Clinical Vignette VII

• Which of the following is the most likely diagnosis?

A 53-year-old male is hospitalized for severe pneumonia which has progressively worsened over the past three days. The patient’s medical history is significant for hypertension, hyperlipidemia, and left-sided total knee arthroplasty performed four weeks ago in the same hospital. His current medications are lisinopril, hydrochlorothiazide, atorvastatin, and PRN acetaminophen. He has no known allergies. Initial lab work performed in the emergency department revealed the following: 

WBC      16.8 K/uL (abnl)          4.0-10.4 K/uL

RBC       4.67 M/uL                          4.50-5.70 M/uL

HGB       14.2 g/dL                            14.0-18 g/dL

HCT       43.0 %                                 42.0-50.0 %

MCV      81.4 fL                                 80.0-100.0 fL

MCH      27.6 pg                                 27.0-33.0 pg

HCHC    32.6 g/dL                            32.0-36.0 g/dL

RDW     13.2 %                                 11.6-14.8 %

PLT       233 K/uL                            142-424 K/uL

MPV      12.2 fL                                 0.0-99.0 fL

The emergency department also performed PA and lateral view chest x-rays which revealed consolidation with air bronchograms in the right middle lobe. The patient was pan-cultured and started on intravenous broad-spectrum antibiotics for health-care associated pneumonia before being admitted to the inpatient general medical floor. The admitting hospitalist physician who assumed responsibility of the patient’s medical care reviewed the initial orders written by the emergency medicine physician and decided to change the deep vein thrombosis prophylaxis from sequential compression devices to subcutaneous unfractionated heparin every 8 hours. Over the course of the patient’s hospitalization, the hospitalist physician checked daily complete blood counts as well as basic metabolic panels. After being hospitalized for 48 hours, the patient’s complete blood count revealed the following:

WBC      12.8 K/uL (abnl)          4.0-10.4 K/uL

RBC       4.55 M/uL                          4.50-5.70 M/uL

HGB       14.1 g/dL                            14.0-18 g/dL

HCT       42.6 %                                 42.0-50.0 %

MCV      82.3 fL                                 80.0-100.0 fL

MCH      28.0 pg                                 27.0-33.0 pg

HCHC    33.1 g/dL                            32.0-36.0 g/dL

RDW     13.5 %                                 11.6-14.8 %

PLT       69.9 K/uL (abnl)          142-424 K/uL

MPV      12.9 fL                                 0.0-99.0 fL

• Provided that the correct diagnosis is made, what is the most appropriate next step in management of this patient?