Case Discussion – Community-Acquired Pneumonia

TG is a 68 y.o. patient admitted to the hospital after complaining of a “severe cold with difficulty breathing”.  A brief note accompanies the patient to the floor, where he is examined by the medical intern who writes the following note:

                           

CC:    “chest pain, cough, difficulty breathing”

PMH:    HTN x 5 years

Gout

Sinusitis (last episode 3 weeks ago)

Medications prior to admission: Enalapril 10mg po QD

Multiple vitamin + iron 1 tab po QD

Current medications: Ceftriaxone 1g IV q24h

Erythromycin 1g IV q6h

Enalapril 10mg po QD

APAP 325-650mg po q4-6h PRN

PE:

Gen:    Ill-appearing male, somewhat undernourished appearing

VS:                   BP 110/85, HR 88, RR 18, T_current 39°C (102.2°F), Wt 60 kg, Ht 166 cm

HEENT:            Purulent white sputum x 2 days

COR:                WNL

CHEST:            Rales and crackles L base

                        LLL dull to percussion

                        Å Egophony

Abd:                 WNL, positive bowel sounds

EXT:                 WNL, no complaints

NEURO:           Oriented to time, person, and place

Labs:

Na 138	Cl 100	BUN 15	Glu 144		Hg 12.5
K 4.3	HCO3 26	SCr 1.1		Plt 125		WBC 12.2
					HCT 34%
AST 18	ALT 24	Alb 3.4

                                                                                    WBC Differential:

80% Neutrophils / 18% Bands / 2% lymphs

Pulse ox:          97% on 2L NC

CXR:                LLL infiltrates

Blood cx:          Pending

Sputum cx:       Pending

A:         68 y/o M in his current state of health until 2 days ago when he developed fever, cough, SOB.  Signs and symptoms consistent with CAP.

P:         1) CAP:  continue current antibiotic regimen.  F/U on cx results, clinical exam.  Check VS q4h.

            2) HTN:  continue enalapril at current dose.  Monitor BP.

1.What are the options, including pro/cons, for antibiotic therapy in TG?

As an inpatient with CAP, empiric treatment should consist of either Macrolides + Beta Lactam or a fluoroquinolone.  Both the Macrolide/Cephalosporin combination and fluoroquinolone combinations have similar spectrums.  Erythromycin tends to be more toxic than other macrolides, with higher incidence of side effects.  Ceftriaxone is not available PO, so the patient would need to remain as an inpatient for the entire antibiotic course.  A fluoroquinolone, such as levofloxacin has similar coverage, and is available PO, and would be allow the patient to complete the course at home.  Both macrolides and fluoroquinolones have some cardiac risk associated with QT prolongation.  Although the patient has no history of arrhythmias, he should be monitored.

2.  You are asked whether TG’s ceftriaxone dose should be increased to 2 grams IV q24h “because that is the dose listed in the Sanford guide.”  Using the paper written by Frei and Burgess as support, discuss whether 2 grams IV q24h is necessary in TG.

Two grams Q24 provides only marginal increases in killing activity for S. pneumonia in monotherapy.  If the strain were identified as PCN resistant, then 2g might be warranted.  Additionally, erythromycin covers S. pneumonia, and should provide sufficient coverage for the organism.

3.                   Medline Search:  Please bring in original research journal articles (not abstracts) that provide the following information.  You should be able to get this info from 1-2 papers.

What are the national resistance rates for the following:

Penicillin-susceptible Streptococcus pneumoniae                         _______________%

Penicillin-intermediate Streptococcus pneumoniae                        _______________%

Penicillin-resistant Streptococcus pneumoniae                             _______________%

Erythromycin-resistant Streptococcus pneumoniae                       _______________%

b-lactamase-producing Haemophilus influenzae                           _______________%

b-lactamase-producing Moraxella catarrhalis                                _______________%

4.                   Medline Search:  Bring one original research article (not abstract) supporting the clinical use of IV to PO conversion of antibiotics in CAP. 

 Chart note:

HD #2.  Pt is doing well.  No change in cough, slight decrease in sputum production.  Lungs still w/ crackles at L base. 

On HD #3 TG is feeling even better and his cough has largely subsided.  His chest examination still reveals slight crackles, but is improved over admission.  TG is afebrile with a T_max of 99.2°F (at 9AM today).  Both blood and sputum cultures remain negative.  The medical intern believes that the patient could be discharged today.  Prior to rounds, she asks your opinion regarding antibiotic therapy.  Specifically, she wonders if home IV antibiotics would be appropriate, and if there is a single drug that might be used?  

5.   Can antibiotic therapy be discontinued with the negative blood and sputum cultures?

Blood cultures have low sensitivity and sputum cutures are notoriously difficult to get.  Patient should complete abx course.

6.  What are the options for oral therapy?

Fluoroquinolones are an option.  Erythromycin PO is possible, as are alternative cephalosporins, but Ceftriaxone is not available orally.

7.  How is duration of therapy decided?

Empirically, based on the latest football scores.