Base info – For all Naloxone trainees

• Language matters
• Person first
• Non judgmental language
• Stigma
• Actively involve individuals to participate in their own care

Public Health Emergency

• Peaks in overdose deaths ’95 and ’99
• 4 pillars strategy of Harm Reduction enacted in early 2000’s along with the foundation of insite.
• Increasing since 2010-11
• Doubling every year, since the last 2 years

Substance classification

• CNS Depressants (D)
  • Opioids* – Fentanyl
    • Further subtypes of opioids
    • Fentanyl Analogues – Synthetics
    • Carfentanil is an Elephant Tranquilizer
  • Alcohol
  • Benzo
  • GHB
• Stimulant (S)
  • Cocaine
  • Meth
  • Nicotine
  • Caffeine
  • Ecstacy

Risk of overdose

• Route of administration
  1. Don’t Use – Least Risk
  2. Swallow
  3. Snort/Smoke/Insert
  4. Injected – Highest Risk
• Lower Tolerance
  • After a break
  • Detox/Jail
  • New
  • Lung/Liver
  • Recent OD
• Age and Physical health – Old / Compromised immune system
• Mixing Substances – Don’t!
  • D+D
  • D+S. Use D before S

Risk Minimization

Testing drugs

• Reagent Kits
• Testkitplus.ca
• Can be borrowed from Karmik
• Fentanyl Dip Sticks – Every supervised consumption site
• Dose-dose variability of synthetic fentanyl causing differing outcomes

Not Using Alone

• IV – 30-40 seconds
• Develop overdose plan
• Leave door ajar
• Call someone

Naloxone basics

• Opioid Antagonist
• Naloxone amendments
  • Mar 22, 2016 – Remove from prescription drug list
  • Oct 13, 2016 – Enable all people to use Naloxone outside a hospital settings
• Good Samaritan Drug Overdose act – Bill C224 – Immunity from Drug possession (simple possession, not distribution amounts / production etc) or breach charges for those who seek help in an emergency (If you’re not on parole/pre-trial release)
• Half-life of naloxone
  • Naloxone 30-90 minutes (least)
  • Morphine/Hydrocodone/Heroin 4h
  • Methadone 24h

Opioid Overdose symptom recognition

• Unconscious/non-responsive
• Depressed breating
• Small pupils

Non opioid overdose symptoms

• Depressants – look a lot like opioid symptoms
• Stimulant – Fast pulse, short of breath, chest pain, elevated temp, agitation

 Response

“They’re dying behind locked doors with kits in their hands/around them”

The pulse is strongest in the arteries. A strong pulse is required to get a PPG of large amplitude from which the respiratory rate induced variations can be discerned. Traditionally, medical practitioners have palpated arteries such as the carotid or the radial to estimate pulse. The really experienced ones can also figure out problems with the left ventricle from the pulse itself. There are two main arteries in the wrist, the radial and the ulnar arteries. They are named based on their anatomic location in the forearm.

Images of actual palpation give further clues towards the sensor position on the wrist.

After deciding a suitable position, the method of mounting on skin has to be decided. The sensor breakout could be house in a 3D printer enclosure with a hole through which the sensor package on the PCB is inserted. The enclosure can be covered with black silicone (from 3M) to interface to the skin acting as a vibration dampener to remove motion artifacts due to sensor motion. The motion artifacts introduced into the pulse signal itself cannot be corrected for. From a design standpoint, we can only expect that respiratory depression due to opioids is also accompanied by cessation of unnecessary motion.

When one has an open sourced project like this, it makes sense to get as many people pitching in as possible. This provides diverse perspectives and speeds up the development process as well, leading to a better device getting into the hands of the user faster. Crowdsourcing hardware might be hard, as not everyone has access to a work bench or the large time chunks it demands. Software, however is more accessible, requiring only a charge laptop, and arduino and the sensor breakout. The hardware needs to work reliably and capture a physiological reading sufficiently well, before one can even think about testing various algorithms. (sub goal – make reliable housing)

Hence, goal – build atleast 3-4 prototypes and reach out to people who would be interested in testing device out. Is this the seed for a “developer testing program” of an open sourced project?

Sarah Blyth is a two term vancouver parks board commissioner, volunteer with the overdose prevention society, manager of the DTES markets and an all-round amazing person. When I reached out to her twitter asking to know more information about the conditions on the ground regarding opioid overdoses, she got back to me immediately and we had a great chat about the problem at hand.

Sarah confirmed the working hypothesis for the overdose deaths I had formulated after Andrea Woo’s (the Globe and mail) gracious response to my unsolicited tweets. The overwhelming majority of deaths occur indoors in users homes and apartments due to respiratory depression. The user cannot detect signs of distress/self inject Narcan in time, nor are any capable bystanders present. 

This scenario is captured very well in this heart-rending overdose incident that led to Mary Purdy’s death.

Marie (Mary’s sister) said Purdy died Jan. 17 of a fentanyl overdose at home. Her two boys sat beside her lifeless body for hours until they were discovered by an ex-boyfriend, who had come to check on her.

“(The six-year-old) said that she fell over, and she wasn’t breathing, but he couldn’t find the phone to call 911, so he sat with her for hours,” said Marie, who choked back tears as she talked about her younger sibling.

Unprompted, Sarah suggested that a solution that detected a flatlined pulse and called 911 to inform them of the location could help. (however, such a device would be quite expensive and would involve recurring costs due the requirement of connectivity to a mobile network). I tried to learn more about the conditions where such an overdose might occur though I didn’t get very far. Only learnt that the indoor conditions might be very similar to condos or closely spaced houses typical to Vancouver. Then, I tried to steer the discussion towards how such a device would get into the users hands. Sarah replied that the overdose prevention society’s pop-up supervised injection site where she volunteers would be a way to reach out to the community. She suggested that the device could even be tested under human supervised conditions at the pop-up tent, which has an enviable record of saving every single user who has ODed on site.

I then introduced my idea of alerting bystanders versus 911 because of the cheaper price. This solution has decreased utility as compared to a transponder with a pulseoximeter, but also can be made at a much cheaper price. While a full fledged system needs a GPS+GPRS module and a pulse oximeter on the wrist, the latter simply has the pulseoximeter, a speaker and lights.

Now, I need to make a few “testable” devices. This shall be interesting.

If there’s one takeaway from Bruno Jaggi’s BMEG 556 at UBC, it’s that the FDA is an amazing resource through the process of medical device development. This has been something I have learnt time and again in a very organic fashion. Once I’ve finished reading all the usual internet links about a certain healthcare device and want to delve deeper, I end up on the FDA’s repositories.

In this case, I started browsing the interwebz to figure out what the best housing for reflectance pulse oximetry was. I started off on an FDA report describing pulseox issues from the perspective of reflection and transmittance. This report talks about the 510k approval process for new pulse oximeters (comparison to an existing approved device with similar specs, for those curious) with a special note on the use of pulse oximeters for over the counter uses.

You see, one of the biggest questions I’ve been asking myself since starting this project was how this device (if marketed), would be classified and if it could ever be “given away” to the intended user without a prescription. A “vital sign” monitor like pulseox, HAS to be classified as a medical device. However, this report refers to nonin finger oximeters for use by high altitude climbers to detect for signs of altitude sickness. Could recreational drug use be one of the exceptions for over the counter use of the MAX30102 sensor? Do I still have to jump through all the regulatory hoops?

Additionally, the document gives a great summary of the types of oximeters, reflectance and transmittance in a single paragraph, which I shall reproduce here.

Pulse oximeter sensors may be implemented in either a transmittance or reflectance configuration. In both configurations, light is scattered by blood, which has time dependent characteristics, and bone or other tissue structures which are not time dependent. Transmittance sensors are configured in a manner where the emitter outputs light which travels through tissue (e.g. finger, toe, and ear) and is received on the opposite side by the detector. Reflectance sensors are configured with the emitter and detector in the same plane. Emitted light must reach the detector by reflection off a surface which typically results in smaller signal strengths in comparison to transmittance sensors. Significant differences in the tissue region sampled are a function of emitter/detector geometry. Differences in light propagation between the transmission and reflectance-based system would affect the relative amount of arterial blood sampled, average photon path length, the absorption characteristics of non-blood regions sampled (e.g. dermis, fat, bone, etc.).

• Blood has time dependent light scattering characteristics while bone and other tissue does not
• Reflectance sensors typically have smaller signal strengths as compared to Transmittance
• Critical variables affecting signal
  • Emitter/detector geometry
  • Amount of arterial blood sampled
  • Average photon path length
  • Absorption on non blood regions
• Motion artifacts!!!!!

For approval of applications, they ask for a desaturation study (6 minute walk test, and looking at SpO2) with 200 data points.

The guidance document for 510k submissions on pulseoximeters is a good resource as well. But this one talks more about what needs to part of the 510k for the