Saturday, May 31, 2008

Building a Pandemic Ventilator

On Thursday May 29, Jeff and I gave a presentation about the Pandemic Ventilator Project to some of my friends and colleagues at work. The presentation went smoothly and was well received. We received encouragement from the attendees to continue working on the project. We had the presentation videotaped so that more people could see it. Thank you Manuel for your help and ideas in videotaping this presentation.

The presentation is about 35 minutes in length overall and is divided into 4 sections below as YouTube videos. The title of the presentation was "Building a Pandemic Ventilator”. It is an overview of what we are tying to achieve with the Pandemic Ventilator Project.

Building a Pandemic Ventilator Part 1
Presented at Grand River Hospital May 29 2008.
The purpose and origins of the Pandemic Ventilator Project and the history of home made ventilators.

Building a Pandemic Ventilator Part 2
Presented at Grand River Hospital May 29 2008.
A description of how the Pandemic Ventilator actually works.

Building a Pandemic Ventilator Part 3
Presented at Grand River Hospital May 29 2008.
Some pandemic planning ideas and the future of the Pandemic Ventilator Project.

Building a Pandemic Ventilator Part 4
Some discussion, questions and a demonstration of Jeff’s Pandemic Ventilator.

Saturday, May 24, 2008

Dr. Eric Toner Blog post

Here is an interesting interview with Dr. Eric Toner about pandemic planning with regards to H5N1. Dr. Toner is with the Center for Biosecurity at the University of Pittsburgh Medical Center. I have referenced articles from this group before. There is a lot of useful information available at the UPMC Biosecurity site, and it is frequently updated.

Dr. Toner talks about how severe a pandemic arising from the H5N1 virus could be, and compares this worst case scenario to the projections commonly used by the CDC flusurge software. In case you are interested in alternative projection models to flusurge, check out the panalysis spreadsheet.

Here is the PDF of the Toner interview

If you would prefer to listen to the audio version the links are here:
Part 1 “What is Avian Flu?” (4:23)
Part 2 “The difference in Death Rate Assumptions” (2:50)
Part 3 “Why we need Hospital Interventions” (6:03)
Part 4 “Why Not Enough is Being Done” (8:40)

You can also go to the Health Business and Policy website directly for the HTML version

Health and Business Policy has more pandemic related interviews available here.

Be aware, most of the information on the Health and Business Policy site seems to be older, from about mid 2006.

Sunday, May 18, 2008

Pandemic Ventilator at the Canada Wide Science Fair

I mentioned earlier that my son Jeff had built his own pandemic ventilator and entered it in a science fair. At the regional science fair he won; Award of Merit, Gold Medal in Senior Engineering, the University of Ontario Institute of Technology Innovation Award, a Conestoga College Entrance Scholarship, a University of Guelph Entrance Scholarship, a University of Waterloo Entrance Scholarship and a Wilfrid Laurier University Entrance Scholarship.

He also got the opportunity to enter in the Canada Wide Science Fair and compete against the top entries from all of Canada. At the Canada Wide Science Fair he won an Honourable Mention in Engineering and the Engineers Without Borders prize. The Engineers Without Borders prize is awarded to a humanitarian engineering project that can improve the lives of people in developing nations. Jeff will also be invited to the next Engineers without Borders Canada national conference.

Here is a link to the WWSEF awards page.

Here is his project report.

Here is a picture of the ventilator in its case as it was presented at the Canada Wide Science Fair

Here is the compressor

Here is the PLC

This pandemic ventilator design has its own air source so it does not rely on hospital high-pressure air sources. This allows it to be able to be used in settings outside of the standard hospital ICU. It has a link to a PC via LabView software. It has a pressure transducer to measure airway pressures. There are alarms for airway overpressure, line occlusion and loss of air from the compressor. The PC keeps track of minute volume, total volume, respiratory rate, PLC connection status and alarm status. It also shows a real time pressure waveform. The PC could be located outside of an isolated patients room in order to reduce the number of times staff have to enter the isolated room. An external monitor such as this can reduce risk of staff exposure and also reduce personal protective equipment usage.

The video shows the ventilator operating with a lung simulator. The patient overpressure, line occlusion and loss of compressed air alarms are demonstrated.

Monday, May 12, 2008

The Cost of Efficiency

Modern hospitals have become much more efficient than they were in 1957 or 1968 when we had our last pandemics. Today, hospitals are run more like a business than they ever were. Even non profit hospitals and hospitals in countries with socialized medicine or single payer systems have had to run more efficiently. This is not entirely a bad thing. Hospitals have had to become more efficient as the ongoing improvements in health care technology became more readily available. Many more high tech health options are possible today, and they are generally more expensive. We treat heart disease, cancer, trauma, premature birth and organ failure much more aggressively than we did 40 or 50 years ago. We can also routinely save or extend more lives than we did back then. Efficiency is how we afford it.

To make hospitals more efficient we utilize space, supplies and staffing as much as we can. We do not have empty rooms. If too many rooms are unused we close wings and convert them to outpatient departments or offices or close some hospitals. We do not let equipment sit idle, we buy just what we need and rent some extra to get us over the peaks. We use just in time supply systems to reduce excess inventory and waste. We hire fewer full time staff and use temporary staff or pay a bit of overtime here and there to handle the peaks. The average length of a hospital stay has been dramatically reduced.

We no longer have any excess capacity left. We designed it that way. Any hospitals that resisted this change in the past were closed and branded inefficient. This efficiency has a cost though. Our efficient health care systems could no longer handle a pandemic even of the type seen in 1968. Pandemics require far more resources than the ordinary ebb and tide of daily business. Too much efficiency can be deadly.

Friday, May 9, 2008

Quick Review of “Definitive Care for the Critically Ill During a Disaster”

This week the report from the “Task Force for Mass Critical Care Summit, January 26–27, 2007” was published in CHEST. The series is titled “Definitive Care for the Critically Ill During a Disaster”. It consists of five separate articles subtitled:
  • Summary of Suggestions From the Task Force for Mass Critical Care Summit
  • Current Capabilities and Limitations
  • A Framework for Optimizing Critical Care Surge Capacity
  • Medical Resources for Surge Capacity
  • A Framework for Allocation of Scarce Resources in Mass Critical Care

I quickly read through all these papers this week. I will review each of them in more detail in upcoming postings. You can get all five of the published articles for free at this location. Thank you CHEST for supplying these articles for free. If you are involved in pandemic planning, I urge you to download these papers and read them. They offer many suggestions and solid frameworks for planning your response to a mass critical care incident.

The publishing of these papers has generated a few news reports this week. Most of the newspaper articles were sensational, focusing mainly on the list of classes of people that would be excluded from care. Here are a couple of news links. AP, Globe and Mail.

When you read these news articles you would think that the summit meeting was all about denying care. When you read the actual papers you will see that the summit was really about providing the best care possible under various worsening and even the nearly hopeless conditions that could possibly occur. The sensational articles referred to the list of recommendations of who would be refused care in the most severe crisis. This list was merely a suggestion, and the authors state in the papers that there must be an ethical discussion of these issues by non medical professional people to determine whether society will accept these criteria.

The papers do not focus only on pandemic planning, but stress that plans must be flexible enough to account for many different types of mass casualty incidents. The included charts list nearly every type of incident and the appropriate responses. Still the main focus is on pandemic preparedness. Short of a nuclear war, a severe pandemic is probably the incident that would most stress the existing critical care infrastructure.

Some of the papers I have read before these on pandemic planning were very complex and tedious to follow. Many other papers focus on the numerous problems, give many “what if “ scenarios and concentrate a lot on how little we know. These papers focus more on how to get to a solution rather than moaning about the hopelessness of it all. The planning goals are focussed on three main areas; stuff, staff, and space. Essentially they say you have to have enough of each. If you are well prepared in two areas and short in the third, you are still limited by that area. They focus less on trying to predict the severity of any incident and more on how hospitals can maximize their ability to respond.

Stuff is things like ventilators, medications, PPE and other medical supplies. Staff is the number of staff that are not affected by the event plus the number of addition personnel that can be trained and used as well as how much you can increase the number of patients existing staff can care for. Space is the suitable areas that can be used to provide complex critical care.

In a nutshell, they recommend that facilities aim to increase by a factor of 3, the amount of critical care (including ventilators) they can provide, and also stockpile enough supplies to last about 10 days, with perhaps some additional buffer, and to ensure they can maximize their staffing and space to make this possible. I think these are very good recommendations. They are very similar to the recommendations I posted on the BMG website last year. I also suggested that facilities try to increase their ability to manage ventilated patients by up to a factor of 3 in one of my posts last year.

They warn that manual ventilation will not work. They are very skeptical that sharing ventilators among several patients will work with real patients that have ARDS. They provide an extensive list of requirements that facilities should look for when purchasing ventilators for surge capacity, but acknowledge that is unlikely that anyone will actually buy that many ventilators ahead of time. They also provide a much shorter list of the minimum requirements for a ventilator in suggestion 3.2:

(1) be able to oxygenate and ventilate most pediatric and adult patients with either significant airflow obstruction or ARDS
(2) be able to function with low-flow oxygen and without high-pressure medical gas
(3) accurately deliver a prescribed minute ventilation when patients are not breathing spontaneously
(4) have sufficient alarms to alert the operator to apnea, circuit disconnect, low gas source, low battery, and high peak airway pressures

The pandemic ventilator should be able to meet those short list minimum requirements.

My son Jeff is taking his own pandemic ventilator design “Norman” to the Canada Wide Science Fair in Ottawa this week. I will have a more detailed report on “Norman” next week. I think you will be impressed with the work Jeff has done. I am.

Friday, May 2, 2008

How Many Ventilators Does New York Really Have?

A couple of weeks ago, I posted a piece on how hard it is to get good numbers on the quantity of ventilators available. I checked through some documents from the New York State Workgroup on Ventilator Allocation in an Influenza Pandemic. Last year they published some preliminary information and asked for public input on setting up guidelines for ventilator use in a pandemic or similar emergency. I sent in some information to them about the Pandemic Ventilator Project and some of my ideas about how to expand the availability of ventilators and clinical capacity in a crisis, but they never asked me for more details. They recently published some guidelines based on that exercise in Disaster Medicine and Public Health Preparedness. I will have to see about getting a copy of that article and reviewing it.

Anyway, I found two documents by the same workgroup stating the number of ventilators in New York. Unfortunately they quote two different numbers. One is 60% higher than the other. Here are the details:

First we have:
Allocation of Ventilators in an Influenza Pandemic: Planning Document
NYS Workgroup on Ventilator Allocation in an Influenza Pandemic
NYS DOH/ NYS Task Force on Life & the Law
Feb 13, 2007 (listed access date)
Available here:

On page 9, it states:
  • the population of New York State is approximately 19 million,
  • there are currently 3,981 adult and pediatric ICU beds staffed,
  • 15% of the admitted patients with pandemic influenza will require intensive care,
  • 7.5% of the admitted patients with pandemic influenza will require ventilators,
  • there are currently 6,100 ventilators in acute care settings in New York State,
  • at any given time, 85% of the ventilators in acute care settings are in use, and
  • 70% of deaths related to pandemic influenza are projected to occur in a hospital.

And then we have:
New York State Workgroup on Ventilator Allocation in an Influenza Pandemic
New York State Department of Health/ New York State Task Force on Life & the Law
March 15, 2007
Available here:

On page 1, it states:

a) Community Demographics
New York State has an estimated population of 19,254,630, which represent 6.5% of the total United States population. Approximately 13% of New Yorkers are age 65 or older; an estimated 18%of the state population over the age of 5 is disabled.

b) State & Local Public Health Infrastructure
NYSDOH is empowered to issue voluntary, non-binding guidelines for health care workers and facilities; NYSDOH is also empowered to issue binding regulations for hospitals that would app to standards of care during a pandemic.

c) Health Care Delivery System
There are more than 650 nursing homes in New York State housing 120,000 beds. Of the 240 hospitals in the state, 44 are classified as trauma centers, and 13 are classified as critical access hospitals (CAH) in rural areas. There are 3,981 adult and pediatric staffed intensive care unit beds throughout the state. There are currently 3,861 mechanical ventilators in acute care settings in New York State; at any given time, 85% of these ventilators are in use.

So here we have 2 documents. Both are produced by the same workgroup on ventilator allocation. Both of these documents list Gus Birkhead and Tia Powell as contributors. One of the documents says that New York State has 6,100 ventilators in acute care settings, and the other document says that they have 3,861 ventilators in acute care settings. Both of them say that they have 3,981 ICU beds.

It is hard to know what numbers to believe. As I said before, how can you know how many ventilators you have to stockpile if you are not even sure how many you have now? How can you know how far you can extend your resources and clinical skills capacity if you are not even sure how many ventilators those workers are supporting now? A definitive census is needed with plans that list actual (validated) numbers of ventilators that exist, how many will be added for surge capacity and how far it is possible to stretch clinical support capacity.

Maybe in their latest article, Powell and Birkhead can tell us which numbers are the real ones.