{"id":988,"date":"2017-04-21T15:29:19","date_gmt":"2017-04-21T15:29:19","guid":{"rendered":"http:\/\/blogs.nejm.org\/frontlines-clinical-medicine\/?p=988"},"modified":"2017-04-21T15:29:19","modified_gmt":"2017-04-21T15:29:19","slug":"brainstorm-subarachnoid-hemorrhages-affected-weather","status":"publish","type":"post","link":"https:\/\/blogs.nejm.org\/frontlines-clinical-medicine\/2017\/04\/21\/brainstorm-subarachnoid-hemorrhages-affected-weather\/","title":{"rendered":"Brainstorm: Are Subarachnoid Hemorrhages Affected by the Weather?"},"content":{"rendered":"
\"\"<\/a>

Harrison Reed, PA-C, practices critical care medicine in Baltimore, MD.<\/p><\/div>\n

When I walked into the ICU and stared at the roster of current patients, my jaw hit the floor.<\/p>\n

\u201cHo-lee cow,\u201d I said as I scanned the list of diagnoses. The entire unit was full of patients with hemorrhages in their skulls.<\/p>\n

\u201cYeah, man.\u201d The physician finishing the previous night\u2019s shift leaned back in his chair. \u201cDidn\u2019t you feel the change in weather this week? That\u2019s when all of the aneurysms pop.\u201d<\/p>\n

Oh, I had felt the change. Or rather, my congested sinuses and obstructed Eustachian tubes had. But it was still my first year at an academic hospital that saw dozens of neurologic catastrophes land on the helipad each month. I had been too focused on keeping patients alive to notice a trend.<\/p>\n

\"\"<\/a>Of course, I know the sayings we toss around on the wards like the tent poles of some unspoken religion: \u201cpatients come in streaks,\u201d and \u201cbad things happen in bunches\u201d and \u201cit\u2019s only quiet until you say it\u2019s quiet.\u201d I just always assumed it was superstitious small talk, something to pass the time on a night shift when the patients were asleep and the coffee pot was empty.<\/p>\n

But perhaps this trend in subarachnoid hemorrhages was something else. Surely, the infinite variables of climate and physiology had the potential to produce a real correlation. Besides, the idea of the weather exacerbating symptoms is not new. Hippocrates noted the effects of wind and rain on human disease as far back as 400 B.C. Even in the 20th<\/sup> century, physicians and laypeople alike thought that inclement weather could trigger severe arthritis pain. This belief was so entrenched that some doctors even advised their patients to move to more temperate regions.<\/p>\n

However, no science had ever proven this ubiquitous idea. Was the supposed correlation just an out-of-control superstition? Was it poorly understood pathophysiology? Or something else entirely?<\/p>\n

In the 1990s, legendary psychologist Amos Tversky decided to find out. He teamed up with physician Donald Redelmeier and tracked a group of patients with rheumatoid arthritis for 15 months. Tversky and Redelmeier recorded patients\u2019 pain, tenderness, and functional status and matched those parameters with variations in local weather. The two researchers found no significant correlation<\/a> between symptoms and climate.<\/p>\n

The perceived effect, Tversky and Redelmeier postulated, was merely a trick of the mind, a process called selective matching<\/em>. Patients simply paid more attention to the weather on days they experienced severe pain. On pain-free days, they had better things to think about.\"\"<\/a><\/p>\n

So, was this the answer to my ICU\u2019s streak of subarachnoid hemorrhages? Like the arthritis patients, were my colleagues paying extra attention to the weather when a patient with subarachnoid hemorrhage landed in our unit? Or were the elements actually wreaking\u00a0havoc on intracranial aneurysms?<\/p>\n

Luckily, plenty of researchers had the same question.<\/p>\n

In 1994, a group of researchers looked back at 18 months of admissions<\/a> and found that days with sharp changes in barometric pressure, as well as winter months, correlated with an increase in cases of subarachnoid hemorrhage. However, a 2010 five-year retrospective study<\/a> examining the same question found that subarachnoid hemorrhage incidence peaked in spring<\/em> and autumn<\/em> and was correlated with changes in humidity<\/em> but not barometric pressure. To further confuse the issue, the very next year a study<\/a>, claiming to be the largest yet, found no correlation between subarachnoid hemorrhage and changes in season or weather of any kind.<\/p>\n

A large meta-analysis<\/a> joined the fray in 2014 and added its own mud to the water. According to that analysis, January is <\/em>the peak month for subarachnoid hemorrhages. Of the included studies that broke weather down to specific measurements, just under half showed a correlation with atmospheric pressure, one-third showed a correlation with temperature, and one-fifth linked hemorrhages with humidity. The only problem: not all of the correlations moved in the same direction.<\/p>\n

That deluge of conflicting data might make you feel like you need a lumbar puncture of your own. The available research certainly leaves this question unresolved. For now, I\u2019ll continue to check the weather report whenever the neurologic intensive care unit fills up.<\/p>\n

But this topic is just one of countless ideas in medicine that could be based on either true physiology or our own flawed psychology. Since writing his arthritis paper, Dr. Redelmeier has gone on to make a career publishing articles with titles like \u201cDriving fatalities on Superbowl Sunday\u201d and \u201cThe survival of Academy Award winning actors and actresses.\u201d On your next shift, you might even have time to read them.<\/p>\n

That is, if the hospital is quiet and the weather outside is beautiful.<\/p>\n

 <\/p>\n

\"Register<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

When I walked into the ICU and stared at the roster of current patients, my jaw hit the floor. \u201cHo-lee cow,\u201d I said as I scanned the list of diagnoses. The entire unit was full of patients with hemorrhages in their skulls. \u201cYeah, man.\u201d The physician finishing the previous night\u2019s shift leaned back in his […]<\/p>\n","protected":false},"author":1271,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[17,29],"tags":[408,278,407,406],"class_list":["post-988","post","type-post","status-publish","format-standard","hentry","category-clinical-implications-of-research","category-patient-care","tag-epidemiology","tag-intensive-care","tag-seasonal-health-disorder","tag-subarachnoid-hemorrhage"],"_links":{"self":[{"href":"https:\/\/blogs.nejm.org\/frontlines-clinical-medicine\/wp-json\/wp\/v2\/posts\/988","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.nejm.org\/frontlines-clinical-medicine\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.nejm.org\/frontlines-clinical-medicine\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.nejm.org\/frontlines-clinical-medicine\/wp-json\/wp\/v2\/users\/1271"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.nejm.org\/frontlines-clinical-medicine\/wp-json\/wp\/v2\/comments?post=988"}],"version-history":[{"count":0,"href":"https:\/\/blogs.nejm.org\/frontlines-clinical-medicine\/wp-json\/wp\/v2\/posts\/988\/revisions"}],"wp:attachment":[{"href":"https:\/\/blogs.nejm.org\/frontlines-clinical-medicine\/wp-json\/wp\/v2\/media?parent=988"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.nejm.org\/frontlines-clinical-medicine\/wp-json\/wp\/v2\/categories?post=988"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.nejm.org\/frontlines-clinical-medicine\/wp-json\/wp\/v2\/tags?post=988"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}