Intern Curriculum – Approach to Fever

Intern Curriculum – Approach to Fever

Seth Politano, D.O.Associate Program Director

Assistant Professor of Clinical MedicineKeck School of Medicine at USC

Case 1

A 42 year old female with history of DM2 and HTN presents to the hospital with a chief complaint of fever and chills x 5 days. She is admitted to your medicine ward team

At what temperature would you say she has a documented fever?

Definition?:

Since an oral temperature is 0.5°F (0.3°C) to 1°F (0.6°C) lower than a rectal or tympanic temperature:

Rectal temperature ≥ 100.4°F - Core temperature

Tympanic temperature ≥ 100.4°F - Core Temperature

Oral temperature ≥ 99.5°F-99.9°F

Axillary temperature ≥ 99.0°F-99.5°F

PEARLS:- This is not absolute, remember that fever is a relative condition- Have a lower threshold for fever at 6am or 6pm- Inability to mount a fever is common in some patients- Keep antipyretics and recent intake in mind when considering

fever

Case 1

A 42 year old female with history of DM2 and HTN presents to the hospital with a chief complaint of fever and chills x 5 days.

Her oral temperature is 101.2

What are the first things to evaluate/consider regarding the patient (taking into account the ER already sent some basic labs?)

When first evaluating the patient:

Although fever is a “normal response”, prolonged episodes can cause damage

&Always evaluate for stability (regardless of what you think is the cause):

Case 1

A 42 year old female with history of DM2 and HTN presents to the hospital with a chief complaint of fever and chills x 5 days.

Her oral temperature is 101.2. A basic review of SIRS criteria reveals that her pulse is 110. Otherwise she does not fulfill any other SIRS criteria.

She reports that her fevers at home (as high as 102) only occur in the evening, usually around 5pm. Given this info, what do her pattern and pulse have to do with fever?

Fever PatternIt is important to note that the cycle of fever pattern is often not very helpful in determining the cause of the disease.

Possible exceptions are: tertian and quartan malaria, abscesses, Pel-Ebstein Fevers and Drug Fever

Relation to PulseLiebermeiser’s rule: For every degree the temperature increases above normal, the pulse will increase by 8-10 beats per minute.

Faget’s Sign: The exception to Liebermeiser’s Rule. This Relative bradycardia may be useful when present, although it is associated with a substantial differential diagnosis, including Typhoid fever, rickettsial diseases, yellow fever, legionnaire's disease, psittacosis, leptospirosis, drug fever, brucellosis, mycoplasma infections, neoplasm and factitious fever.

Case 1

A 42 year old female with history of DM2 and HTN presents to the hospital with a chief complaint of fever and chills x 5 days.

What are you going to ask her in the HPI? Past Family/Social/Personal/Medical History?

Hints to Obtain from History:(Since Presentation can be non-specific !!!!) • Detailed Fever History• Medication Review• Family illnesses• Ethnicity• Detailed history of past surgeries• Recent sick contacts and TB contacts/risks• Host Factors (?Immunocompromised)• Recent travel• Environmental exposures associated with jobs or hobbies • Animal exposure• Unusual dietary habits• High risk behavior• Sexual History including Contraceptives• Gynecologic History • Hypersensitivities to environmental agents/meds or FHx of such

Case 1

A 42 year old female with history of DM2 and HTN presents to the hospital with a chief complaint of fever and chills x 5 days.

What are you looking for on her physical examination?

Hints to Obtain from Exam:Vital Signs: All of them…. Stability!!!!General: Appearance - Do they look sick? Anxious? Are they altered/encephalopathic?HEENT: Eyes and Fundoscopic Exam, Nuchal Exam, Thyroid,

Oral Infections, Dental Exam/Gum Exam, Sinuses Chest: Murmurs? Pulm: Bronchial Sounds, Decreased Breath Sounds, Adventitious SoundsAbdomen: Tenderness, Organomegaly, AscitesSkin: Rashes, Nail Exam, Wounds/Decubitus UlcersMS: Joint Exam, Muscle Tenderness. Thrombosis.Neurologic Exam: Mental Status, Encephalopathy,

Localizing on Exam?Genital/pelvic exam and rectal exam Look for FluidLook for indwelling devicesLymphadenopathy

Case 1

A 42 year old female with history of DM2 and HTN presents to the hospital with a chief complaint of fever and chills x 5 days.

As you write your note, what is your basic differential diagnosis?

Of Course… the Differential is VERY Broad:

Infection (TB, PNA, UTI/Prostatitis, BSI, Endocarditis, Abscess, Line Infection, Sinusitis, Meningitis, Arthritis Osteomyelitis/Wound, Infectious Diarrhea/c. Diff)

Inflammatory (Rheumatic Disorders, Vasculitis, Neoplasms)

Drug Fever (Beta-Lactam antibiotics, Ampho B, Chemo, Drug Interactions)

Thrombotic (DVT/PE/MI)

Neurologic (Hypothalamic disorder, Spinal Cord Injuries, ICH)

Endocrine (Thyrotoxicosis, Adrenal Insufficiency, Subacute Thyroiditis)

Gastrointestinal (IBD, Pancreatitis, Cholecystitis)

Hospital Acquired Fever Differential (> 48 hours)

Hospital Acquired PneumoniaCatheter/Line Infection/Blood Stream InfectionUTIWound Infection/Decubitus ulcersPseudomembranous colitisSinusitisAbscessSeptic Thrombophlebitis/ThombosisDrug ReactionIschemic DiseasesAcalculous CholecystitisPancreatitisEndocrine DisordersPost Operative State/Atelectasis?Alchohol Withdrawal

Case 1

A 42 year old female with history of DM2 and HTN presents to the hospital with a chief complaint of fever and chills x 5 days.

What would you order as far as the “basics?”

Fever WorkupAt a minimum in ALL Patients:- CBC with differential and micro review- CXR PA and Lateral. Add Decubitus if needed. Infiltrates negative if dry- Urinalysis (with Microscopy) and Urine Culture - 2 sets of blood cultures + Cultures from any central catheter -Electrolytes and Metabolic Panel, LFTs, Hepatitis Panel, HIV Test, PPD

Plus any other Specific Procedures/Labs to Obtain Data-Autoimmune Workup (RF, ANA, etc as history guides… ESR? CRP?)-Specific Viral Serologies-Lumbar Puncture, Thoracentesis, Arthrocentesis, Paracentesis-CT Scan of Head-CT PE Protocol/Dopplers of extremities-Echocardiogram-Stool Cultures - Gram Stain, O&P, C. diff Toxin etc-Sputum Cultures (Have RT induce if needed)-Skin Biopsy

ESR

Normal: Men = Age/2 Women = Age+10/2

Elevated in:Acute or Chronic InflammationInfectionTissue InjuryThyroid DiseaseAzotemia

An elevated ESR does not rule in or out disease

As opposed to the ESR, the CRP increases more quickly with an acute process, and decreases for quickly when the underlying state resolves .

ESR > 100

T - TBO - OsteoE - EndocarditisV – Vasculitis (Temporal Arteritis, PMR, ANCA)A - AbscessN – Neoplasm (esp Lymphoma, Plasma Cell)

Case 2

You are the ward intern

The float admits a 48 year old AAF with a history of DM and prior IVDU. She was admitted for diarrhea, nausea and fevers up to 102.5 of 6 days duration after injecting heroin, Vital signs are stable but notable for temp ranging from 101-102.4. She has a new regurgitant murmur on examination (per ROR account) , splinter hemorrhages and diffuse abdominal pain, notably worse in the LLQ. The patient spikes fevers around 1pm and 11pm every day. The patient has been waiting in the ER for 48 hours, and we have two sets of blood cultures from the 11pm fever spikes which remain to be negative for 2 days. There is another set “cooking” from the float.

1) When do you draw blood cultures?

2) What special information do you tell the lab about the blood cultures?

3) Peripheral blood smear does not reveal malarial forms. In addition to the basic labs/imaging, what would you suggest in regards to workup further primary team with these recurrent fevers? (hint: imaging study)

1) When do you check blood cultures on your call night?

Tell the nurse to draw them at 12pmThe bacteriologic burden is highest in the blood stream approx 1 hr before fever

spikes

2) What special information do you tell the lab about the blood cultures?

If you are suspecting endocarditis, tell the lab to continue following the cultures for at least 4 weeks. Usually if they do not turn negative in a week then they are discarded. The “culture negative” causes of endocarditis commonly grow around two weeks (aka the HACEK group)

3) Peripheral blood smear does not reveal malarial forms. In addition to the basic labs/imaging, what would you suggest to the primary team with these recurrent fevers?

Although not specific for the entity, spiking fevers at certain times of the day may suggest an intraabdominal abscess.

Case 3

A 89 year old man with history of vascular dementia, CAD (MI x 2 and s/p stent), DM and BPH is brought in from the nursing home for documented temperature of 102 degrees.

When would you start him on empiric antibiotics?

What would you give to lower the temperature?

In what circumstances would you lower the temperature?

Treatment of The Fever Itself:

1) Give empiric Antibiotics when there is high suspicion of the source of infection or if the source is unknown and the patient is unstable… Then take it from there.…

2) To Treat or Not To Treat the Numbers… Tylenol 650mg po q4h for most fevers with discomfort

NOTE: neoplastic fevers respond to NSAIDS better

3) Don’t always lower the temperature so readily.

This decreases your ability to know when to draw cultures and may lower the patient’s defense mechanism. Once workup has been performed (and possibly repeated) then temperature can be lowered. However, have low threshold for lowering the temperature when there is a hypermetabolic state that would be damaging (i.e concurrent MI, CVA, AMS) or if the patient is very symptomatic

Hyperthermia

As opposed to Fever, Hyperthermia is an increase in temperature over the body’s thermoregulatory set-point. This occurs when body metabolic heat production or environmental heat load exceeds normal heat loss capacity or when there is impaired heat loss.

These patients usually will have temperature elevations above 102 degrees

- Heat Stroke: Exertional vs. Non-Exertional

- Heat Exhaustion

- Thyrotoxicosis

- Drug Induced

- Pheochromocytoma

- Central Hyperthermia/Dysregulation (post trauma/CVA)

Malignant Hyperthermia

1) Halogenated inhalation agents and depolarizing muscle relaxants are most often responsible. 2) + Family History. 3) High Fevers and severe muscular rigidity is characteristic:

Other typical findings include HypotensionTachycardia/arrhythmiasTachypnea/hypoxia and/or hypercapniaLactic acidosis, hyperkalemia, rhabdomyolysisDisseminated intravascular coagulation

Neuroleptic Malignant Syndrome Meds: Seen in about 0.2 percent of patients who receive neuroleptic agents, usually within the first 30 days of therapy, but can happen over years. Others implicated include Phenergan and Reglan

Clinical: Over a period of 24 to 72 hours, symptoms commonly include• Altered Mental Status• Muscle rigidity• Extrapyramidal abnormalities• Autonomic dysfunction (Tachycardia, labile blood pressure,

diaphoresis, tachyarrhythmias, tacypnea and incontinence)

Laboratory: • Hemoconcentration with leukocytosis and hypernatremia, • Rhabdomyolysis• Acidosis, Hyperkalemia, HypoCa, HypoMg• Increased Cr, AST/ALT and Alk Phos

Serotonin Syndrome:

Meds: Many drugs/combination implicated: These include MAOIs, TCAS, SSRIs, opiates, cough medicines, weight-reduction agents, antiemetics, antimigraine agents, drugs of abuse.

Clinical: • N/V/Diarrhea Prodrome• Fever• Agitation/AMS• Tachycardia• Hypertension with Mydriasis• Hyperreflexia/Myoclonus

Case 4

A 52 year old woman with no past medical history comes to the ER for chief complaint of fevers up to 102 degrees, chills and a rash of 4 weeks duration. She is frustrated by her PCP, who is unable to give her an answer despite an extensive workup.

What is this called?What is the differential?

Fever of Unknown Origin(1) a temperature greater than (101°F) on several occasions, (2) more than 3 weeks' duration of illness, and (3) failure to reach a diagnosis despite 1 week of “active” investigation

Studies show that H&P can give the answer in approximately 70% in these cases. Must Think of uncommon causes such as:Infection (TB, Prolonged Mononucleosis, Syphilis, Abscess)

Slow-Growing HACEK, Brucella, Borrelia, Trypanosoma, Leishmania, Toxoplasmosis, Coxietta. Also: Sinusitis, Prostatitis, Cholangiitis)

Occult malignancy (HCC, RCC, Leukemia, MDS)Rheumatic (PAN, Still’s, Wegener’s, Sarcoidosis, PMR/TA, Cryoglobulinemia, IBD, Granulomatous Hepatitis)Periodic Fever Syndrome (FMF, TRAPS, Muckle-Wells)Other: Factitious, Drug, Embolism/ThrombosisIn 5-15% of cases – a source never found…

Case 4

A 52 year old woman with no past medical history comes to the ER for chief complaint of fevers up to 102 degrees, chills and a rash of 4 weeks duration. She is frustrated by her PCP, who is unable to give her an answer.

How do you approach the workup?

Fever of Unknown Origin - Workup

Begins Similar to Fever, but more extensive::(CBC with Diff and Smear, UA, LFTS, BMP, UA with Micro, CXR, Blood Cultures and other Fluids….)

+PPD, Muscle Enzymes, ANA, RF, CRP/ESR, VDRL, SPEP, HIV, CMV, EBV

If Negative: CT Chest, Abdomen and Pelvis and consider Colonoscopy and/or TEE

If Negative G67 or 11IN Scan

May Move on to Liver and Bone Marrow Biopsy

If Still No Answer some may start empiric Treatment for TB!!!

Case 5

A 62 year old HM with history of Stage II colon cancer, s/p Sx and now on FOLFOX treatment, presents with a complaint of fevers, rigors, dyspnea on exertion and productive cough.

What are some considerations in the cancer patient what presents with fever?

1) They are more immunosuppressed

2) What is their access?3) Are they Neutropenic?4) Examine Mucosal Integrity5) Malignancies can cause

fever6) Be worried about mets

Neutropenic Fever

Line Infections

-ALWAYS suspect with fever in a patient with dialysis catheter, Central Line, Portacath… !!!!

- A Clean entry site does not rule out line infection!- Dx best with: 1) Semi-Quantitative culture: >15 CFU at catheter tip 2) Qualitative - Draw blood cultures at PIV and from catheter at same time. IF time to positivity is less for central line than PIV, then line is source

-As a general rule (For Central Lines)1)Remove the catheter2)Start antibiotics 3)Redraw cultures after period of treatment4)If needed, replace Line once cultures are negative x2-3 days5)Some HD patients get “treated through the line” for bacterial

infections due to access problems

Case 6

A 38 year old African American man with h/o Metastatic Gastric Adenocarcinoma, HTN and Dyslipidemia has c/o Fever and chills up to 103o at home for 3 days. S/P complete cycle of ChemoRx. Patient has been on TPN for 2 months. Denies any dysuria, pain near Portacath site, chest pain, dyspnea or cough. Has taken Tylenol which doesn’t help the fevers but alleviates the malaise. He is admitted to you, with vital signs of T 102.5, P 110, BP 92/62 and RR 14 with 100% Room Air Saturation. Exam is non-revealing for source of fever. You initiate a standard workup which reveals a WBC count of 25 with 96% Polys and 7 bands. Chest X-Ray is Clear. Suspecting Line infection you start the patient on IV Cefepime and Vancomycin, and give aggressive fluid management.

The Lab calls you overnight to inform you that prelim Blood Cultures from the Portacath and PIVs are growing budding yeast with pseduohyphae. What is your Next Step?

A. Stop all antibiotics and add FluconazleB. Stop all antibiotics and add AnidulofunginC. Continue regimen without ChangesD. Continue regimen and add FluconazoleE. Continue regimen and add Anidulofungin

Explanation:

- Candida Infection suspected so must broaden coverage

- Whereas Candida Albicans is susceptible to Azoles, other species such as glabrata and krusei are inherently resistant and only responsive to candins.

- Due to presence of tunneled catheter, other causes cannot be ruled out until micro results are final, so other antibiotics should be continued

Case 6 (cont)

1)What should be done with the line?

A. Call IR to remove the line immediatelyB. Do not remove the central line and “treat through” itC. Wait on Calling IR

2) Which Subspecialty NEEDS to be consulted (besides perhaps infectious diseases)??

Ophthalmology

Hypothermia

Different stages exist, but clinically significant hypothermia is defined as a drop in the body’s core temperature to 95 degrees or LESS

#1 Mistake: Thinking they are not infected, as this can be present in approx (25%) of patients with SIRS

EtOH ingestion

Endocrine: Myxedema, hypothyroidism, hypopituitairism, hypoglycemia, AI

Head injury: Central regulatory disorder

Drugs: Esp BZDs

Thank You!