Lung Ultrasound Dr Piyush Mallick.MD Vice Chairman Anesthesia & ICU Al Zahra Hospital

WHY USG BY ANAESTHETIST? Ultrasonography performed by the provider not only have diagnostic value but it dose guide many life saving therapy.(we have already started doing Nerve blocks. Findings directly correlated with the patient’s presenting signs and symptoms Easily repeatable & reproducible if the patient’s condition changes

Ultrasound in ITU and OT & ER

US in medical education Long back - In 2004, a conference on compact Ultrasonography hosted by the American Institute of Ultrasound in Medicine (AIUM)concluded that “the concept of an ‘ultrasound-stethoscope’ is rapidly moving from the theoretical to reality.” Some medical schools are now beginning to provide their students with hand‐held ultrasound equipment for use during clinical rotations

Basics of US

MACHINE

PROBES

Frequency of probe and depth

TYPE OF PROBES Curvilinear (2‐5 MHz) Better penetration, low resolution Abdominal imaging Linear probe (5‐10 MHz) Lesser penetration, better resolution Superficial structures eg. vessels, lung ultrasound

USG image Reflected signal gives information about depth and nature of tissue On the grey scale: – High reflectivity (e.g. bone): White – Low reflectivity (e.g. muscle): Grey – No reflectivity (e.g. air): Black Deeper structures on lower portions of display screen and superficial on upper portion

US NOMENCLATURE Echogenic Anechoic Hypoechoic Hyperechoic Isoechoic

Colour Doppler Flow toward transducer = RED Flow away from transducer = BLUE Blue Away Red Towards (BART)

VARIOUS USES IN OT & ICU Diagnoses of various lung pathologies Central vein insertion & Arterial line Diagnostic procedures like aspiration of pleural,Pericardial and ascites fluid Endotracheal tube confirmation and Guidance in cricothyroidotomy FAST & eFAST in trauma patients Guideline for ICP measurement by ONSD study and TCD Echocardiography (TEE & TTE) DVT & PE studies Nerve Blocks

Endotracheal tube and RT confirmation

Lung ultrasound: WHY ??? Sensitivity (%)-Specificity (%) Pleural effusion Alveolar consolidation Interstitial syndrome * Complete pneumothorax Occult pneumothorax

Lung ultrasound TEN BASIC SIGNS The bat sign The A-line Lung sliding The quad sign The sinusoid sign The tissue-like sign The shred sign The B-line (& lung rockets) The stratosphere sign The lung point

Bat sign Basic step Allows to locate the lung surface in any circumstances (acute dyspnea, subcutaneous emphysema...)

A lines Horizontal lines (roughly parallel to the chest wall) Brightly echogenic and located between the rib shadows when the probe is positioned longitudinally Normal reverberation artifact More prominent in COPD, asthma

B lines A comet-tail artifact Arising from the pleural line Well-defined - laser-ray like Hyperechoic Long (does not fade) Erases A lines Moves with lung sliding Pulmonary oedema

How to optimize PEEP ? Disappearance or minimum B lines suggest optimum PEEP. Clinical correlation must.

Lung sliding and seashore sign Slight and bright horizontal movement of the pleural line More evident during active and passive respiration

Causes of Absent Sliding Pneumothorax Atelectasis Main‐stem intubation ARDS Pleural adhesions

Lung point Sudden, on-off visualization of a lung pattern (lung sliding and/or B-lines)at a precise area where the collapsed expiratory lung slightly increases its surface of contact on inspiration Lung point indicates volume of pneumothorax

Pleural effusion: The quad sign Quad image between pleural line, shadow of ribs, and the lung line (deep border, always regular) Quad sign and sinusoid sign are universal signs allowing to define any kind of pleural effusion regardless its echogenicity

Lung consolidation: Shred sign Shredded line, instead of the lung line: a specific sign

LUNG PULSE Vertical movement of the pleural line synchronous to the cardiac rhythm More commonly seen on the left hemithorax than the right Caused by transmission of heart beats through consolidated, motionless lung

LUNG PULSE Commonly present in: – Massive atelectasis – Main‐stem intubation Absent in: – Pneumothorax:Intrapleural air prevents transmission of eitherHorizontal or vertical movements to the parietal pleura Visualization of a lung pulse excludes a pneumothorax.

RECENT EVIDENCE Pulmonary Embolism & Lung sign Can we differentiate Viral (H1N1 & Ebola) to bacterial infection?

Protocol for lung USG

PROTOCOL FOR LUNG USG STEP 1 Look for Lung Sliding Present on anterior‐inferior areas of the two hemithoraces in supine patient– NPV of 100% (pneumothorax is ruled out) Absent lung sliding‐‐ Poor specificity in ICUpatients (78%) Poor PPV (22%) Consider other differentials

STEP 2 Look for B lines Visualisation of even one isolated B line demonsrates adherence of visceral to parietal pleura True NPV of 100%

STEP 3 Look for lung point 100% specificity for ruling in pneumothorax Sensitivity of this sign is low because in the case of pneumothorax with complete retraction of the lung, no lung point is visualized

STEP 4 Look for lung pulse In a patient with cardiac activity with absent lung sliding due to massive atelectasis or main‐stem intubation, lung pulse is a common finding (sensitivity 93%) Helps to differentiate between differentials of absent lung sliding

Lung US PROFILEDESCRIPTIONSUGGESTIVE OF RULES OUT A PROFILEPREDOMINENT A LINES PLUS LUNG SLIDING AT ANTERIOR SURFACE COPD, PE, posterior pneumonia Pulmonary oedema B PROFILEPREDOMINENT B LINESPulmonary oedema COPD, PE, posterior pneumonia A/B PROFILEANTERIOR‐PREDOMINENT B LINES AT ONE SIDE, PREDOMINENT A LINES AT OTHER SIDE Pneumonia C PROFILEANTERIOR ALVEOLAR CONSOLIDATION

BLUE PROTOCOL

THANK YOU