Fever in the Elderly :How to surmount

The unique diagnostic and therapeutic challenges

• Emergency medicine practice

• October 1999 vol 1, number 5

Definition of elderly • Medical researchers consider elderly > 64yrs

old.• Fever is common compliant. • Elder visited to ES , about 10 % have a fever.• Among,70-90% will be admitted,7-10% will die

within one month .• Fever in elderly should be regarded with

concern. It presence usually presages serious disease.

• Fever in Younger patients, a benign viral syndrome.

• Fever in the elderly is associated with bacterial disease.

Pathophysiology of the development of fever

• Leukocytes was stimulated by infection , toxins, drugs, immune complexes, neoplasm.

• Cytokines release:IL-6, IL-1 ,TNF• Stimulate hypothalamus release PG-E • Affects:vasomotor centers heat production

behavior changes heat conservation

sympathetic nerves heat production

• Elderly people often have a lower baseline temperature

• In addition to the blunted fever response , makes an elderly patient less likely to reach a temperature traditionally considered a fever.

• Older patient are more likely to develope infection than younger adults

• Increased susceptibility is multifactorial • 1) Fragile skin with decreased vasculature and l

ess subcutaneous tissue contributes to slower wound healing and increased risk for skin infection.

• 2) less vigorous cough and decreased mucocillary clearance may predispose to pneumonia, particularly in COPD

• 3) DM , malignancies can diminish the immune response

• 4) Impairments in cell mediated immunity also contribute to increased infection rates.

Definition of fever

• Temperature >101F(38.3C)

sensitivity 40%

specificity 99.7%

If lowering the fever criteria to 99F(37.2C)

sensitivity 83%

specificity 89%

Clinical pathway: Evaluation of fever in the elderly patient

• Fever in elderly patient:

1. Rise of 2 F(1.1C) above baseline

2. Oral temperature of 99 F(37.2 C)

3. Rectal temperature of 99.5 F(37.5C)

• If fever defined as 101F(38.3C), a significant no of elderly have no fever with infection but they have a rise of 2.4F(1.3C)

• If change in temp of at least 2 F from baseline in elderly, indicate a serious underlying infection

Fever in edelderly patient : 1.Rise of 2C above baseline 2.Oral temp of 99F(37.2C)

3.Rectal temp of 99.5F(37.5C)

Temperature >41C

Complete history and physical with review of medical records and

additional information from any caretakers

Hyperthermia,Consider infection,

environmental Exposure

neruoleptic malignant syndrome

If Temp > 41C • Hyperthermia 1 Consider infection 2 Non –infectious life –threateni

ng cause of fever in the elderly a) Environment exposure heat stroke b) Drugs induced Salicylism c) Neuroleptic malignant syn

drome

• Large amount of life threatening fevers in elderly was caused by infection

• But have three condition that are not caused by infection

• Include 1 heat stroke , 2 salicylism, 3 neuroleptic malignant syndrome

• Thyroid storm and sympathomimetic overdose are also occasional causes of the threatening hyperpyrexia

• All of these conditions usually have fever over 103F and altered mental status

• But sepsis and meningitis are more common

• For these reason , aggressive antibiotics was also used while investigating possible non-infectious etiologies

Heats stroke

• Patient’s thermoregulatory mechanisms are unable to adequately respond to heat stress.

• Increase in body temperature leading to organ dysfunction and failure

• Temp usually excess of 41C (106F)• Classic heatstroke, precipitants include exposure to high

ambient temperature, • patient with a preexisting disease ( coronary artery dise

ase , diabetes, alcohol , and obesity )or medication ( phenothiazines, anticholinergics, sedatives, diuretics) that limits thermoregulation

Heat stroke S/S Symptoms• Fever• Altered mental status

(agitation, confusion)• Headache • Dizziness• Weakness• Anorexia • Stupor

Sign• Hyperthermia • Altered mental status (coma , s

tupor, agitation)• Hot, dry skin ( not universal )• Neurological deficits in severe

cases• Oliguria ( may be sign of rhabd

omyolysis in exertional heat stroke)

• Hypotension• ECC changes• Disseminated intravascular co

agulation(DIC)

Work up of stroke

• Rule out other cause of elevated temp (culture , and LP when indicated)

• Urinalysis , CPK , creatinine to rule our rhabdomyoslysis

• Electrolytes• Elvaluate for multiorgan dysfunctin (eg, liver functio

n tests and chest x-ray• PT, PTT (anticipation of DIC)• ECG (may show ST depression,T wave changes)

Treatment of stroke • Rapid cooling with evaporative methods( water sprayed on disrobed

patient along with use of fans)• Cooling should exceed 0.1 to 0.2 C/min with aggressive treatment u

ntil temp reaches 39C(102F), do not overshoot.• Use continuous rectal probe monitoring• O2 • Antibiotics• Benzodiazepines for shivering • Aspirin or acetaminophen should not be given• If rhabdomyolysis is present, fluid should be alkalinized and furose

mide administered to keep urine output at 100 ml/hr.• IV are generally indicated but should be used with care to avoid pul

monary edema • Complication include cardiovascular dysfunction (including CHF ), D

IC acute renal failure , rhabdomyolysis , seizure , liver injury (very common) , ARDS, electrolyte disorders, and death.

Drug induced hyperthermiaDrugs that cause muscular hyperactivity• Amphetamines• Designer amphetamines• Monamine oxiddase inhibitors• Cocaine• Methaqualone • Lithium• Antipsychotics• Tricyclic antidepressants• Halothane, cocaine, succinylcholine (malignant hyperthermia)• Lysergic acid diethylamide(LSD)• Phencyclidine (PCP)• Strychnine• Isoniazid (INH)• Sympathomimetics (theophylline, ephedrine, pseudoephedrine)• Serotonin syndrome(MAOIS+SSRIs, TCAs. Meperidine, dextromethorphan ,tryptopha

n )

Drug induced hyperthermia

Drugs that cause hypermetabolism • Salicylate • Thryoid hormone • Dinitrophenol • Symmpathomimetics • Ethanol withdrawal • Sedative hypnotic withdrawalDrugs that impair thermoregulation• Ethanol • Antipsychotics (Phenothiazines)

Drug induced hyperthermia

Drugs theat impair heat dissipation

• Anticholinergics

• Skeletal muscle relaaxants

• Antipsychotics

• Sympathomimetics

Salcylates poisoning

Symptoms• Mild or early poisoning (1 to 12 hours after acute

ingestion): nausea , vomiting , abdominal pain , headache, tinnitus, dizziness , fatique

• Moderate or intermediate poisoning (12 to 24 hours after ingestion ): fever, sweating , deafness, lethargy, confusion , hallucinations, breathlessness

• Severe or late poisoning ( greater than 24 hours after acute ingestion or unrecognized, untreated chronic ingestion ): coma, seizures, fever

Salcylates poisoning

• Sign• Mild or early: lethargy , ataxia , mild agitation , h

yperpnea, mild abdominal tenderness• Moderate or intermediate: fever, asterixis, diaph

oresis, deafness, pallor, confusion , slurred speech, disorientation .agitation , hallucinations, tachycardia, tachypnea, orthostatic hypotension

• Sever or late : dehydration , coma , seizures, hypothermia or hyperthermia , tachycardia, hypotension, respiratory depression, pulmonary edema, arrhythmias , papilledema

Treatment of Salcylates poisoning

• Rapid cool patient• Alkalinize urine with D5W with 3 ampules of sodi

um bicarbonate begin drip at 150ml/hr and target urine pH of 7.5

• Monitor serum electrolytes• Consider dialysis for renal failure if persistent aci

demia , pulmonary edema , deterioration despite supportive care, or severe mental status changes or coma , in the aged with comorbid disease.

Neuroleptic malignant syndrome• Precipitants : neuroleptic drugs( phenothiazines, butyrophenones, th

ioxanthenes)Symptoms• Elevated temp • Rigidity • Dyspnea• Tremor • Urinary incontinence • Dysphagia• Diaphoresis• Drowsiness• Confusion• Agitation

Neuroleptic malignant signs

• Elevated temperature (usually 38.5 to 42C)• Rigidity (classic lead pipe, which may be localized,

trismus, masked facies and dyskinesia)• Altered level of consciousness (from confusion and

agitation to lethargy , stupor, coma and mutism)• Autonomic dysfunction (tachycardia ,labile blood pr

essure , diaphoresis , tachypnea , hyperreflexia , pallor and dysrhythmias cardiac arrest)

Neuroleptic malignant Workup

• Diagnosis is established clinically and by exclusion

• Urinalysis (check for myoglobinuria) and creatinine phosphokinase to rule out rhabdomyolysis.

• BUN , Cr, LFTs , electrolytes, CA and Mg.

• Drugs level are typically normal.

Treatment of Neuroleptic malignant

• If infection is suspected, antibiotic administration is reasonable pending culture results

• Treatment is focused on the alleviation of symptoms and prevention of complication and consists of hydration, fever reduction , benzodiazepine sedation, and maintenance of appropriate fluid and electrolyte balance.

• Dantrolene sodium 2.5mg/kg/d iv , maxiumumof 10mg/kg/d (if muscle relaxation required)

• Some authorities bromocriptine 2.5mg -10mg po q8h ,• Benzodiazepines for muscle rigidity.• Amantadine 100mg bid (preferred for NMS in Parkinsons dis

ease)

Differential diagnosis• . • The predominant cause of fever in elderly,PUS have respiratory , urinary tract, and soft tissue infectious.• Bacteremia and sepsis had 40% occurred in elderly and estimated 6

0% will be deaths • Gangrene of the appendix and gallbladder are more common in eld

erly • 60% of tetanus and majority of shingles occur in the elderly.

Infection

• Endocarditis

• Pneumonia • Bacterial meningitis • Sepsis • Cholecystitis • Urinary tract infection • Tuberculosis• Appendicitis

Relative Mortality when compared with young adults

• 2-3x• 3x• 3x• 3x• 2-8x• 5-10x• 10x• 15-20x

If infectious diagnosis is missed, will increase mortality in the older adult

Differential diagnosis• If infectious diagnosis is missed, will increase mortality in

the older adult. • The predominant cause of fever in elderly, PUS have respiratory , urinary tract, and soft tissue infectious.• Bacteremia and sepsis had 40% occurred in elderly and

estimated 60% will be deaths • Gangrene of the appendix and gallbladder are more com

mon in elderly • 60% of tetanus and majority of shingles occur in the elde

rly.

Final diagnoses of febrile Elderly presenting to ED

Infection 89.4 %• Respiratory tract infections 31.5 % pneumonia 24.9% bronchitis 6.0% pharyngitis /Sinusitis . 1.3% • Urinary tract infection 21.7%• Skin /soft tissue infection 5.3 %• Bacteremia/sepsis 17.7%• Cholecystitis /Biliary tract 3.0 %• Diverticulitis /Abscess 2.3 % • Colitis/Enteritis 2.3 % • Meningits /Encephalitis 1.1 %• Osteomyelitis 1.1 % • Appendicitis 0.6 % • Epididymitis/Prostatitis 0.6 %• Viral syndrome 2.6 %Noninfectious 10.4%Diagnosis Unknown 5.7%

ED evaluation

• Ask family members or caretakers about recent falls, anorexia, decreased activity, new incontinence, or confusion

• elderly behavioral change ---hint of an underlying infection

• At least 75% of all episodes of functioal decline in elderly are due to infection

Historical clues to infections in the elderly

• Acute confusion or delirium• Change in functional status • Change in behavior• Anorexia• Weight loss• weakness • Lethargy • Recurrent falls• New urinary incontinence

Fever of unknown origin UFO

• UFO is defined as temp >38.3C , lasting longer than three wks without a diagnosis after one wks of hospital investigation

Diagnosis of UFO in the elderlyGeneral class ification Specific causes % subtotal

Infection Intraabdominal abscess 12%

Tuberculosis 6 %

Infective endocarditis 10%

orther 7%

Collagen vascular diseases Temporal arteritis 19%

Polyarteritis nodosa 6%

Orther 3%

Neoplasms Primary tumors lymphomas /hematologic cancerDegenerative CNS disorder

9%

Neurologic Degenerative CNS disorder 10%

Hemolytic cardiopulmonary Hemolytic disease

thrombophlebitis

Gastrointestinal Inflammatory bowel disease

Alcoholic hepatitis /cirrhosis

Granuloma hepatitis

Rheumatologic endocrine Stills disease

Pheochromocytoma

Hyperthyroid

Pharmacological psychogenic Drugs fever

Factitious

unknown 9%

Toxicity ?Unstable vital signs?Acute change in mental status?

1.Order the following :chest x-ray , urinalysis and urine culture, and blood culture .Evaluate need for LP 2 Administer stat broad –spectrum Antibiotics. If no obvious source, Consider: third –generation cephalosporin plus aminoglycoside or imipenem.3 Admit the patient

YES --

Source for fever?PneumoniaUTISoft-tissue infection Meningitis

No

S/S of pneumonia in Elderly patients

• > 65% absent fever

• > 65% Change in mental status

• 10 % recent falls

• > 50 % lack cough, sputum

• Likewise ,less to have classic symptoms of weight loss , night sweats and hemoptysis

PE of pneumonia

• Elderly with pneumonia (about 26-75%) had Tachypnea>30 breath /min

• A fast RR may precede other clinical findings of pneumonia by as much as 3 or 4 days.

• Pulse oximetry

• Presence of crakles

pneumonia

• One study, 75 yr old elderly with chest complaints or fever, >80 % had chest x-ray finding.

• Other study,¼ elderly patients had acute confusion with pneumonia patch in chest x-ray.

• Despite elderly had pneumonia, acutely ill and dehydrated patient may lack a characteristic infiltrate.

• On the other hand, COPD ,and CHF may obscure x-ray finding

pneumonia

• WBC : WBC increase , indicate infection WBC decrease , indicate worse prognosis• Sputum culture: Gram’s stain may help in diagnosis. Not recommended unless TB or fungus suspected, does not assist EP in making diagnosis• Blood culture: 28% pneumonia cases will be positive does not assist EP in making diagnosis

Urinary tract infection

• Dysuria , urgency , frequency , fever, chills , nausea, flank and costovertebral pain may be attenuated or even absent.

• Instead altered mental status , vomiting abdominal tenderness, respiratory distress

s/s Of Pyelonephritis In Elderly patients

Sign/Symptom• Gastrointestinal symptoms• Pulmonary symptoms• Constitutional symptoms• Costovertebral angle tenderness• Irritative voiding symptoms

Frequency

11%

14%

20%

50%

54%

Urinary tract infection

• Fever• Chills• Nausea• Flank and costovertebral pain • Altered mental status • Vomiting • Abdominal tenderness• Respiratory distress• rales

PE of Genitourinary

• Costovertebral angle tenderness indicate Upper UTI • But less than half of the elderly with pyelonephritis had c

ostovertebral angle tenderness.• Suprapubic tenderness indicate cystitis• Prostatitis• Pain in the perineum , radiating to the thighs and penis, v

oiding urine is painful and the stream is thin , frequency of micturition , high fever.

• A rectal examination reveals tender, swollen gland. The urine may or may not grow pathogenic organisms on culture.

• Exam of the external genitalia may reveal redness, tenderness, or discharge.

Intra-abdominal infection in elderly

• Most common: appendicitis , cholecystitis and diverticulitis.

• Elderly usually lack of focal tenderness.• Even GI perforation , peritonitis can occur

without pain or fever. • Elderly with appendicitis, 60% death.• Complication such as Gangrene ,

perforation, abscesses, peritonitis, more than the younger.

PE of Intra-abdominal infection in elderly

• Abdominal tenderness is an important finding• Cholecystitis :74-84 % RUQ pain or

epigastric pain.• Appendicitis :most case had RLQ pain• Diverticulitis :2/3 case had LLQ pain • Elderly patients have no significant abdominal te

nderness with surgical emergency : 25% Cholecystitis , 34%appendicitis ,13-30% diverticulitis

Diagnostic abdominal infection

• CBC/DC

• LFT, amylase, lipase

• If cholecystitis , RUQ sonography is

considered.

Diverticulitis disease is generally made clinically , though complication such as obstruction and abscesses are best seen on CT