |
| Device Sequence No | 1 |
| Device Event Key | 0 |
| Manufacturer | ORGANON IRELAND LIMITED SWORDS |
| Manufacturer Address | DUBLIN, EI |
| Patient Number | Treatment | Outcome | Date |
|---|---|---|---|
| 1 | 0 | 2015-10-21 |