2Maintaining body temperature how does the body do this Heat productionBasal metabolic rateVoluntary movementShiveringHeat lossRadiationConductionConvectionEvaporation – includes diaphoresis
3Maintaining body temperature Heat productionBasal metabolic rateVoluntary movementShiveringHeat lossRadiationConductionConvectionEvaporation – includes diaphoresisWater loss via respiration.
4Body temperatureCore temperature is the temperature of the internal environment of the body.This temperature is relatively constant.It is regulated by the hypothalamus – (Gk – hypo – below, thalamos – chamber.) The hypothalamus activates, controls and integrates the peripheral autonomic nervous system, endocrine processes, and many somatic functions like temperature, sleep and appetite.
6Body temperatureCore temperature is the temperature of the internal environment of the bodyThis temperature is relatively constant.It is regulated by the hypothalamusThe surface temperature is the temperature at the surface of the bodyThe environmental temperature and blood circulation has a greater impact on this temperatureThe range of temperature is greater
7Body temperature regulation Sensory receptors – primarily the skin.Hypothalamus – controls core temp.Effector system –- prevents heat loss by –ShiveringPeripheral constrictionRelease of epinephrine – increases BMR.- Promotes heat loss by –SweatingPeripheral vasodilation
9Factors affecting body temperature Age – very young, elderlyExerciseHormonal level – ovulationCircadian rhythm – higher in the late afternoon, early eveningStressEnvironmentAlteration in body function – infection, dehydration
10Terms related to body temperature Normothermia – 36.1 – 37.2AfebrileFeverFebrilePyrexiaHyperthermiaRigorhypothermia
11Moderate high grade temperature 38-40 C Low grade feverTemperatureNormal to 38Possible causeInflammatory response to mild infection, allergy, disturbance of body tissue by trauma, surgery, malignancy or thrombosisModerate high grade temperature38-40 CMay be caused by wound, respiratory or UTIHyperpyrexia= to 40 CMay be caused by bacteraemia, damage to the hypothalamus ore high environmental temperatures
12Patterns of feverSustained a constant body temperature continuously above 38 that demonstrates little fluctuationIntermittent fever spikes interspersed with usual temperature levels. Temperature returns to acceptable levels at least once in 24 hours.Remittent fever spikes and falls without a return to normal temperature levelsRelapsing periods of febrile episodes interspersed with acceptable temperature values. Febrile episodes and periods of normothermia may be longer than 24 hours
13S&S of fever ONSET Increased HR Increased RR Shivering – why? Pallor & cold skin – why?Patient c/o feeling cold‘goose bumps’Cessation of perspirationRise in temperature
14S&S of fever PROGRESSION Absence of shivering Skin feels warm to touch – forehead, cheeks.Increased P & RRIncreased thirstMild to severe degydrationDrowsy, restless + / - delirium (if very high)AnorexiaMalaise, weakness, ‘aches & pains’
15S&S of fever ABATEMENT Skin flushing, feels hot Sweating Decreased shiveringPossible dehydration
16FeverFlushing can occur on the face or over the entire body.
17Hyperthermia – 38-41C Heatstroke Those at risk The very young the very oldCardiovascular disease, hypothyroidism,diabetes or alcoholismMedications (phenothiazine's, anticholinergic, diuretics, amphetamines and beta –adrenergic receptor antagonistThose who exercise or work strenuously - athlete, construction workers and farmers
18Signs and symptomsGiddiness, confusion, delirium, excess thirst,nausea, muscle cramps, visual disturbances and even incontinence.
19Hyperthermia - heatstroke Victims of heatstroke do not sweat because of severe electrolyte loss and hypothalamic malfunctionsHeatstroke greater than 40.5 C produces tissue damage to the cells of all body organs. Vital signs may indicate temp greater than 41C , tachycardia, and hypotension.Temperatures above 41C can cause convulsions and a temperature of 43 C renders life unsustainable.Heat exhaustion occurs when profuse diaphoresis results in excess water and electrolyte loss
20hypothermiaBody temperature drops and mechanisms to increase heat production are ineffectiveCausesEnvironmental exposureMedication ( alter perception , cause heat loss through vasodilatation, inhibit heat generation eg panadol, alcohol)Metabolic conditions eg hypoglycemia and adrenal insufficiencyExposure of internal organs during surgery
21hypothermia Core temperature Mild (33.1-36) Moderate (30.1 – 33) Severe (27 -30)Profound ( less than 27)To 35- shivering , loss of memory, depression and poor judgment34.3 – cardiac dysrythmias , loss of consciousness, unresponsive to pain
22hypothermiaFrostbite- when the body is exposed to subnormal temperatures the ice crystals that form inside the cell can result in permanent circulatory and tissue damage. The area is white , waxy and firm to the touch)
24Conditions requiring frequent monitoring Patient’s condition affects their BMRPost operativelyCritically ill patientsPatients susceptible to infectionImmuno compromisedThose undergoing chemotherapy, radiation therapy or steroid therapyPatient has local or systemic infectionPatients receiving a blood transfusion
25Types of thermometers Tympanic Electronic Digital Disposable (not used in hospitals)
26Contraindications/ cautions for oral temperature Children younger than 5 yearsConfused or combative patientsThose that cannot close their mouth fully (injury , surgery)Unconscious patients or those prone to convulsionsMouth breathersMouth infectionWait 15 minutes after patient smokes, drinks, eatsPlace thermometer in the sublingual pocketLeave insitu for 2 minutes with lips closed
30Contradictions/ cautions for rectal temperature Don’t use this route if patient has rectal or perineal injuries or surgeryA rectum full of soft faeces may cause an inaccurate reading (lower)This site is least used (because of its intrusive nature) but it is more accurate than the others though there is lag time with febrile states.Lubricate and insert (at least 4 cm) gentlyDon’t leave patient unattended and ensure that patient doesn’t moveLeave insitu for 2 minutes
31Cautions and /contraindications for tympanic temperature Remove hearing aidsDon’t use the ear that the patient has been lying onMost commonly used siteWax buildup may lower temperatureOtitis media may increase temperatureThe tip of the thermometer has to fit snugly and point to the tympanic membrane to read accurately
35Contraindications and cautions for axilla temperature Area must be dry and cleanThere must be contact with both skin surfacesThe thermometer may have to be helped in positionThe least accurate site (surface temperature)The thermometer must be insitu for 5 minutes