Blog Post 2 - GE
- gellis82
- Sep 23, 2019
- 5 min read
Author: Gordon Ellis
Date: September 22, 2019
Project: Anesthesia Delivery and Monitoring
Team Members: Adin Field, Gordon Ellis, Jordon Bibian, Anagha Arvind
Blog Contents:
1. Additional Background Research
a. Further background on general anesthesia
b. Further information on current options in monitoring anesthesia depth and their function
2. Value Proposition Canvas
3. Potential Interview Questions
4. Elevator Pitch
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Additional Background Research:
General Anesthesia and Further Information
- General anesthesia is typically used for procedures that either result in significant blood loss, that affect the patient's breathing, exposes the patient to a cold environment, or are time-intensive
- Patients usually need to avoid eating and drinking six hours prior to the surgery as general anesthesia ends up relaxing the digestive tract and airway muscles that prevent food and acid from reaching the lungs from the stomach
- Certain medications (like aspirin and some blood thinners) can result in complications during surgery and may need to be avoided for at least a week prior to the surgery; certain vitamins and herbal remedies like ginseng and garlic can also lead to complications during surgery
- After the anesthesia is applied through the arm via an intravenous line and gas is given through a mask if necessary, either a laryngeal airway mask or a tube that is inserted down the windpipe through the mouth can be applied to ensure the patient is receiving a sufficient amount of oxygen. The tube also helps ensure fluids aren't entering the lungs. Muscle relaxants are given to the patient prior to tube insertion to relax the patient's windpipe muscles.
- After the surgery is complete, the anesthesia medication will be reversed in order to wake the patient back up. Experiences waking up vary where some patients will feel no side effects while others may experience effects like nausea, sore throat, vomiting, or chills. The anesthesia may remain in the patient's system for a few days afterwards, potentially resulting in impaired reflexes and judgement and sleepiness.
Further information on current options in monitoring anesthesia depth and their function
- Current anesthetic drugs result in analgesia through paralysis of the striated muscles and amnesia and blockade of the autonomic and harmonic response to painful stimuli. Due to this, estimation of anesthesia depth can not be based on changes of the patient's cardiac and respiratory rhythm, blood pressure, production of sweat and tears, or pupil size
- Measurements of contractions of the lower esophageal sphincter with the use of a special manometer have been used in the past. Although the response of the esophagus to stimuli is related to the depth of anesthesia, it can not be considered a safe method of intraoperative anesthesia monitoring. The electroencephalogram of the frontalis muscle, which is the least sensitive to neuromuscular blockers, is another available but unreliable method.
- New devices have been developed due to advances in medical technology that analyze the electrical activity of the brain and can be used intraoperatively in order to monitor anesthesia depth. The three most often used devices are the AEP (Auditory Evoked Potentials) monitor, the Narcotrend, and the BIS (Bispectral Index Monitoring).
- The AEP monitor records the electrical activity of the brain stem and cortex after auditory stimuli that are delivered to the patients through headphones. The signal is processed mathematically and is finally shown on the screen of the device as a number from 0 to 100. The lower the number on the screen, the greater the depth of anesthesia is.
- The Narcotrend records brain activity without the application of any stimulus. The monitor analyses the signal of the encephalogram and categorizes anesthesia depth through a system of 6 letters. It also produces a number from 0 to 100 (Narcotrend index). The stages are: = awake, 0-2= sedation, C0-2= light anesthesia, D0-2= general anesthesia, 0-2= general anesthesia with deep hypnosis, F0-1= general anesthesia with heavy depression of reaction to painful stimuli. Although its initial use showed great promise, clinical data now illustrates that it is unable to estimate reliably the depth of anesthesia and prevent cases of awareness.
- The only reliable anesthesia depth monitor is the BIS. BIS functions similarly to the Narcotrend, and records the electroencephalogram from 3 electrodes. After processing it with mathematical algorithms, it generates a number from 0 to 100. When the BIS value is lower than 40, the patient is in a deeply sedated state whereas when the value is over 80, the patient is under light sedation
- However, the BIS is fairly expensive where two thousand and two hundred dollars are required in order to prevent one case of awareness since routine BIS monitoring costs around sixteen dollars per use and has a "number needed to treat of 138."
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Value Proposition Canvas:
Value Map
- Products and Services
o Low-cost, accessible way to monitor anesthesia depth in patients under the influence of
general anesthesia during surgery
- Gain Creators
o Low-cost and easily accessible for developing areas
o Potentially reliable enough and easy to use so do not need extensive training for places with few anesthesiologists
- Pain Relievers
o Fewer cases of intraoperative awareness and its consequences
o Easier/less dangerous surgeries
Customer Profile (Anesthesiologists and their assistants)
- Gains
o Fewer complications when sedating and keeping the patient sedated during surgery
o Potentially less money spent on dealing with lawsuits from patients who experienced
these complications
- Customer Jobs
o Sedate patients during surgery and help ensure they stay sedated until surgery is
complete
o Deal with billing, hiring, other business-related aspects
o Evaluate patients about to undergo surgery
- Pains
o May need to learn new techniques associated with usage of new monitor
o Different kinds of potential complications may arise depending on the invasiveness and
the kind of new product that is developed
Potential Interview Questions:
- Which anesthesia monitor do you currently use the most and what do you enjoy most and least about it? (For anesthesiologist/nurse)
- Can you describe your experience with general anesthesia and what side effects you experienced afterwards? (For patient who has been under general anesthesia)
- How many surgical cases are performed each year, and what are your most common ones? (For anesthesiologist/nurse)
- What are some novel technologies currently being developed in anesthesia monitoring? (For anesthesiologist/nurse)
- Can you describe a typical day for you? (For anesthesiologist/nurse)
- Why has it been so difficult thus far to produce an anesthesia monitor that can reliably help prevent the need to rely on the patient's physical / external vitals? (For anesthesiologist/nurse)
Elevator Pitch:
We are a small team of four engineering students at Boston University trying to develop a better way for anesthesiologists and nurse anesthetists to monitor general anesthesia delivery more effectively during surgeries to prevent instances of intra-operative and intra-anesthetic awareness. Our current ideas revolve around exploring the viability of direct monitoring of anesthetic drug levels / metabolites in the blood stream, preferably through something similar to pulse oximetry. We are not sure if we would like to focus on a high resource or low resource setting yet, but we hope that the product we develop will be cheap enough, effective enough, and easy enough to use to find some sort of application in either setting.
References:
https://www.ncbi.nlm.nih.gov/pubmed/15172773
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2683150/#R5
https://www.mayoclinic.org/tests-procedures/anesthesia/about/pac-20384568
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