Date post: | 21-Apr-2017 |
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Ultrasound Guided Pleural Procedures
Gamal Rabie Agmy ,MD ,FCCP Professor of Chest Diseases, Assiut University
OVERVIEW
• Evidence base for use of thoracic ultrasound– diagnostic and interventional
• Pleural effusion– Characteristics of effusions– Transudates vs exudates– Colour fluid sign– Formulas for volume estimation
• Pneumothorax
• Pleural thickening Identification, DD with pleural effusion
• Pleural tumours
WHY ULTRASOUND?• Not all opacification is fluid… 1
1 Psallidas et al. Clin Med 2014
WHY ULTRASOUND?
• Higher diagnostic sensitivity vs. plain chest radiography– pleural effusion +/- consolidation
• Accessible to clinician and patient– instant feedback to inform decision-making process
• Provides additional diagnostic information– echogenicity, septations, pleural thickening, underlying viscera
• Improves procedural outcomes– eliminates “dry tap”, limits risk of iatrogenic complications
THE EVIDENCE FOR FLUID
• Better than clinical examination 1
– 15% of clinically specified puncture sites inaccurate / “at risk”– 80% of these successfully aspirated / accessible with TUS– If clinical site not identified, TUS achieved in 54%– TUS prevented iatrogenic organ puncture in 10% of cases
• Reduces cost / complications in thoracentesis 2
– 61,261 thoracenteses, 47% performed without TUS– MV modelling and analysis– TUS reduced risk of pneumothorax by 19%– OR 0.81; 95% CI 0.74-0.90
1 Diacon et al. Chest 20032 Mercaldi et al. Chest 2013
INTERVENTIONS
• Thoracic ultrasound (TUS)– necessary for any pleural intervention for fluid– more sensitive than CXR for detection of fluid 1
– improves diagnostic accuracy and reduces complications 2
• BTS Pleural Disease Guidelines 3
1 Eibenberger KL et al. Radiology 19942 Diacon AH et al. Chest 2003
3 BTS Pleural Disease Guidelines. Thorax 2010
Normal lung surface
Left panel: Pleural line and A line (real-time). The pleural line is located 0.5 cm below the rib line in the adult. Its visible length between two ribs in the longitudinal scan is approximately 2 cm. The upper rib, pleural line, and lower rib (vertical arrows) outline a characteristic pattern called the bat sign.
SIZE OF EFFUSION ON US
Size / Volume measurement1: • 2cm depth of fluid = 480mls• 4cm depth of fluid = 960mls
Supine patients2:• Size calculation:
» Visceral – parietal (mm) x 20 = volume (mls)1
» Distance between posterior chest wall and lung of >50mm predicts >500ml thoracentesis vol2
1 = Balik, ICM 20062 = Roch, Chest 2005
Relative precision on estimating the fluid1 rib space small2-3 rib spaces moderate4>rib spaces large
Sonography Guided Interventions
1-Pleural effusion
Different Models of Cope Needle
Abrams Needle
Lung Biopsy Needles
Instruments for Ultrasound – guided Biopsy Forceps of the Pleura
• Compared to thoracoscopy the sensitivity of ultrasound guided forceps pleural biopsy in the diagnosis of malignant and tuberculous lesions was 85% and 88% respectively.
• The technique was absolutely specific in the diagnosis of malignant and tuberculous lesions.
Instruments for Ultrasound – guided Pleural Brushing
Procedure
9 (41%) PFC9 (41%) PB
15 (68%) BFP16 (72%) PFC + BFP12 (55%) PB + PFC18 (82%) PB + BFP19 (86%) PB + PFC + BFP
Diagnostic Yield
Different Models of Catheters for Pleural Drainage
2-Pneumothorax
the "seashore sign" (Fig.3).
Absent lung sliding
Exaggerated horizontal artifacts
Loss of comet-tail artifacts
Broadening of the pleural line to a band
Lung point
Loss of lung impulse
The key sonographic signs of Pneumothorax
3-Pleural thickening
4-Pleural tumors