Lipoid Pneumonia - Crossbow's Research

Yesterday saw the appearance of a very alarming and saddening news story on the BBC.

The man who unfortunately lost his life was apparently a long term smoker, who had used ecigs for a period of around 6 or 8 months, before stopping due to problems with his breathing. His death at the age of merely 57 cannot be viewed as anything other than a tragedy.

The coroner who examined Mr Miller recorded an open verdict on the cause of death, which was given as “severe lipoid pneumonia”. It has been suggested by Dr Rob Allcock (who, according to available information, is a consultant in respiratory medicine) that this was linked to the use of electronic cigarettes.

These are about all the independently-verifiable details currently available.

I am not a doctor (like I am sure, most of you), and this was the first time I had heard of lipoid pneumonia, necessitating some research. On the plus side, I do have a fairly good knowledge of electronic cigarettes, and this seemed like rather a leap of logic to me.

Here's a brief summary of what I found out about lipoid pneumonia.

There are 2 forms of lipoid pneumonia, and it is unclear at this point which led to Mr Miller's untimely demise.

Exogenous lipoid pneumonia is caused by the inhalation of lipids (fats and oils) from outside of the body. It's most commonly seen in elderly patients (in their 60's and 70's), and is more likely in people with an impaired swallowing ability and “the consistent use of the various kinds of oils – mineral, animal, and less commonly, the vegetable oils found in laxatives, nasal drops, mouth spray, oral lubricants, insecticides or traditional folk remedies” (and perhaps not surprisingly, fire eaters, for whom it is an occupational hazard). It tends to be associated with long exposure to oils (one study had a mean of 9.5 years, but brief exposures of as little as a month have been known (with liquid paraffin).

Endogenous lipoid pneumonia is caused by a build-up of the body’s natural fats (it is also known as cholesterol pneumonitis) in the lung. It's most commonly seen in people with chronic bronchial obstruction (often tumours or foreign bodies). In fact it has a very large association with cancers of the lung (and to a lesser extent with Hodgkin's lymphoma):

“In one research conducted, endogenous lipoid pneumonia was diagnosed in the resected lungs of 33 of 147 patients with lung cancer. It was found in 16 out of 89 (18%) of patients with adenocarcinoma and in 17 of 55 (31%) patients with squamous cell carcinoma. In 23 cases, it was observed that endogenous lipoid pneumonia was localized to lung parenchyma distal to the airway obstructed by the tumour, and of these 16 were patients with squamous cell carcinoma. Out of 5 patients with adenocarcinoma, 4 had endogenous lipoid pneumonia present distal to the tumour and having spread to isolated segments.”

Smoking (perhaps not surprisingly) also has an effect on levels of fat within lung tissue “When normal lung tissue is chemically analysed, it shows a total fat content of 8.63 per 100 g of dry tissue, of which 19% is cholesterol; although this percentage shows a marked increase in smokers. When the breakdown of these cells takes place, it results in the lipid gaining access to lung parenchyma and it is phagocytosed by the pulmonary macrophages”.

(For those without a medical dictionary to hand, lung parenchyma indicates the functional parts of the lung, and phagocytosed is the body’s attempt to remove dead cells and foreign bodies at the cellular level using white blood cells.)

So that's the medical research, but how does this relate to ecigs? Certainly mineral oil and animal fats should never be found in an eliquid, but natural flavourings may contain essential oils. It's worth bearing in mind that essential oils are used in aromatherapy, and the NHS seems happy with inhalation of essential oils in this context.

Dose is clearly a key element, so how much oil might we find in an eliquid? A great many will not contain any at all, but a natural fruit flavouring (i.e. one based on actual fruit extracts) may have up to 2% in the concentrate (as estimated by Peter Cole at Decadent Vapours), so based on a heavy vaper using about 5ml a day of eliquid with 20% flavouring, this would equate to 0.02ml of volatile oils.

This would seem unlikely to carry a significantly higher risk factor than aromatherapy, and considerably less than the ingestion of liquid paraffin as a laxative which seems fairly typical of exogenous lipoid pneumonia cases.

Is this death a tragedy? Yes, it certainly is.

Is it an electronic cigarette related tragedy? It seems very unlikely.

Without a more detailed diagnosis (with regard to endogenous or exogenous lipoid pneumonia) and without sight of any analysis of the ‘oily residue’ found in Mr Miller’s lungs, it's impossible to be sure, but this could easily be yet another smoking-related tragedy.