Exam 3 🤲

Fluid Loss: Patients may come in wet with sweat; episodes of diuresis can result in loss of multiple liters of fluid per hour along with electrolytes.
- Fluid and electrolytes must be replaced promptly to maintain homeostasis.

Temperature Control Center:
- Located at the base of the brain near the pituitary gland.
- Responds to temperature fluctuations via thermoreceptors in the skin, extremity muscles, and spinal cord.
- Operates via a negative feedback system to maintain core temperature homeostasis and optimal physiological function through the sympathetic nervous system (SNS) hormone response:
- Vasoconstriction: Response to cold (shivering).
- Vasodilation: Response to heat (sweating).

Basic metabolic rate (BMR) is influenced by food intake, physical activity, and hormones.
Muscle contraction generates heat, particularly during shivering.
The sympathetic nervous system stimulates the production of hormones.
- Higher BMR means more heat production; BMR is typically higher in younger individuals and decreases with age.

Vasoconstriction is activated by SNS, alongside hormonal changes such as epinephrine, shunting blood away from the periphery to increase central muscle activity and minimize heat loss.
Example: Chilly sensation after eating is due to blood being redirected to the stomach for digestion.

The body converts chemical energy into thermal heat via circulating epinephrine and norepinephrine.
Fevers can signify a stressor to the body from disease or extreme activities/conditions such as heat stroke.

Radiation: Heat loss due to differences in skin and air temperatures, and types of exposure to air.
Conduction: Transfer of heat from one surface to another (e.g., ice packs).
Convection: Air movement, e.g., wind or fan.
Respiration: Increased breathing as a response to temperature rise; inhaling cooler air and exhaling warm air.
Evaporation: Induced by vasodilation causing sweating, which can lead to diaphoresis in extreme cases.

Decreased metabolic activity, ability to shiver/sweat, fat insulation, and perception of extreme temperatures (less vasoconstriction/vasodilation).
Alcohol (ETOH): A vasodilator that accelerates heat loss, especially in hypothermic situations.
Cocaine: A vasoconstrictor increasing the risk for hyperthermia.
Obesity: Generates more heat but cannot dissipate it effectively.

Sedatives: Such as opioids/antipsychotics blunt neuro-regulatory functions, increasing risk for hypothermia.
Antihypertensives: Like clonidine, affect vasoconstriction in hypothermic conditions.
Diuretics: Lead to dehydration, hindering sweat evaporation and increasing hyperthermia risk.
Anticholinergics: Decrease sweat production, raising hyperthermia risk.

Alcohol/Substance Abuse/Mental Health Issues: Cognitive impairment may lead to decreased reaction to environmental stressors.
Chronic Medical Conditions: Congestive heart failure (CHF), diabetes, autoimmune disorders that reduce body heat production.
Neurological Conditions: Stroke (CVA), traumatic brain injury (TBI), neoplasm, spinal cord injuries.
Thyroid Disorders: Hyper or hypothyroidism impact BMR significantly.

Cardiac arrest due to ventricular arrhythmias occurs at core temperatures between 32-35°C (89.6-95°F).
Patients may exhibit increased BP, HR, and RR with respiratory alkalosis; urine output increases due to cold diuresis (e.g., increased frequency of urination).
Mild Hypothermia: Core temp between 32-35°C; individuals may shiver to generate heat.
Moderate Hypothermia: Core temp between 28-32°C; may exhibit decreased shivering and altered mental status.
Severe Hypothermia: Core temp <28°C; no compensatory mechanisms are active.

Treatment must start with ABCs (Airway, Breathing, Circulation).
Passive external rewarming for mild hypothermia, active rewarming techniques in moderate to severe cases.
Active Rewarming Measures: Use of heated blankets, warm ambient air, and IV fluids to prevent further cooling.
For severe hypothermia, invasive measures may be required, but care is needed to avoid complications like arrhythmias.

Afterdrop: A phenomenon where rewarming leads to a drop in core temperature as cold, peripheral blood returns to the core.
Frostbite: Prolonged cooling leading to tissue injury; severity linked to exposure duration and environmental conditions.

Bacterial Meningitis: Rapid symptom development with potential for septic shock, high ICP leading to brain herniation.
Viral Meningitis: Usually less severe, flu-like symptoms, managed with supportive treatment.
Meningococcal Meningitis: Characterized by a purpuric rash, neck stiffness, fever, and altered mental status.

Diagnosis through lumbar puncture, where CSF analysis reveals low glucose, high protein, and high WBC count.
Initial treatment with intravenous antibiotics and supportive care.