The NWS standard appears to require a complex calculation of the average high temperature. Do hospitals in heat plagued areas each have their own standard?
Am J Psychiatry. 2000 Aug;157(8):1327-9.
Heat intolerance in patients with chronic schizophrenia maintained with antipsychotic drugs.
Hermesh H, Shiloh R, Epstein Y, Manaim H, Weizman A, Munitz H.
email: [email protected]
Abstract
OBJECTIVE:
Schizophrenia may be associated with hyperthermic syndromes such as febrile catatonia, neuroleptic malignant syndrome, and heatstroke. The authors hypothesized that an exercise-heat tolerance test would disclose abnormal thermoregulation in schizophrenic patients.
METHOD:
Seven male schizophrenic outpatients in remission maintained on depot antipsychotic treatment and eight healthy comparison subjects completed a heat tolerance test that consisted of two 50-minute bouts of walking a motor-driven treadmill at 40xC (relative humidity=40%).
RESULTS:
A significantly higher rise in rectal and skin temperatures was observed in the patient group. No differences in heart rate, blood pressure, or perspiration were detected.
CONCLUSIONS:
Schizophrenic patients maintained on antipsychotic drugs exhibit impaired heat tolerance. Possible explanations are a reduced ability to convey heat from the body's core to the periphery with or without excessive heat production. The hyperthermic response to the heat tolerance test may reflect a dysfunction associated with schizophrenia, a neuroleptic-induced side effect, or both
So we all agree it is a risk, but locking people indoors all the time is not an option either. Can anyone provide examples of hospital poutdoors heat risk policies?
I cannot provide examples of policy. Partially, this is because I live in a cold place. However, the whole question of heat tolerance needs to consider heat regulation, activity (heat generation) and vulnerability to rhabdomylogis. People on antipsychotics have impaired thermoregulation and as has been pointed out this is due to a mixture of central and peripheral (e.g. anticholinergic effects). However, when agitation is present people generate more heat and it can lead to a syndrome resembling exertional heat stroke - and what used to be called catatonic excitement is one mechanism. Many drugs in addition to antipsychotics increase the risk of rhabdomyolysis (e.g. antihyperlipidemics), which can be very problematic (and dangerous). In addition to policies, I think people on antipsychotics need psychoeducation about these risks, need to keep adequately hydrated. And we should not forget the photo-sensitivity that goes with antipsychotic use for many people - sun protection is important too.
You are spot on. I also brief lithium patients about how to survive outdoors in a Carolina summer (temp right now is 95 and heat index 118).
There is a related issue: sunburn. I have seen a number of patients (all on the first generation antipsychotics) who showed rapid onset of sunburn--perhaps only 10 to 15 minutes of exposure--during a summer day. One patient came in after a short bike ride to my (former) office with have his face burned, half ok--just from the brief bike ride.
Unfortunately few practitioner's remember how prevalent photosensitivity once was with the TCA's and chlorpromazine
Another relevant issue is excessive layers of clothing in patients with schizophrenia, even in hot weather, further interfering with regulation of core temp while on antipsychotics.
Arnold VK, Rosenthal TL, Dupont RT, Hilliard D. Redundant clothing: a readily observable marker for schizophrenia in the psychiatric emergency room population. J Behav Ther Exper Psychiatry. 1993;24:45–47.
Cooling centers save lives. In areas of the world with high temps and poor electric system reliability fans and AC are not available to many persons, and access to water may be very poor. Factors for poor access to water include climate change and endemic water shortages in population centers undergoing rapid growth, like Lima, Peru. Multiple reports of heat wave deaths this past week in Pakistan with these conditions. Unknown to what degree antipsychotics or other medications contributed to these deaths, but this is an important public health question.
Thanks for the reference. I am currently trying to get a patient down from 5-6 shirts to just 1 or 2 since folks in the community will count first and ask questions later. One of our local MHC patients actually survived several summers here dressing in layers much to my surprise but he used to hose off in people's yards. He is now on clozapine and has an apartment.
We settled on a policy whereby patient activites outside would be limited in very cold or very hot weather. Provided the patient is dressed appropriately, we can have an activites outside for 30 minutes if the tempertuere is above 95 and 15 minutes if the temperature is below 33
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