MedSurg Module 7

What are factors that affect thermoregulation?

-environmental temperature

-humidity

-human behavior

S/Sx of Alterations in Thermoregulation

-chills, shivering

-diaphoresis, flushing

-fatigue (confusion, delirium, agitation, hallucinations in extreme cases)

-headache, dizziness

-changes in HR (tachycardia for hyperthermia & early stage hypothermia, Brady for severe hypothermia)

Patho of Fever

-body temp elevates d/t change in hypothalamic set point

-pyrogens act on hypothalamus which then releases prostaglandins

-hypothalamic set point temp increases, heat generating mechanisms kick in, body temperature rises & reaches new baseline

How do NSAIDs or aspirin reduce fever?

inhibit prostaglandin production (prostaglandins are released by hypothalamus to stimulate heat production)

What are the benefits of a fever?

-inhibits bacterial growth by making growing conditions less favorable

-increases efficiency of immune cells

Nursing Interventions - Hypothermia

-remove wet or damp clothing

-move to warm, dry, sheltered environment

-active warming: heat blankets, forced air warming systems, circulating water garments or mattresses, connective air heaters or warmers

-passive warming: blankets or metal-plastic sheets that reflect heat

-monitor VS, cardiac rhythm, mental status

Nursing Interventions - Hyperthermia

-move to cool, shaded environment

-oral replacement of fluids & electrolytes

-remove excess clothing

-use of misting fans, douse with cold water

-ice packs

-core temperature monitoring

-IV rehydration

-monitor vitals, cardiac rhythm, mental status, serum electrolytes

Malignant Hyperthermia

-autosomal dominant inheritance muscle disorder

-triggered by anesthesia, muscle relaxants, stress, cardiac glycosides, sympathomimetics

-hyper metabolic condition in skeletal muscle cells that involves altered mechanisms of calcium function at cellular level

-disruption of calcium causes hyper metabolism, which in turn increases muscle rigidity

-sustained muscle contraction causes hyperthermia & subsequent damage to CNS

-myoglobin, CPK, & potassium are released into circulation leading to arrhythmias & kidney damage

S/Sx - Malignant Hyperthermia

-tachycardia >150

-hypotension/unstable BP

-decreased cardiac output

-ventricular arrhythmias

-muscle rigidity

-temp elevation

-tachypnea

-profuse diaphoresis

-oliguria

-cola-colored urine

-cyanosis/mottling

-excessive bleeding

Management of Malignant Hyperthermia

-discontinue anesthesia

-hyperventilation of 100% O2

-dantrolene (2.5mg/kg)

-central line placement

-cold NS infusion (15ml/kg Q15 for at least 45 minutes)

-active cooling

-monitor core temperature

What populations are at risk for alterations in thermoregulation?

-older adults

-malnourished individuals

-disorders restricting mobility

-peripheral neuropathies

-endocrine disorders: hypothyroidism, diabetes, adrenal insufficiency

-medications: clonidine, beat blockers, calcium channel blockers, topiramate, anticholinergics, psychomotor stimulants

-athletes: football, cyclists, runners

-firefighters, field laborers, military

-urban living

-surgical patients

Hypothermia

-core body temp

Mild Hypothermia

-90-95 degrees

-impaired judgement, cognition

-vigorous shivering

-fine motor skill impairment

-tachypnea

-tachycardia

-polyuria/diuresis

-pallor

-cold extremities

Moderate Hypothermia

-82-90 degrees

-bradycardia

-bradypnea

-dysarthria

-further mental impairment

-paradoxical undressing

-gross impairment of motor control

-cessation of shivering

-muscle rigidity

-hyporeflexia

-cyanosis

Severe Hypothermia

-

Risk Factors for Frostbite

-inadequate insulation against cold

-wet clothing

-fatigue

-dehydration

-poor nutrition

-smoking

-alcohol use

-impaired peripheral circulation

-previous history of frostbite

S/Sx - Frostbite

-grade 1 (hyperemia or frostnip): increased blood flow, edema

-grade 2: blister development, partial thickness skin necrosis

-grade 3: dark blisters, SQ tissue necrosis

-grade 4: numb, cold, bloodless, full-thickness necrosis into muscle & bone

Prevention of Frostbite

-maintain peripheral perfusion

-exercise

-protection from cold

Treatment of Frostbite

-protect from further damage

-rewarm

-pain management

-wound care

Hyperthermia

-heat exhaustion

-heat stroke

Heat Exhaustion

-100.4-104

-sweating

-flushing

-fatigue

-dizziness

-headache

-weakness

-muscle cramps

-nausea

-tachycardia

-postural syncope

-mild confusion/agitation

Heat Stroke

->104

-confusion

-delirium

-hallucinations

-hot, dry, red skin

-anhidrosis

-elevated troponin

-seizures

-coma

-organ damage: brain, heart, kidney, liver

Classic Heat Stroke

-occurs in individuals who have impaired thermoregulatory physiology & are deficient in mechanisms for heat dissipation or lack the awareness or the means to escape from a hot environment

Exertional Heat Stroke

-typically occurs in young, healthy individuals who engage in strenuous physical exercise during hot weather or in environments that restrict heat dissipation

Patho of Heat Stroke

-brain & liver cells sustain damage from heat

-blood-brain barrier permeability is increased

-sympathetic nervous system shunts blood flow to skin for that release, causing hypo perfusion of vital organs

-systemic inflammatory response can lead to DIC

Interventions - Heat Stroke

-ABCs: oxygenate & prepare for intubation, monitor ABGs

-large bore IV for IVF

-core temperature monitoring

-no antipyretics b/c hypothalamus is overload & aspirin does not help

-ice water immersion, dousing

-vital signs & cardiac monitoring

-electrolyte/coagulation monitoring

-urinary catheter insertion, monitor I&O, specific gravity