Transcript Spinal Anesthesia for Ambulatory Surgery

Spinal Anesthesia for Ambulatory
Surgery
SubTitles:
• Ambulatory Surgeries:
- Overview.
- Criteria of Selection.
• Anesthesia Management:
- Pre-operative Assessment.
- Intra-operative (Spinal).
- Post-operative care.
Overview on Ambulatory Surgeries
• History:
– Historians dispute whether Crawford Long, in 1842, or
William Morton, in1846, first used Ether for anesthesia in
the United States. But what these two pioneers had in
common was that their patients were outpatients.
– After that time and for more than 100 years,
hospitalization of patients both before and after operation
was the norm.
Overview on Ambulatory Surgeries
• History:
- Over the past 4 decades, ambulatory surgery has grown
from less than 10% to over 70% of all elective surgical
procedures.
Rationale for Ambulatory Surgery
Facility Design
Essential Components of Ambulatory Surgery Facility:
Facility Design
1. Hospital Integrated.
(shared with inpatients)
2. Hospital-based.
(Facility within a hospital handles only out patients)
3. Freestanding.
(separated buildings for outpatients associated to a hospital or medical
center)
4. Office-based.
(usually are private diagnostic and operative suites managed by
conjunction of physicians and health care providers for patients
convenience)
Role of Anesthesiologist In Ambulatory Surgery
Patient Selection Criteria
• Selection of procedure.
• Duration of surgery.
• Patient characteristics ( ASA, Age, MH
susceptibility ).
• Contraindications.
Selection of Procedure
• Suitable procedures for ambulatory Surgery:
Selection of Procedure
• Non-Suitable procedures for ambulatory
Surgery:
- Procedures associated with major postoperative
complications, i.e. bleeding or major fluid shifts (e.g. extensive
plastic surgery, reduction mammoplasty, liposuction).
- Procedures requiring prolonged immobilization and
parenteral opioid analgesic therapy.
Duration of Surgery
• Was originally limited to procedures lasting less than 90
minutes.
• Now, 3 – 4 hours surgeries are routinely performed on an
ambulatory basis.
Patient Characteristics
• Originally, ASA I and II patient are only eligible for ambulatory
surgery.
• Now, with improvement in Anesthesia and surgical care ASA III and
even some ASA IV in whom medical condition is stable are eligible
for ambulatory surgery.
• Therefore, the ASA physical status should not be considered in
isolation because the type of surgical procedure, the anesthetic
technique, and a multitude of medical and social factors can also
influence decisions regarding a patient's suitability for ambulatory
surgery.
Evidence Base:
In a large, prospective outcome study, 24% of ambulatory surgical patients were ASA physical
status III, and these patients had the same low incidence of morbidity as ASA I and II patients.
by Warner and coworkers, JAMA, 1993
Patient Characteristics
• Morbid Obesity ( BMI > 40 kg/m2 ) is no longer considered an
exclusionary criterion for day-case surgery. However morbidly
obese patients with preexisting cardiovascular (e.g.,
hypertension, congestive heart failure, angina) or respiratory
(e.g., asthma, chronic obstructive pulmonary disease)
conditions had a higher incidence of perioperative morbidity
than did healthy outpatients undergoing similar procedures
on an ambulatory basis.
• Elderly obese patients are more likely to experience natural
oxygen desaturation and episodic airway obstruction.
Patient Characteristics
• OSA syndrome was not associated with increased risk of
unanticipated hospital admission.
• Smoking associated with increased risk of respiratory
complications and wound infection.
• MH-susceptible patients are not appropriate criteria for
admission and is eligible for ambulatory surgery provided that
anesthesia and surgery was uneventful.
Patient Characteristics
Extreme of Age
• Elderly patients: Even the “elderly elderly” patient (>100
years) should not be denied ambulatory surgery solely on the
basis of age, provided that: medical condition is stable, the
procedure went uneventfully, family care for transportation
and home care is available.
(EB: A study found that elderly patients experienced less
postoperative cognitive dysfunction and disorientation after ambulatory
(versus inpatient surgery). ( Kitz DS, et al, Anesthesiology 1988)
Patient Characteristics
Extreme of Age
• Premature infants:
– Under GA, there is increased risk which is greatest in premature
infants younger than 46 weeks’ postconceptual age of postoperative
apnea. In some studies, this risk persist until the 60th postconceptual
week. ( Fisher LA, et al: Anesthesiology 1995),(Malviya S, et al: Anesthesiology 1993)
– Anemia ( hematocrit < 30%) in this group of patient alone increase the
risk postoperative apnea by evidence. (Welborn LG, Hannallah RS, et al:
Anesthesiology 1991).
– There was no relationship between apnea and use of intraop opioid or
muscle relaxant, and the use of IV caffeine may prevent apnea and
desaturation in this group of patients. ( Cote CJ, et al Anesthesiology 1995),(Welborn
LG, Hannallah RS, et al: Anesthesiology 1989)
Contraindication to Ambulatory Surgery
1. Potentially life-threatening chronic illnesses (e.g., brittle
diabetes, unstable angina, symptomatic asthma).
2. Morbid obesity complicated by symptomatic
cardiorespiratory problems (e.g., angina, asthma).
3. Multiple chronic centrally active drug therapies (e.g., use of
monoamine oxidase inhibitors such as pargyline and
tranylcypromine) and/or active cocaine abuse.
4. Ex-premature infants less than 60 weeks’ postconceptual age
requiring general endotracheal anesthesia.
5. No responsible adult at home to care for the patient on the
evening after surgery.
Anesthesia Management
• Pre-operative Assessment:
- Pre-operative evaluation.
- Pre-operative preparation.
• Intra-operative ( Spinal ).
- Facts.
- Literature Review.
• Post-operative care.
Pre-operative Evaluation
Objective :
to identify patients who have concurrent medical
problems requiring further diagnostic evaluation or active
treatment before elective surgery in order to minimize
cancellations or complications.
1.History ( most valuable tool ) and Physical Examination:
- Identify the general and specific medical condition of
patient, medications, and risk assessment.
- Specific anesthetic concerns: airway assessment, active
cardiac or respiratory disease, previous operations and
anesthesia charts if available.
- Preoperative assessment 1 to 2 weeks before surgery
was found to reduce preoperative anxiety when compared with
assessment on the evening before surgery.
Pre-operative Evaluation
2. Laboratory testing:
- Routine preoperative laboratory testing of patients before
ambulatory surgery is unjustified and extremely wasteful of
valuable health care resources.
- For outpatients undergoing superficial surgical procedures
(e.g., biopsy, dilatation and curettage, herniorrhaphy,
arthroscopy, vein stripping), no laboratory tests appear to
be indicated in males, and only a hemoglobin (or
hematocrit) test is indicated for adult females of childbearing age.
- Obviously patient with chronic disease require additional
workup accordingly.
Pre-operative Preparation
Objective: reducing the risks inherent in ambulatory surgery,
improving patient outcome, and making the surgical
experience more pleasant for the patient and their family.
Pre-operative Preparation
• Non-pharmacological:
• pre-anesthesia visit alone can be more effective than
medications in relieving preoperative anxiety.
• Educational programs: video instructions, books, pamphlets,
and hypnosis all seems to be beneficial.
• Preoperative preparation should also include written and
verbal instructions regarding arrival time and place, fasting
instructions, and information concerning the postoperative
course, effects of anesthetic drugs on driving and cognitive
skills immediately after surgery, and the need for a
responsible adult to care for the patient during the early
postdischarge period (<24 hours).
Pre-operative Preparation
• Pharmacological:
- The use of premedication in the outpatient setting has
been a subject of considerable debate over the past 30 years.
- The primary indications for preoperative medication
include anxiolysis, sedation, analgesia, amnesia, and prophylaxis
against postoperative emesis and aspiration pneumonia.
Pharmacologic Preparation
• Benzodiazepines:
- Superior to barbiturate(residual sedation)
- Prospective studies have not found recovery to be
prolonged after the use of appropriate doses of sedative
premedication in the outpatient setting (midazolam 1-2mg IV).
- Midazolam has become the drug of choice because its
shorter elimination half-life and its anesthetic sparing effects and
lack of significant side effects facilitate the recovery process after
ambulatory surgery.
Pharmacologic Preparation
• Benzodiazepines:
- In addition to its well-known anxiolytic properties,
midazolam may be effective in reducing postoperative pain and
nausea and improving patient satisfaction.
- Midazolam (0.5 mg/kg PO) allowed children to be
separated from their parents as early as 15 minutes after oral
ingestion, without prolonging recovery even after brief surgical
procedures.
- In geriatric patients, premedication with midazolam
(0.5-1.0 mg IV) did not adversely affect mental and psychomotor
recovery, even after brief ambulatory procedures.
Pharmacologic Preparation
Pharmacologic Preparation
• α2-Adrenergic Agonists: ( Clonidine and dexmedetomidine)
- Premedication with α2-adrenergic agonist drugs
produce sedation and anxiolysis while also decreasing the heart
rate and blood pressure during anesthesia and opioid
requirements after surgery.
Pharmacologic Preparation
• α2-Adrenergic Agonists:
• Clonidine: Shown to be :
- Effective in decreasing emergence delirium after
sevoflurane anesthesia.
- Reduce emetic symptoms after breast surgery under GA.
- Facilitate glycemic control in type-2 diabetic patients.
- Reduce postoperative myocardial ischemia in patients
with preexisting cardiac disease.
- When compared to oral midazolam, less effective in
reducing anxiety but produced greater anesthetic- and analgesicsparing effects in children.
Pharmacologic Preparation
• α2-Adrenergic Agonists:
• Dexmedetomidine: ( like clonidine but..)
- More highly selective α2-agonist that has a shorter
duration of action than clonidine.
- Could prove valuable adjunct during surgery because of
its anesthetic and analgesic sparing effects and ability to
decrease postoperative pain.
Pharmacologic Preparation
Pharmacologic Preparation
• Nausea and Vomiting Prevention:
- Very common postoperative complication and contribute
to patients’ dissatisfaction and delayed discharge.
- The cost-effective combination of droperidol,
dexamethasone, and ondansetron is increasingly being used for
antiemetic prophylaxis of outpatients undergoing a wide variety
of surgical procedures.
- Antihistamines (e.g. Dimenhydrinate, hydroxyzine) used
effectively to prevent PONV specially in middle ear or strabismus
surgery. In combination with droperidol can reduce vomiting up to
24 hours without delaying discharge.
Intra-operative Management
• Monitored Anesthesia Care.
• Local Infiltration Techniques.
• Regional Anesthesia:
- Peripheral Nerve Block.
- IV regional anesthesia.
- Epidural.
- Spinal.
• General Anesthesia.
Spinal Anesthesia
• Bier's breakthrough in spinal
anaesthesia was made in 1898
when he performed the first
planned spinal anaesthetic on a
series of 6 patients for lower
extremity surgery. Each of them
received a spinal dose of cocaine
and did well except for having
nausea, vomiting and headache
afterwards.
August Karl Gustav Bier (24 November 1861, Bad Arolsen – 12
March 1949) was German surgeon and the pioneer of spinal
anaesthesia.
Spinal Anesthesia for Ambulatory
Surgery
Facts :
• Probably considered the simplest and most reliable regional
anesthetic technique, but …..
• Unfortunately, the incidence of side effects is surprisingly high.
• Needs longer recovery time.
• Most troublesome complication is the residual effect of the
block on motor, sensory, and sympathetic nervous system
function  ( delayed ambulation, impaired balance, dizziness,
and urinary retention ).
Spinal Anesthesia for Ambulatory
Surgery
Facts :
• Although the incidence of post–dural puncture headache can
be minimized with the use of small-bore, 25-gauge pencilpoint needles, the incidence of failed blocks appears to be
higher.
• The goal is to apply the most appropriate technique and to
select the most appropriate anesthetic-adjuvant combination
to avoid prolonged undesirable effects and thus, delayed
discharge.
Spinal Anesthesia for Ambulatory
Surgery
What to use:
• Local Anesthetics used for spinal like: Lidocaine, tetracaine,
Bupivacaine, Levobupivacaine, Ropivacaine, Prilocaine.
• Adjuncts i.e.: Vasoconstrictors (Epinephrine, phenylphrine),
Opioids (fentanyl, sufentanyl, morphine), α-adrenergic
agonists (clonidine).
Table 51-2 -- Drug Selection for Hyperbaric Spinal Anesthesia
Dose (mg) *
Duration (min)
To T10 To T4
Plain
Local Anesthetic Mixture
Epinephrine, 0.2 mg
Lidocaine (5% in 7.5% dextrose)
50-60 75-100 60
75-100
Tetracaine (0.5% in 5% dextrose)
6-8
100-150
Bupivacaine (0.75% in 8.5% dextrose) 8-10
10-16
70-90
12-20
90-120 100-150
Ropivacaine (0.5% in dextrose)
12-18 18-25
80-110 —
Levobupivacaine
8-10
90-120 100-150
*
12-20
Doses are for use in a 70-kg adult male of average height.
Spinal Anesthesia for Ambulatory
Surgery
Facts :
• Prolonging subarachnoid-induced analgesia with fentanyl
rather than epinephrine avoids the prolonged time to
micturition and reduces the time to discharge from the
hospital. However, the adjunctive use of the opioid increases
the incidence of pruritus and PONV.
• Mini-doses of lidocaine (10-30 mg), bupivacaine (3.5-7 mg), or
ropivacaine (5-10 mg) techniques combined with a potent
opioid analgesic (e.g., fentanyl, 10-25 µg, or sufentanil, 5-10
µg) results in faster recovery of sensory and motor function.
Spinal Anesthesia for Ambulatory
Surgery
Facts:
• The mini-dose spinal technique involving lidocaine (10- 30 mg)
and fentanyl (10-25 µg) for outpatient laparoscopic
gynecologic surgery has been reported to offer significant
advantages over both conventional spinal and general
anesthetic techniques with respect to hemodynamic stability
and speed of recovery.
• Short-acting local anesthetics (e.g., lidocaine and procaine)
are clearly preferable to bupivacaine, ropivacaine, and
tetracaine in achieving a rapid recovery.
Spinal Anesthesia for Ambulatory
Surgery
Facts:
• The use of lidocaine is controversial because of numerous
reports of transient neuropathic symptoms (i.e., radicular
nerve root pain).
• Intrathecal bupivacaine and ropivacaine should be reserved for
ambulatory procedures with an anticipated duration of more
than 2 hours because of their more prolonged recovery times.
• Compared with bupivacaine, the duration of sensory blockade
with ropivacaine was two thirds and the duration of motor
block was half.
• Hyperbaric ropivacaine also produces a faster onset of
analgesia compared with isobaric ropivacaine.
Literature Review Abstracts
A comparison of spinal anesthesia with small-dose lidocaine and
general anesthesia with fentanyl and propofol for ambulatory prostate
biopsy procedures in elderly patients. (Namiki A et al, 2006).
Design: prospective, randomized blind study.
Patients: 80 patients, ASA 1-2, aged 60-80 years.
Intervention: group L: (40 patients received 10mg spinal hyperbaric Lidocaine),
group F/P: (40 patients received 1 mcg/kg fent. and 1mg/kg propofol induction and
90mcg/kg/hr propofol maintenance)
Results: both groups provided acceptable operating conditions for surgeons –
higher incidence of hypotension in F/P group – shorter time for discharge in group F/P
– no major postop side effects and high rate of satisfaction in both groups –
Significantly lower total costs in L group.
A randomised study of lidocaine and prilocaine for spinal
anaesthesia (G. Ostgaard, et al 2001)
• Background: Transient neurologic symptoms (TNS) are common after
lidocaine-induced spinal anaesthesia (SA). Recent data indicate that TNS may be
less frequent after prilocaine-induced spinal anaesthesia, for which reason the
isobaric solution was compared with lidocaine.
Prilocaine is an amide local anesthetic with similar pharmacologic properties
to lidocaine and equipotent to it within a range of 40-70 mg.
• Methods: 99 patients randomised to receive 80mg isobaric prilocaine or
lidocaine, both concentration 20mg/ml.
• Results: TNS occurred in 7/49 patients in the lidocaine group and in 2/50
in the prilocaine group (ns).
• conclusions: TNS also occurred with isobaric prilocaine SA - The frequency was
not significantly different from that following lidocaine SA but larger studies are
needed to establish the relative risk of TNS following SA induced by the two local
anaesthetics - . Isobaric prilocaine has a longer duration of action than an equal
dose of lidocaine and may be an alternative drug for spinal anaesthesia of
intermediate or short duration.
A Prospective Comparison of Spinal Anesthesia with
Hyperbaric Bupivacaine and Hyperbaric Prilocaine. (Serrati J et al,
2010)
• Design: double blind controlled clinical trial.
• Methods: 119 patients randomized to receive 5 mg hyperbaric
bupivacaine 0.5% (HB group, 58 patients) and 30 mg of hyperbaric
prilocaine (HP group, 61 patients). ( arthroscopy or inguinal hernioplasty)
• Results: - no difference in onset time and motor block at incision time.
- at 60 minutes post anesthesia HP group had partial motor blocking while
HB group remained under complete block. - from block time to filling
discharge criteria in PACU: HP average time 92 minutes and HB 103 minutes.
- Length of stay in PACU : HP 40 minutes, HB 52 minutes. - Fast-track (bypass
phase 1 recovery) accomplished in 11 patients on HP and 6 patients of HB.
A Prospective Comparison of Spinal Anesthesia with
Hyperbaric Bupivacaine and Hyperbaric Prilocaine. (Serrati J et al,
2010
• Conclusion:
- HP group sent home 25 minutes earlier than HB group.
- HP 1% is suitable agent for lower body surgical procedures lasting
less than 60 minutes.
- There was no incidence of TNS in both groups.
- HP could be an alternative to lidocaine for ambulatory anesthesia.
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 intrathecal anesthesia in ambulatory
surgery. (Camponovo C et al - Anesth Analg – 2010)
• Methods:
- 90 patients receive one of the three spinal agents for less than 60
minutes procedure.
• Results and conclusion:
- No major adverse reactions or transient neurological symptoms
were observed in the study.
- Onset and sensory level of block was comparable in all 3 agents.
- The hyperbaric solution showed faster times to motor block onset
and shorter duration of surgical block, suggesting its superiority for the
ambulatory setting.
Urinary retention after spinal anaesthesia with hyperbaric
prilocaine 2% in an ambulatory setting. (Kreutziger J - Br J Anaesth - 2010)
• Background: This prospective study was carried out to evaluate the
time to spontaneous micturition, quantify the rate of necessary bladder
catheterizations, and identify the risk factors for urinary retention after
intrathecal prilocaine administration.
• Methods: ASA I/II patients (16-80 yr) undergoing ambulatory lower limb
surgery were enrolled and received spinal anaesthesia using hyperbaric prilocaine
2% (60 mg). Ringer's lactate was administered for peroperative volume
replacement. Bladder ultrasound was performed hourly until spontaneous
micturition or catheterization, when bladder filling reached 600 ml, and they were
unable to urinate spontaneously.
• Results: 86 patients completed the study (49 males and 37 females).
37.8% of the women and 12.2% of the men required catheterization.
Mean time between spinal anesthesia and catheterization was 190 min,
and 260 min to micturition. Age <40 or >60 yr and female gender were
predisposing factors for urinary retention.
Urinary retention after spinal anaesthesia with hyperbaric
prilocaine 2% in an ambulatory setting. (Kreutziger J - Br J Anaesth - 2010)
• Conclusion:
- After spinal anaesthesia with hyperbaric prilocaine 2% (60 mg) for
ambulatory lower limb surgery, 23% of patients required postoperative
urinary catheterization.
- Postoperative bladder ultrasound and early catheterization are
essential to avoid bladder distension and facilitate discharge in patients after
intrathecal prilocaine 2% administration in ambulatory surgery.
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