By: 13 October 2016
Analgesic techniques for breast and anterior chest wall procedures

Focus on acronym approach to Serratus Anterior Plane Block


Authors: Dr. Sher Mohammad1 , Dr. Sailaja Pothuneedi2, Dr. Sandeep Puppalwar

1 Consultant anaesthetist, 2 ST7 anaesthetics, 3 Clinical Fellow anaesthetics

Royal Hallam shire Hospital, STH NHS Foundation Trust, Glossop Road, Sheffield.



The surgical procedures on anterior chest wall are mostly undertaken under GA. Most of these procedures are associated with moderate to severe pain post-operatively. A variety of regional techniques are considered for effective post-operative pain relief. Some of the regional techniques used are thoracic epidural analgesia, paravertebral blocks, intercostal nerve block, intrapleural technique and wound infiltration.

Most of these techniques have been mentioned in detail in streamline journals. A relatively new technique has been introduced such as serratus anterior plane block. We will not delve into the details of these approaches but the pros and cons will be briefly discussed. The technique of serratus anterior plane block is mentioned here in such a way that it is easy to remember.

Option Pros Cons
Thoracic epidural 1.Good pain relief but risk  higher vs benefit

2.Less PONV encountered

3.Less morphine needed 4.LessImmunosuppression and recurrence of cancer

1.Technical difficulty, increased risk   vs benefit

2.Undetaken when awake only

3.Expertise required



6.Risk of urinary retention

7.Bilateral block

Paravertebral block 1.Good pain relief

2.Can be done U/S guided or    land mark technique

3.Unilateral block

4.Less PONV

5.Reduce use of opioids – less immunosuppression and less recurrence

6.Can provide surgical anaesthesia

1.Expertise needed

2.Risk of pneumothorax 0.5%

3.Epidural spread

4.Dural puncture

5.Intrathecal injection

6.Failure rate 5%

Intrapleural Block




1.Easy to perform

2.Analgesia is good

3.Is performed while under GA

4.Success rate is good

1.Pneumothorax 100%

2.Can damage lung and heart

3.Useless if chest drain insitu

4.Bilateral not recommended

5.Becoming obsolete

Intercostal nerve block 1.Good pain relief

2.Less PONV

3.Reduce use of opioids

4.Simple to do

1.Multiple injections

2.Risk of local anaesthetic   toxicity

3.Risk of intravascular injection


Serratus anterior plane block 1.Good pain relief

2.Safer as can be done USG

3.Can be done while under GA

4.Reduced use of opioids

5.Less complications

6.Surgical anaesthesia+Sedation

1.New technique

2.Learning curve

3.Thoraco acromial artery injection

4.Pneumothorax low risk

5.Can provide analgesia(T2-T9)only

Morphine PCA 1.Patient controlled

2.Pain relief can be good


1.Venous access needed

2.PONV risk increased



5.Respiratory depression


Simple analgesics+ LA infiltrate 1.Easy to administer

2.Non interventional


1.Pain relief waxing and waning

2.Local infiltration – short acting compared to blocks

3.Chronic surgical pain





Serratus Anterior Plane Block

Serratus anterior (SA) plane block is a relatively new regional anaesthetic technique introduced by Blanco a few years ago. It is an alternative approach for providing analgesia to the anterior chest wall, such as for breast surgery and rib fractures.

A brief anatomy is explained in the diagram above. The plane lies between serratus anterior (SA) and latissimus dorsi (LD) muscles with nerves and vessels sandwiched between them. Local anaesthetic is injected at this site and, similar to TAP block, hydrodissection can be seen while using ultrasound. A dose of bupivacaine 0.25 per cent between 30-40 mls can be used. Catheter techniques can also be used successfully for continuous analgesia.

To memorise the technique, indications and contra-indications, refer to the acronym”SERRATUS”.


S. SA originates on anterior surface of ribs 1-8

Scapular medial border is the insertion

Superficial to SA is LD

Sandwiched between the two are T2-9 nerves

Superficial SA block can be done while injecting into this  plane

E. End point is hydrodisection of this space

R. Rib fracture is an indication

Reconstructive and other breast procedures are indications

Relief of pain post-sternotomy (below manubrium)

R. Recurrence of cancer is less as morphine (affects immunity) is avoided

Respiratory problems like pneumonia avoided

Related complications to epidural or PVBs avoided

A. Absolute contra-indications:   A. Allergy to LAs

A. Absence of consent

A. Anatomy distorted due to trauma

T. Technique is easy and safe

Toxicity avoided by correct strength and volume of LAs

U. USG confirms the spread of LAs

S. Static and dynamic pain scores confirm patient satisfaction.



NB: the above acronym is being taken from the latest version of our handbook The STH-KTH Handbook of Acronyms. Anyone interested, just drop email Sher Mohammed and you will get it, its free.