All posts by DrMRod

3D Printed Multi-Patient Ventilator Adapter

The 3D printing of an adapter to connect multiple patients to single ventilator is a concept that has been floating around in the news over the past few weeks. Conceptually, the setup is simple, use two 4-way splitters to connect the inspiratory and expiratory limbs of a ventilator to 4 intubated patients. Although the implementation and management of patients ventilated in this manner is not as simple. The first mention of this concept comes from a 2006 article from the Journal of Academic Emergency Medicine entitled “A single ventilator for multiple simulated patients to meet disaster surge.” The first reported implementation occurred in 2017 when Emergency Physicians at Sunrise medical center in Las Vegas successfully placed two patients on a single ventilator after an influx of intubated patients overwhelmed their ED during the Las Vegas Shootings.

Currently, at least one hospital in New York is attempting to place multiple patients on single ventilators during the COVID-19 crisis. It seems unlikely that this technique will be successful in patient with severe lung disease; however, there are groups that are working on more complex valve systems to make the process function better.

Here is my video discussing the 3D printing of a simple Multi-Patient Ventilator adapter:

Here is a great article from PulmCrit discussing the mechanics of performing multi-patient ventilation:

The General Public Does Not Understand How Surgical Gloves Work.

A large pet peeve of mine is seeing the general public use surgical gloves incorrectly as a means of infection control and protection. I most commonly see gloves being worn by grocery checkout attendants and by law enforcement. Gloves offer little direct protection from day to day interactions and provide a false sense of security that prevents the wearer from performing hand hygiene as frequently as they should.

In order to protect oneself and prevent the spread of infection, an individual needs to clean their hands between each interaction with a new individual. The typical use of gloves by non-medical individuals involves continuing to wear the same gloves for hours or even days at a time. Every time the wearer touches a new surface, object, or person, their gloves pick up whatever was there; when they touch the next surface, object, or person with those gloves, they transfer it and facilitate the spread of disease.

In addition to spreading the disease to others, most people subconsciously touch their clothing and face constantly throughout the day and since they have interacted with hundreds of people with their gloves, its like hundreds of people have touched them.

When I care for a patient in the operating room I use hand sanitizer, don gloves, interact with my patient or dirty equipment, remove my gloves, then use hand sanitizer again before I can interact with a clean environment again. Although we seem pretentious when we do it, we should constantly be reminding the people that wear gloves in public, to change their practice. Grocery workers and law enforcement such as the TSA are facilitating the spread of disease to countless people every day though ignorance of basic hand hygiene techniques.

Here’s a video I made addressing similar concerns over every day, seeing dozens of people wearing surgical gloves in public during the COVID-19 crisis:

3D Printed HEPA Filter Adapter for 3M 6000 Series Respirators

**Disclaimer: Personal protective equipment (PPE) for use in the medical field is extensively tested and FDA approved; any non-FDA approved PPE should be used only in emergency situations when no FDA approved device is available. The information provided here should be considered educational in nature and not medical advice.

The spread of COVID-19 in the US has revealed a severely inadequate supply of personal protective equipment, especially N95 masks. The dwindling supply has lead some healthcare providers to search for creative solutions for respiratory protection. One emerging method is to purchase a reusable 3M 6000 series respirator for use in the hospital environment, however, the cost of replacement filters is high and availability of all N95 filter types is low. With the CDC currently recommending that masks be disposed of after every COVID patient interaction, the cost and availability of replacement filters makes use of these masks impractical.

Small HEPA filters are inexpensive, in high availability, and filter 0.3 micron particles with greater efficiency (> 99.9 %) than N95 masks (95%), making them at least as safe as CDC recommended masks. To utilize these filters I designed and 3D printed an adapter cassette to use inexpensive Roomba vacuum HEPA filters with a 3M 6000 series respirator. With the filter, PLA Filament, and silicone sealant, the final product comes to a total of about $3 each. I also propose that one mask port be capped with a 3D printed cover so only one filter needs to be used with each patient interaction.

In this video I discuss the design, assembly, and testing of a 3D printed cassette to adapt inexpensive HEPA filters to a reusable respirator:

If you would like to replicate this project here are the items that you will need:
1. Filter Cassette 3D Models
2. 3M 6000 Series Respirator
2. HEPA Filters
3. Silicone Sealant
4. Quick drying adhesive

List of tools that you will need:
1. 3D Printer
2. Clamp

3D Printed Emergency Drug Tray

In order to provide immediate access to emergency medications in our Obstetric ORs, we have a medication drawer that is easily accessible to all anesthesia personnel by badge access. Although there have been multiple ideas for organizing the drawer with easy access and safety in mind, the current state or the drawer leaves much to be desired:


Considerations for a new design included clear grouping of medication classes, sturdy construction, easy to clean surface, and modular design for easy revision in the future. I designed a new drawer inlay and discussed the design with the our residents. With some input from them, I clearly separated emergent GA drugs and emergent epidural medications to draw their eyes quickly to drugs that should be grabbed for each situation. Here is the first iteration of the design:


After printing out an example syringe inlay, feedback was that the finger wells were too small to grab the syringe quickly, so the wells were increased in size. Feedback was positive and the design was accepted readily by the department. After a few months of use the pharmacy began stocking rocuronium syringes instead of rocuronium vials. Due to the modular design, it was straightforward to revise the inlays and replace only one section of the inlay. After a couple weeks of use, it became apparent that the succinycholine and rocuronium syringes were being swapped when restocked, so I reprinted the rocuronium inlay in a different color to draw the eyes to the difference.

Here are the inlays currently in use in our all of our Obstetric ORs:



3D Printed Epidural Cart Organizer

The epidural cart that we roll into labor and delivery rooms had a poor organizational system for commonly used items during epidural placement. The tegaderms, tape, and other items were stored in an “organizer” that was essentially a cardboard box sitting on top of the cart;


This system was not straightforward to inventory and it was often discovered, once already in the patient’s room, that items needed to be restocked. As it was a just box resting on top of the cart it was also occasionally knocked onto the floor.

To allow for better restocking and improved access to the individual items, I designed and 3D printed a new organizer. The design implements clear labelling, maximizes utilization of the space, and has suction cups integrated to prevent falling from the cart. The organizer was printed on a Prusa i3 MK3s with a total print time of about 20 hours, printed in 2 parts due to print ped dimension constraints.


Here is the organizer in use:


3D Printed Spinal and Epidural Needle Organizer.

There’s little worse than your patient sitting at the bedside and having to rummage through a pile of spinal and epidural needles during difficult neuraxial placement. I designed and 3D printed inserts for our existing storage bins for better organization. My goals were to reduce time searching for specific equipment, allow for better inventory/restocking of equipment, and provide a method for non-anesthesia personnel to assist anesthesia personnel that are performing a sterile procedure.

Here is the 3D Design:

The geometry and size of the inserts were not conducive to effective printing so the models were split into more appropriate shapes and sizes. This would also allow for efficient reprinting of certain components if they required adjustments:

The components were sliced in Cura 4 and printed on a modified Creality Ender 3 with a total print time of approximately 30 hours. The components were affixed to the storage bins with double sided tape producing the following product:


3D Printed Battery Holder for McGrath Video Laryngoscopes.

Our department has a large number of McGrath video laryngoscopes. The battery packs were stored in the anesthesia tech room as follows:


This seemed like a poor way to store batteries that cost $75 each. I Designed and 3D printed a tray to hold the batteries; the goal being to provide better organization, improved accessibility, and assist the techs with inventory/ordering. Here is the 3D design:


And here is the final printed product:


Unanticipated Glottic Papilloma

We provided a general anesthetic to a 35 year old male for surgical reduction of a displaced clavicular fracture. The patient’s history was significant for obesity and daily tobacco smoking. During preoperative assessment the patient was noted to have a hoarse voice; however, we were reassured by the patient’s report that his voice had been this way for “a very long time.” A previous anesthetic record was avalible and notable for two hand mask ventilation with an oral airway and grade 2B intubation view with direct laryngoscopy. His BMI had increased from 27 to 39 since the previous record.

We performed a standard induction which was initially notable for very difficult mask ventilation. We performed planned video laryngoscopy with a McGrath MAC #4 resulting in the following view:


Due to difficult mask ventilation we proceeded with intubation without fully investigating the mass. The mass was mobile posteriorly and we were able to easily pass a 6.0 ETT into the trachea:


Since the patient’s injury required urgent repair, we proceeded with the surgery without delay. We called for an intraoperative ENT consult. The ENT surgeon used a gum bougie to delineate the mass and determined that it was attached anteriorly and such masses are unlikely to compromise an airway acutely. Since extubation was likely safe, the ENT surgeon did not perform a biopsy or excision, so the patient could be properly consented for the procedure at a later date. We extubated the patient fully awake without complication.

In the PACU we questioned the patient again with family present. The patient’s wife immediately reported that she noticed a worsening of the patient’s usual hoarseness over the past 3 months.

The patient returned to the OR 1 week later for definitive diagnosis and excision of the mass. We induced the patient and intubated with a Karl Storz C-MAC S MAC #4 and 5.0 microlaryngoscopy ETT:

The mass was resected by the ENT surgeon and was shown to be a papilloma by pathology.

Lego Minifig Anesthesiologist.

What better addition to your office knick knacks than a Lego Minifig anesthesiologist. Unfortunately, the only available minifigs are generic doctors; no accessories are available to indicate our noble profession. I started with the Lego “surgeon” minifig and planned to create my own Lego sized laryngoscope. I found a 3D model on Thingiverse by user Mvetto labelled laryngoscope pendant to start with. I edited the proportions to fit a minifig hand and exaggerated the size of the blade to make it the model somewhat comical. Here is the result, a custom anesthesiologist minifig. 


You can find the minifig on Amazon: Link

If you’re interested in anesthesia and operating room lego builds, the flickr account of canadian anesthesiologist Lucie Filteau has some really cool setups: Here

Large esophagus on laryngoscopy.

The following was encountered while intubating a 50 year old male with a history of neck radiation for the treatment of esophageal cancer and resection of his epiglottis and tongue base. The patient was 20 hours NPO and denied any history suggestive of active esophageal pathology.


We optimized airway positioning with external laryngeal manipulation and placed an endotracheal tube over a gum bougie and continued to the patient’s unrelated orthopedic fixation.