Available via license: CC BY-NC-ND 4.0
Content may be subject to copyright.
Spinal anaesthesia for ambulatory surgery
W. Rattenberry
1
, A. Hertling
2
and R. Erskine
3
,
*
1
Queen’s Medical Centre, Nottingham, UK,
2
New York University School of Medicine, New York, USA and
3
Royal Derby Hospital, Derby, UK
*Corresponding author: robbie.erskine@nhs.net
Learning objectives
By reading this article, you should be able to:
Explain the historical context of spinal anaes-
thesia in the ambulatory setting.
Describe the ideal characteristics of an ambula-
tory spinal anaesthetic.
Recognise the central role of prilocaine and 2-
chloroprocaine in the ambulatory setting.
Select the right drug for the right patient and the
right procedure.
Ambulatory surgery places high demands on anaesthetic
technique. In this setting, rapid onset and offset of anaes-
thesia, rapid recovery of protective reflexes, mobility and
micturition, and good control of postoperative pain and
nausea are required. Since the inception of ambulatory sur-
gery, the favoured anaesthetic technique has been general
anaesthesia with short-acting drugs. Concerns about the time
to perform spinal anaesthesia and the risks of prolonged
motor block and urinary retention have limited its use.
Whilst in the UK, ‘ambulatory surgery’refers solely to
patients being discharged from the hospital shortly after
surgery, in the USA this term may also apply to admissions for
up to 23 h. In this article, we will consider ambulatory surgery
to mean that the patient is discharged home before midnight
on the day of surgery.
Spinal anaesthesia has become increasingly popular for
inpatient surgery, but, until recently, its use has been
limited in ambulatory surgery by the lack of a safe, licensed
short-acting local anaesthetic agent. An ideal intrathecal
agent for ambulatory surgery should have a rapid onset of
motor and sensory blockade, predictable regression within
an acceptable time frame, and a low incidence of adverse
effects. Historically, lidocaine was the preferred agent in
this setting, providing a dense block with rapid recovery,
but the identification of a high incidence of transient
neurologic symptoms (TNS) has effectively excluded it from
use.
1,2
Until recently, the only local anaesthetic prepara-
tions licensed for intrathecal use have been hyperbaric
William Rattenberry FRCA is a specialty trainee in anaesthesia
whose interests include quality improvement and regional
anaesthesia.
Arthur Hertling MD FASA is a professor of clinical anaesthesiology
at New York University School of Medicine. He is the director of the
regional anaesthesia fellowship programme and of ambulatory
anaesthesia. Previously an orthopaedic surgeon, his interests include
regional anaesthesia and long-term outcomes.
Robbie Erskine FRCA is a consultant anaesthetist at the Royal Derby
Hospital with extensive experience of ambulatory spinal anaesthesia.
He won the British Association of Day Surgery (BADS) gold award for
a presentation of the first use of intrathecal 2-chloroprocaine in day
surgery in the UK. He has authored guidelines for BADS.
Key points
Spinal anaesthesia can provide many of the
desired properties of the ideal technique for
ambulatory anaesthesia.
Prilocaine and 2-chloroprocaine are the intra-
thecal local anaesthetic agents of choice and
should be available for ambulatory surgery.
Spinal anaesthesia provides an alternative
approach for patients with comorbidities that
predispose them to higher perioperative risk.
Benefits may include reduced postoperative
nausea and vomiting, reduced postoperative
pain, early postoperative discharge and lower
cost.
Proficiency with the use of short-acting spinal
anaesthetics should be a core competency of
anaesthesia specialty training.
Matrix codes: 1A02,
2G01, 3A06
BJA Education, 19(10): 321e328 (2019)
doi: 10.1016/j.bjae.2019.06.001
Advance Access Publication Date: 13 August 2019
Accepted: 3 June 2019
©2019 The Authors. Published by Elsevier Ltd on behalf of British Journal of Anaesthesia. This is an open access article under the CC BY-NC-ND license
(http://creativecommons.org/licenses/by-nc-nd/4.0/).
For Permissions, please email: permissions@elsevier.com
bupivacaine alone in the USA, and hyperbaric bupivacaine
and plain levobupivacaine intheUK.Bothdrugsareof
limited utility in the ambulatory setting because of their
long duration of action.
1
Low-dose bupivacaine and ‘uni-
lateral’blocks have been used in an attempt to reduce block
duration, with limited success.
1
In 2010, hyperbaric prilocaine 2% was licensed for spi-
nal anaesthesia in the UK, followed in 2013 by plain 2-
chloroprocaine 1%. The US Food and Drug Administration
(FDA) approved plain 2-chloroprocaine 1% in 2017. These
short-acting drugs fulfil the key criteria of an ideal intra-
thecal agent for ambulatory surgery and have expanded
the choices available to the patient and anaesthetist when
performing spinal anaesthesia for ambulatory procedures.
Spinal anaesthesia with these agents does not necessarily
require adjuvants such as intrathecal opioids or the pro-
vision of sedation, and may be associated with reduced
postoperative analgesic requirements, lower rates of
postoperative nausea and vomiting (PONV) and quicker
readiness for discharge.
3e5
Intrathecal local anaesthetics
In this article we review the intrathecal local anaesthetic
agents relevant for ambulatory surgery. The availability and
licensing of these drugs for intrathecal use in the UK and USA
are summarised in Table 1.
Lidocaine
Lidocaine is an amide local anaesthetic with a rapid onset and
fast recovery of motor and sensory block, making it well
suited for ambulatory surgery.
6
The drug received FDA
approval in 1948, and the hyperbaric 5% formulation became
available for intrathecal use in 1954. In the early 1990s,
neurotoxicity concerns arose after several published case
Table 1 Summary of local anaesthetic availability and licensing for intrathecal use in the UK and the USA
Drug Chemical
structure
Medicines and
Healthcare products
Regulatory Agency
(MHRA) licence, UK
FDA approval,
USA
Licensed indication Notes
Lidocaine Amide No No Not applicable High incidence of
transient neurologic
symptoms.
2
Not recommended.
Bupivacaine Amide Marcain Spinal 0.5%
Heavy:
Hyperbaric bupivavaine
0.5% (AstraZeneca)
Hyperbaric bupivacaine
0.5% (Mercury Pharma)
Marcaine Spinal:
Hyperbaric
bupivacaine 0.75%
(Hospira)
UK: ‘urological and lower
limb surgery lasting 2e3
hours, abdominal surgery
lasting 45e60 minutes’
USA: not specified
Plain bupivacaine is not
licensed for intrathecal
use in the UK or USA.
Levobupivacaine Amide Chirocaine;
Levobupivacaine 0.25/
0.5/0.75% (Abbvie)
Levobupivacaine 0.25/
0.5/0.75% (Fresenius
Kabi)
No UK: ‘surgical anaesthesia’
USA: not applicable
No licensed hyperbaric
levobupivacaine
preparation.
Ropivacaine Amide No No Not applicable No commercial
preparation of
hyperbaric ropivacaine.
Plain ropivacaine used
off-label in USA.
Mepivacaine Amide No No Not applicable May have high incidence
of transient neurologic
symptoms.
2
Used off-label in USA.
Articaine Amide No No Not applicable No preservative-free
preparation.
Experimental only.
Procaine Ester No No Not applicable Concerns about
neurotoxicity.
14,15
Experimental only.
Prilocaine Amide Prilotekal:
Hyperbaric prilocaine 2%
(Sintetica)
No UK: ‘short term surgical
procedures’
USA: not applicable
Appropriate for
procedures up to 90 min
duration.
2-Chloroprocaine Ester Ampres:
Plain 2-chloroprocaine
1% (Sintetica)
Clorotekal:
Plain
2-chloroprocaine 1%
(B. Braun)
UK: ‘planned surgical
procedure should not
exceed 40 minutes’
USA: ‘those suitable for
Clorotekal’s short
duration of action’
50 mg may be effective
for up to 60 min for lower
limb procedures.
60 mg may last up to 90
min; but, doses exceeding
50mg are not approved by
MHRA or FDA.
17
Spinal anaesthesia for ambulatory surgery
322 BJA Education
-
Volume 19, Number 10, 2019
reports of cauda equina syndrome associated with continuous
spinal anaesthesia with hyperbaric lidocaine 5%, delivered via
intrathecal microcatheters.
2
The first report of TNS after single-shot lidocaine spinal
anaesthesia was published in 1993.
2
Although initially
described with lidocaine 5%, the incidence is not dose- or
concentration-dependent.
2
It is also not exclusively caused by
lidocaine, but the relative risk compared with other local an-
aesthetics (bupivacaine, prilocaine, procaine, levobupiva-
caine, ropivacaine, and 2-chloroprocaine) is 7.31 (95%
confidence interval 4.16e12.86).
2
A Cochrane systematic review published in 2009 found
that TNS occurs after one in seven spinal anaesthetics with
lidocaine.
2
The syndrome typically presents as pain in the
buttocks and lower extremities after recovery from uncom-
plicated spinal anaesthesia. Neurological examination, MRI,
and electrophysiological tests are typically normal, and in
almost all cases, the symptoms resolve within 5 days.
2
Although the exact cause is still unclear, the lithotomy posi-
tion is associated with a higher risk of TNS occurring.
2
Lidocaine is no longer licensed for intrathecal use in the UK
or USA, and we do not recommend its intrathecal use because
of the unacceptably high risk of TNS. It remains a safe and
popular choice for epidural anaesthesia.
Bupivacaine
Concerns about the high incidence of TNS with lidocaine and
the absence of alternative licensed short-acting agents for
ambulatory procedures prompted researchers to evaluate the
use of low-dose intrathecal bupivacaine, to mitigate the long
duration of action observed with usual doses.
7
Bupivacaine is a long-acting amide local anaesthetic,widely
used for intermediate- to long-duration surgery. In the UK and
USA bupivacaine is currentlyonly licensed for intrathecal use in
a hyperbaric formulation although plain bupivacaine is widely
administered off-label by the intrathecal route. The onset of
block onset occurs within 5e8 min and typically lasts 1.5e3h.
Regression of the block below the level of S2 to allow mobi-
lisation and micturition is slow, ranging from 240 to 380 min.
6
Low-dose (<10 mg) intrathecal bupivacaine is associated
with a shorter time to voiding and discharge home, although a
few patients may still have a long recovery time.
6,8
Strategies
aimed at using low doses of bupivacaine for bilateral blockade
are associated with an unacceptably high failure rate.
7
The
addition of fentanyl may facilitate the use of lower doses of
intrathecal bupivacaine and reduce postoperative pain scores
after knee arthroscopy when compared with bupivacaine
alone, but the benefits of adding fentanyl need to be balanced
against the potential for opioid-related adverse effects,
particularly pruritus, which occurs in up to 75% of patients.
7
There is no evidence that the use of intrathecal fentanyl re-
duces time to discharge.
7
Unilateral spinal anaesthesia with low-dose bupivacaine
can be effective for knee arthroscopy where a dense motor
block is not essential.
7
An adequate block may be accom-
plished with hyperbaric bupivacaine 4e5 mg, administered
with the operative side in the dependent position for 10e15
min.
7
Time to recovery is reduced to approximately 3e4h,
which is still inferior to 2-chloroprocaine and prilocaine.
1,6,7
We do not recommend the use of intrathecal bupivacaine
for ambulatory surgery in the UK. In the USA, it remains the
only FDA-approved local anaesthetic for procedures lasting
more than 60 min.
Levobupivacaine
Levobupivacaine is the S(e)-enantiomer of bupivacaine. The
speed of onset and quality of the block are comparable with
hyperbaric bupivacaine, but isobaric levobupivacaine may
have a shorter duration of sensory and motor block than
hyperbaric bupivacaine.
9
The time to mobilisation still ex-
ceeds 5 h, precluding it from routine use in ambulatory sur-
gery.
9
Isobaric levobupivacaine is licensed for intrathecal use
in the UK but not in the USA.
Ropivacaine
Ropivacaine is the S(e)-enantiomer of propivacaine. It is a
long-acting amide local anaesthetic with reduced lipid solu-
bility and lower toxicity than bupivacaine. Compared with
bupivacaine, it has a shorter duration of sensory and motor
block, a less dense motor block, and a lower incidence of hy-
potension and bradycardia has been reported.
10
Intrathecal hyperbaric ropivacaine is considered superior
to isobaric ropivacaine because of its faster onset and offset,
and more predictable and higher spread.
10
Whiteside and
colleagues
11
demonstrated that 3 ml hyperbaric ropivacaine
0.5% provided a mean duration of sensory block to T10 of 56.5
min, with a mean time to mobilisation of 253 min,
whichdalthough faster than the recovery times observed
with hyperbaric bupivacainedstill exceeds the time for block
resolution with prilocaine and 2-chloroprocaine
1,6
Ropivacaine is not currently licensed for intrathecal use in
the UK or USA. The hyperbaric ropivacaine preparation is not
available in the USA, but isobaric ropivacaine is sometimes
used intrathecally off-label.
Mepivacaine
Mepivacaine is an amide local anaesthetic that differs from
bupivacaine by the absence of a single butyl group on the
tertiary amine, making it less lipophilic, less potent, and
shorter acting than bupivacaine.
12
Mepivacaine is sometimes
used off-label intrathecally in the USA as a substitute for
lidocaine, and has a similar duration of action. The anaes-
thetic block produced by 45 mg isobaric mepivacaine 1.5%
lasts about 180 min.
12
Reducing the dose to 30 mg results in an
incomplete anaesthetic block in 28% of patients, making the
use of lower doses to decrease block duration inadvisable.
12
The frequency of TNS associated with intrathecal mepi-
vacaine may be similar to that of lidocaine.
2
Therefore, at
present, mepivacaine cannot be recommended for routine
intrathecal use. Mepivacaine is not licensed for intrathecal
use in the UK or USA.
Articaine
Articaine is an intermediate-potency, short-acting amide
local anaesthetic that is rapidly metabolised because of an
additional ester group in its structure. It has a fast onset,
producing acceptable anaesthesia for procedures lasting up
to 1 h and a time to first spontaneous voiding of approxi-
mately 3.5 h.
13
Articaine is not licensed for intrathecal use in the UK and
there is no available preservative-free preparation. In the USA,
it is only approved for dental surgery and commercially
available only in combination with adrenaline (epinephrine).
Spinal anaesthesia for ambulatory surgery
BJA Education
-
Volume 19, Number 10, 2019 323
Procaine
Procaine is a short-acting ester local anaesthetic with a similar
onset and duration of action to lidocaine but with a substan-
tially lower incidence of TNS.
2,14
Concerns have been raised
regarding its narrow therapeutic index, neurotoxicity, a high
rate of inadequate block, andintraoperative nausea.
14,15
Further
research into its pharmacodynamics and adverse effects are
required beforethis drug may be recommended. Procaine is not
licensed for intrathecal use in the UK or USA.
Prilocaine
Prilocaine is an amide local anaesthetic with fast onset, in-
termediate potency and intermediate duration of action. It is
associated with a low incidence of TNS.
2
The hyperbaric
preparation has been shown to have a significantly faster
onset and offset and a reduced time to first voiding compared
with plain prilocaine.
16
Dose-finding studies have concluded
that prilocaine doses between 40 and 60 mg are appropriate
for lower limb and lower abdominal procedures lasting up to
90 min.
1
The time to discharge from hospital after intrathecal prilo-
caine is dose-dependent, but patients may typically be dis-
chargedwithin approximately4 h after administration.Doses of
up to 60 mg can be used safely and effectively in ambulatory
surgery. Perianal procedures can be performed with as little as
10 mg. This dose providesan effective saddle block with little or
no haemodynamic disturbance and patients may retain the
ability to ambulate throughout.
1
The hyperbaric preparation
can be manipulated for use for both saddle anaesthesia and
periumbilical and laparoscopic ambulatory procedures. Adju-
vants such as clonidine and fentanyl are not necessary to ach-
ieve adequate anaesthesia, and the risk of increased adverse
effects of these agents must be taken into consideration.
1,16
Prilocaine is relatively contraindicated in sickle cell disease
because of the risk of methaemoglobinaemia caused by
an ortho-toluidine metabolite.
1
In healthy adults, the dose
required to produce clinically apparent methaemoglobinaemia
is 6 mg kg
1
, which vastly exceeds the typical intrathecal dose.
1
Prilocaine 5% was used via the intrathecal route in the UK
from the 1960s until 1978 when it was withdrawn for commercial
reasons related to production and stability of the drug.
1
Hyper-
baric prilocaine 2% was licensed in the UK in 2010. At present,
prilocaine is not approved for intrathecal use in the USA.
2-Chloroprocaine
2-Chloroprocaine is an ester local anaesthetic with a very
short duration of action that is caused by very low protein
binding and rapid metabolism by pseudocholinesterase. It
was first used intrathecally in 1952 but was not used routinely
for spinal anaesthesia because lidocaine was the established
agent for short procedures.
17
In the early 1980s there were
reports of permanent neurological deficits after inadvertent
intrathecal injection of large volumes of 2-chloroprocaine 3%
with a sodium bisulphite preservative intended for the
epidural space.
17
It is unclear whether sodium bisulphite or
the high concentration of 2-chloroprocaine was the cause of
neurotoxicity.
17
A preparation of plain 2-chloroprocaine 1% that is free of
both antioxidants and preservatives was introduced in 2004
and has been found to be no more toxic than other local an-
aesthetics, with a very low risk of TNS.
2,6,13
Intrathecal 2-chloroprocaine has a rapid onset of sensory
block (3e5 min). The duration of block is dose-dependent,
with complete resolution of sensory block after 70e150 min
with 30e60 mg.
6
A dose of 40e50 mg of the 1% solution pro-
vides profound motor and sensory block up to T10e12, which
is adequate for procedures such as knee arthroscopy or foot
surgery. Up to 60 min of adequate surgical anaesthesia may be
achieved, despite being licensed for procedures lasting up to
40 min. Although the use of lower doses such as 30 mg have
been described, they may be associated with an inadequate
duration of anaesthesia.
17
It has been our experience that
discharge time is not significantly prolonged when 50 mg
compared with 40 mg doses are used. A dose of 60 mg typically
provides a surgical block lasting in excess of 60 min, but the
FDA states that ‘doses above 50 mg have not been adequately
tested for efficacy and safety’. Similarly, in the UK, the
maximum recommended dose is 50 mg.
Plain 2-chloroprocaine 1% may be used for perineal
procedures but a saddle block is difficult to achieve consis-
tently because the preparation is isobaric.
17
The addition of
adrenaline to prolong the duration of block is not recom-
mended as it can cause flu-like symptoms and back pain.
17
Plain 2-chloroprocaine 1% was licensed in the UK in 2013,
and in the USA in 2017.
Intrathecal opioids
Fentanyl and sufentanil are widely used off-label in conjunc-
tion with local anaesthetics by the intrathecal route, with the
goal of improving the quality of intraoperative anaesthesia by
reducing visceral pain. These opioids have been reported to
provide superior postoperative analgesia, but are associated
with higher rates of opioid-induced adverse effects, including
pruritus, PONV and postoperative urinary retention (POUR).
7
For ambulatory surgery, spinal anaesthesia supplemented by
early oral analgesia and locoregional techniques makes the
routine addition of intrathecal opioids unnecessary.
Advantages of ambulatory spinal
anaesthesia
Choice for the patient and informed consent
Clinicians have an ethical and legal obligation to respect pa-
tient autonomy, and have a duty to discuss the options for
anaesthesia, taking reasonable care to ensure that the patient
is aware of the ‘material risks’of each option.
18
In UK case
law, ‘material risks’have been defined as those to which a
reasonable person in the patient’s position would be likely to
attach significance, or to which the doctor should reasonably
be aware that the particular patient would be likely to attach
significance.
18
The choice of general or spinal anaesthesia should not be
presented simply as ‘you will be asleep’vs ‘you will be awake’.
The discussion regarding spinal anaesthesia should include
the option of receiving anxiolytic medications and drugs to
provide moderate or deep sedation.
Improved patient engagement
Under spinal anaesthesia, patients may choose to observe
certain aspects of their procedure and have the opportunity to
interact with their surgeon. This can have psychological
benefits and improve patient satisfaction.
19
Spinal anaesthesia for ambulatory surgery
324 BJA Education
-
Volume 19, Number 10, 2019
Pain
Central neuraxial block is associated with reduced post-
operative pain scores and decreased need for analgesia in the
PACU.
4
The progressive regression of sensory blockade allows
the introduction of systemic analgesics, titrated according to
the severity of pain, facilitating a smooth transition from
anaesthesia to effective analgesia.
Postoperative nausea and vomiting
PONV is unpleasant for the patient andis a common reason for
delayed discharge.
5
Spinal anaesthesia is likely associated with
a reduced incidence of PONV when compared with general
anaesthesia, but numerous factors contribute to the risk of
PONV with both techniques.
5
Hypotension, blocks above the
level of T5, and the addition of intrathecal morphine increase
the incidence of PONV with spinal anaesthesia.
5
Short-acting
spinal anaesthesia for ambulatory surgery facilitates the
avoidance of systemic opioids, which reduces the risk of PONV.
The reduced duration of unopposed vagal activity with short-
acting agents may further reduce this risk.
5
Comorbidities
Patients presenting for ambulatory surgery are increasingly
older, sicker, and more obese. The use of short-acting intra-
thecal agents enables patients who were previously excluded
because of their comorbidities and the risks associated with
general anaesthesia, to benefit from ambulatory surgery.
Spinal anaesthesia has minimal effects on pulmonary
physiology if the motor block is kept below T6 and is known to
reduce postoperative pulmonary complications in patients
with chronic obstructive pulmonary disease.
20
Obesity is associated with an increased risk of difficult
airway, aspiration, and respiratory compromise with general
anaesthesia.
21
Where appropriate, regional anaesthesia is
preferred to general anaesthesia in obese patients.
In patients with significant gastro-oesophageal reflux dis-
ease, spinal anaesthesia may reduce the risk of pulmonary
aspiration by avoiding the loss of protective airway reflexes
that occur with general anaesthesia.
Patients with obstructive sleep apnoea may have increased
sensitivity to benzodiazepines, neuroleptics, and opioids,
worsening the severity of apnoea through central respiratory
depression and pharyngeal muscle relaxation.
22
Opioid-free
spinalanaesthesiawithout sedationmay therefore be beneficial.
Patients with diabetes may benefit from an opioid-sparing
spinal anaesthetic technique that may reduce the risk of
PONV.
5
Spinal anaesthesia may allow a faster return to oral
intake, reducing disruption to their normal ant i-hyperglycaemic
regimen.
Elderly patients may benefit from avoiding general anaes-
thesia and sedation, which contributes to postoperative
confusion and may play a role in postoperative cognitive
decline. Further research is warranted to quantify the benefits
of ambulatory spinal anaesthesia to patients with comorbid-
ities and advanced age.
Cost
Ambulatory spinal anaesthesia has the potential to improve
operating theatre efficiency and reduce cost. Compared with
general anaesthesia, the time to readiness for surgery with
spinal anaesthesia is typically only a few minutes longer.
Despite this slight delay, the potential ability to bypass PACU
may lead to cost savings.
Gebhardt and colleagues compared intrathecal 2-
chloroprocaine and total intravenous anaesthesia for knee
arthroscopy and reported that patients receiving spinal
anaesthesia met discharge criteria earlier and at a lower cost.
3
Potential complications of ambulatory spinal
anaesthesia
Delayed mobilisation
Delayed mobilisation and discharge have been problematic
issues with the use of bupivacaine spinal anaesthesia for
ambulatory surgery. Full return of sensory and motor function
is required for mobilisation. Prilocaine and 2-chloroprocaine
have substantially faster block resolution than bupivacaine.
1,6
We recommend that after the return of normal motor and
sensory function patients be mobilised with direct supervision.
Postoperative urinary retention
Spontaneous micturition is the last function to recover after
motor block resolution, and requires the regression of sensory
block to below the S3 dermatome.
1
The incidence of post-
operative urinary retention (POUR) depends on risk factors
related to the patient, surgery, and anaesthesia.
1
Complica-
tions include bladder overdistension, which may be accom-
panied by an autonomic response and may have an adverse
effect on urodynamics, as well as risk of infection.
Prilocaine is associated with a lower risk of POUR than
bupivacaine, but the exact incidence of urinary retention is
not known and depends on dose and other risk factors.
1
Re-
ported mean times to micturition with prilocaine range from
218 to 306 min.
1
There are no known reported cases of POUR
secondary to intrathecal 2-chloroprocaine.
6
Avoiding excessive intravenous fluids during surgery may
minimise the risk of POUR.
1
We recommend giving no more
than 500 ml to avoid bladder overdistension, whilst recog-
nising that some patients may require additional volumes of
fluids and vasopressor therapy to treat hypotension caused by
spinal anaesthesia-induced sympathectomy.
Ambulatory surgery units may consider allowing low-risk
patients aged <70 yrs and without a history of voiding diffi-
culty to undergo low-risk procedures (not hernia or urological
surgery) with short-acting spinal anaesthetics, particularly 2-
chloroprocaine, to be discharged from hospital before void-
ing.
1,6
High-risk patients should be required to void prior to
discharge. Bladder catheterisation should be performed if
bladder volume exceeds 600 ml.
1
Discharging low-risk pa-
tients before voiding requires a robust local support frame-
work and thorough education of patients.
Post-dural puncture headache
Post-dural puncture headache (PDPH) is an unpleasant
complication of spinal anaesthesia that may be severely
debilitating. The risk of PDPH is very low with modern spinal
anaesthesia and is unaffected by the local anaesthetic used.
23
Epidural blood patch is effective in 70e98% of patients with
PDPH if carried out more than 24 h after the dural puncture, and
72% of cases will resolve within 7 days without treatment.
23
We recommend using a 25e27 G non-cutting spinal needle,
balancing the increased risk of PDPH with larger needles with
the increased likelihood of technical failure with smaller
needles.
23
All patients must be informed of what to do in the
Spinal anaesthesia for ambulatory surgery
BJA Education
-
Volume 19, Number 10, 2019 325
event of a postoperative headache, and there should be a local
protocol in place for their management.
Hypotension and bradycardia
Spinal anaesthesia commonly causes both hypotension and
bradycardia, primarily through preganglionic sympathetic
blockade. General anaesthesia is also commonly associated
with hypotension caused by the vasodilatory and negatively
inotropic effects of many anaesthetic agents. In both cases,
hypotension can be effectively managed with the judicious
use of fluids and vasopressors.
Neurotoxicity and nerve injury
Neurotoxicity has beendemonstrated with all local anaesthetic
agents in studies using animal models.
2
In clinical practice the
incidence of TNS with prilocaine and 2-chloroprocaine is very
low, and comparable with that of bupivacaine.
2
The national audit of major complications of central neu-
raxial block in the UK (3rd National Audit Project [NAP3])
showed that whilst the consequences can be devastating,
major complications are extremely rare.
24
The risk of per-
manent nerve damage with spinal anaesthesia is no more
than one in 160,000.
24
It should be borne in mind that pe-
ripheral nerve injury is also common with general anaes-
thesia, occurring in one in 350 cases.
24
Effective ambulatory spinal anaesthesia
Ambulatory surgical procedures at the level of the umbilicus
and below are well suited to spinal anaesthesia. The choice of
drug and dose must be targeted to the location of the surgical
Saddle Block?
>T10 block?
>40 min?
2-Chloroprocaine 1%
40-50 mg
(4 - 5 ml)
GENERAL Varicose veins, inguinal
hernia, lumps and bumps
ORTHOPAEDICS Knee arthroscopy
(including bilateral), anterior cruciate
ligament, medial patellofemoral
ligament repair, foot and ankle surgery
GYNAECOLOGY Hysteroscopy,
transvaginal tape, minor repair
UROLOGY Cystoscopy, bladder
neck incision
YES
Hyperbaric
prilocaine 2%
60 mg (3 ml)
GENERAL Epigastric/umbilical
hernia
UROLOGY Ureteroscopy +/- stent
and laser
YES
NO
Hyperbaric
prilocaine 2%
40-60 mg
(2-3 ml)
YES
NO
ORTHOPAEDICS Anterior cruciate
ligament, medial patellofemoral
ligament repair
GENERAL Inguinal/femoral hernia,
Hyperbaric
prilocaine 2%
10-20mg (0.5-1 ml)
YES
NO
GENERAL Haemorrhoids, perianal
fistula, abscess, examination under
anaesthesia of rectum
GYNAECOLOGY Vulval surgery
UROLOGY Circumcision,
meatoplasty
bilateral herniae, bilateral varicose
veins
GYNAECOLOGY Vaginal repair,
colposuspension, colpocleisis +/-
vaginal hysterectomy
UROLOGY Transurethral resection
of prostate
Fig 1 Algorithm for procedure targeted spinal anaesthesia for ambulatory surgery (R. Erskine, G. Turner, E. Erskine, 2015). If hyperbaric 2% prilocaine is not
available alternative techniques may be effective, including using high-dose (60 mg) plain 1% 2-chloroprocaine, mepivacaine, ropivacaine, or low-dose bupiva-
caine. The literature to support these techniques is not strong, and they may not be recommended reliably.
Spinal anaesthesia for ambulatory surgery
326 BJA Education
-
Volume 19, Number 10, 2019
field and the length of surgery. Intravenous access and
monitoring should be established before spinal anaesthesia.
If a saddle block is required, 10e20 mg of hyperbaric pri-
locaine 2% administered in the sitting position is effective,
reducing adverse cardiovascular effects and enabling rapid
postoperative mobilisation.
25
Hyperbaric bupivacaine can be
used if prilocaine is not available. Discharge may not be
delayed if lower limb motor and sensory functions are not
affected.
If a block of T10 or above is required, for example for an
epigastric hernia repair, 60 mg hyperbaric 2% prilocaine would
be suitable.
If a block at T10 or below is required, the anticipated
duration of surgery should guide the decision to use either
40e50 mg plain 2-chloroprocaine 1% for procedures estimated
to last up to 40 min, or 40e60 mg hyperbaric prilocaine 2% for
procedures lasting up to 90 min. The surgical preparation time
must be included in these calculations.
We have designed a simple and pragmatic flowchart to
assist colleagues in deciding which drug and at what dose is
most appropriate for common ambulatory procedures (Fig. 1).
Providing an ambulatory spinal anaesthesia
service
We recommend that prilocaine, if commercially available, and
2-chloroprocaine should be on the formulary wherever
ambulatory surgery is conducted. Education of surgeons and
preoperative, operating theatre and recovery staff is funda-
mental to the success of an ambulatory spinal anaesthesia
service. Specialty-specific lists of procedures commonly per-
formed in the ambulatory setting, describing the preferred
anaesthetic approach and highlighting all those amenable to
short-acting spinal anaesthesia, can be very useful to col-
leagues usually working in other services. Advice on how to
supplement analgesia with locoregional techniques and sys-
temic analgesia should also be provided. Establishing local
protocols for patient mobilisation after spinal anaesthesia and
the management of POUR and PDPH are recommended.
Conclusions
Ambulatory surgery can be performed effectively with spinal
anaesthesia. The availability of intrathecal prilocaine and 2-
chloroprocaine have increased the options available to the
anaesthetist and provide more effective and predictable
anaesthesia than low-dose and unilateral bupivacaine spinal
anaesthesia. The adverse effects of ambulatory spinal
anaesthesia, including delayed mobilisation and POUR, are
reduced with short-acting agents, making spinal anaesthesia
a safe, effective and economical alternative to general
anaesthesia.
Declaration of interest
R.E. is an advisor to Sintetica UK on day case spinal anaes-
thesia. A.H. is a consultant for Sintetica (Switzerland) and for
B Braun USA.
MCQs
The associated MCQs (to support CME/CPD activity) will be
accessible at www.bjaed.org/cme/home by subscribers to BJA
Education.
References
1. Manassero A, Fanelli A. Prilocaine hydrochloride 2% hy-
perbaric solution for intrathecal injection: a clinical re-
view. Local Reg Anesth 2017; 10:15e24
2. Zaric D, Pace NL. Transient neurologic symptoms (TNS)
following spinal anaesthesia with lidocaine versus other
local anaesthetics. Cochrane Database Syst Rev 2009; 2:
CD003006
3. Gebhardt V, Zawierucha V, Sch€
offski O, Schwarz A,
Weiss C, Schmittner MD. Spinal anaesthesia with chlor-
oprocaine 1% versus total intravenous anaesthesia for
outpatient knee arthroscopy: a randomised controlled
trial. Eur J Anaesthesiol 2018; 35: 774e81
4. Liu SS, Strodtbeck WM, Richman JM, Wu CL.
A comparison of regional versus general anesthesia for
ambulatory anesthesia: a meta-analysis of randomized
controlled trials. Anesth Analg 2005; 101: 1634e42
5. Borgeat A, Ekatodramis G, Shenker C. Postoperative
nausea and vomiting in regional anaesthesia. Anesthesi-
ology 2003; 98: 530e47
6. Saporito A, Marcello C, Perren A et al. Does spinal chlor-
oprocaine pharmacokinetic profile actually translate into
a clinical advantage in terms of clinical outcomes when
compared to low-dose spinal bupivacaine? A systematic
review and meta-analysis. J Clin Anesth 2019; 52:99e104
7. Nair GS, Abrishami A, Lermitte J, Chung F. Systematic
review of spinal anaesthesia using bupivacaine for
ambulatory knee arthroscopy. Br J Anaesth 2009; 102:
307e15
8. Teunkens A, Vermeulen K, Van Gerven E, Fieuws S, Van
de Velde M, Rex S. Comparison of 2-chloroprocaine,
bupivacaine, and lidocaine for spinal anaesthesia in pa-
tients undergoing knee arthroscopy in an outpatient
setting: a double-blind controlled trial. Reg Anesth Pain
Med 2016; 41: 576e83
9. Sahin A, Turker G, Bekar A, Bilgin H, Korfali G.
A comparison of spinal anesthesia characteristics
following intrathecal bupivacaine or levobupivacaine in
lumbar disc surgery. Eur Spine J 2014; 23: 695e700
10. Mohta M. Ropivacaine: is it a good choice for spinal
anesthesia? J Anaesthesiol Clin Pharmacol 2015; 31: 457e8
11. Whiteside JB, Burke D, Wildsmith JA. Comparison of
ropivacaine 0.5% (in glucose 5%) with bupivacaine 0.5%
(in glucose 8%) for spinal anaesthesia for elective surgery.
Br J Anaesth 2003; 90: 304e8
12. Zayas VM, Liguori GA, Chisholm MF, Susman MH,
Gordon MA. Dose response relationships for isobaric
spinal mepivacaine using the combined spinal epidural
technique. Anesth Analg 1999; 89: 1167e71
13. Snoeck M. Articaine: a review of its use for local and
regional anesthesia. Local Reg Anesth 2012; 5:23e33
14. Hodgson PS, Liu SS, Batra MS, Gras TW, Pollock JE,
Neal JM. Procaine compared with lidocaine for incidence
of transient neurologic symptoms. Reg Anesth Pain Med
2000; 25: 218e22
15. Johnson M, Swanson J. Procaine spinal neurotoxcity.
Anesthesiology 2008; 109: 349e51
16. Camponovo C, Fanelli A, Ghisi D, Cristina D, Fanelli G.
A prospective, double-blinded, randomized, clinical trial
comparing the efficacy of 40 mg and 60 mg hyperbaric 2%
prilocaine versus 60 mg plain 2% prilocaine for intra-
thecal anesthesia in ambulatory surgery. Anesth Analg
2010; 111: 568e72
Spinal anaesthesia for ambulatory surgery
BJA Education
-
Volume 19, Number 10, 2019 327
17. Goldblum E, Atchabahian A. The use of 2-chloroprocaine for
spinal anaesthesia. Acta Anaesthesiol Scand 2013; 57: 545e52
18. Orr T, Baruah R. Consent in anaesthesia, critical care and
pain medicine. BJA Educ 2018; 18: 135e9
19. Camponovo C, Wulf H, Ghisi D et al. Intrathecal 1% 2-
chloroprocaine vs. 0.5% bupivacaine in ambulatory sur-
gery: a prospective, observer-blinded, randomised,
controlled trial. Acta Anaesthesiol Scand 2014; 58: 560e6
20. Hausman Jr MS, Jewell ES, Engoren M. Regional versus
general anaesthesia in surgical patients with chronic
obstructive pulmonary disease: does avoiding general
anaesthesia reduce the risk of postoperative complica-
tions? Anesth Analg 2015; 120: 1405e12
21. Members of the Working Party, Nightingale CE,
Margarson MP, Shearer E et al. Peri-operative manage-
ment of the obese surgical patient 2015: association of
anaesthetists of great britain and Ireland society for
obesity and bariatric anaesthesia. Anaesthesia 2015; 70:
859e76
22. Martinez G, Faber P. Obstructive sleep apnoea. BJA Educ
2011; 11:5e8
23. Turnbull D, Shepherd D. Post-dural puncture headache:
pathogenesis, prevention and treatment. Br J Anaesth
2003; 91: 718e29
24. Cook TM, Counsell D, Wildsmith JAW. Major complica-
tions of central neuraxial block: report on the third na-
tional audit Project of the royal college of anaesthetists. Br
J Anaesth 2009; 102: 179e90
25. Gebhardt V, Herold A, Weiss C, Samakas A,
Schmittner MD. Dosage finding for low-dose spinal
anaesthesia using hyperbaric prilocaine in patients un-
dergoing perianal outpatient surgery. Acta Anaesthesiol
Scand 2013; 57: 249e56
Spinal anaesthesia for ambulatory surgery
328 BJA Education
-
Volume 19, Number 10, 2019
