44

Nothing like the Daily Mail for raising an eyebrow:

The bizarre requests to use CT scanners, normally intended for four-legged animals, at the UK’s leading veterinary college in north London were revealed as hospitals face pressure to adapt beds and wards for an increasingly obese population.

[...]

The practice of referring patients to zoos is commonplace in America where obesity has reached epidemic levels.

Is there more systematic evidence or at least coming from non-tabloid sources on the common use of animal CT scanners for obese patients in the US? (I'm pretty sure that's what the newspaper meant by "America" because the US tops the obesity charts, although apparently Brazil and Mexico are not that far behind.)

A reason to doubt the newspaper statement is that simple supply and demand theory suggests that in a country with a high number of obese people equipment manufacturers would make suitable equipment. On the other hand, it's possible for demand to outstrip supply for any number of reasons, including a more rapid change in demand (rapid obesity increase).

Community
  • 1
Fizz
  • 57,051
  • 18
  • 175
  • 291
  • 14
    "The practice of referring patients to zoos is commonplace in America where obesity has reached epidemic levels." Wow, I live in America and I usually don't see many people *that* obese. I think its true they may have referred extremely obese people to the zoo, but that is a small fraction of the total population. Exaggerations probably make pretty good clickbait. – JSCoder says Reinstate Monica Dec 26 '17 at 02:16
  • 12
    @JavaScriptCoder The very obese people are usually at home because they don't move around easily anymore. Which is why you can't see them in the public. Unless there is something that bothers them which makes them consult the EMS or a doctor. – jjack Dec 26 '17 at 07:34
  • 6
    This happened in House M.D. and Scrubs. That almost certainly contributed to the idea that it's commonplace. – Richard Dec 26 '17 at 11:44
  • @Richard What happened there? – jjack Dec 26 '17 at 13:46
  • 2
    I wouldn't know if it is common place, but being not obese and having undergone MR (which is kinda the same space-wise) recently, and from what disturbing amounts of obesity I've seen in the US, I can imagine this being very well not far from truth. You know, even when you're not obese, you gotta be a really tough one in order not to get a claustrophobic fit in one of these things... – Damon Dec 26 '17 at 14:13
  • @jjack - http://scrubs.wikia.com/wiki/My_New_Suit – Richard Dec 26 '17 at 14:19
  • @Damon - Especially if you've ever read Poe's `The Premature Burial`. – Don Branson Dec 26 '17 at 16:51
  • 5
    Yes, "America" means the USA. This is completely standard usage of English. – David Richerby Dec 26 '17 at 19:26
  • @JavaScriptCoder From my own experience the diameter of MRI tubes at least in Europe is pretty small. I could easily see someone that's not even that heavy but just.. bloated to have a hard time fitting, particularly since you also need some spare space for good imagery I'd expect. – Voo Dec 26 '17 at 20:03
  • @Voo If you're just bloated you have a different medical condition which might not require you to get an MRI. – jjack Dec 26 '17 at 20:19
  • @jjack I mean having too large a volume to fit into the tube, nothing to do with the predicament they're trying to analyse. I had a MRI thanks to a torn anterior cruciate ligament. – Voo Dec 26 '17 at 20:21
  • @Voo I'm sorry. I'm not trying to infringe on you for your injury. – jjack Dec 26 '17 at 20:24
  • 4
    What's the reputation of the Daily Mail? Would gross exaggeration or outright fabrication be unprecedented? – President James K. Polk Dec 26 '17 at 21:12
  • @JamesKPolk Obese people don't only get sick, they want to fly with airlines too. – jjack Dec 26 '17 at 22:00
  • Yea, my dad is a doctor and he did it all the time. Eventually it got so bad that the hospital had to buy a zoo CT scanner. – Byte11 Dec 26 '17 at 22:13
  • 2
    How many zoos actually have an MRI scanner? They are expensive and probably not essential for the level of care a zoo needs to provide. I would not be surprised if this story is false, simply because zoos don't have MRI machines. – Thomas Dec 26 '17 at 23:04
  • 1
    @Thomas In 2008, two zoos which responded to a limited inquiry had CT scanners, but no MRIs. http://onlinelibrary.wiley.com/doi/10.1038/oby.2008.410/full. Since the question asks specifically about CT, your assumption that this story is false is false. – jjack Dec 27 '17 at 10:39
  • @Fizz No, patients most definitely are not taken to the zoo. If a physician takes on a patient that's too obese for a scanner, the physician will resort to exercising their clinical skills, and assess the patient through a physical exam. –  Dec 29 '17 at 15:58
  • @JavaScriptCoder My dad is a cardiologist at on of the area's largest hospitals in midwestern America. He had to constantly refer people to the zoo to get CT scans. It got so bad that the hospital bought an elephant catscanner for the hospital. It's not rare. – Byte11 Jan 05 '19 at 04:57

2 Answers2

63

A 2011 literature review looked at the problem as it related to one particular condition: Difficulties in diagnosing pulmonary embolism in the obese patient: A literature review.

They conclude that there is a problem - not only are many CT scanners unable to handle morbidly obese patients (although this is improving), there are no guidelines for when this poses a problem:

With the increasing prevalence of morbidly obese patients, clinicians will more frequently be faced with obese patients with signs and symptoms suggestive of PE who either cannot receive thoracic imaging at their hospital because of their size or the imaging is inconclusive [...]. The clinician in this situation must first decide whether they should transfer the patient to another facility with a ‘heavyweight’ CT scanner. There are no guidelines to aid the physician in this situation. Locating these facilities is difficult since there is no website or national registry cataloging these CT scanners. In addition, risks are involved with such transfers, especially the risk of re-embolization during travel. Often there are questions about whether third party payors will provide reimbursement for these transfers. Finally, even though the patient may be transferred for the study, there is no guarantee that the study will be diagnostic since image quality may be poor, as described previously.

So, there is no protocol to contact local zoos.

Further, they reference another paper that considered the zoo angle for CTPA. ( CT pulmonary angiography is a particular subset of CT (computer tomography) diagnostic test.

In 2008, Ginde et al. published a study in which they surveyed 136 US academic hospitals and a random sampling of all non-federal USA hospitals with emergency departments to determine the availability of CT scanners capable of imaging obese patients. They located two 500 lb (227 kg) weight capacity scanners in their sample of hospitals and eight in the 136 academic centers they contacted. In addition, they contacted 145 zoos and 28 veterinary schools to see if any of these facilities had scanners used for large animal studies which could be used for obese humans. Only two zoos had CT scanners; both would not image humans. Sixteen of the veterinary schools had large weight capacity scanners but only four would consider scanning humans. Most of the veterinary schools had policies specifically prohibiting imaging human patients. Therefore, the rumor that zoos and veterinary schools will perform CTPA on very obese patients with suspected PE is false.

I checked the abstract of the cited 2008 paper and it concurred, on an even broader scale - all CT and MRI imaging:

Animal facilities are not a viable alternative for diagnostic imaging of human patients.

This is not evidence that it never happens - anecdotes would counter that - but merely that, as of 2008, it wasn't a common occurrence and wasn't a recommended practice.

Oddthinking
  • 140,378
  • 46
  • 548
  • 638
  • 2
    Like @ventsyv, I had doubted there was any serious research on the topic. One of those "pleased to be proved wrong" moments. – Oddthinking Dec 26 '17 at 04:22
  • 9
    To quantify the affair a little better, the 2nd paper says "Typically, CT and MRI equipment have table weight limits of 350–450 lb to avoid equipment damage and are additionally limited by gantry/bore diameter." And [another paper](https://www.ncbi.nlm.nih.gov/pubmed/18036363), which sets the limit more conservatively at 300 lbs, tells us how many US residents exceeded this: "The percentage of US adults, >or=20 years, weighing>or=300 pounds was 0.10%, 0.79%, and 1.50% in 1976 to 1980, 1988 to 1994, and 1999 to 2004, respectively (p trend<0.001)." – Fizz Dec 26 '17 at 14:16
  • 3
    This answer is well-researched but seems rather out of date. It wouldn't be surprising if generally increasing levels of technology had led to more zoos having higher-quality CT scanners since 2011, which could be more suitable for human use than the ones present most of a decade ago. – David Richerby Dec 26 '17 at 15:58
  • Maybe there has also been a decrease in funding for zoos since 2011? – jjack Dec 26 '17 at 17:44
  • 2
    @DavidRicherby: I concede the data is 10 years old now; I was careful to mention it. Don't forget that hospitals, too, benefit from advances, and I would like to think high-capacity scanners have improved there too, following the trend the first paper identified in 2011. Note also the non-technological aspects identified in the papers that are unlikely to improve as fast - zoo policies (presumably protecting from legal risk), insurance policies (who pays for travel/procedures?), travel risks, etc. – Oddthinking Dec 26 '17 at 21:37
10

There is anecdotal evidence to support the notion that some obese patients might have been referred to a zoo. Here is a recent NY Times article that explores the standard of care obese patients are receiving. From the article:

When an obese patient cannot fit in a scanner, doctors may just give up. Some use X-rays to scan, hoping for the best. Others resort to more extreme measures. Dr. Kahan said another doctor had sent one of his patients to a zoo for a scan. She was so humiliated that she declined requests for an interview.

I read another article (I can not find it at the moment) in which told a similar story. That article pointed out that the obese patient was turned down by the zoo as they are not trained to work on people.

That makes me believe obese people being treated at the zoo is not a regular occurrence but I doubt there is any serious research on the topic.

Laurel
  • 30,040
  • 9
  • 132
  • 118
ventsyv
  • 7,136
  • 2
  • 27
  • 44
  • 2
    "She was so humiliated"..... the main reason why I seriously doubt there is anything to the idea this is anything but obscure and rare. – PoloHoleSet Dec 26 '17 at 15:11
  • 1
    No one would make this up... – jjack Dec 26 '17 at 17:43
  • @PoloHoleSet If the alternative was between not getting a necessary MRI (The only MRI I've ever had was in Europe and the tube there definitely would not have fit a large percentage of the US population) or being humiliated, I think I'd go for the latter. You very rarely die from humiliation. Still I assume legal complications (who pays for it?) make it rare in any case. – Voo Dec 26 '17 at 19:59
  • @Voo - I might feel that way, too, but I don't know, first-hand, the societal shaming and disapproval that someone too obese to fit into an MRI lives with on a daily basis. Couple that with probably constant messages that their condition will be prematurely fatal and I can see many not feeling it's worth the humiliation to hear of yet one more way they are going to die if they don't lose weight. An emergency one? Sure, but that, by definition, isn't going to be "common." Understanding that people may feel this way doesn't mean I agree, either. I mean, it's the reason why many don't go to a gym – PoloHoleSet Dec 26 '17 at 20:09
  • 15
    @jjack it's demeaning to a poorly-defined and yet largely unpopular segment of the populace in a manner that a fair number of people would find amusing, and that can be used to win internet arguments or make political points. There are *absolutely* people out there who would make this up. – Ben Barden Dec 26 '17 at 22:34
  • 1
    @BenBarden I agree, this goes under "social engineering" (I'm not happy with this term). – jjack Dec 26 '17 at 22:37
  • 2
    "*I* haven't done it, but another doctor I know of has" sounds like a classic urban legend. (And if the patient was too humiliated to discuss the case, there ought to be zero chance that the reporter actually confirmed the case, as medical confidentiality would preclude putting the reporter in touch with the patient without the patient's consent.) – 1006a Dec 27 '17 at 06:17
  • @1006a It is a real problem however, see here: http://onlinelibrary.wiley.com/doi/10.1038/oby.2008.410/full – jjack Dec 27 '17 at 10:41
  • @jjack "*Typically, CT and MRI equipment have table weight limits of 350–450 lb to avoid equipment damage and are additionally limited by gantry/bore diameter*" while the number of 350 lb people is growing, it's still a pretty fringe portion of the set of obese people. For a 5'9" adult starts at 203 lbs, so you can bet it's a lot lower for females. Thus, it's **not common**, but certainly has happened. – RonJohn Dec 27 '17 at 14:11
  • @RonJohn Having seen some obese females on tv, I slightly doubt it's a lot lower. Maybe obesity washes out the classical gender difference in weight. Just a thought. – jjack Dec 27 '17 at 14:14
  • 1
    @jjack "on tv" that's correct: **on TV**. Where spectacle is the name of the game, you're going to see the 400 lb woman, not the 175 lb woman. – RonJohn Dec 27 '17 at 15:22
  • @RonJohn It's possible. – jjack Dec 27 '17 at 17:19
  • @jj "*It's possible.*" Two words: reality TV. Three more words: Honey Boo Boo. – RonJohn Dec 27 '17 at 17:32
  • @RonJohn The "it's possible" was for reality tv. That there is a problem with sticking obese people into regular CTs is shown by the scientific study I linked. – jjack Dec 27 '17 at 17:57