Train of Four Motor Point Stimulation and Monitoring

The assessment of neuromuscular blockage is common practice in the operating room, in which such agents are employed. Still today, the use of simple hand held stimulators and visual monitoring of these responses are the norm. The investigators want to study the potential for employing a non-invasive quantitative device with built in sensors that will hopefully accurately determine the degree of neuromuscular blockade. This system utilizes commonly employed train of four (TOF) electrical stimulation pulses, an incorporated force sensor and an automated detection system. This system will not only utilized pre-blockade, but also throughout an entire surgical procedure and during reversal therapy. For comparisons, the investigators will use both the prototype device and a standard hand held TOF for the assessment of neuromuscular blockage. In other words, the planned protocol will involve testing the effectiveness and accuracy of the device concurrently with peripheral nerve stimulation, during a procedure as is done for the current standard of care. All protocols will be carried out under the direct guidance and supervision of anesthesiologists and/or nurse anesthetists.

Project Summary:

In this study the investigators propose to evaluate a train of four (TOF) stimulator that assess the neuromuscular junction of a patient under anesthesia. The goal of this project is to evaluate a novel device in comparison to the standard of care with a hand held stimulator.

Background and Significance:

The assessment of neuromuscular blockage is common practice in the operating room, in which such agents are employed. Still today, the use of simple hand held stimulators and visual monitoring of these responses are the norm. The investigators now want to study the potential for employing a non-invasive quantitative device with built in sensors that will hopefully accurately determine the degree of neuromuscular blockade. This system utilizes commonly employed train of four (TOF) electrical stimulation pulses, an incorporated force sensor and an automated detection system. This system will not only utilized pre-blockade, but also throughout an entire surgical procedure and during reversal therapy. For comparisons, we will use both the prototype device and a standard hand held TOF for the assessment of neuromuscular blockage.

In other words, the planned protocol will involve testing the effectiveness and accuracy of the device concurrently with peripheral nerve stimulation, during a procedure as is done for the current standard of care. All protocols will be carried out under the direct guidance and supervision of anesthesiologists and/or nurse anesthetists.

The procedure involves applying the device to a suitable anatomic location for train of four (TOF) stimulation/monitoring and then applying a small electrical pulse to stimulate the patient's motor point. The location for this stimulation has historically been on the patients forearm over the ulnar nerve area or on the patients face in the distribution of the facial nerve. The stimulation applied to these areas is equivalent to that applied in the current accepted standard of care. All responses measured by the device will be recorded electronically and compared to anesthesiologist's/nurse anesthetist's interpretation of the number of muscle twitches induced by peripheral motor point stimulation. These comparisons will be analyzed for correlation between number of muscle twitches and degree of force generation sensed by the device, with the aim of more accurately determining the degree of the patients neuromuscular blockade.

This device application and monitoring will be carried out on anesthetized surgical patients at different time points in the procedure, under the same conditions as the currently utilized peripheral nerve stimulators to judge neuromuscular transmission and anesthesia effectiveness. We will also use the system on other anatomical locations that may be easier to gain assess to under certain surgical procedures: e.g., on the bicep, quadriceps, or tibialis anterior muscles. Such locations have been described by anesthesiologists as viable options.

Pre and post-surgical care will be unchanged and follow current standard of care. The only change will be that alongside current peripheral nerve stimulation, our non-invasive TOF device will also be utilized for assessing the relative degree of neuromuscular blockage.

Currently, there is no clinically available device that is automated and records the TOF conducted the anesthesiologist and their staff. Developing a method for completed this assessment is expected to save the anesthesiologist's time and prevent human error and increase consistency.

This device and approach is similar to the muscle force system which we have employed to study patients with neuromuscular disorders at the University of Minnesota for over 20 years.

Specific Aims/Study Objectives:

The investigators hypothesize that the use of an advance TOF device with automated data storage and a unique user interface will demonstrate enhanced efficacy for monitoring neuromuscular blockade in patients. The investigators will continue to recruit subjects for this study until we have completed the study.

Research Design and Methods:

The study population will include female and male participants ranging from 18-80 years of age. The investigators are requesting a total of 400 participants in the study. After the investigators have collected data from these individuals they will analyze the data to determine the efficacy of the testing method. If the initial population size is extremely variable or does not allow the investigators to conduct a proper analysis, they will request additional subjects to make a conclusion on this device.

Subject will be identified by the anesthesiologist prior to surgery, consent will be obtained prior to surgical procedures. The information that will be collected from their medical records will include their age, height, weight, history of muscular disease i.e. myotonias, malignant hyperthermia, previous adverse reactions to anesthesia, complete anesthetic records from procedure. Data will be securely stored and locked in Mayo B172.

Data and Safety Monitoring Plan:

It is not anticipated that the use of this device will produce any side effects or emotional upset. The stopping rules of the study include any unexpected complications with the use of the TOF stimulator in the OR. The patient will be unconscious or sedated during monitoring.

Statistical Considerations:

Historically, FDA clinical trials have utilized anywhere from 100-400 patients for determining the relative safety and efficacy of a medical device or technology. The obtained data will be analyzed to determine such factors and could be utilized for FDA approval of a monitoring system for clinical use.

Direct comparison of the devices qualitative evaluation of scoring from the administering anesthesiologist will be used for the final analysis.

Data and Record Keeping:

The data will be recorded by Dr. Michael Loushin, Dr. Paul Iaizzo, Dr. Jake Hutch, Tinen Iles, the data will be stored securely in Mayo B172 or with the anesthesiologist. The data will be stored from the automated TOF and the manual TOF performed in Mayo B172 or with the anesthesiologist.

References:

Eligibility Criteria:
Inclusion Criteria:

* Normal, healthy subjects (adults) admitted for surgical procedures.

Exclusion Criteria:

* Under 18 years of age or over 80 years of age, anesthetic paradigm does not include NMBAs.