Therapeutic Gastrointestinal Endoscopy

David Westaby, Martin Lombard, David Westaby, Martin Lombard

• Publisher: CRC Press
• Year: 2019
• Print ISBN:
  9780367455088
• eBook ISBN:
  9781000723731
• Topic: Medicine
• Subtopic: Gastroenterology & Hepatology

From screening and diagnosis to prevention and treatment, every aspect of gastrointestinal endoscopy as a therapeutic measure is addressed in this volume. The authors are recognized authorities in this field, and in Therapeutic Gastrointestinal Endoscopy they present a problem-oriented, evidence-based textbook. In each chapter, it cites the key medical literature that can be studied for further reference. The book uses dozens of figures, photographs and illustrations to address the key issues of assessment, diagnosis and options for treatment. The authors present cohesive arguments for the preferred chosen management regime.

1	Introduction M. Lombard and D. Westaby

PRELIMINARIES

While many of the authors in this book were pioneers in endoscopic techniques and had to ‘boldly go where no endoscopist had gone before’, it is now inconceivable that anyone would undertake advanced therapeutic procedures without personal tuition and training by an expert. We have had to assume in this book that basic endoscopic training has been completed, and there are many excellent texts which address this aspect. Nonetheless, there are some important points of preparation which we wish to emphasize before endoscopic therapeutic procedures are undertaken.

Patient preparation

It is vital that the patient understands what is entailed in therapeutic endoscopy. The general public have a reasonable appreciation that surgical operations carry an element of risk. However, many patients have come to be aware that endoscopy is a routine procedure, and frequently do not appreciate that there are risks associated with sedation and diagnostic upper or lower endoscopy. When therapeutic procedures are involved, it may be necessary to appraise the patient that this is a surgical operation undertaken through the endoscope, particularly where they are undertaken as ‘day-case’ procedures.

Consent

The question of informing the patient is increasingly important. The more open and honest approach adopted in recent years is certainly a great step forwards, in general. It requires, however, an increased level of skill, compared with the bland reassurances which were sometimes given in the past, for it to work well. Relatives and friends may try to collude with clinical staff, for example to shield the patient with cancer from ‘distress’, which may be merely their way of coping, or a genuine appreciation of the likely effect of bad news. Certainly a crude, early disclosure may be catastrophic. Patients must be given bad news in boluses which they can digest. The speed of first-rate, modern management can work against this process of gradual disclosure, understanding and acceptance. The judgement of the clinical team is crucial here. It is no longer appropriate, however – if it ever was – to commit a patient to dangerous, painful and unpleasant treatments without their being in possession of an appropriate understanding of what is going on. The legal background, with its emphasis on ‘informed consent’, has produced added challenges. Nevertheless, it remains a cruel and callous disregard of our patient care to provide a list of all the possible complications of a procedure without regard to the psychological effects this may have, not least on the ability of the patient to relax and cooperate through what can be a harrowing procedure. We need to temper our wish to tell all and avoid possible litigation with some common sense and compassion. Consent must be informed, but need not be omniscient.

Fasting and fluids

Traditionally, patients have been asked to fast for 8–12 hours prior to endoscopic procedures. In practical terms this usually means fasting from midnight before an elective procedure and, with increasing workload, the procedure may not take place until the late afternoon or evening. This can cause unnecessary discomfort to patients and for some can be dangerous. Recent work has indicated that fluids can be taken up to 4–6 hours before endoscopy without adverse consequence. It may be the case that small (thirst-quenching) sips can be taken right up to the time of endoscopy. The difficulties of allowing different limits for different patients in a busy service is more likely to require adherence to the ‘6 hour rule’.

For certain procedures fasting for longer may be necessary. For any patient – particularly for elderly patients – fasting for longer than 6 hours we feel an intravenous infusion of colloid is essential. This is particularly important for patients undergoing a therapeutic procedure as sedation is nearly always required and frequently the patient will have to fast for a variable period after the procedure until it is clear that there are no adverse consequences.

Jaundiced patients may have to fast for several procedures over several days, for example ultrasound scan, computed tomography (CT) scan and endoscopic retrograde cholangiopancreatography (ERCP). The elderly in this situation are particularly susceptible to dehydration and hepatorenal complications, and intravenous fluids can be vital for those patients.

Diabetic patients should be managed with a glucose infusion and a sliding scale of insulin. It may not always be possible to ensure that these patients are treated on a morning list. In this case, where it will not interfere with the specific planned procedure, a light breakfast can be given.

Bowel preparation

It is beyond the scope of this book to compare different means of bowel preparation. Suffice to say that large-bowel endoscopy, with its attendant risk of perforation, is generally not worthwhile without adequate preparation.

Undoubtedly, large-volume orthograde lavage solutions (e.g. polyethylene glycol solutions) give the best results, though they pose difficulty for some patients because of the volume required to be taken, and in the elderly can occasionally produce fluid and electrolyte imbalance. Lower-volume solutions with phosphate may be as effective for most patients. Occasionally, patients will require a combination of means with a fluid only diet for several days. It is important to discontinue iron supplements during the process of bowel preparation.

Purgation with phosphate enemas as proprietary preparations is often sufficient for left-sided colonoscopy.

Anticoagulation

For elective procedures, it is best to stop oral anticoagulants and use a heparin regimen which can be controlled and reversed if necessary, around a therapeutic procedure. For more acute procedures, a full therapeutic manoeuvre may not be possible, but valuable diagnostic information (e.g. source of bleeding) may still be obtained.

For patients with jaundice, a single intravenous dose of vitamin K is usually sufficient to correct the coagulopathy. There is no evidence to indicate that undertaking procedures with fresh-frozen plasma or with platelet transfusions will reduce the potential for complications in patients with an underlying coagulopathy.

Antibiotics

For most therapeutic procedures, antibiotics are unnecessary. They should be used for procedures in which there is a significant risk of perforation, where a normally sterile site will be breached or instrumented (e.g. the biliary tree or at gastrostomy), or where a patient is at risk for other reasons (e.g. valvular heart disease, cystic fibrosis, post-splenectomy).

Broad-spectrum antibiotics should be used and specific cover for coliforms is essential. Often, prophylaxis can be given orally on the morning of the procedure and orally again once the patient recovers.

PROCEDURES

Intravenous sedation, oxygen supplementation and monitoring

Many diagnostic endoscopic procedures can be undertaken with adequate explanation to the patient and without sedation. Topical pharyngeal anaesthesia with lignocaine 2% when used for gastroscopy has been shown to improve patient tolerance. Most comparative studies of upper endoscopy also indicate that, even where sedation is used, tolerance is further improved by the addition of topical oropharyngeal anaesthesia.

Most therapeutic procedures are undertaken with sedation, often in combination with analgesia and occasionally with a general anaesthetic.

Our preference is to use short-acting benzodiazepine such as midazolam. This has sedative, tranquillizing and amnesic properties. Heretofore, there has been a tendency to use midazolam in doses of 5–10 mg or diazepam in doses of 10–20 mg. Recent work and our own experience has shown that much lower starting doses (30 μg/kg; average 2–4 mg) with sequential increments if necessary during long procedures are effective. Thus in a personal series of over 1000 patients undergoing therapeutic ERCP, the average dose used was less than 5 mg midazolam and doses over 10 mg were used in only 2% of patients. Adverse excessive sedation can be reversed with flumazenil 250–500 μg intravenously (iv). In some units this has been used as routine reversal to shorten recovery. In our experience this is unpredictable, as flumazenil has an even shorter half-life than the agonist benzodiazepines and it can produce a false sense of security, particularly in elderly patients. It is also expensive. This practice is unnecessary with lower doses of midazolam.

Opiates are usually used in addition, e.g. pethidine 25–50 mg or fentanyl 50–100 μg. Adverse effects or hypotension can be reversed with naloxone 400 μg iv or intramuscularly (im).

Concern is occasionally expressed at the potential synergist effects of using opioids and benzodiazepines together. Clearly, the dosages used are important here. A safe practice is to give opiate first, followed by buscopan or atropine if required. Once the pulse begins to quicken (anticholinergic effect), the benzodiazepine is given in small boluses of 2–3 mg. as required, titrated to the anxiolytic response in the patient.

Systemic hypoxia can occur as a result of sedation, endoscopic intubation, the position of the patient for some procedures, or because of the patient’s own underlying cardiorespiratory status. Published series indicate that severe hypoxia (saturation <90%) occurs in 10% to 70% of patients depending on those factors. Giving supplemental oxygen during the procedure can prevent this and pre-oxygenation may be particularly important in patients at risk as the greatest oxygen desaturation seems to occur immediately following intubation. Both nasal cannula and oral oxygen delivery systems seem equally effective.

It is clearly important that monitoring of vital signs is undertaken throughout the procedure. Electrical pulse oximetry and automatic blood pressure monitoring are useful adjuncts to personal nursing care, though there is no published data to indicate that they reduce complications.

Nursing and endoscopy assistants

Endoscopy nurses must be trained and highly skilled as they form an integral part of the clinical management team. It is not possible to undertake a number of the procedures described in this book without skilled technical assistance.

We recommend that all of our trainees spend time assisting these techniques, as it is the only way they gain an understanding of what they can expect from their assistants when they are performing the procedure themselves. It is also an excellent opportunity to become familiar with the equipment.

In addition to technical expert assistance, the importance of nursing the patient through the procedure cannot be overstated. Because of the amnesic properties of drugs used to achieve conscious sedation, patients need repeated reassurances during the procedures.

The moving patient

It can be tempting to equate the moving patient with a moving target where difficult therapeutic procedures demanding of patience and calm are concerned. However, a major advantage of conscious sedation’ over general anaesthesia is that some biological feedback is retained when potentially traumatic therapeutic procedures are undertaken, i.e. if the patient is in discomfort, they can usually signal this. This should not be interpreted by the endoscopist that more sedation is required. In our experience, patients who move during endoscopy do so for one of three reasons: (i) too much air is insufflated causing gaseous distention of a viscus (a common occurrence with the novice endoscopist); (ii) the patient is paradoxically stimulated by the hypnotic (common with a history of alcohol excess or longstanding use of anxiolytics); and (iii) a visceral perforation has occurred (rarely, it is hoped).

With expert nursing, the conscious sedated patient will remain quiet and relaxed throughout the procedure. Incremental sedation should be used for signs of wakeful distress or anxiety, not if the patient is trying to warn of an impending problem.

Recovery and postoperative care

As most procedures are undertaken with sedation, they will require a period of recovery in a sedated state. Thus, fasting is usually continued for 2–3 hours following a procedure and fluid replacement may be required for certain patients. The patient should continue to be monitored with nursing observations of pulse and blood pressure. By this time, if serious complications have oc...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• List of Contributors
• Preface: Problem-oriented endoscopy
• 1 Introduction
• 2 Benign oesophageal obstruction
• 3 Malignant oesophageal obstruction and tracheo-oesophageal fistulae: endoscopic palliation
• 4 Upper gastrointestinal malignancy: palliation with thermal laser, photodynamic therapy and argon beamer
• 5 Endoscopic screening for upper gastrointestinal malignancy
• 6 Acute non-variceal gastrointestinal bleeding
• 7 Endoscopic therapy of oesophageal and gastric varices
• 8 Enteral nutrition
• 9 Bile duct stones
• 10 Biliary obstruction and leaks
• 11 Malignant strictures of the biliary tree
• 12 Acute pancreatitis
• 13 Chronic pancreatitis
• 14 Benign obstruction of the colon
• 15 Cancer surveillance and screening
• 16 Colon cancer prevention
• 17 Palliation of malignant lower gastrointestinal disease
• 18 Management of lower gastrointestinal bleeding
• Index