What is the clinical significance of a Complete Blood Count (CBC) showing leukocytosis with an elevated white blood cell (WBC) count of 14.9, erythrocytosis with a Red Blood Cell (RBC) count of 5.46, neutrophilia with an absolute segmented neutrophil count of 11.2, monocytosis with an absolute monocyte count of 1.7, and an increased immature granulocyte count of 0.18, along with a Comprehensive Metabolic Panel (CMP) indicating hyperglycemia, hyponatremia, hypokalemia, and hypochloremia?

From the Guidelines

You should seek immediate medical care for hypokalemia (low potassium level of 2.9 mEq/L) and leukocytosis (elevated white blood cell count of 14.9) with neutrophilia (elevated neutrophil count of 11.2), as these findings suggest a possible underlying infection or inflammatory condition that requires prompt evaluation and treatment. The laboratory results indicate several abnormalities that require attention, including hypokalemia, which is potentially dangerous and requires correction with potassium replacement therapy, typically with oral potassium chloride supplements (40-80 mEq/day divided into multiple doses) or intravenous potassium if levels are critically low or symptoms are present 1. The elevated white blood cell count with neutrophilia, along with the presence of immature granulocytes (0.18) and elevated monocytes (1.7), suggests an active infection or inflammatory process, which is supported by studies demonstrating a high probability of underlying bacterial infection in older adults with elevated WBC counts or left shift, even in the absence of fever 1. Additionally, the mildly elevated glucose (116 mg/dL) indicates prediabetes, and the slightly low sodium (134 mEq/L) and low chloride (94 mEq/L) levels may contribute to the overall clinical picture.

The presence of an elevated WBC count (14,000 cells/mm3) or a left shift warrants a careful assessment for bacterial infection in any resident with suspected infection, with or without fever, as recommended by the Infectious Diseases Society of America 1. A complete blood cell count with differential, including peripheral WBC and differential cell counts, should be performed for all residents suspected of having infection within 12–24 h of onset of symptoms, consistent with local standards of practice 1.

Given the potential for serious complications, including muscle weakness, cardiac arrhythmias, and other serious complications associated with hypokalemia and possible underlying infection, prompt medical evaluation and treatment are essential to prevent morbidity, mortality, and to improve quality of life. The combination of findings suggests a possible underlying infection or inflammatory condition that requires evaluation by a healthcare provider to determine the cause and appropriate treatment, and to guide further management and therapy 1.

From the Research

Patient's Blood Test Results

The patient's CBC results show:

• WBC: 14.9
• RBC: 5.46
• Segmented neutrophil count: 11.2
• Monocytes absolute count: 1.7
• Immature granulocytes: 0.18 The CMP results show:
• Glucose: 116
• Sodium: 134
• Potassium: 2.9
• Chloride: 94

Possible Causes of Leukocytosis

• According to the study 2, unexplained or persistent leukocytosis can be caused by a state of continued inflammation, recently described as the persistent inflammation-immunosuppression and catabolism syndrome (PICS).
• The study 2 also found that patients with leukocytosis often have extensive tissue damage rather than active infection driving the leukocytosis.

Neutropenia Associated with Antibiotic Use

• The study 3 found that ceftaroline use was independently associated with neutropenia, and prolonged ceftaroline use was an independent risk factor for developing mild neutropenia.
• The study 4 found that intravenous ceftriaxone treatment is associated with a fall in neutrophils, which can be predicted by routine baseline blood indices.

Monocyte Count as a Marker for Antibiotic Cessation

• The study 5 found that absolute monocyte count (AMC) >100 cells/μL may be a safe threshold for empiric antibiotic cessation in febrile neutropenia without etiology in pediatric oncology patients.

Hematologic Impact of Antibiotic Administration

• The study 6 found that the concurrent administration of antibiotics and clozapine resulted in an abnormal drop in blood counts, and further reduction of white blood cell/absolute neutrophil below baseline prior to infection.
• The study 6 also found that ciprofloxacin or moxifloxacin may have less risk of reductions in white blood cell/absolute neutrophil counts than penicillins, cephalosporins, and other antibiotics.