Table of Contents

Table of Contents

Published August 2022

Authors: Brandon Fainstad, MD1, Henry Kramer, MD3, Josephine Cool, MD2, Carolina Ortiz-Lopez3, Noelle Northcut, MD4, John M Cunningham, MD4, Chi Zheng, MD4, Anna Neumeier, MD5, Irene Ma, MD, PhD6

Section Editor: Josephine Cool, MD3

1 Assistant Professor, Department of Medicine, University of Colorado.  2 Assistant Professor, Division of Hospital Medicine, the University of Colorado. 3 Instructor of Medicine, Harvard Medical School, Section of Hospital Medicine, Beth Israel Deaconess Medical School. 4 Assistant Professor, Division of Hospital Medicine, Denver Health. 5 Assistant Professor, Division of Pulmonary and Critical Care, University of Colorado. 6 Professor, Division of General Internal Medicine, University of Calgary.


  1. Describe the appropriate indications and contraindications to performing a thoracentesis.
  2. Achieve a minimum passing score (MPS) for thoracentesis on a validated assessment checklist in a simulation setting.  
  3. Practice performing a thoracentesis with full or partial supervision in the clinical setting until achieving an Unsupervised Practice Standard (UPS) using a validated assessment checklist.

Teaching Instructions

There are three stages to this procedure training and assessment process that aim to satisfy all components of the Learn, See, Practice, Prove , Do and Maintain framework.1

To effectively prime the learner for the simulation they should watch this procedural video, review the clinical checklist and take the pre-quiz the day before the simulation.

Ideally, the simulation training closely precedes (days to weeks) the clinical procedure, to best reinforce learning.  We recommend scheduling the simulations to be timed with the rotation where the learner is most likely to encounter the relevant procedure.

Both the learner and the instructor should perform the simulation with systematic and deliberate practice.  Treat the simulation as if it were a real-life procedure with sterile technique.  Simulation-Based Mastery-Learning (SBML), whereby the learner doesn't graduate the simulation training until they have met a minimum passing score (MPS), is a well-studied paradigm to ensure deliberate practice and effective feedback.2


Below is a Competency Assessment Tool (CAT) used for both thoracentesis SBML simulation training and to assess competency for unsupervised practice in the clinical setting.

The CAT includes three components:

1. Error-counting checklist

  • mirrors the clinical checklist
  • more specifically defines each potential error in an attempt to accurately capture mistakes.
  • The cutoffs for mistakes allowed in the MPS (<24 mistakes) and UPS (<7) were established through an Angoff standard-setting process amongst 25 procedural experts.

2. Global Skills Assessment (GSA) – ranging from novice to expert.

3. Entrustment Score (ES) – ranging from ‘critical deficiencies' (not ready to perform on live patients) to ‘educator' (ready to serve as an instructor and back-up for complex situations).

We recommend making the checklist accessible to the learner and going through the following steps in a 60-90 minute simulation, depending on the trainee's experience with the procedure.

1. The instructor and trainee discuss the non-technical steps: indications, contraindications, consent process, & optimization of position and environment.

2. The instructor reviews the components of the procedural kit with the learner and demonstrates the proper technique for each step listed under “procedural steps” in the clinical checklist.

3. The trainee then familiarizes themselves with the kit components and practices the procedural steps.

4. The trainee signals when they are ready to do a full simulation with an assessment.  The assessment checklist is designed for the clinical setting and will have its limitations in a simulated environment.  Each simulation setting will vary in the steps can be physically demonstrated.  In such cases, the instructor should simply elicit a verbal explanation of the intended step or thought process. 

  • Reassemble the kit and simulator for a complete simulation.
  • With the checklist out of the learners view, quiz their knowledge on the non-technical steps, then place the clinical checklist back in clear view.
  • Perform each subsequent step from “Pre-procedural US” through “Procedural Steps”, then quiz the trainee on post-procedural steps.
  • Throughout the simulation, the instructor marks mistakes made or instances when prompting was needed to avoid a mistake.  At the end of the simulation, the instructor determines a global skills score and enstrustment score (see page 2 of the assessment checklist below)
  • The trainee repeats the simulation until they have accomplished a MPS:
    • Mistakes < 24 mistakes, Global > 2 and Enstrustment > 2

Provide support and guidance to the trainee while also taking notice of mistakes being made and when a prompt was needed to avoid mistakes. 

Complete the checklist assessment either during or right after the procedure, depending on whether you are also wearing sterile protective equipment. 



Pre-brief– remove checklist from view

1. Assess learner experience – For learners who have not yet successfully completed a thoracentesis, the supervisor should plan to wear sterile protective equipment.

2. Confirm indication(s) and contraindications –This is often assumed by the time the decision to perform the procedure has been made, but in practice many trainees lack this knowledge.

3. Confirm consent has been obtained via the patient or surrogate –  If consent is unable to be obtained, confirm the emergent indication for the procedure.



Setting-up– place checklist in clear view to reinforce learning through repetition and reduce procedural errors.7

1. Optimize patient positioning– to access the largest pocket of fluid.

    • Often upright and learning forward over a table + pillow. 
    • Lateral decubitus or semi-recumbent can be considered.

2. Perform a pre-procedure ultrasound

    • Using a low-frequency curvilinear or phased array transducer with the indicator pointing cranially at a depth of >8cm, scan the posterior chest from mid-scapular to mid-axillary regions.
    • Identify the largest area of hypoechoic (black) fluid >2 cm from pleura to atelectatic lung.
      •  select insertion space as laterally as possible (>10cm from spine) as infracostal vessels are most tortuous medially 
      • select insertion space at least 1 rib space above the diaphragm
    • Using a high frequency linear transducer with color or power doppler flow:
      • Assess for tortuous infracostal vessel overlying chosen site.

3. Gather all supplies

4. Perform a timeout with the patient's nurse before opening any sterile supplies. Include the patient in the time-out if possible.

5. Prepare sterile gear

    • Don mask, eye protection, and sterile gloves (cap and gown are optional).
    • Prep site with 2 chlorhexidine scrubs x 30 seconds.  This differs from the method used with iodine-based solutions (“apply and let dry”).  Sterilize an area larger than the aperture of the drape.

6. Prepare supplies

    • Draw up lidocaine using the largest needle or filtered catheter provided.  The smaller bore needles are reserved for anesthetizing the track.
    • Identify the IV tubing (with one-way valves) used for draining pleural fluid and remove any packaging


Quiz answers are on page 3.

Example procedure note

Indication: Pleural effusion *** of unknown etiology/ with associated dyspnea or hypoxemia/ at risk of complications if not drained
Procedure: Thoracentesis
Performing provider: _
Supervising Physician (if applicable): _
Consent: obtained and saved in the chart
Time-out: performed

Procedure: Patient was positioned upright and leaning forward . ***R/L*** posterior chest was examined with ultrasound and identified a pleural effusion at least 2cm from parietal to visceral pleural. Subcostal vessels were identified with the ultrasound. Site was marked and prepared with a chlorhexidine scrub, and a sterile perforated drape was placed over the insertion site.  An intradermal wheal of 1% lidocaine injected with a 25g needle. A 21g needle was attached to the same syringe and advanced with negative pressure with additional 1% lidocaine injected along the needle insertion path until pleural fluid was aspirated.  The needle was then slightly withdrawn and an additional 2cc of lidocaine was injected just superficial to the pleural interface.   The skin was then punctured with an 11 blade scalpel.  Then a thoracentesis needle with overlying catheter was advanced slowly through the skin and soft tissues with negative pressure until the needle entered the pleural cavity and pleural fluid fluid was aspirated.  The needle and catheter were advanced an additional 0.5-1 cm. The flexible catheter was advanced over the needle until it was ‘hubbed', and the needle was removed.  A simple IV tubing with two ***one-way valves*** was then connected, with a 60cc syringe connected to the short arm of IV tubing and a collection bag connected to the long arm of IV tubing. Fluid was aspirated and pushed into the collection bag until flow was discontinued and the patients symptoms improved. The catheter was then withdrawn and the site cleaned and bandaged with gauze and bandage.  The patient tolerated procedure well with minimal blood loss and no immediate complications.

Amount of fluid drained: ***
Color of fluid: clear, yellow, bloody, green  ***
Lidocaine amount: 5-10 ml ***


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  2. Schildhouse R, Lai A, Barsuk JH, Mourad M, Chopra V. Safe and Effective Bedside Thoracentesis: A Review of the Evidence for Practicing Clinicians. J Hosp Med. 2017 Apr;12(4):266-276. doi: 10.12788/jhm.2716. PMID: 28411293.
  3. Dancel, R., Schnobrich, D., Puri, N., Franco‐Sadud, R., Cho, J., Grikis, L., … & Soni, N. J. (2018). Recommendations on the use of ultrasound guidance for adult thoracentesis: a position statement of the Society of Hospital Medicine. Journal of hospital medicine13(2), 126-135.
  4. Daniels CE, Ryu JH. Improving the safety of thoracentesis. Curr Opin Pulm Med. 2011 Jul;17(4):232-6. doi: 10.1097/MCP.0b013e328345160b. PMID: 21346571.
  5. Ault MJ, Rosen BT, Scher J, Feinglass J, Barsuk JH. Thoracentesis outcomes: a 12-year experience. 2015;70(2):127-132
  6. Patel MD, Joshi SD. Abnormal preprocedural international normalized ratio and platelet counts are not associated with increased bleeding complications after ultrasound-guided thoracentesis. AJR Am J Roentgenol. 2011 Jul;197(1):W164-8. doi: 10.2214/AJR.10.5589. PMID: 21700980.
  7. Berg, D., Berg, K., Riesenberg, L. A., Weber, D., King, D., Mealey, K., … & Tinkoff, G. (2013). The development of a validated checklist for thoracentesis: preliminary results. American Journal of Medical Quality28(3), 220-226.
Josephine Cool


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