Special Operations Forces Medical Handbook

4-14

Follow-up Actions
Return Evaluation: Reevaluate or refer patients with delayed recovery. If poor response or late deterioration
(5-10% of patients), suspect inadequate antibiotic dosing (e.g., changing from IV prematurely) or a complication
such as empyema or pleural effusion. Identify the organism if possible. If available, do follow-up chest x-ray in
6-8 weeks to evaluate resolution of inltrate.
Evacuation/Consultation Criteria: Evacuate if unstable: respiratory rate >30/min, falling BP, increasing
tachycardia, fatigue or drowsiness, cyanosis or decreasing saturation of O 2 despite oxygen therapy. Consult
pulmonologist, internist or infectious disease specialist as needed and for pleural effusion (see Pleural Effusion
section), empyema and hemoptysis (possible occult malignancy).

Common Causes of Pneumonia (in developed countries)
Streptococcus pneumoniae 40-70%
Mycoplasma pneumoniae 10-20%
Legionella species 10-15%
Haemophilus influenzae 10-15%
Influenza virus 5-10%
Chlamydia pneumoniae, Moraxella catarrhalis, Staphylococcus aureus, Gram negatives, other 5-10%

Respiratory: Pleural Effusion

COL Warren Whitlock, MC, USA

Introduction: A pleural effusion is uid in the space between parietal pleura on the chest wall and visceral
pleura around the lungs. If the uid accumulation is large (>1/3 of the hemithorax or over 1-2 liters), it can
interfere with the mechanical ability to breathe. The two major types are transudative effusions, which are
passive uid accumulations, and exudative effusions due to irritation and inammation. Transudative effusions
are usually bilateral, slightly greater on the right side and are usually caused by heart failure, low albumen
in circulation and rapid loss of albumen in the urine (nephrotic syndrome). Exudative effusions are caused
by inammatory involvement (including infection) of the overlying visceral pleura, which often results in acute
pleurisy and the leakage of serous uid into the pleural space. The type of cells in the uid may indicate
the cause of the effusion. A large number of neutrophils containing bacteria indicate an early empyema (see
Empyema) while large cells of abnormal shape may indicate cancer. Atypical lymphocytes can occur with viral
infections such as inuenza or Coxsackie virus.

Subjective: Symptoms
Stabbing chest pain with breathing or cough (pleuritic pain), or chest pressure or tightness that changes with
position (mimicking angina).
Focused History: Have you had a recent respiratory illness? (typical for an effusion). Do you have chest
pain during every deep breath? (Chest pain worsens with inspiration.) Have you had fever? (indicates a
complicated or infected effusion or empyema) What makes the symptoms better? (Pain may be minimized by
shallow breathing, minimal talking or exercise, or by holding/lying on the affected side.)

Objective: Signs
Using Basic Tools:
Inspection: May lean towards or lie on affected side, and use arms to support and minimize chest movement
(splinted respirations).
Palpation: Warm skin over affected area. Abnormally large or small liver with possible ascites. Peripheral
edema in heart failure.
Percussion: Dullness means a pleural effusion or empyema.
Auscultation: Chest: Clear, although occasionally a pleural friction rub may be heard. If rales and rhonchi are
heard, a pneumonic process such as pneumonia is likely. Heart: Extra sounds (murmurs, rubs and gallops)
may indicate signs of cardiac failure.
Using Advanced Tools: Labs: Elevated WBC or increased neutrophils on differential supports infection;