By: 26 April 2021
New ways to describe spinal anaesthesia, contra-indications and complications – and why spinal blocks sometimes fail

Sher Mohammad and others look at different approaches to performing spinal anaesthesia 


The tale of spinal anaesthesia

According to history, Hippocrates (470-400BC) discovered for the first time “water of the brain”; Valsalva (1692) mentioned watery fluid around canine spinal cord; and Magendie (1825) described the circulation of the fluid around brain and spinal cord and named it CSF.

In 1855, Friedrich Gaedcke was the first person to chemically isolate cocaine from a coca plant and called this alkaloid as erythroxyline, and James Leonard injected cocaine between the spinous processes of lumbar vertebrae, first in a dog and then in a man. Heinrich Quickie (1890) was the first man to perform lumbar dural puncture in Kiel, Germany. Controversy developed as to who was the first to conduct spinal anaesthetic, however, August Bier, a German surgeon is considered to be the father of spinal anaesthesia, probably working in collaboration with Quinkie. On August 16, 1898, Bier performed the first intrathecal anaesthetic on his assistant. He also reported a postdural puncture headache, which lasted for nine days. The technique of spinal anaesthesia was introduced across the Atlantic by Rudolph Matas (1899).

Fidel Pages (1921), a Spanish army surgeon, developed the technique of lumbar epidural anaesthesia and Doglioti described the loss of resistance technique. Ralph Huber (1940) a Seattle dentist was the inventor of the Tuohy needle, but it is known by the name of Edward Tuohy, an anaesthetist in the US who popularised it in 1945.

Lemmon (1940) at the Mayo Clinic, used the first continuous spinal technique and saddle anaesthesia was described by Adriani and Roman-Vega in 1946. Lastly, spinal morphine was administered by Wang in 1979. Currently, ultrasound and other imaging are used as adjuncts in difficult cases such as a patient with morbid obesity.


Practical steps when doing spinal anaesthesia

Individual anaesthetists have their own ways of performing central neuraxial anaesthesia. We have looked at different approaches and collected evidence from the literature and reached a conclusion as to how to describe it.

The following is an acronymic approach of doing spinal anaesthesia, the readers do not need to agree with our description. Remember the acronym ”SPINAL”. The same is applicable whilst doing epidural technique.

S   See the patient in the ward

Spot any problem with SAB (see patient’s notes)

Side effects and benefits discussed

Steps of procedure explained

Sterile trolley available

Spinal pack checked

Standard monitoring/resuscitation equipment checked

Stop before you block approach

P Patient identified in anaesthetic room

     Peripheral IV cannulation (large bore)

Practitioner scrubbed

Prepare LA for S/C and LA for SAB

Position upright/lateral

Pour antiseptic spray on the back and use clean drapes

Palpate for L2/3 or L3/4 interspaces

I   Inject lignocaine S/C

Introducer pushed in

N   Neuraxial needle into introducer

Needle in midline→ advanced cephalad

A   Ascertain CSF at the hub

L   LA (e.g. bupivacaine) injected

Leave out needles together, followed by dressing

Lay down the patient flat

LA effects/numbness checked

Liaise with surgeon to start procedure


Contraindications and complications of spinal anaesthesia

Like any other intervention, spinal and epidural anaesthesia have contraindications as well as complications. The following table explains most of them. Again refer to ”SPINAL”

  Contraindications   Complications
S Shocked patient


Spinal/epidural abscess

Syndrome e.g. Ehler Danlos

S Spinal cord injury(high approach SAB)


P Previous failed spinal

Pulmonary hypertension?

Patient refusal

P PDPH* (see below)

Patchy/Failed block*(see below)

I ICP raised I Itching if opiates used
N Neuro-anatomical deformity N Nerve damage
A Aortic stenosis

Abnormal coagulation

Agoraphobic patient

A Acute urinary retention
L Learning difficulty

Long surgical procedures

LA allergy

L Lumbar spinal bleeding/haematoma


Factors causing PDPH and the clinical features of PDPH

  Factors causing PDPH   Clinical presentation of PDPH
P Pregnancy

Patient in young group

P Postural nature

Presentation: bifronto-occipital

(radiates to the neck)

D Design of bevel(cutting)

Difficult spine

Delivery vaginal

Dural ectasia*(see below)

D Delayed onset
P Puncture attempt(multiple) P Photophobia and visual disturbances
H History of PDPH H Hearing loss,tinitus


Why spinal anaesthesia sometime fails?

Most experienced anaesthetists would consider the incidence of spinal anaesthesia failure as less than 1%. Gaston Labat (1922), who is considered as the father of modern regional anaesthesia quoted two essential components of successful spinal anaesthesia, first the dura mater must be punctured and second the subarachnoid injection of local anaesthetics must be made.

A failed spinal block could result from a dry tap, lumen of spinal needle blocked (which could happen if the spinal needle is pushed in without stylet) and poor positioning of the patient. Rarely, the CSF seen is not CSF but local anaesthetic injected subcutaneously. The failure of spinal anaesthesia may be because of low dose LA, baricity of injectate and the dead space of needle. Some clinicians think it may happen as a result of barbotage while doing the procedure.

In pseudo-successful lumbar puncture, CSF appears at the hub of the needle but that could be from an arachnoid cyst. Similarly, dural ectasia will result in an unsuccessful spinal block.


Dural ectasia

Dural ectasia refers to the ballooning or widening of the dural sac, which can result in posterior dural scalloping and is associated with herniation of nerve root sleeves. Clinical scenarios giving rise to dural ectasia (see CT and MRI images) could be easily by remembered by referring to the acronym ”MANTLE”.

M Marfan’s syndrome

A   Ankylosing spondylosis


N   Neurofibromatosis type-1

Neuroma (cystic)

T    Tarlov’s cyst

Tethered spinal cord syndrome

L     Loeye-Dietz syndrome

E     Ehler Danlos syndrome


CT and MRI images credit: Radiopaedia


Features of Dural Ectasia

To memorise the features of this rare condition, refer to “ECTASIA”

E   Exhaustion/weakness

C   Cephalgia

T Tailbone pain (lower backache)

A   Anaesthesia/numbness of perineum

S   Standing worsens symptoms

Supine posture relieves symptoms (but not always)

I  Incontinence/retention of urine

A   Add to diagnosis (see CT scan/MRI images)


How it affects the Central Neuraxial Anaesthesia

Patients with dural ectasia have a high CSF pressure, so when local anaesthetics are administered, spread of injectate is restricted. Subsequently, even in the hands of experienced anaesthetists, spinal failure happens. The strategy for a successful outcome is to have a combined spinal and epidural approach. One should bear in mind that the incidence of PDPH is very high in such patients. Moreover, patients with Ehler-Danlos syndrome may be resistant to effect of local anaesthetics and alternatives techniques should be discussed with the patient.



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  2. Cotungo DFA.De ischade nervosa commentaries. Naples, Italy: Fratres Simonis,1764
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  8. Gaston Labat 1922. Text book of Regional Anaesthesia



Dr.Sher Mohammad [1],

Dr. Prateek Verma [2],

Dr. Amith Dalvi [3]

Dr. Nishant Kalra [4]

Dr. Sibghatullah M Khan [5]

1.Consultant Anaesthetist

2.ST5 Anaesthetics

3.ST3 Anaesthetics

4.MTI Anaesthetics

Sheffield Teaching Hospitals, NHS Foundation Trust, Glossop Road Sheffield

5.Associate Consultant Obstetric Anaesthetist, Women Wellness and Research Centr, Doha, Qatar