hypothermia – why am i so cold? david feldstein, md primary care conference 5/26/04
TRANSCRIPT
Hypothermia – Why Am I So Cold?
David Feldstein, MD
Primary Care Conference
5/26/04
Objectives
Etiologies of hypothermia Clinical manifestations of hypothermia Causes of hypothermia in psychiatric
patients
I have not received any financial compensation for this talk
Case
CC: DeleriumHPI: 48 y.o. institutionalized man with hx
schizophrenia behavioral changes X 2 weeks slurring of speech and decrease in ambulation
and eating labored breathing day of admission. temperature 33.3 orally at his institution.
Case (cont)
PMH Gunshot wound to the head Paranoid schizophrenia HTN NMS secondary to ClozarilMeds: Aripiprazole (Abilify), ClonazepamSH Institutionalized for 20 years No access to tobacco, alcohol or illicit drugs
Case (cont)PE: T 33.2 rectal; HR 60; 129/76; RR 16; 95% RA Gen: Spontaneously opening eyes and moving
extremities. NAD HEENT: Pupils 1mm and sluggish Neck: Nonpalpable thyroid Lungs: Bibasilar crackles with poor effort CVS/Abd – WNL Neuro: Not following commands, Nml tone,
1+ DTRs, No clonus Skin: Cool to touch, no rashes Ext: 1+ pitting edema to knees bilaterally
Hospital Course
Head CT and LP were performed Blood cultures sent Vancomycin and Zosyn started empirically 12 hours after arrival in ED patient was
found to be completely unresponsive to painful stimuli
Temp 33.3 rectal; HR 52; BP 125/72
Definition of Hypothermia
Mild 32-35°C (90-95°F) Moderate 28-32°C (82-90°F) Severe < 28°C (82°F)
Causes of Hypothermia
Decreased Heat Production Increased Heat Loss Impaired Thermoregulation Miscellaneous
Decreased Heat Production Endocrine
HypopituitarismHypoadrenalismHypothyroidism
Insufficient FuelHypoglycemiaMalnutrition
Neuromuscular InefficiencyExtreme Age Impaired Shivering Inactivity
Increased Heat Loss Environmental Exposure Induced Vasodilation
EtOHDrugs
SkinBurnsPsoriasis
IatrogenicCold Infusions
Impaired Thermoregulation Peripheral Failure
Neuropathies Central Failure
MetabolicDrugsTraumaCVAHypothalamic dysfunctionMSWernicke’s
Miscellaneous
Sepsis Pancreatitis Carcinomatosis Uremia
Kramer et al.
Retrospective screening of patients over 60 with hypothermia in a community hospital in Jerusalem (1983-86)
Prognosis of Hypothermia (Kramer)
In hospital mortality – 74% Acute renal failure – 12% DIC – 9%
Back To My Patient WBC 1.9 –nml diff Hct 37 Plts 65 INR 1.1 / PTT 48.5 Na 140 K 5.7 Cl 110 CO2 25 Bun/Cr 23/1.0 Glucose 67
AST 62/ ALT 132 GGT 63 Tbili 0.4 TSH 5.16 / Free T4 0.8 Cortisol 18.6 Tox Screen – + benzos Head Ct – old trauma LP – 2 nucleated cells CXR- mild pulm edema ABG 7.26/61/105/26
Further Hospital Course Transferred to TLC Went for Head CT with contrast Woke up in scanner and combatative Temp 35.3 and patient back to baseline
per caregivers Given 10mg Haldol for outbursts 1 hour after Haldol was again
unresponsive with Temp 33.9
Clinical Manifestations CNS – amnesia, apathy decr level of
consciousness coma CVS – Tachy brady atrial/ventricular
arrythmias decreased co asystole Resp – Tachypnea decr ventilation with
bronchorrhea/bronchospasm loss of airway protection pulm congestion apnea
Renal – Cold diuresis decrease urine output Endocrine – Incr catechols, adrenal steroids and
thyroxine decr insulin activity decr BMR Neuromuscular – Incr muscle tone shivering
loss of shivering rigidity decr nerve-conduction and areflexia
Laboratory Manifestations
CBC – hemoconcentration/thrombocytopenia Lytes – hyperkalemia/hypernatremia Bun/Cr – increased Glucose – intially increased then can be
decreased Coags – increased ABG – hypercarbia/hypoxia/acidosis EKG – bradycardia/Osborne waves/atrial or
ventricular arrythmias
Osborne Waves
Antipsychotics in Hypothermia Chlorpromazine (Thorazine) – attempts to
use to induce hypothermia in 1950’s Multiple case reports of typical and
atypical antipsychotics causing hypothermia
Heh 19888 institutionalized patients with schizophreniaMeasured oral temp off antipsychotics then on
Haloperidol and then on ClozapineOral temp dropped on both antipsychoticsGreater drop with clozapine
Antipsychotics in Hypothermia (cont) Scwaninger 1998
Describes 10 cases of hypothermia secondary to atypical antipsychotics reported to German Federal Institute for Drugs and Medical Devices
Kramer 1989Found 22% of older patients with hypothermia in one
hospital were on antipsychotics (thioridazine most common)
Possible Mechanism
HypothalamusDopamine receptor antagonismSerotonin (5-HT2) antagonism
PeripheryAlpha receptor antagonism
Preventing vasoconstriction
Take Home
Hypothermia can occur without “cold” exposure
Antipsychotics may cause hypothermia much more commonly than we are aware
In the elderly hypothermia has a very poor prognosis
Without treatment hypothermia will progress with significant morbidity and mortality
References:1. Danzl DF, Prozoz RS. Accidental Hypothermia. NEJM
1994; 331(26):1756-60.2. Hanania NA, Zimmerman JL. Environmental Emergencies:
Accidental Hypothermia. Critical Care Clincs 1999; 15(2):235-49.
3. Kramer MR, Vandijk J, Rosin AJ. Mortality in elderly patients with thermoregulatory failure. Archives of Internal Medicine 1989; 149(7):1521-3.
4. Heh CW, Herrera J, DeMet E, et al. Neuroleptic-Induced Hypothermia Associated with Amelioration of Psychosis in Schizophrenia. Neuropsychopharmacology 1988; 1(2):149-56.
5. Schwaninger M, Weisbrod M, Schwab S. Hypothermia Induced by Atypical Neuroleptics. Clinical Neuropharmacology 1998; 21(6):344-6.