BENCH TESTS OF SIMPLE, HANDY VENTILATORS FOR PANDEMICS: PERFORMANCE, AUTONOMY AND ERGOMETRY

Erwan L’Her MD PhD and Annie Roy RRT

Respir Care 2011;56(6) 751-760

Given the inevitability of virulent germs, encroachment of man into biologically active areas and worldwide population movement through Asian airports, a 10% pandemic flu outbreak requiring a 5% ICU admission rate is likely and would overwhelm the mechanical ventilation capabilities of hospitals. Low technology ventilators would be required to meet this challenge should society decide to incur the expense of also reserving a provision of drugs and equipment. Six ventilators varying in price, by a factor of as much as 18x were compared.  The outcomes of the testing were proportionate to cost. The comparison findings were, that, given the certainty of ARDS, and concomitant changes in compliance, the cheapest units would be unable to provide a proper level of mechanical ventilation performance. The study liked the CAREVENT ALS, O-TWO MEDICAL TECHNOLOGIES, Mississauga, Ontario Canada (2300USD) and the MEDUMAT EASY, WEINMANNN GERLITE FUR MEDIZN, Hamburg, Germany (2600SD)

LUNGLORD COMMENT:

For those who know the LUNGLORD and have attended one of his lectures, you are aware of his vigorous and enthusiastic interest in this subject matter.  Forgive his antics and think well of his ardent desire and cogent arguments. As for this article, the LUNGLORD compares his love of car magazines and technical journals.   When they compare the Fiat 500 to the twin turbo Ferrari that costs 20x more, few comparisons can be made if the reader dwells in a world of reality with budgets and competing priorities. Like ergonomics.  Please.  This is to laugh.  In the comparison, several very adequate machines are tested.  But, at up to 3,000 dollars a ventilator, which hospitals would be inclined-with no immediate need– to accept an outlay of 600,000 USD to purchase a minimal defense umbrella of two hundred machines? One 750 USD ventilator seemed adequate,  the ALLIED HEALTH CARE, EPV 100, St. Louis Missouri.  Also tested were simpler machines, at 140 dollars apiece, the VORTRAN VAR-PLUS, VORTRAN MEDICAL TECHNOLOGY, Sacramento California.

A combination of these two ventilators is worthy of consideration in LUNGLORD’s flexible response plan herein described. 200 simple VORTRAN machines could deliver life saving ventilation for 2,800 USD until severity of the disease bloom is known. A modest number of EPV 100s @ 750 USD x 50 units = 37,500 USD–(the price of a single PB 840), could give a 3 tiered hierarchy of access to resources. As patients become sicker they would be evaluated and either triaged out of the system or taken to a more capable machine, up to the current generation ventilators in daily use.  As for the basic ventilators, these are not designed to save the sickest patients.  We will not know who is who when we intubate them. We are certain that the worst cases will not survive and will heavily drain resources in the meantime.  So, for the patients whose course and prognosis includes hypoxia and very poor lung compliance, these would be extubated and allowed to succumb in the hope that the next person ventilated might have a mild enough case that they may benefit from the rare and rationed medications/care available.

People will be arriving hourly and this triage decision will have to be made.

Criticisms of the simplest machines include widely varying quality, compliance and potential malfunction issues. A Fiat 500 would likely get a non severe patient over the steep mountain of disease.  It is preferrable to walking, which would be a bag/ETT or bag/mask combo, or not taking the risky trip at all.

LUNGLORD believes that Wright Respirometers will be necessary to check the level of patient ventilation hourly and that ancillary staff should be trained ahead of the curve (ie: now) to check tidal volumes/saturations/suction then reporting to the RCP any abnormal findings. A disposable PEEP valve cranked down to 30cm could be placed in the inspiratory limb to limit the potential for barotrauma, another on the expiratory side for adequate PEEP levels.

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C-REACTIVE PROTEIN ALONE OR COMBINED WITH CARDIAC TROPONINS FOR RISK STRATIFICATION OF RESPIRATORY ICU PATIENTS

Savas Ozsu MD,  Gurdal Yilmaz MD, Ismaul Yilmaz….

(Respir Care 2011;56(7);1002-1008)

A retrospective study was performed comparing the level of C-Reactive Protein, to the likely survivabiltity of ICU patients.  This protein increases  within hours of injury or inflammation.   It is a strong marker for pulmonary lung infection, embolus and DVT.  Most often CRP levels are already elevated by the time the patient arrives in the ICU.   Levels of >10 mg /dL were considered to be threshold with ranges of nonsurvivabilty ranging from 1.7 to 6.6 times greater risk of death. 48% of those with CRP greater than 10mg/dL required mechanical ventilation.   Combining CRP with other blood markers showed no improvement in predictive capabilty of outcome.    Other studies are mentioned within this article with similar prognostic down spin.   One study by Grander, estimated that for every unit increase over 10 mg/dL raised post ICU discharge mortality by 146%.

LUNGLORD COMMENT:  This could also be used as a tool for consultation with the patient’s family as to withdrawl of ventilator support.

SYNOPSIS OF ARTICLE: ACCURACY AND RELIABILTY OF EXTUBATION DECISIONS BY INTENSIVISTS Aiman Tulimat MD  Babak Mokhlesi MD

RESPIR CARE 2011, 56(7) 920-927

Early extubation leads to a second ventilator regime, which dramatically increases LOS as well as morbity and mortality. These Cook County Physicians came to the conclusion that intensivist physicians with a mean of 13 years of advanced critical care medicine experience made the wrong extubation decision 55% of the time.  The patients were vignettes – that is – a dossier of information of individual patients, who, in actuality, were extubated early and subsequently died after reintubation.  The doctors were given full information about the patient up to the moment – in real life – that the patient was extubated.   The physicians were asked if they would extubate at this point in their recovery.  32 case studies were used.   The criticism of the study was that the physicians did not see the patients, did not watch the patient’s breathing trial.

LUNGLORD COMMENT  The criticism of the study is invalid.  Testing to become board certified is accomplished with the same testing methods.  Further, the criticism is non sequiter because physicians spend less as little as 10 minutes/day/ per ventilator patient at bedside.  They do not always watch the actual breathing trial in all cases.  LUNGLORD would have liked for there to be a nuance thought inserted into just 8 of the vignettes stating that the RCP has undefined misgivings about extubation and thinks we should wait at least 24 more hours.   Then, in those cases, determine how many physicians would have continued down the extubation path.  This would have demonstrated physician strength of reliance on their RCPs. 

LUNGLORD CONCLUSIONS

Breathing is the RCPs business.  It’s best to leave important decisions to professionals who live at the bedside. If board certified intensivists are making such decisions-should resident MDs have any contact with a ventilator at all?  It’s a self answering rhetorical question.   

Conclusion two. Reconsider doing your pulmonary fellowship at Cook County.  

ScienceDaily (Dec. 23, 2007) — Lack of sunlight may increase the risk of lung cancer, suggests a study of rates of the disease in over 100 countries. Lung cancer kills over a million people every year around the globe. The researchers looked at the association between latitude, exposure to ultraviolet B (UVB) light, and rates of lung cancer according to age in 111 countries across several continents. They took account of the amount of cloud cover and aerosol use, both of which absorb UVB light, and cigarette smoking, the primary cause of lung cancer. International databases, including those of the World Health Organization, and national health statistics were used. Smoking was most strongly associated with lung cancer rates, accounting for between 75% and 85% of the cases. But exposure to sunlight, especially UVB light, the principal source of vitamin D for the body, also seemed to have an impact, the findings showed.The amount of UVB light increases with proximity to the equator. And the analyses showed that lung cancer rates were highest in those countries furthest away from the equator and lowest in those nearest. Higher cloud cover and airborne aerosol levels were also associated with higher rates of the disease. In men, the prevalence of smoking was associated with higher lung cancer rates, while greater exposure to UVB light was associated with lower rates. Among women, cigarette smoking, total cloud cover, and airborne aerosols were associated with higher rates of lung cancer, while greater exposure to UVB light was associated with lower rates. The associations for a protective role for UVB light persisted after adjusting for smoking. The link between cancer and sunlight is chemically plausible, say the authors, because laboratory research has shown that vitamin D can halt tumour growth by promoting the factors responsible for cell death in the body. “Although cigarette smoking is the main cause of lung cancer, greater UVB exposure may reduce the incidence of the disease,” they conclude. Journal reference: Could ultraviolet B irradiance and vitamin D be associated with lower incidence rates of lung cancer? J Epidemiol Community Health 2007; 62: 69-74.

LUNGLORD COMMENT Only a million die per year in the world from lung CA?  Only one in 8,000 people/year? Okay, half the world’s population is under 30–a little early to have a replication error. But, only one in 3,000.  Still seems low.  Hmmmm.

Regarding sunshine–consider– the poorest nations on Earth are on the equator where there is less discretionary income. Have they adjusted pack/years for this as well?  If more of these people are outside and working-presumeably doing manual labor, wouldn’t their physical activity maintain CV tone and improve outcomes?   More fundamentally,  Is proper diagnosis of lung cancer being made in the third world, where there aren’t Xray machines?  People with cancer die from endobronchial obstruction or extralumenal restriction leading to a run away pneumonia. They are in the ground before anyone knows what killed them. Autopsy is unheard of outside a few cities.  It is a ritual desecration of the body.  

In Lunglord’s opinion–It was insightful to ban smokers from the Butt Hut.  As it turns out, we may be administering another form of therapy.

Vitamin D Linked to Lung Cancer Survival, Study Suggests

Tracheal malacia is a widening and weakening of a one to two inch length of the windpipe leading from the vocal cords to where the windpipe divides into the right and left main stem bronchus.

If the cuff pressure is over inflated for 4 to 12 hours, the balloon pressure of the endotracheal tube can press so strongly against the tracheal wall that it is squeezed up against other structures in the neck or chest-depriving it of oxygen and blood nutrition. This area becomes like scar tissue and also can become floppy since it no longer has structural rigidity.  On inhalation the floppy part is sucked into the airflow and the patient cannot get a good breath.  Surgery is virtually impossible.  A mesh stent is often placed, but the tissue is so friable- unstable – that the stent pushes through the tracheal wall in time after thousands of cycles of inspiratory and expiratory pressures placed on the trachea.  Bad. But, look at this….this is unprecedented…..

LUNGLORD COMMENT:

The link below will take you to a remarkable stem cell press release, Apparently, the 3D 320 rez CAT scanner did a super precise image of this persons trachea as well as his right and left main stem bronchus. Once they had the precise measurements, they then got the cells to grow to that shape, length, diameter and thickness. Cut and paste.  Lung transplants will soon be a thing of the past. Frankenstein comes after wards.  You may want to consider taking superb care of yourself at this point.  You may retain youth, health and not have to die before the 22nd century. BTW, lungs are designed to last 125 years until we are all emphysematous from air pollution, but never fear, then we would just get a new pair-like Birkenstocks-or better yet- a surgery free, viral upload of resequenced youthful you genes which would turn yours truly into Lunglord two point 0. 

http://gizmodo.com/5819128/surgeons-perform-the-worlds-first-synthetic-organ-transplant

The Global Burden of Asthma^*

Sidney S. Braman, MD, FCCP

CHEST 2006  vol 130 no. 1 sup  4s-12s

There has been a sharp increase in the global prevalence, morbidity, mortality, and economic burden associated with asthma over the last 40 years, particularly in children. Approximately 300 million people worldwide currently have asthma, and its prevalence increases by 50% every decade. In North America, 10% of the population have asthma. Asthma is underdiagnosed and undertreated, although the use of inhaled corticosteroids has made a positive impact on outcomes. The increasing number of hospital admissions for asthma, which are most pronounced in young children, reflect an increase in severe asthma, poor disease management, and poverty. Worldwide, approximately 180,000 deaths annually are attributable to asthma….

LUNGLORD COMMENT:

At this rate of expansion of disease–soon we will be living in Frank Herbert’s Dune. Although this asthmatic surge will be good news for the Respiratory Care Practioner profession, as much as an impending F5 hurricane is good for coastal plywood sales, LUNGLORD is not delighted in such news. The signal is clear-more suffering and devastation are coming ashore….

WELCOME TO LUNGLORD

This website is under construction.  I will be creating a page for the sale of six sequential novels about pulmonary based critical care.   As these books are offered to the public, a synopsis for each will be posted along with art I created which is emblematic of what the books represent, This art will be sold in poster and tee shirt form.  Blogs will also be provided as well as interesting games which are being devised.  Right now however, a vast learning curve is going on behind the scenes to figure out just how all this is done.

Be patient.  Target date for website opening and also sale of books is September 1st.   Stop by and watch the site come together.

Frank E. Little Jr.