Download OUTPATIENT SURGERY

OUTPATIENT
SURGERY
Dr Abdollahi
Another Name
Ambulatory surgery
Day-case surgery
Same-day surgery
Come and go surgery
In the early 1900s, an american
anesthesiologist, Ralph Waters,
opened an outpatient anesthesia clinic
in Sioux City, lowa.
This facility, which provided care for dental
and minor surgery cases, is generally
regarded as the prototype for the modern
freestanding ambulatory (and officebased) surgery center.
Interestingly, there was little ,interest in
ambulatory surgical care until the late
1960s,when the first hospital-based
ambulatory surgery units were
developed.
Over the last 3 decades, outpatient surgery has
grown at an exponential rate, progressing from
the practice of performing simple procedures on
healthy outpatients to encompassing a broad
spectrum of patient care in freestanding
ambulatory surgery centers. Formal
development of ambulatory anesthesia as a
subspecialty occurred with establishment of the
Society for Ambulatory Anesthesia (SAMBA)in
1984 and the subsequent development of
postgraduate subspecialty training programs.
By 1985, 7 million elective operations in the
United States (over 30% of all elective
surgical procedures) were performed on
an ambulatory basis. Currently, more than
60%of all elective surgery is performed in
the outpatient surgical setting, and it is
expected that this number will increase to
more than 70% in the near future.
The growth in ambulatory surgery would
have not been possible without the
development of improved anesthetic and
surgical techniques. The availability of
rapid, shorter -acting anesthetic, analgesic,
and muscle relaxant drugs has clearly
facilitated the recovery process and
allowed more extensive procedures to be
performed on an ambulatory basis,
irrespective of preexisting medical
Conditions.
Overnight admission
An alternative to same- day surgical
concept is a planned overnighte
admission to the hospital after
surgery.
This approach (AM admit,23 hour,
short stay, come and stay ) is often
classified as outpatient surgery and
preserved many of its advantages.
Outpatient surgery allows a person to
return home on the same day that a
surgical procedure is performed.
Benefits of ambulatory surgery
Patient preference, especially children and the elderly
Lack of dependence on the availability of hospital beds
Greater flexibility in scheduling operations
Low morbidity and mortality
Lower incidence of infection
Lower incidence of respiratory complications
Higher volume of patients (greater efficiency)
Shorter surgical waiting lists
Lower overall procedural costs
Less preoperative testing and postoperative medication
FACILITY DESIGN AND SAFETY
Patient selection
Characteristic of the patient
type of operation
psychosocial aspect of the patient
Human and physical resource for pre
& post op care
Proximity to EMS
Resource of skill set of both
anesthesiologist and surgeon
Surgical procedures suitable for ambulatory
surgery should be accompanied by minimal
postoperative physiologic disturbances and
an uncomplicated recovery.
The primary predictors of prolonged stay or
unanticipated admission after day-case
surgery are related to the surgical
procedure (e.g., blood loss, pain,
postoperative nausea and vomiting
(PONV).
Operative procedures suitable for
ambulatory surgery
Patients undergoing procedures that are likely to be
associated with postoperative surgical complications or
major fluid shifts should be admitted to the hospital
overnight. Although autologous blood transfusions are
used for more extensive outpatient plastic surgery (e.g.,
reduction mammoplasty, liposuction), lengthy rocedures
associated with excessive fluid shifts should be handled in
an overnight (23-hour) recovery facility. Similarly,
operative procedures requiring prolonged immobilization
and parenteral opioid analgesic therapy are more ideally
suited to a 23-hour stay. The availability of newer
analgesic therapies (e.g., continuous local anesthetic
infusions) and ambulatory patient-controlled analgesia
(e.g., subcutaneous, intranasal, transcutaneous) may
alter the latter recommendation in the future.
Duration of Surgery
The duration of surgery in the ambulatory
setting was originally limited to procedures
lasting less than 90 minutes because
investigators have found that the operating
and anesthetic time is a strong predictor of
postoperative complications (e.g., pain,
emesis)and delayed discharge, as well as
unanticipated admission to the hospital
after ambulatory surgery .
Patient Characteristics
Most patients seen in ambulatory
surgical facilities are classified as
ASA physical status I or II. However,
because of improved anesthesia and
surgical care, increasing numbers of
medically stable ASA physical status
III (and even some IV) patients are
able to undergo operations
away from conventional medical
centers.
American Society of Anesthesiologists (ASA)
Classification of Physical Status
I.
A normal healthy patient
-no discernible disease; animals entered for ovariohysterectomy,
castration, declaw, cosmetic procedures
II. A patient with mild systemic disease
-skin tumor, fracture without shock, cruciate repair, uncomplicated
hernia, cryptorchidectomy, localized infection, compensated cardiac
disease
III. A patient with severe systemic disease
-fever, dehydration, anemia, cachexia, moderate hypovolemia
IV. A patient with severe systemic disease that is a constant threat
to life
-uremia, toxemia, severe dehydration or hypovolemia, severe
anemia, cardiac decompensation, emaciation, high fever
V. A moribund patient not expected to survive 24 hrs. with or
without surgery
-extreme shock or dehydration, terminal malignancy or infection,
severe trauma
Age is usually not a factor in the
selection of the patient for outpatient
surgery.
Any infant with apnea in PACU or
anemia regardless of age should be
admitted to the hospital.
Contraindications in infant
1. premature infant with Hct <30%
(apnea )
2. history of RDS
3. History of sudden death in family
Susceptibility to Malignant
Hyperthermia
MH-susceptible patients can be
successfully managed with non
triggering anesthetics (e.g., local
anesthesia) in the outpatient setting .
Contraindications to Outpatient
Surgery
1. Serious, potentially life-threatening
diseases that are not optimally
managed (e.g., brittle diabetes,
unstable angina, symptomatic
asthma)
2. Morbid obesity complicated by
symptomatic cardiovascular
(e.g., angina) or respiratory (e.g.,
asthma) problems.
3. Multiple chronic centrally active drug
therapies (e.g., use of monoamine
oxidase inhibitors such as pargyline
and tranylcypromine) and active
cocaine abuse because of the
increased risk of intraoperative
cardiovascular complications,
including death.
4.Ex-premature infants less than 60
weeks' postconceptual age requiring
general endotracheal anesthesia
5. Lack of a responsible adult at home
to care for the patient on the evening
after surgery.
PREOPERATIVE ASSESSMENT
Preoperative Preparation
Nonpharmacologic Preparationsia
Pharmacologic Preparation
opioid
Routine use of narcotic (opioid)
analgesics for premedication is not
recommended unless the patient is
experiencing acute pain .
Prevention of Nausea and
Vomiting
Butyrophenones
Phenothiazines
Gastrokinetic drugs (Metoclopramide and
domperidone)
Anticholinergics
Dexamethasone, 4 to 8 mg intravenously,
Nonpharmacologic Techniques
Acupuncture and acupressure
Prevention of Aspiration
Pneumonitis
1.H2 Receptor Antagonists and Proton
Pump Inhibitors
2.Antiacid
3.Gastrokinetic Agents
(Metoclopramide)
4. NPO Guidelines
ANESTHETIC TECHNIQUES
Quality, safety, efficiency, and the
cost of drugs and equipment are all
important considerations in choosing
an anesthetic technique for outpatient
surgery.
The ideal outpatient anesthetic should
have a rapid and smooth onset of
action, produce intraoperative
amnesia and analgesia, provide good
surgical conditions with a short
recovery period, and have no adverse
effects.
Outpatient surgery requires the same basic
equipment as inpatient surgery for delivery of
anesthetic drugs, monitoring, and resuscitation.
Standard intraoperative monitoring equipment for
outpatient operations should include an ECG,
blood pressure cuff, pulse oximeter, and
capnograph.
If nondepolarizing muscle relaxants are used, a
neuromuscular monitor should also be available.
Increasingly, cerebral monitors are also being
used to improve titration of anesthetic drugs and
facilitate faster recovery.
The choice of anesthetic technique
depends on both surgical and patient
factors. For many ambulatory
procedures, general anesthesia
remains the most popular technique
with both patients and surgeons.
Although central neuraxis blockade has
traditionally been popular for
peripheral extremity and lower
abdominal procedures, its use in the
ambulatory setting can delay
discharge because of residual motor
and sympathetic blockade.
Peripheral nerve blocks facilitate the
recovery process by minimizing the
need for postoperative opioid
analgesics. Therefore, an increasing
number of ambulatory cases are
being performed with a combination
of local anesthetic nerve blocks and
intravenous sedation (so-called
monitored anesthesia care [MAC]) .
Despite a higher incidence of side
effects, general anesthesia remains
the most widely used anesthetic
technique for managing ambulatory
surgery.
General Anesthesia
warming devices
Tracheal intubation causes a high
incidence of postoperative airwayrelated complaints, including sore
throat, croup, and hoarseness
LMA
The laryngeal mask airway (LMA) was first
introduced in 1983 as an alternative to
tracheal intubation or a facemask for
airway management. When compared with
anesthesia with a mask and oral airway,
patients with an LMA had fewer desaturation
episodes, fewer intraoperative airway
manipulations, and fewer difficulties
in maintaining an airway .
The incidence of postoperative sore
throat after ambulatory surgery was
18% with an LMA versus 45% with a
tracheal tube and 3% with a face
mask.
The LMA frees the anesthesiologist's
hands for record keeping, monitoring,
and drug administration. Hand fatigue
from maintaining the airway with a
mask is also eliminated .
Although there is no ideal anesthetic
drug or technique for outpatients, a
vast array of pharmacologically active
drugs, when combined in a rational
manner and carefully titrated, can
produce the desired anesthetic
conditions with an acceptable
recovery profile and reasonable cost.
An altenative to the LMA is the cuffed oropharyngeal
airway device. Even though this device is easy to
insert after induction without muscle relaxants, its
ability to maintain an obstruction-free airway is
less adequate than that of other curently used
airway devices.
Although the LMA device has been used in
paralyzed patients undergoing laparoscopic
surgery, most practitioners in North America still
prefer tracheal intubation in these situations to
minimize the risK of gastric distention and ensure
adequate ventilation in the Trendelenbmg
posinduction .
Anesthetic Drugs
Induction of general anesthesia is
typically accomplished with a rapidacting intravenous anesthetic.
Propofol has virtually replaced the
barbitmates for induction of
anesthesia in the ambulatory
setting because of its favorable
recovery profile
The most popular technique for maintenance
of anesthesia is a combination of a volatile
anesthetic and nitrous oxide. The
extremely low solubility of nitrous oxide and
the newer volatile anesthetics (sevoflurane
and desflurane) contributes to a more rapid
onset and recovery from general
anesthesia .
Although it has been suggested that the use
of nitrous oxide is associated with PONY,
controlled studies have questioned the
clinical importance of nitrolls oxide in
producing this side effect.When compared
with a target-controlled infusion of propofol
for maintenance of anesthesia, the use of
desflurane or sevoflurane produced similar
anesthetic conditions with shorter
emergence times and at a lower drug cost.
Inhaled Anesthetics
Volatile anesthetics are most
commonly used for maintenance of
ambulatory anesthesia .
isoflurane was the most commonly
used anesthetic for maintenance of
ambulatory anesthesia before the
introduction of the less soluble drugs
sevoflurane and desflurane.
Barbiturates
Thiopental (3 to 6 mg/kg) is the prototypical
intravenous induction drug with a rapid
onset and a relatively short duration of
action as a result of redistribution of the
drug . However, thiopental impairs fine
motor skills for several hours after surgery
and can produce a "hangover“ sensation.
Methohexital appears to be associated
with shorter awakening times, but
complete recovery of fine motor skills
may still require 6 to 8 hours after an
induction dose. when compared with
thiopental, methohexital is associated
with a higher incidence of pain on
injection, involuntary muscle
movement, and hiccoughing
Although propofol resulted in faster
emergence from anesthesia and a
lower incidence of PONV than
methohexital, the barbiturate
compared favorably with propofol
when used for induction only in
outpatient procedures lasting longer
than 90 minutes. Unfortunately,
methohexital is no longer widely
available.
Benzodiazepines
Although midazolam (0.2 to 0.4 mg/kg IV) has been used
for induction of anesthesia in outpatients, its onset of
action is slower and recovery is prolonged in comparison
to the barbiturate compounds and propofol. When combined
with nitrous oxide and a potent opioid analgesic, lower doses
of midazolam (0.1 to 0.15 mg/kg) can be used to induce
general anesthesia. If midazolam is used for induction and
flumazenil, a specific benzodiazepine antagonist, is
administered at the end of surgery, prompt recovery can be
achieved after outpatient surgery.
When compared with propofol, recovery after flumazenil
antagonism of midazolam anesthesia offered no clinically
significant advantages.
Etomidate
Etomidate (0.2 to 0.3 mg/kg) has also been used for
induction and maintenance (1 to 3 mg/min) of
general anesthesia during short outpatient
procedures. Recovery tends to be faster than after
thiopental and compares favorably with
methohexital. Disadvantages of etomidate include
pain on injection, a high incidence of PONV,
myoclonic movements, and transient suppression
of adrenal steroidogenesis. Given its side effect
profile, the use of etomidate should be restricted to
clinical situations in which its hemodynamic
stability offers a distinctive advantage over the
other available induction drugs (e.g., elderly
outpatients with clinically significant coronary
artery or cerebrovascular disease).
ketamine
Ketamine is a unique sedative-analgesic that can be used
for both induction and maintenance of general anesthesia.
However, ketamine compares unfavorably with both the
barbiturates and propofol for minor gynecologic procedures
because of its prominent psychomimetic effects and higher
incidence of PONV during the early postoperative period.
Use of the more potent S(+)-isomer of ketamine may
decrease some of the adverse effects associated with the
racemic mixture in the ambulatory setting. Premedication
with a benzodiazepine (e.g., midazolam, 0.05 mg/kg IV)
decreases the incidence of ketamine-induced emergence
reactions. Small doses of ketamine (10 to 20 mg IV) have
been used as an alternative to potent opioid analgesics
during induction of anesthesia with propofol.
propofol
Propofol is an intravenous anesthetic with an extremely high
metabolic clearance rate Although propofol costs more than
the barbiturate anesthetics do, the use of propofol may
contribute to significant savings because of decreased
recovery costs. When compared with methohexital,the use
of propofol was associated with fewer perioperative side
effects (e.g., less hiccoughs, nausea, and vomiting) and
faster overall recovery times.the faster intermediate recovery
with propofol-based anesthetics may also yield significant
savings in nursing costs (e.g.,less overtime). For example, a
I5-minute reduction in the phase I recovery room stay could
save 1000 nursing hours in a 4,000-case per year
ambulatory surgical .
Midazolam remains the most commonly
used anxiolytic premedication for pediatric
outpatients. After receiving O.5 mg/kg of
midazolam orally, children can be easily
separated from their parents within 30
minutes without prolonging the discharge
time even after short surgical procedures.
..
rectal methohexital is administered
(20 to 30 mg/kg) before volatile
anesthesia, recovery times will be
prolonged.
Rectal etomidate (6 mg/kg) or ketamine (5 to 10
mg/kg) can roduce a rapid onset of hypnosis
without cardiorespiratory epression in children
undergoing outpatient procedures.Although
ketamine (2 to 4 mg/kg intramuscularly) can be an
extremely useful drug for induction of anesthesia
in an uncooperativ e or mentally retarded child,
home readiness is delayed when larger doses of
ketamine (>5mg/kg) are combined with volatile
anesthetics.In addition, psychomimetic reactions
have been reported in children after ketamine
administration
Volatile anesthetics
Volatile anesthetics are associated with
a higher incidence of vomiting in the
early recovery period than propofol
based anesthetic techniques .
Opioid Analgesics
Opioid compounds are frequently
administered in the immediate
preinduction period to suppress
autonomic responses to tracheal
intubation and during the
maintenance period to treat acute
autonomic responses to painful
(noxious) stimuli .
The use of small doses of potent
opioids (e.g., fentanyl, 1 to 2 µg/kg,
alfentanil, 15 to 30 µg/kg, sufentanil,
0.15 to 0.3µg/kg, or remifentanil, 0.5
to 1µg/kg) can effectively attenuate
the cardiostimulatory response to
laryngoscopy and intubation, as well
as the skin incision.
Remifentanil is an ultrashort-acting
opioid analgesic with potency similar
to that of fentanyl. It is rapidly
metabolized by nonspecific tissue
esterases, a process that allows for
rapid systemic elimination, with a halflife of 8 to 10 minutes.
Morphine, hydromorphone,
oxymorphone, and meperidine have
all been used in outpatient anesthesia
However, these opioid compounds are
less popular than the more potent,
rapid, and shorter-acting opioid
analgesics (e.g., fentanyl, sufentanil,
alfentanil, and remifentanil).
morphine was associated with
increased nausea and vomiting in the
postdischarge period. Motion-induced
emesis is a major concern when
morphine and its more lipophobic
congeners are used in the ambulatory
setting.
Muscle Relaxants
Many superficial outpatient surgical
procedures do not require the use of
neuromuscular relaxants.
When remifentanil is used in
combination with propofol for
induction of anesthesia, tracheal
intubation can be performed without
any muscle relaxants .
Succinylcholine remains the most
commonly used muscle relaxant to
facilitate tracheal intubation in the
ambulatory setting because it has a
rapid onset and its short duration of
action obviates the need for reversal
drugs.
Use of the short- and intermediateacting nondepolarizing muscle
relaxants (e.g., cisatracurium,
mivacurium) allows reversal of
neuromuscular blockade even after
brief surgical procedures.
Cost-effective technique involves the
use of succinylcholine for tracheal
intubation followed by small (4 to 8
mg) bolus doses of mivacurium during
the maintenance period. This relaxant
technique minimizes the need for
muscle relaxant reversal drugs after
short laparoscopic procedures.
Mivacurium may be advantageous for
use during the maintenance period
because reversal is seldom required if
the drug is properly titrated
Antagonist (Reversal) Drugs
antagonists may also produce
unwanted side effects (e.g., dizziness,
headaches, PONV) that should
be considered before routinely using
these drugs. In addition, because
their duration of action is often shorter
than the agonist (e.g., naloxone,
flumazenil), a "rebound“ of the agonist
effect may occur.
Pediatric Considerations
In unruly, frightened, or mentally
retarded children, preoperative
sedation is required before taking the
patient into the operating room. In
general, sedative premedication is not
offered to children younger than 12
months, but it is often used for
toddlers or preschool-aged children.
Midazolam remains the most commonly
used anxiolytic premedication for
pediatric outpatients. After receiving
O.5 mg/kg of midazolam orally,
children can be easily separated from
their parents within 30 minutes
without prolonging the discharge time
even after short surgical procedures.
REGIONAL ANESTHESIA
Regional anesthesia can offer many
advantages for the ambulatory patient
population .
Epidural and Spinal Techniques
Spinal anesthesia is the simplest and most reliable
regional anesthetic technique. However, the
incidence of side effects is surprisingly high when
used in the ambulatory setting. The most
troublesome complications of outpatient spinal
anesthesia are residual effects of the block on
motor, sensory, and sympathetic nervous system
function, which can contribute to delayed
ambulation, dizziness, urinary retention, and
impaired balance.In addition, post-dural puncture
headache and backache remain problems after
spinal anesthesia.
Epidural anesthesia is technically more
difficult to perform, it has a slower
onset of action, the potential for
intravascular or intrathecal injection
exists, and it is associated with a
greater chance of an incomplete
sensory block than spinal anesthesia .
Intravenous Regional Anesthesia
For short superficial surgical
procedures «60 minutes) limited to a
single extremity, the intravenous
regional (Bier) block technique with
0.5% lidocaine is a simple and
reliable technique.
The addition of adjuvant (e.g.,
ketorolac, 15 mg, clonidine, 1 µg/kg,
dexmeditomidine, 0.5 /µgkg) will
improve the quality of postoperative
analgesia.
Peripheral Nerve Block
Monitored Anesthesia Care
The combination of local anesthesia
with intravenous sedative and
analgesic drugs is extremely popular
in the ambulatory setting. It has been
suggested that up to 50% of all
outpatient procedures could be
performed with a MAC technique and
that the cost of perioperative care
can be reduced by up to 80% in
comparison to general anesthesia.
Many different sedative-hypnotic drugs have been
used during MAC (including barbiturates,
benzodiazepines ketamine, and propofol) with a
wide variety of delivery systems (e.g., intermittent
boluses, variable-rate infusion, target-controlled
infusion, patient-controlled sedation). The most
commonly used sedation techniqueis a small dose
of midazolam (1 to 2 mg) or propofol (0.5 to I
mg/kg), or both, followed by a propofol infusion at
25 to 100 µg/kg/min. Methohexital has also been
used successfully during MAC as intermittent
boluses (10 to 20 mg) or as a variable-rate infusion
(1 to 3 mg/min).
Cerebral Monitoring
;Monitoring patient vital signs remains the most
common method for determining the "depth of
anesthesia" during surgery.
Recent studies have suggested that the use of
cerebral monitoring improves early recovery after
general anesthesia in the ambulatory setting
because of its ability to minimize both "overdosing"
and "underdosing “ with both intravenous (e.g.,
propofol) and inhaled anesthetic (e.g., sevoflurane
and desflurane) drugs during the maintenance
period.
Optimal Anesthetic Techniques
The optimal anesthetic technique in the
ambulatory setting would provide for
excellent operating conditions, rapid
"fast-track" recovery without
postoperative side effects or
complications, and a high degree of
patient satisfaction.
Fast-Tracking Concepts
Bypassing the PACU has been termed "fasttracking" after ambulatory surgery.
If careful titration of short-acting drugs
permits safe transfer of patients directly
from the operating room suite to a less
labor intensive recovery area, some
patients can be discharged home within 1
hour after surgery .
Multimodal Approaches to
minimizing side Effects
1. Minimally invasive surgical
approaches (e.g., laparoscopic
adrenalectomy and nephrectomy
arthroscopic knee and shoulder
reconstructions).
2-For routine antiemetic prophylaxis,
the most cost-effective combination
consists of low dose droperidol (0.5
to 1 mg) and dexamethasone (4 to 8
mg).
3-The addition of low-dose ketamine
(75 to 150 µg/kg) to a multi modal
analgesic regimen improved
postoperative analgesia and
functional outcome after painful
orthopedic surgery procedures.
Acetazolamide (5 mg/kg IV) reduces
referred pain after laparoscopic surgery
with CO2 insufflation.
4- One of the keys to facilitating the recovery process
is the routine use of local anesthetics as part of a
multimodal regimen.
After arthroscopic knee surgery, instillation of 30 mL
of O.5% bupivacaine into the joint space reduces
postoperative opiate requirements and permits
earlier ambulation and discharge.The addition of
morphine (1 to 2 mg), ketorolac (15 to 30 mg),
clonidine (0.1 to 0.2 mg), and/or triamcinolone (10
to 20 mg) to the intra-articular local anesthetic
solution can further reduce pain after arthroscopic
surgery.
DISCHARGE CRITERIA
Discharge after General Anesthesia
and Monitored Anesthesia Care
The three stages of recovery after
ambulatory surgery are the early,
intermediate, and late recovery
periods . The early and intermediate
recovery stages occur in the
ambulatory surgical facility, whereas
late recovery refers to the resumption
of normal daily activities and occurs
after discharge home
Early recovery
The time interval during which patients
emerge from anesthesia, recover control of
their protective reflexes, and resume early
motor activity. During this phase of
recovery, patients are cared for in the
PACU, where their vital signs and oxygen
saturation are carefully monitored and
supplemental oxygen, analgesics, or anti
emetics can be readily administered.
Intermediate recovery
During the intermediate recovery
period, patients are usually cared for
in a reclining chair and progressively
begin to ambulate, drink fluids, void,
and prepare for discharge. Most
ambulatory surgical facilities have a
separate area for the intermediate
recovery of outpatients to a homeready state
late recovery
The late recovery period starts when the
patient is discharged home and continues
until functional recovery is achieved and
the patient is able to resume normal
activities of daily living. The anesthetics,
analgesics, and anti emetics can also have
an effect on the patient's recovery during
the postdischarge period. However, the
surgical procedure itself has the highest
impact on the patient's full functional
recovery.
Factors that predict a more prolonged
stay in the day-surgery unit include
female gender, advanced age, longer
operations, large fluid or blood loss
and opioid use, nondepolarizing
muscle relaxants, postoperative pain
and PONY, and spinal anesthesia.
Guidelines for safe discharge from an
ambulatory surgical facility include
stable vital signs, return to baseline
orientation, ambulation without
dizziness, minimal pain and PONY,
and minimal bleeding at the surgical
site.
post anesthetic discharge
scoring (PADS) system
(1) vital signs, including blood pressure, heart
rate, respiratory rate, and temperature
(2) ambulation and mental status
(3) pain and PONY
(4) surgical bleeding
(5) fluid intake/output
Patients who achieve a score of 9 or greater
and have an adult escort are considered fit
for discharge (or home ready).
.Discharge after regional
Anesthesia
With spinal or epidural anesthesia,
it is generally accepted that motor and
sensory function returns before
sympathetic nerve function.
Residual blockade of the sympathetic
nerve supply to the bladder and
urethra may cause urinary retention.
Before ambulation, these patients
should have normal perianal (S4-5)
sensation, the ability to plantar-reflex
the foot, and proprioception of the big
toe. Thus, discharge criteria after
spinal and epidural anesthesia should
include the return of normal
sensation, muscle strength, and
proprioception, as well as the return
of sympathetic nervous function.
Controversies Related to
Discharge Criteria
well-hydrated outpatients can be safely
discharged home without
demonstrating an ability to tolerate
oral fluids after surgery .
The requirement to void before discharge has also been
challenged.The inability to void and urinary retention may be
caused by pain (which inhibits normal bladder detrusor
function) or by opioid analgesics, spinal or epidural
anesthesia, administration of drugs with anticholinergic
effects, and prolonged blockade of the autonomic innervation
to the bladder. Patients may be discharged earlier if voiding is
not a discharge requirement. Delaying discharge for voiding
after spinal or epidural anesthesia with short-acting local
anesthetics is unnecessary in low-risk patients (e.g., age <70
years; no hernia, rectal, or urologic surgery; no history of
voiding problems).
1. The majority of operations today are performed on
an outpatient basis.
2. Although restrictions on the types of cases
appropriate for ambulatory surgery have been
reduced, hospital admissions after outpatient
procedures should not be common.
3. Preoperative administration of the combination of
midazolam and fentanyl can make patients sleepy
up to 8 hours later. Preoperative sedation is not
required for every patient.
4. Postoperative pain is less after regional
anesthesia, although performing a block requires
more time than does induction of general
anesthesia and has a higher incidence of failure .
5. Even when thiopental is used only for induction, psychomotor
impairment can be evident up to 5 hours after administration
compared to only 1 hour after propofol.
6. Although some drugs have faster recovery time than others, actual
discharge from an ambulatory center may depend more on
administrative issues, such as obtaining the written discharge order
from the surgeon or anesthesiologist.
7. Nausea probably is the most important factor contributing to a delay
in discharge and an increase in admission after ambulatory surgery.
Combination therapy probably is the most effective way to control
postoperative nausea and vomiting.
8. Pain may be associated with nausea, and treatment of the pain
frequently decreases nausea.
KEY POINTS
1. The continued growth in ambulatory surgery is related to
expansion in minimally invasive surgical techniques and
office-based procedures.
2. Preexisting medical conditions are rarely, if ever an
exclusionary criterion for ambulatory surgery.
3. Routine laboratory testing is not recommended before
ambulatory surgery.
4. The choice of anesthetic technique has a significant effect on
postoperative side effects and discharge time. The use of
local anesthesia with sedation, so-called monitored
anesthesia care, is associated with the fewest side effects
and the shortest time to discharge home.
5. The use of propofol for induction or maintenance of
anesthesia (or both) is associated with a reduced incidence
of postoperative nausea and vomiting
6. The use of desflurane or nitrous oxide (or both) in conjunction with antiemetic
prophylaxis will facilitate the "fast-track" recovery process.
7. The use of potent opioid analgesics (e.g., fentanyl, sufentanil) in combination
with local anesthetics will decrease the time to discharge home after spinal
anesthesia.
8. Multimodal ("balanced") analgesic and antiemetic regimens will allow most
outpatients to be fasttracked after ambulatory surgery under general
anesthesia.
9. Fast-tracking after ambulatory surgery is accomplished by taking the patient
directly from the operating room to the day-surgery step-down unit
("bypassing the PACU")or simply discharging the patient home from the
PACU("PACUbypassing").
1O. Outcomes after ambulatory (and office-based) surgery are no different than
after inpatient (hospital-based) surgery procedures. Recent data
suggest that for elderly patients, the surgical outcome may be improved.
QUESTIONS ??