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eMedicine Journal
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Emergency Medicine
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Pulmonary
Pneumonia, Immunocompromised Synonyms, Key Words, and Related Terms: acquired immune deficiency syndrome, AIDS, atypical pneumonia, dyspnea, emphysema, human immunodeficiency virus, HIV, hypoxia, Pneumocystis carinii pneumonia, PCP, tuberculosis |
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 | AUTHOR INFORMATION | Section 1 of 11    |
Authored by James L Morse, MD, CM, Staff Physician, Section of Emergency Medicine, Yale New Haven Hospital
Coauthored by Christopher MB Fernandes, MD, Professor and Head of Emergency Medicine, McMaster University; Chief of Emergency Medicine, Hamilton Health Sciences
James L Morse, MD, CM, is a member of the following medical societies: American College of Emergency Physicians, American Medical Association, and Emergency Medicine Residents' Association
Edited by Dana A Stearns, MD, Assistant Director of Undergraduate Education, Department of Emergency Medicine, Massachusetts General Hospital; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Paul Blackburn, DO, Program Director, Department of Emergency Medicine, Maricopa Medical Center; Assistant Professor, Department of Surgery, University of Arizona; John Halamka, MD, Chief Information Officer, CareGroup Healthcare System, Assistant Professor of Medicine, Department of Emergency Medicine, Beth Israel Deaconess Medical Center; Assistant Professor of Medicine, Harvard Medical School; and Barry Brenner, MD, PhD, FACEP, Professor of Emergency Medicine, Professor of Internal Medicine, and Professor of Anatomy and Neurobiology, Research Director, Department of Emergency Medicine, University of Arkansas for Medical Sciences
| Author's Email: | James L Morse, MD, CM |  |
|---|---|---|
| Editor's Email: | Dana A Stearns, MD |
eMedicine Journal, August 31 2004, VOLUME 5,
Number 8
| INTRODUCTION | Section 2 of 11  |
Background: Pneumonia in the immunocompromised host involves infection and inflammation of the lower respiratory tract. It most commonly is seen in patients infected with a human immunodeficiency virus (HIV), those receiving myelosuppressive chemotherapy, those who have undergone organ transplantation, or those with a traditional immunosuppressive illness such as Hodgkin disease.
Pathophysiology: The upper and lower airways of the respiratory tract commonly are affected, with infection acquired by means of inhalation, aspiration, hematogenous spread, or direct contiguous extension.
Frequency:
Mortality/Morbidity: In AIDS patients, PCP has a case fatality rate of 20% per episode. Up to 50% of deaths in patients with cancer and after organ transplantation are due to pneumonia.
Sex: Homosexual males have a particularly high risk for AIDS and subsequent PCP.
| CLINICAL | Section 3 of 11 |
History: HIV-seronegative, immunocompromised patients present acutely, while HIV-seropositive individuals may have initial nonspecific symptoms weeks to months before diagnosis. Other findings may include the following:
Physical: Findings at physical examination may include the following:
Causes:
| DIFFERENTIALS | Section 4 of 11 |
Asthma
Bronchitis
Chronic Obstructive Pulmonary Disease and Emphysema
Congestive Heart Failure and Pulmonary Edema
Endocarditis
Pneumonia, Aspiration
Pneumonia, Bacterial
Pneumonia, Empyema and Abscess
Pneumonia, Mycoplasma
Pneumothorax, Iatrogenic, Spontaneous and Pneumomediastinum
Pulmonary Embolism
Tuberculosis
| WORKUP | Section 5 of 11 |
Lab Studies:
Imaging Studies:
Procedures:
| TREATMENT | Section 6 of 11 |
Prehospital Care:
Emergency Department Care:
Consultations:
| MEDICATION | Section 7 of 11 |
The goal of pharmacologic therapy is to eradicate the infection.
Drug Category: Antibiotics -- Empiric antimicrobial therapy must be comprehensive and should cover all likely pathogens in the context of the clinical setting.
| Drug Name | Trimethoprim and sulfamethoxazole (Bactrim) -- Inhibits bacterial synthesis of dihydrofolic acid by competing with para-aminobenzoic acid; inhibits folic acid synthesis; inhibits of bacterial growth. |
|---|---|
| Adult Dose | 160 mg TMP and 800 mg SMZ PO bid |
| Pediatric Dose | <2 months: Do not administer >2 months: 15-20 mg/kg/d, based on TMP, PO tid/qid |
| Contraindications | Documented hypersensitivity; megaloblastic anemia due to folate deficiency |
| Interactions | May increase PT when used with warfarin (perform coagulation tests and adjust dose accordingly); coadministration with dapsone may increase blood levels of both drugs; coadministration of diuretics increases incidence of thrombocytopenia purpura in elderly patients; phenytoin levels may increase with coadministration; may potentiate effects of methotrexate in bone marrow depression; hypoglycemic response to sulfonylureas may increase with coadministration; may increase levels of zidovudine |
| Pregnancy | C - Safety for use during pregnancy has not been established. |
| Precautions | Discontinue at first appearance of skin rash or sign of adverse reaction; obtain CBCs frequently; discontinue therapy if significant hematologic changes occur; goiter, diuresis, and hypoglycemia may occur with sulfonamides; prolonged IV infusions or high doses may cause bone marrow depression (if signs occur, give 5-15 mg/d leucovorin); caution in folate deficiency (eg, chronic alcoholism, elderly patients, anticonvulsant therapy, malabsorption syndrome); hemolysis may occur in G-6-PD deficiency; AIDS patients may not tolerate or respond; caution in renal or hepatic impairment (perform urinalyses and renal function tests during therapy); give fluids to prevent crystalluria and stone formation |
| Drug Name | Ceftriaxone (Rocephin) -- Third-generation cephalosporin with broad-spectrum gram-negative activity. Low efficacy against gram-positive organisms and high efficacy against resistant organisms. Arrests bacterial growth by binding to one or more penicillin binding proteins. Used because of increasing prevalence of penicillinase-producing microorganisms. |
|---|---|
| Adult Dose | 1-2 g IV qd or divided bid depending on type and severity of infection; not to exceed 4 g/d |
| Pediatric Dose | >7 days: 25-50 mg/kg/d IV; not to exceed 125 mg/d Infants and children: 50-75 mg/kg/d IV divided q12h; not to exceed 2 g/d |
| Contraindications | Documented hypersensitivity |
| Interactions | Probenecid may increase levels; coadministration with ethacrynic acid, furosemide, and aminoglycosides may increase nephrotoxicity |
| Pregnancy | B - Usually safe but benefits must outweigh the risks. |
| Precautions | Adjust dose in renal impairment; caution in breastfeeding and allergy to penicillin |
| Drug Name | Prednisone (Deltasone) -- Corticosteroids have been reported to reduce the probability of declining oxygenation, respiratory failure, and death by approximately one-half in patients with moderate-to-severe PCP. |
|---|---|
| Adult Dose | Days 1-5: 40 mg PO bid Days 6-10: 40 mg PO qd Days 11-20 or for duration of therapy: 20 mg PO qd |
| Pediatric Dose | 4-5 mg/m2/d or 1-2 mg/kg PO qd; taper over 2 wk as symptoms resolve |
| Contraindications | Documented hypersensitivity; viral infection; peptic ulcer disease; hepatic dysfunction; connective tissue infections; fungal or tubercular skin infections; GI disease |
| Interactions | Coadministration with estrogens may decrease prednisone clearance; concurrent use with digoxin, may cause digitalis toxicity secondary to hypokalemia; phenobarbital, phenytoin, and rifampin may increase metabolism of glucocorticoids (consider increasing maintenance dose); monitor for hypokalemia with coadministration of diuretics |
| Pregnancy | B - Usually safe but benefits must outweigh the risks. |
| Precautions | Abrupt discontinuation of glucocorticoids may cause adrenal crisis; hyperglycemia, edema, osteonecrosis, myopathy, peptic ulcer disease, hypokalemia, osteoporosis, euphoria, psychosis, myasthenia gravis, growth suppression, and infections may occur with glucocorticoid use |
| FOLLOW-UP | Section 8 of 11 |
Further Inpatient Care:
Further Outpatient Care:
Deterrence/Prevention:
Complications:
Prognosis:
| MISCELLANEOUS | Section 9 of 11 |
Medical/Legal Pitfalls:
| TEST QUESTIONS | Section 10 of 11 |
CME Question 1: Which of the following drugs are used in the treatment of Pneumocystis carinii pneumonia?
A: Trimethoprim sulfamethoxazole
B: Dapsone
C: Corticosteroids
D: Pentamidine
E: All of the above
The correct answer is E: All the antibiotics listed have a role in the treatment of Pneumocystis carinii pneumonia. Corticosteroids must be included in the treatment of this disease because of their important effect on outcome.
CME Question 2: Which of the following organisms is the usual cause of pneumonia in the immunocompromised HIV-seronegative patient?
A: Aspergillus species
B:
Cytomegalovirus
C: Mycobacterium tuberculosis
D: Legionella species
E: All of the above
The correct answer is E: All of the organisms listed have been found to cause pneumonia in immunocompromised HIV-seronegative patients; these patients tend to present with acute symptoms.
Pearl Question 1 (T/F): A patient with a recent heart transplant presents with pneumonia. Gram-positive bacillus is the likely pathogen.
The correct answer is False: A gram-negative bacillus is the likely pathogen.
Pearl Question 2 (T/F): Febrile, neutropenic patients with signs of toxicity or with underlying disease should be admitted.
The correct answer is True: Consider admission for the febrile, neutropenic patient when evidence of toxicity (eg, high fever, hypoxia, respiratory failure, sepsis) is present or when another underlying disease is present.
Pearl Question 3 (T/F): Pneumothorax and hyperglycemia are complications of Pneumocystis carinii pneumonia and treatment.
The correct answer is False: Pneumothorax and hypoglycemia are complications of Pneumocystis carinii pneumonia and treatment; other drug adverse effects are common and include allergic reactions and thrombocytopenia.
Pearl Question 4 (T/F): The WBC count is very useful in diagnosis of pneumonia in immunocompromised patients.
The correct answer is False: The test is nonspecific, and results are not useful if they are normal.
| BIBLIOGRAPHY | Section 11 of 11 |
| NOTE: |
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| Medicine is a constantly changing science and not all therapies are clearly established. New research changes drug and treatment therapies daily. The authors, editors, and publisher of this journal have used their best efforts to provide information that is up-to-date and accurate and is generally accepted within medical standards at the time of publication. However, as medical science is constantly changing and human error is always possible, the authors, editors, and publisher or any other party involved with the publication of this article do not warrant the information in this article is accurate or complete, nor are they responsible for omissions or errors in the article or for the results of using this information. The reader should confirm the information in this article from other sources prior to use. In particular, all drug doses, indications, and contraindications should be confirmed in the package insert. FULL DISCLAIMER |
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