The
essentials of good day surgery
In order to achieve good results in day surgery and avoid the pitfalls
described above the following are essential:
• selection of appropriate procedures and patients;
•
preadmission assessment and information;
• anaesthesia and surgery with minimal morbidity and complications;
• postoperative and postdischarge analgesia;
• discharge criteria and postoperative instructions;
• follow-up and audit.
Day
surgery selection
The aim of day surgery selection is to avoid predictable complications
and morbidity. In selecting suitable procedures and patients, consider:
• the procedure to be undertaken;
• the social circumstances;
• the fitness of the patient.
Criteria
for suitable day-case procedures
• Minimal physiological trespass;
• not associated with excessive blood loss or fluid shifts;
• very low risk of serious postoperative complications (e.g.
bleeding or airway obstruction);
• duration of up to 1 hour, 2 hours maximum;
• pain must be controllable with oral analgesics after discharge;
• the patient should be reasonably ambulant afterwards.
Relatively
uncontroversial day-case procedures (Table 69.5)
make up the bulk of day
surgery. However, other more major operations may now be included as minimally
invasive surgical techniques using laparoscopy and lasers reduce postoperative
problems and pain. Open abdominal, intrathoracic, intracranial and major
vascular procedures are still universally considered to be unsuitable.
In
general, longer and more invasive operations are associated with more pain,
bleeding or other complications, although this is not absolutely true — some
may simply be time-consuming without increasing morbidity. Laparoscopic surgery
in particular is associated with increased morbidity and overnight admission,
particularly for procedures such as cholecystectomy. Tonsillectomy is also
controversial: while routinely performed on a day-case basis in many centres,
anxiety about the risk of bleeding deters others. The pathology is important
— small haemorrhoids or incisional hernias are suitable, very large ones may
not be.
The
push to ambulatory surgery in the USA has led to the inclusion of major surgery,
such as mastectomy and vaginal hysterectomy, often with little regard for
patient comfort and preference. This has resulted in a backlash, with
legislation to prohibit the ‘drive-through’ mastectomy.
• Day surgery needs ready access to a hospital or GP after discharge,
although the demand on these should be minimal.
• A responsible adult to escort the patient home and care for them at
least until the following morning is mandatory. For more major day-case
operations, longer care may be needed. Elderly or disabled partners may be
unsuitable.
• Patients must have reasonable home circumstances with good toilet facilities, few stairs to climb and access to a telephone.
•
Patients should live within 60 minutes’ travelling distance, both to
reduce discomfort on the way home and to have ready access to hospital care if
needed. Patients should not travel home by public transport.
• Other options have been used where home circumstances are not ideal,
such as hospital hotels supplying overnight supervision at low cost or, more
rarely, transfer to a community hospital. An overnight stay in hospital (the
‘23-hour admit’) may permit more procedures and patients to be considered
suitable ‘day cases’, but may not achieve the benefits of day surgery.
• Developing countries with long
distances and difficult travelling conditions to reach medical care may find
that these are obstacles to introducing day surgery.
The
fitness of the patient for general anaesthesia
The patient should be medically stable and have been screened before
admission to exclude major health problems. The American Society of
Anesthesiologists (ASA) classification of patient fitness is often used, with
the stipulation that ASA 1, 2 and stable 3 patients are suitable, although this
may be difficult to define with accuracy. The aspects of patient fitness which
have been shown to relate to complications during surgery and to unplanned
overnight admission are severe symptomatic respiratory disease, symptomatic
cardiac disease and hypertension.
Age. 70 is often taken as an upper age limit, but the physiological age
of the patient is more important than actual age. Elderly patients may be
suitable for day-case procedures under local or regional anaesthesia.
The lower age limit depends on the facilities available, the experience
of the staff and the procedures undertaken. The
Obesity.
Weight limits expressed as body mass index (BMI) (weight in kg/height in in2)
are often imposed, although there is little hard evidence as to what is
unacceptable. Surgery and anaesthesia are undoubtedly more difficult and have
more complications in overweight patients, who may also have more health
problems. Although a BMI of 30 is often taken as an upper limit, in otherwise
fit patients problems do not really become apparent until the BMI exceeds 35.
Respiratory
disease. Asthmatics with no history of hospital admission for their asthma, and
patients with chronic obstructive airways disease, are suitable for day surgery
if they have reasonable exercise tolerance, usually expressed as the ability to
climb a flight of stairs.
Hypertension.
Untreated or previously unrecognised hypertension in apparently fit patients
is the commonest predictable reason for cancellation on the day of surgery, and
‘white coat hypertension’ on the patient’s arrival in hospital is a
recurring source of strife between surgeons, anaesthetists and GPs. However,
this type of hypertension has been shown to be related to abnormal left
ventricular function and to perioperative myocardial ischaemia. A preadinission
blood pressure (BP) is mandatory, and BP _ 175/105 mmHg should
Cardiac
disease. Unsuitable conditions include cardiac failure, symptomatic valvular
disease, severe or rest angina, fast ventricular arrythmias, unpaced second or
third degree heart block, or myocardial infarction within the previous 6 months.
In patients with lesser degrees of heart disease, further cardiac assessment may
be required.
Diabetes.
Well
controlled noninsulin-dependent diabetes (NIDDM) usually poses no problems.
Although otherwise fit insulin-dependent diabetics have been considered
suitable, in practice, even with a well-controlled and well-motivated patient,
the stress of surgery and fasting can upset the patient’s diabetic control,
making their day surgery episode difficult and time-consuming for medical staff.
Drug
therapy. Patients taking anticoagulants, systemic steroids, digoxin, drugs for
dysrrhythmias and angina, and monamine oxidase inhibitors need individual
anaesthetic evaluation before booking for day surgery. Oestrogen containing
oral contraceptives need not be discontinued except for lower limb operations,
particularly where a tourniquet will be used.
This
is only a guide. There are no absolute exclusions — the severity must be
evaluated — and local or regional anaesthesia may be suitable for patients who
cannot safely be given a general anaesthetic. Simple guidelines (Table
69.7)
should be circulated to surgical staff and displayed in out-patient departments.
Assessment
before admission for surgery
This is an essential component of well-organised day surgery. The timing
should allow any problems to be sorted out, but not be so far in advance that
the patient develops new problems.
Methods
of assessing patients
Surgeons are not good at assessing patients for anaesthetic fitness,
particularly in the middle of a busy clinic. The ideal would be to have the
patient seen by an anaesthetist, preferably the one who will anaesthetise the
patient. This is usually impracticable in terms of time, cost and available
anaesthetic time. The best alternative is a filtering process (Fig.
69.1) with
specially trained nurses using patient questionnaires (Table
69.8) and locally
agreed protocols of suitable criteria. Borderline cases are referred for
anaesthetic opinions, and consultant anaesthetists involved in day surgery
should be identified to advise.
Assessment
clinics
A good assessment clinic prevents cancellation on the day of surgery for
predictable reasons, particularly hypertension. It also speeds up the process of
admitting the patient, and may reduce unplanned overnight admission for those
who have not arranged for an escort home. It can reduce unnecessary
investigations, perioperative complications and risk. Patient compliance may be
improved — given information and the opportunity to discuss anxieties, they
are more likely to turn up for their operations and to have obeyed their
preoperative instructions (Fig. 69.2). It should also increase the number of
suitable patients by addressing problems, and by arranging for borderline cases
to be considered for local or regional anaesthesia. Assessment clinics are
cost-effective (Table 69.9).
Preadmission
in formation
This has been identified as a cause for patient dissatisfaction.
Providing clear concise information means that patients arrive well prepared,
having obeyed the fasting instructions, and knowing what to expect from the
surgery and in the recovery period. The prolonged fluid fast of former times may
be detrimental to recovery, and although a 4—6-hour fast from solid food is
essential, clear fluids my be allowed up to 2—3 hours preoperatively.
Information about expected levels of pain and restrictions on activity after
specific procedures helps the patient to plan their care at home — for
instance mothers of small children may need to arrange for help for longer than
just overnight. All of the important information (Table
69.10) should be on one
page, or patients may not read it. Separate leaflets on individual procedures
are useful. Resist the temptation to overload the patient with information.
Anaesthesia
for day surgery
Anaesthetic morbidity is a major reason for unplanned admission, in
particular sleepiness, dizziness and nausea (Fig. 69.3). The choice is between
local or regional anaesthesia with or without mild sedation, or general
anaesthesia with local anaesthetic where appropriate to provide postoperative
analgesia.
Local
or regional anaesthesia is perhaps the
ideal, although it is not suitable for all procedures or patients. It is
excellent for elderly patients and is usually economical, although it may be
more time consuming than general anaesthesia, and necessitates gentle surgery.
Patients and surgeons may express a preference for general anaesthesia.
The
type of local anaesthesia must be carefully chosen. Central anaesthetic blocks,
epidural, spinal or caudal, may be less suitable because of the time taken to
carry out the block and allow it to work, the time taken for the patient to
mobilise and the high incidence of urinary retention.
Suitable
blocks are listed in Table 69.11. The ideal choice of agent is a long-acting
one, such as bupivacaine, and if speed of onset is important lignocaine may be
mixed with this. Prilocaine will be needed for Bier’s blocks
General
anaesthesia
Propofol, a newer anaesthetic agent, has established itself as the agent
of choice for the induction, and often also the maintenance, of day-case
patients because of its good anaesthetic conditions, rapid problem-free
recovery and lack of postoperative nausea and vomiting (PONV). Indeed, it is
antiemetic, a major advantage in day surgery. Children are increasingly induced
intravenously. For inhalation induction sevoflurane has now replaced halothane
in many countries because of its ease of use and speed of recovery.
Maintenance
of anaesthesia is commonly with a volatile agent, such as isoflurane or
enflurane, and nitrous oxide in oxygen. The newer volatile agents, desflurane
and sevoflurane, with ultrafast immediate recovery times, have proved
disappointing, as like all volatile anaesthetic agents they have a high
incidence of PONV which delays recovery, and little advantage has been shown to
justify their increased cost. Many day surgery anaesthetists therefore use
propofol by infusion to maintain anaesthesia, as well as for induction —total
intravenous anaesthesia (TIVA). The increased cost may be justified in view of
the excellent recovery, particularly after longer procedures and where the risk
of PONV is high.
Short-acting
opioids, such as alfentanil or fentanyl, are usually included in the general
anaesthetic to reduce the dosage of other drugs and to provide some analgesia in
the early postoperative period.
The
laryngeal mask airway (LMA) has become popular in day surgery as it allows fast
easy control of the airway, and endotracheal intubation and its hazards often
can be avoided. It is now commonly used for straightforward laparoscopies, and
for dental and head and neck procedures.
Sedation
This is given ideally by an anaesthetist, but sometimes by other
medically qualified personnel. The sedationist must not be involved in the
procedure: the single-handed operator— sedationist is neither safe nor
medicolegally defensible. Monitoring is required and supplemental oxygen is
usually given. Sedation means that the patient is relaxed and calm while
maintaining rational verbal contact. It is all too easy to oversedate the
patient beyond this level, so that the patient is anaesthetised and airway
control may be lost. Sedation is best left to experienced anaesthetists.
The
use of midazolam, a short-acting benzodiazepine, is popular but its long-lasting
postoperative amnesia may mean that postoperative instructions are forgotten.
Propofol in low dose is very suitable for sedation, with faster wake-up and less
amnesia, although some patients may prefer not to recall events in theatre.
Small doses of opioids may also be used with caution, but may result in
respiratory depression or apnoea.
Analgesia
Good pain control is essential. It is a major reason for delay in
discharge (Fig. 69.3), unplanned overnight admission, GP consultations after
discharge, and, not least, patient distress and dissatisfaction. It limits early
patient mobilisation and prolongs return to normal function. The use of
morphine, while successful in controlling pain, is less successful in day
surgery because of its sedation and high incidence of nausea, which may only
become apparent after the patient leaves the DSU. In order to avoid its use, a
mixture .of analgesic methods is needed — so-called balanced or multimodal
analgesia. Nonsteroidal anti-inflammatory drugs (NSAIDs) plus local anaesthesia,
where possible, form the basis, with additional short-acting opioids and other
mild analgesics if needed. Although none of these methods is sufficient alone,
in combination they are very effective.
The
best local anaesthesia will not last longer than the evening of surgery, so it
is important to provide sufficient oral analgesia for 3—5 days
postdischarge. These should be prepared in packs supplied to the DSU and
prescribed according to the expected pain for that operation (Table
69.12).
Combinations of regular NSAIDs with simpler analgesics for break-through pain
are successful. Unless clear instruction on their use is given, patients’
compliance may be poor (Table 69.13).
Discharge
The patient must be seen before discharge by the surgeon and the
anaesthetist, or their deputies. Formal discharge criteria are required, with
documentation signed by the individual delegated to discharge the patient,
usually a nurse. The patient and their escort must be given clear instructions
on what to do after their general anaesthetic and surgery, including stitch
removal and follow-up where needed (Tables 69.14 and
69.15).
Follow-up,
audit and quality control
Good day surgery practice means that the incidence of non-attendance,
cancellations, complications before and after discharge, overnight admission and
readmission is audited, and improvements are made where needed. Where possible,
a telephone call to the patient the next day reassures the patient and gives
immediate feedback on the adequacy of analgesia and other problems. Specific
audits should be conducted on patient satisfaction with their overall
management,
morbidity related to specific types of surgery and anaesthesia, and the adequacy
of postoperative analgesia. The involvement of community services and GPs should
be monitored.