Core Topics in General & Emergency Surgery: Companion to Specialist Surgical Practice (14 page)
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Authors: Simon Paterson-Brown MBBS MPhil MS FRCS
The admission, operation and discharge of a patient within a day requires accurate forward planning, with the procedure occurring on a scheduled day at a scheduled time. Day surgery pioneered the role of preoperative assessment, performed up to 6 weeks prior to surgery. As a result nursing, anaesthetic and surgical assessment on the day of admission is both rapid and minimal. Pre-assessment of patients also ensures that ‘on the day’ cancellation for clinical reasons is rare. Cancellations not only waste hospital resources but cause distress to patients and their families and often disrupt work commitments.
To maximise day surgery throughput, pre-assessment may be accomplished by:
automatic assignment to day surgery of all patients undergoing a procedure included in the BADS's trolley of procedures (
Box 3.1
) or the Audit Commission's updated basket of procedures (
Box 3.2
);
hospital-wide pre-assessment for all elective surgical procedures (with procedure-specific exclusions for major surgical procedures such as major bowel resection and aortic aneurysm repair).
Successful pre-assessment should focus on educating the patient and their carers about their condition, identifying any preoperative risk factors and optimising the patient's condition. All three aspects need to be performed well in order to maximise success on the day of surgery. Strict assessment criteria ensure patient safety, and identifying any anomalies at pre-assessment allows for timely correction of these factors. Day surgery pre-assessment is best performed by trained nurses in nurse-based pre-assessment clinics. The availability of a consultant anaesthetist to deal immediately with some queries and concerns further improves efficiency. The most common treatable exclusion factors are hypertension and identifying an overnight carer for patients living on their own.
Pre-assessment clinics use a patient questionnaire to screen for social and medical problems. Most questionnaires follow a standard format to screen and triage the suitability of patients for day surgery. Questionnaires should address the generic status of the health of the patient, but additional questions may be added for specific surgical specialities.
Patient information leaflets should also be available covering both general day surgery information and information specific to the proposed operation. These may have been issued at the outpatient consultation where first-stage consent is usually obtained. The later pre-assessment visit allows the patient to ask questions that may have arisen since their consultation, and subsequent discussion leads to better understanding by the patient and family, and may reduce anxiety levels.
29
Involvement of the patient at this stage permits flexibility and choice regarding their operating date and improves non-attendance rates.
Investigations:
Routine investigations are unnecessary in the a symptomatic day surgery patient
30
and preoperative testing should be limited to circumstances in which the results will affect patient treatment and outcomes. Investigations should not be prescriptive but should be tailored to the individual's needs because most investigations required can be predicted from the history alone. Even when minor abnormalities are found they rarely entail cancellation. A full blood count is only required if there is a risk of anaemia, chronic renal disease, rectal bleeding or haemorrhage. Similarly, analysis for urea and electrolytes is only indicated if the patient has renal disease or is taking diuretics. Urinalysis is often routinely performed as part of the preoperative routine but, again, unsuspected disease is more likely to be picked up on history alone. In Oxford, routine urine testing of more than 30 000 day case admissions resulted in only one cancellation, caused by unsuspected diabetes mellitus.
19
The incidence of electrocardiographic (ECG) abnormalities increases with age but minor preoperative ECG abnormalities do not predict adverse cardiovascular perioperative events in day surgery.
31
The only indications for preoperative ECG include chest pain, palpitations and dyspnoea, but these patients have often already been excluded from day surgery by other comorbidity. A chest X-ray examination is also unnecessary. If required, then the patient is probably unsuitable for day surgery in the first place.
Testing for sickle cell disease is more controversial. Patients with sickle cell disease usually present in childhood with chronic haemolytic anaemia. Preoperative screening in adults is unlikely to identify a patient with previously unknown sickle cell disease but will, of course, identify those with sickle cell trait. However, the ‘at-risk’ population (those of African, Asian and Mediterranean origin) is often difficult to define in Britain today as a result of ethnic mixing. Furthermore, those factors that precipitate sickling (hypotension, hypoxaemia and acidosis) are unlikely to occur during day case surgery.
On arrival at the day unit on the prearranged day of operation, most documentation is already complete and bureaucracy is minimised. Any change of circumstance, either social or medical, should be noted since the time of pre-assessment, and the preoperative surgical visit by the person performing the operation need only consist of verification of the consent and marking the appropriate operation site. The final anaesthetic assessment is performed at this time and not in the anaesthetic room, where levels of anxiety are already high. Many day surgery units have successfully introduced staggered admission times for patients, which is more convenient for both patient and the day unit. In most centres, the 12-hour fasting ritual has now been replaced by regimens of no solids (including milk) within 4–6 hours and up to 300 mL of clear fluid within 2 hours of surgery.
Discharge after inpatient surgery for procedures suitable for day surgery usually occurs at least 24 hours after its completion. By then, there is little concern regarding postoperative complications or the adverse effects of the anaesthetic. In contrast, discharge on the day of surgery must address strict discharge criteria if complications are to be avoided. Before returning home, patients may be seen by the surgeon and anaesthetist involved in their care, but the final decision to discharge is usually nurse initiated, based on clear and agreed discharge guidelines. Some units adhere to strict scoring systems that address vital signs, patient activity, postoperative nausea and vomiting (PONV), pain and bleeding,
32
but whether such regimented protocols offer any advantage over the checklist of criteria outlined in
Box 3.3
is debatable. Generic criteria have their limitations. For example, the criterion of being able to ‘walk unaided’ from the day unit may be inappropriate following orthopaedic surgery to the foot. Common sense in such situations is clearly required and the individual surgical procedure or type of surgery undertaken may prompt additional specific criteria.
33
Box 3.3
Discharge criteria
Vital signs stable for at least 1 hour
Correct orientation as to time, place and person
Adequate pain control and supply of oral analgesia
Understanding the use of oral analgesia supplied, supported by written information
Ability to dress, walk (if appropriate)
Minimal nausea, vomiting or dizziness
Oral fluids taken
Minimal bleeding (or wound drainage)
Has passed urine (if appropriate)
Has a responsible escort for the homeward journey
Has a carer at home for next 24 hours
Written and verbal instructions given about postoperative care
Knows when to return for follow-up (if appropriate)
Emergency contact number supplied
Developing and maintaining good practice in day surgery requires attention to detail in all aspects of anaesthetic and surgical care. Special considerations apply to management of children in the day unit.
Day surgery may be performed under four basic anaesthetic techniques: sedation, local, regional or general anaesthesia, with or without premedication. Where local or regional anaesthetic techniques can be applied safely, advantages arise both for the patient and for the efficient running of the service.
In day surgery, premedication relates to any drugs administered in the day unit before the patient leaves for surgery and they are usually administered orally or rectally. There is a widely held belief that premedication sedatives for anxiety are unnecessary in day surgery and, if given, recovery time may be prolonged. In most cases this is true, but up to 19% of patients suffer significant anxiety and these may benefit from sedative premedication.
34
Other premedication drugs commonly used in day surgery include oral ranitidine 150 mg for known acid reflux and NSAIDs for postoperative pain if the procedure is of short duration. In addition, the patient's normal drug therapy, including antihypertensive agents, should be given as normal.
Sedation:
Sedation, commonly used in dental and endoscopy practice, may be defined as ‘a technique in which the use of a drug or drugs produces a state of depression of the central nervous system enabling treatment to be carried out, but during which verbal contact with the patient is maintained’.
35
Standards of monitoring for sedation in gastrointestinal endoscopy were published in 1991 and address safety issues such as the availability of resuscitation equipment and the safe use and administration of benzodiazepines.
36
Patient responses to sedative agents vary considerably and they should be titrated to the desired clinical effect to minimise overdose. Ideally, the sedationist should be an experienced anaesthetist. Monitoring during the procedure is mandatory and consists of pulse oximetry to measure oxygen saturation, an assessment of the patient's level of consciousness, and ECG and blood pressure monitoring, especially for patients with a history of ischaemic heart disease or cardiac arrhythmias. Oxygen supplementation is provided by oxygen mask or nasal cannulae.
In surgical practice, intravenous sedation should be kept simple and consists in adults of midazolam at a titrated dose of 0.07 mg/kg. Dosage is reduced in the elderly patient because hypotension and respiratory depression can occur. It is a better amnesic drug than diazepam and its solubility has reduced the incidence of pain on injection or phlebitis. As it has a short half-life of 2–4 hours, ‘hangover’ effects are reduced. If overdose occurs, the competitive benzodiazepine antagonist flumazenil is given, but as its half-life is only approximately 1 hour, it is important to recognise that re-sedation may occur and premature discharge of the patient must be avoided.
Sedo-analgesia is a combination of a benzodiazepine and an analgesic agent such as pethidine (meperidine) or morphine. It is often used in the more painful endoscopic procedures such as colonoscopy. The longer-acting traditional opioids are often now replaced by the more rapid onset short-acting agents such as fentanyl (50–200 μg i.v.), alfentanil and remifentanil, which act within several minutes.
As with sedation, perioperative monitoring is required and should include pulse oximetry, with ECG and blood pressure monitoring in the elderly or cardiovascularly unfit. Several local anaesthetic agents are available (
Table 3.2
) but toxic reactions can occur in overdosage. Toxic blood levels lead to circumoral tingling, tinnitus and dizziness. Serious overdosage is reflected in loss of consciousness, convulsions or cardiac dysrhythmia. Dosage levels therefore need to be controlled. Higher dosage can be administered if it is given with adrenaline (epinephrine; 1:200 000), which causes vasoconstriction. This assists haemostasis, slow absorption and prolongs anaesthesia. The administration of adrenaline is contraindicated, however, in end-artery procedures such as in the penis or in the digits of the hand or feet.
Table 3.2
Dosage and application of local anaesthetic agents
Local or regional anaesthesia may be used alone, with sedation or with general anaesthesia to prolong pain relief after completion of the procedure. Cocaine, which also has vasoconstrictor properties, may be topically applied to the nasal mucosa prior to nasal surgery. Amethocaine (tetracaine), which is systemically toxic, is mainly used for topical anaesthesia in ophthalmology. Prilocaine is short acting, has less toxic levels in the blood and is useful in intravenous regional anaesthesia such as Bier's block. Field infiltration with local anaesthetic and adrenaline may be used for the removal of minor ‘lumps and bumps’. Bupivacaine (and the newer ropivacaine) has a long duration of action, lasting several hours, but can take up to 30 minutes to achieve simple nerve block. It is therefore a useful adjunct for wound infiltration or nerve block in association with general anaesthesia.
Spinal anaesthesia is not widespread in UK day surgery practice, in contrast to many other parts of the world. The main advantage of spinal anaesthesia is for operations below the waist such as arthroscopic surgery on the knee, foot surgery, haemorrhoidectomy or other rectal surgery, neurological surgery and inguinal hernia repair. The principal reasons for selecting spinal anaesthesia are in the obese or those with cardiorespiratory disease who would otherwise be excluded from day surgery.
37
The techniques and drugs used in general anaesthesia today permit up to 90 minutes of anaesthetic time for day surgery. The use of the laryngeal mask rather than the endotracheal tube has changed anaesthetic practice in day surgery since its introduction in 1988. Muscle relaxants are not required with its insertion, which is quicker and easier, and it is tolerated in light anaesthesia, allowing rapid patient turnaround. The introduction of total intravenous anaesthesia using propofol for induction and maintenance of anaesthesia has major advantages over inhalation agents; these include reduced PONV, early recovery and rapid control of the depth of anaesthesia, making it ideal for day case surgery. PONV after surgery is best prevented rather than treated, but is more likely if surgery lasts more than 1 hour or involves laparoscopy, dental procedures, squint surgery or correction of bat ears.
Adequate hydration reduces PONV and intravenous fluid should be administered during longer procedures. Intravenous fluids at a dose of 20 mL/kg significantly reduce the incidence of postoperative drowsiness and dizziness.
38
Pain management during anaesthesia is based on a concept of multimodal analgesia, which is a combination of two or more analgesic agents or analgesic techniques to minimise side-effects. A common strategy is to use an NSAID or short-acting opioid in combination with regional or local anaesthesia. The administration of stronger opiates such as morphine and pethidine at this stage is to be avoided as its longer-lasting effects may lead to unplanned overnight admission. Administration of analgesia in recovery and on the day ward before discharge should be given before ‘breakthrough’ pain occurs and is based on the accurate measurement of pain by the patients themselves.
The safe, effective and efficient surgery required for a day case procedure demands the competence of a trained surgeon, a consultant or an experienced specialist registrar. In the past, the day surgery list of intermediate procedures was delegated to the most junior surgical trainee to perform without supervision. Not surprisingly, this led to prolonged operating times, patient cancellations, increased complications and an inevitable rise in the unplanned overnight admission rate. As surgical trainees may no longer work unsupervised, such poor-quality practices should be features of the past. Nevertheless, some consultant surgeons' attitudes towards day surgery remain lukewarm, mainly because many have never considered the importance of their role in the overall delivery of patient care and the need for them to be more actively involved in the process of care through the hospital system. A frequent excuse was that the surgery itself was mundane and lacked the technical challenge of complex major procedures. With the introduction of more major minimal access procedures into the field of day surgery, this excuse no longer holds true. Indeed, many day surgery experts would contend that any intermediate or major surgery performed on a day case basis is a true surgical challenge if morbidity is to be maintained at near zero levels.
Day surgery rates for specific procedures still vary between individual surgeons, between hospitals and even between regions. In November 2011, there was still a 17% variation in day case rates for inguinal hernia repair and varicose vein surgery between the best and the worst performing Strategic Health Authorities (SHAs) in England, whilst the rates for day case laparoscopic cholecystectomy in all SHAs ranged from 23% to 56%!
13
The reasons for such variations are complex and remain largely unexplained, but often reflect an inability to organise healthcare effectively and follow guidelines.
39
–
42
Whilst these variations were understandable in the development phase of day surgery, they become increasingly difficult to justify as we move to a genuine National Healthcare system, with equal access to treatment for all. A new generation of surgeons and anaesthetists who are more familiar with the skills and techniques necessary to provide high-quality day surgery should ensure that most of these extreme variations disappear over the next few years.
Laparoscopic cholecystectomy:
The day case rate for laparoscopic cholecystectomy in the UK is just under 40% and still shows large variations between surgeons, trusts and regions.
13
The reasons for this relate to fears about reactionary haemorrhage, delayed haemorrhage and bile leak. Reactionary haemorrhage occurs within 4–6 hours after surgery and can be addressed within the ordinary working day if the surgery is performed before noon. Delayed haemorrhage usually occurs 3–4 days after cholecystectomy and even if the patient had undergone their operation as an inpatient, they would still have gone home before the secondary haemorrhage was apparent. Bile leaks rarely become apparent before 48 hours after surgery: accessory duct injury is often insidious, diathermy injury to the biliary tree may take days to leak and cystic duct stump leakage likewise. Again, if the patient had undergone inpatient surgery the likelihood is that they would already have been discharged home. It is therefore more important to warn these patients of possible delayed complications and that they should seek medical review in the first few days after discharge if alarm symptoms such as abdominal pain, nausea and vomiting occur. The NHS Institute published a clinical pathway in 2007 which noted that 70% of laparoscopic cholecystectomies could be safely performed as day cases
40
and this target has been recommended to NHS commissioners as part of the 18-week programme.
43
Successful day case laparoscopic cholecystectomy relies on rigorous patient selection, accepting only well-motivated and non-obese patients, and attention to detailed surgical technique. Patients require approximately 6 hours of recovery time and the procedure is best performed early in the operating day.
Good operative technique is also relevant when creating the pneumoperitoneum, as carbon dioxide inadvertently placed in the extraperitoneal space can cause considerable discomfort. Shoulder tip pain from diaphragmatic irritation has been related to the size of the gas bubble under the diaphragm
46
and attempts should therefore be made to expel as much gas as possible at the end of the procedure. Blood in the peritoneal cavity is an irritant, and liver bed haemostasis and peritoneal lavage before exiting the abdomen are worthwhile. While much of the postoperative pain in laparoscopic cholecystectomy is deep in nature, laparoscopy port sites should always be infiltrated with a long-acting local anaesthetic (such as bupivacaine). There appears to be little difference between infiltration at the beginning or the end of the procedure.
47
Prostatectomy:
For benign prostatic disease, the current national day case rate for laser ablation is 10% and for transurethral resection is just over 1%, although the rates are 30% in London and 10% in south central England.
13
Patients requiring prostatectomy tend to be older and less fit and many have previously been excluded from day surgery by their comorbidity. Conventional transurethral resection of the prostate (TURP) can be performed as a day case but postoperative haemorrhage remains a problem. Over the last decade, laser prostatectomy day case programmes have been developed,
48
,
49
with the patients discharged with a catheter in situ, returning to the day unit approximately 1 week later for trial without catheter. Some units now perform over 90% of prostatectomies as day cases.
50
Head and neck:
In the UK, 6% of tonsillectomies are performed on a day case basis due to worries about reactionary haemorrhage. This risk is small and in a series of 668 adults and children undergoing day case tonsillectomy in Salisbury, the reactionary haemorrhage rate was 0.3%, each occurring within the first 6–8 hours after the operation while the patient was still on the day unit.
51
Secondary haemorrhage occurs in approximately 1% of post-tonsillectomy patients and occurs several days after discharge, but may cause rapid airway obstruction at home with fatal consequences. The Salisbury Unit has a high readmission rate of 6% that reflects their policy of readmitting even minor bleeds for 24 hours in case they herald a more major bleed.
Similarly, parathyroid surgery has not been deemed suitable for day case surgery because of the risk of haemorrhage and hypocalcaemia. Nevertheless, McLaren and colleagues have demonstrated high and safe day surgery rates in patients with positive preoperative localisation.
52
Bariatric and other surgery:
Bariatric or weight loss surgery is increasingly performed in the UK, as a result of the growing number of morbidly obese in the population who fail to respond to dietary methods or exercise. Obesity is a risk factor for any surgery,
17
but shorter, minimal access procedures such as laparoscopic gastric banding have been performed successfully as day case procedures,
53
the limiting criteria being the 150-kg weight limit of most operating trolleys. Of greater significance is perhaps the implied message that BMI should no longer be seen as a limiting factor in the delivery of day surgery generally.
Other areas of surgery are developing fast-track or short-stay admissions as a preferred clinical pathway for their patients, for the same reasons surgeons applied day surgery techniques 30 years ago for hernia and paediatric surgery: when delivered to a high standard, safely and efficiently, patients and providers benefit. Kehlet described his experience in developing enhanced recovery programmes in colorectal surgery a decade ago and the principles have been extended to broader aspects of surgery.
54
,
55
Clinicians using techniques as diverse as abdominoplasty, colorectal cancer surgery, thoracic surgery and even endovascular aortic grafting are now using these techniques to shorten lengths of stay while enhancing patient care.
56
–
59
Upon completion of anaesthesia at the end of a surgical procedure, the patient is transferred to the operating theatre recovery area known as ‘first-stage recovery’. Formerly, patients remained here for a predetermined period, commonly 30 or 60 minutes. However, the development of short-acting anaesthetic agents, the introduction of minimally invasive surgical techniques and individual patient variability meant that patients were often ready for transfer to ‘second-stage recovery’ before their predetermined time. Therefore, ‘time-based recovery’ is no longer necessary and has in many units been superseded by ‘criteria-based recovery’, where discharge is determined by the observations of stable vital signs, return of protective reflexes and the ability to obey commands.
60
‘Second-stage recovery’ occurs back in the ward or trolley area of the day unit itself, where patients recover sufficiently to allow safe discharge home. Certain patients may be suitable for direct transfer to second-stage recovery from the operating theatre itself (
Fig. 3.3
) and include patients who have received local or regional anaesthesia with or without minimal sedation.
Figure 3.3
Staged patient recovery.
Before leaving the day unit, patients require specific information regarding their medication, wound care and when they are able to bath or shower, arrangements for suture removal or dressing renewal, when they can resume normal activities and arrangements for follow-up (if appropriate). It is also important to offer a contact telephone number for emergency purposes on the night of discharge. In addition, patients must be clearly instructed not to drive a motor vehicle for at least 24 hours.
61
Appropriate preoperative information may also have a beneficial effect on return to work after surgery.
62
The most common reason for a patient visiting their general practitioner after day surgery is to obtain certification for time off work. The second commonest reason, usually in an unplanned manner, relates to worries about their wound. After discharge, many day surgery units therefore offer outreach or telephone follow-up for their patients 24 hours later. This can be an effective evaluation tool, where any identified actual or potential problems can be highlighted to the day surgery team for action. This may only be necessary after specialised surgery (e.g. cataract surgery, where a change of dressing can be combined with outreach follow-up) or after the introduction of an unfamiliar procedure to the unit.