Anaesthesia for children having endoscopy on a gastroenterology list

Key points.

• •Children having an endoscopy often require procedures rarely seen elsewhere.
• •Abdominal muscle tone and spontaneous breathing can help guide the endoscope during colonoscopy.
• •A native airway technique (where spontaneous breathing is maintained without an airway adjunct) can work well, but is not suitable for all patients.
• •Children who are allergic to soy or egg can still be given propofol.
• •Always consider whether or not tracheal intubation is required.

Learning objectives.

By reading this article, you should be able to:

• •Describe the key procedures performed at endoscopy.
• •Explain how anaesthesia can affect the planned procedures.
• •Discuss how the procedures required should affect your choice of anaesthetic technique.
• •List the indications for tracheal intubation during endoscopy.

Upper and lower gastrointestinal (GI) endoscopies are indicated for the investigation of a wide variety of disease processes in childhood. Table 1 summarises the key pathologies, endoscopic investigations, and therapeutic procedures that may be undertaken during paediatric endoscopy.

Table 1.

List of common pathologies requiring diagnostic endoscopy or additional procedures.

	Pathologies for diagnostic endoscopy	Additional procedures
Pan-GI disorders	Inflammatory bowel disease	Video capsule endoscopy
	Post-transplant lymphoproliferative disease	Balloon enteroscopy
	Graft vs host disease
	Chronic intestinal pseudo-obstruction
	Polyposis syndromes	Polypectomy
	Vascular disorders (e.g. angiodysplasia and Blue rubber bleb naevus syndrome)
Oesophagus	Reflux oesophagitis	pH impedance study
	Barrett's oesophagus
	Oesophageal stricture	Balloon dilatation∗
	Oesophageal dysmotility	Oesophageal manometry
	Achalasia	Botox injection
	Eosinophilic oesophagitis
	Varices	Injection or banding∗
	Caustic ingestion
Stomach	Gastric erosions, ulcers, and gastritis
	Gastric outlet obstruction
		Removal of foreign body
		Gastrostomy insertion
Small intestine	Coeliac disease
	Peptic ulcer disease
Colon	Colitis
	Colonic dysmotility	Colonic/anorectal manometry
	Hirschsprung's disease	Suction rectal biopsy
	Polyps	Polypectomy
Anus/rectum	Fissures
	Haemorrhoids
Others	Functional GI disease, food aversion

^∗These therapeutic procedures are usually carried out in the operating theatre by other surgical specialists (e.g. interventional radiologists or hepatologists), and are not discussed further in this article.

This article discusses these diseases and procedures with particular reference to specific requirements for anaesthesia, and useful anaesthetic techniques for children having GI endoscopy.

Common pathologies

Gastro-oesophageal reflux disease

Gastro-oesophageal reflux is common in childhood and normal in early infancy. It usually resolves by the age of 1 yr and does not usually require any intervention. Reflux becomes pathological when it is associated with troublesome symptoms (e.g. poor weight gain or unexplained crying) or with complications, such as reflux oesophagitis or recurrent aspiration pneumonia.1, 2 Once pathological signs and symptoms are present, it is known as gastro-oesophageal reflux disease (GORD) and may require investigation and treatment.

Reflux is most commonly a result of transient lower oesophageal sphincter relaxation unrelated to swallowing. Other mechanical factors include the presence of a hiatus hernia, dysmotility, or delayed gastric emptying. Chronic severe GORD is most likely to occur in children with neurological impairment (e.g. cerebral palsy), and those with oesophageal anatomical or motility disorders (such as a hiatus hernia, operated achalasia, or after oesophageal atresia or congenital diaphragmatic hernia).

Diagnosis of GORD can be made clinically in older children who have typical signs and symptoms, but, in others, endoscopy with oesophageal pH monitoring and biopsies may be necessary if medical therapy has failed or where other diagnoses are suspected (e.g. eosinophilic oesophagitis). The features of reflux oesophagitis at endoscopy include erythema, erosions, ulcerations, and peptic strictures. A normal endoscopic appearance does not exclude oesophagitis, so biopsies should be performed in all patients.³ Severe reflux oesophagitis can progress to Barrett's oesophagus (associated with carcinoma), scarring, and oesophageal strictures that may require balloon dilation.

Treatment for GORD includes advice regarding feeding (smaller, more frequent meals, possibly with thickened feeds), medical therapy (H₂-receptor antagonists, proton pump inhibitors, and baclofen), and fundoplication surgery in selected cases.

Coeliac disease

Coeliac disease is a common autoimmune condition that is triggered by the ingestion of gluten (proteins present in wheat, barley, and rye). It affects 1% of the UK population. Coeliac disease is distinct from wheat allergy. In coeliac disease, gluten causes an immune-mediated enteropathy of the small bowel resulting in a wide variety of both GI and non-GI symptoms. Gastrointestinal symptoms include chronic diarrhoea, abdominal distension, failure to thrive, and nutritional deficiencies. Coeliac disease is associated with other autoimmune diseases, in particular autoimmune thyroiditis and Type 1 diabetes, and with Turner, Williams, and Down syndromes.

Despite the high prevalence of coeliac disease, many children remain undiagnosed until later in life. The gold standard of diagnosis is positive serology [immunoglobulin A (IgA) tissue transglutaminase antibodies and total IgA] along with a confirmatory biopsy.⁴ If the serological testing is strongly positive and the child has typical symptoms, then no biopsy is required; however, endoscopy and biopsy are required if there is any doubt about the diagnosis. Characteristic histological changes seen on small bowel biopsy include subtotal villous atrophy with an increase in intra-epithelial lymphocytes and lymphocytic infiltration of the lamina propria. These appearances may be patchy, and so multiple biopsies are necessary. Mucosal damage is entirely reversible with a gluten-free diet, which must continue for life. Unrecognised coeliac disease can lead to serious long-term complications, such as osteoporosis, infertility, small bowel adenocarcinoma, and lymphoma.

There is a small group of children who can present in ‘coeliac crisis’ that is characterised by explosive diarrhoea, abdominal distension, dehydration, electrolyte disturbance, and hypoalbuminaemia. This may require treatment with steroids.⁵

Inflammatory bowel disease

Inflammatory bowel disease (IBD) describes a group of chronic inflammatory diseases, the most common of which are Crohn's disease and ulcerative colitis (UC). Up to 25% of cases of IBD present in childhood.⁶

Crohn's disease can involve any part of the GI tract (Fig. 1) and may be patchy, with the unaffected tissue interspersed with affected areas known as skip lesions. Inflammation in Crohn's disease is usually transmural. Various phenotypes exist, including stricturing and fistulising disease. Crohn's disease can present in many ways and not just as the classical triad of weight loss, abdominal pain, and diarrhoea. Ulcerative colitis principally affects the large bowel, although microscopic inflammation can be present in other parts of the intestine. Inflammation is continuous without skip lesions, and it affects only the superficial layer of the colon; therefore, UC does not cause strictures or fistulae. UC usually presents with lower abdominal pain and diarrhoea containing blood or mucus. Combined oesophagogastroduodenoscopy (OGD) and colonoscopy with multiple biopsies are required for the investigation of suspected IBD (Fig. 2). Routine surveillance of disease progression and response to therapy may also be necessary.⁷

Fig 1.

Ulcer seen in small bowel on video capsule endoscopy VCE.

Fig 2.

Severe colitis of indeterminate cause.

Treatment for IBD includes nutritional therapy (e.g. an exclusive liquid diet to induce remission); anti-inflammatories (e.g. sulphasalazine and mesalamine); immunosuppressants (such as 6-mercaptopurine, azathioprine, methotrexate, or steroids); and, more recently, biological agents—most commonly infliximab (a monoclonal antibody against tumour necrosis factor-α).

Early diagnosis in children can prevent significant morbidity, including growth impairment. Children with persistent severe colitis refractory to medical treatment may require colectomy, and surgery may also be necessary for localised disease, severe stricturing, abscesses, or complicated fistulae.

Dysmotility

Gastrointestinal dysmotility disorders include GORD (discussed previously), chronic constipation, and chronic intestinal pseudo-obstruction (CIPO). Constipation is one of the most common complaints in children and accounts for a quarter of all referrals to paediatric gastroenterologists. Intractable constipation refers to constipation refractory to conventional treatment, such as laxatives and stool softeners, and is associated with significant morbidity and a poor quality of life. Organic causes (such as anatomical, endocrine, neurological, or inflammatory causes) account for a minority of childhood constipation; most cases are functional, often with a large behavioural component.

Colonic or anorectal manometry (ARM) may be required for diagnosis of suspected neuropathic GI disorders. A definitive diagnosis of Hirschsprung's disease is made by suction rectal biopsy, with histology confirming a lack of ganglion cells. Equivocal results may be confirmed with a surgical open rectal biopsy. Treatment for Hirschsprung's disease is surgical with the Duhamel pull-through procedure being the preferred technique in our institution.

Treatments for constipation depend on the cause, and may include behavioural modifications; high dietary fibre; stimulant and osmotic laxatives; botulinum injections for non-relaxing anal sphincters; and, in the most severe cases, surgery. An anterograde continence enema involves the formation of a small stoma, usually using the appendix, to provide access for intermittent passage of a catheter into the caecum, so allowing manual anterograde colonic irrigation (i.e. from the caecum towards the rectum and, ultimately, the toilet).

Chronic intestinal pseudo-obstruction describes the clinical manifestation of a group of rare conditions resulting in severe GI dysmotility. It causes significant morbidity and mortality, and is characterised by repeated or continuous features of bowel obstruction in the absence of a mechanical obstructing lesion. Chronic intestinal pseudo-obstruction can sometimes be detected in utero, but is usually diagnosed in the first year of life. The most common symptoms include abdominal distension, vomiting, abdominal pain, failure to thrive, and constipation. It is commonly associated with intestinal malrotation or urological abnormalities (megacystis and megaureter). Chronic intestinal pseudo-obstruction can be a result of a primary GI disease (e.g. an enteric neuropathy or myopathy), or secondary to systemic disease, such as a mitochondrial myopathy, metabolic disorder, muscular dystrophy, or connective tissue disorder.

Investigations are used to rule out other conditions, such as mechanical obstruction; manometry studies, including antro-duodenal manometry, colonic manometry, and ARM, can also help in diagnosis. Treatment options are limited, and two-thirds of patients will require parenteral nutrition (PN). Complications of PN (hepatic failure, central line infections, and thromboembolic events) are a significant determinant of morbidity and mortality in these children. Intestinal transplantation is recommended for patients with significant PN-related complications. The overall mortality in childhood for patients with chronic intestinal pseudo-obstruction is between 10% and 32%.⁸

Endoscopy-related procedures

Bowel preparation

Children having lower GI procedures will require pretreatment for bowel preparation. This may simply involve an enema (e.g. for ARM), but will more commonly involve oral laxatives. Standard bowel preparation in our institution involves a low-fibre, and ultimately liquid-only, diet along with a combination of senna, sodium picosulphate, and magnesium citrate. For this treatment to be effective, it is important to also drink lots of water; a nasogastric tube may be needed for children who will not take the laxatives or are not drinking enough liquids. Those with severe constipation may be admitted for several days of extended bowel preparation (e.g. with Klean-Prep) before the procedure.

Percutaneous endoscopic gastrostomy insertion

The usual indication for percutaneous endoscopic gastrostomy (PEG) is nasogastric tube dependence, for example, in failure to thrive or neurological impairment resulting in unsafe swallowing. In certain conditions, such as gastroparesis, a gastrojejunostomy (PEG-J) device might be used.

The insertion site is located during endoscopy by transillumination of light from within the stomach through the abdominal wall. Firm prodding of the abdomen with a finger at the chosen site should be seen as a clear indentation from within the stomach; if not, then something (usually transverse colon) may be lying between the stomach and the abdominal wall, and standard PEG insertion should not be attempted. (Laparoscopy-assisted PEG insertion is the preferred option in our institution.) Provided this is not the case, a cannula is pushed through a small abdominal incision into the stomach under endoscopic vision. A soft guide wire or thread is then inserted through the cannula, and snared via the scope. The endoscope, snare, and wire are withdrawn together, leaving the distal end of the wire coming out of the abdominal incision. A gastrostomy tube with an integral bumper is then attached to the guide wire and pulled down through the mouth and out of the incision. The endoscopist will usually reintroduce the scope to confirm placement of the gastrostomy, and a jejunal extension can be sited if required. The procedure is reversed for removal or change of the PEG.

Prophylactic antibiotics should be given and tracheal intubation is advised. Care should be taken to avoid movement of the tracheal tube as the scope is moved. There is a high risk of accidental extubation as the scope is being withdrawn (during an OGD in general, but especially during PEG removal), and therefore, the tracheal tube should be firmly secured. Our preference is for the tracheal tube to be taped and also held by someone throughout any OGD.

Video capsule endoscopy

Video capsule endoscopy (VCE) takes images of the entire GI tract, but it is especially useful for the small intestine, which is not easily accessible with traditional endoscopy.

After a prolonged fast, the video capsule (11 × 26 mm) is either swallowed or preferably placed endoscopically into the duodenum. The capsule contains a camera with a flashing light source, and transmits images to sensor pads attached to the patient who also wears a belt holding a data recorder and battery pack. Approximately 50 000 high-quality colour images are recorded during each VCE procedure, which are compiled into a digital video for analysis. The capsule is passed within 24–48 h.

The most frequent indication for VCE in children is IBD, both for diagnosis and assessment of response to treatment. Other indications include protein-losing enteropathies, such as secondary to intestinal lymphangiectasis (Fig. 3), obscure GI bleeding (including chronic iron deficiency anaemia), suspected small bowel polyps, tumours, and intestinal graft vs host disease after haematopoietic stem cell transplant.⁹

Fig 3.

Intestinal lymphangiectasia seen on VCE.

Balloon enteroscopy

Single or double balloon enteroscopy (BE), also known as push-and-pull enteroscopy, is an endoscopic technique for visualising the small bowel. Indications are similar to those for VCE, and, often, abnormalities found at capsule endoscopy are investigated by BE, as it allows for biopsies and therapeutic interventions.

Balloon enteroscopy involves the use of a balloon at the end of the scope and an over-tube balloon, which fits over the scope. Having this system allows the operator to concertina the small bowel progressively, enabling visualisation of the entire small bowel (Fig. 4). This is often a slow and not particularly gentle process, and can take up to 3 h; tracheal intubation is strongly advised.

Fig 4.

Abdominal X-ray showing double balloon enteroscope in jejunum.

Balloon enteroscopy involves a relatively high risk of complication compared to standard endoscopy, in particular of perforation, pancreatitis, and bleeding.

Anorectal manometry

Anorectal manometry assesses rectal and anal sphincter function. A balloon attached to a catheter is inflated in the rectum whilst examining the anal sphincter tone; distension in this way mimics the presence of faeces in the rectum and should normally result in relaxation of the internal sphincter (known as the recto-anal inhibitory reflex). The test is not painful and is ideally performed awake, not only because it provides more information, but also because all anaesthetic agents interfere with the results. It is not clear which anaesthetic technique interferes the least; our gastroenterologists much prefer a TIVA technique using propofol, but some centres do advocate volatile anaesthesia.¹⁰ Irrespective of anaesthetic technique, a light plane of anaesthesia is best if possible.

Suction rectal biopsy

Suction rectal biopsy allows a deeper biopsy to be taken to look for the presence of ganglia in the submucosal layer—their absence is diagnostic of Hirschsprung's disease. There are many different instruments available, but the principle is that the device is positioned against the posterolateral rectal wall and suction is applied (either via wall suction or a syringe) to suck the bowel wall into the device. A blade is then deployed to take the biopsy. There is always some bleeding, but this is usually self-limiting, and major bleeding and perforation are rare. As the biopsy is being taken above the dentate line, it is not painful.

Colonic manometry

Colonic manometry is used to evaluate colonic neuromuscular function. It enables the measurement of intraluminal pressures, and is useful in the investigation of slow-transit constipation and where surgical intervention is being considered. It may also help to clarify the pathophysiology of persistent lower GI symptoms after surgery for Hirschsprung's disease, evaluate colonic involvement in a child diagnosed with CIPO, or assess the function of a diverted colon before possible re-anastomosis. The administration of opioids (other than ultrashort-acting ones, such as remifentanil) should be avoided so as not to disturb motility.

Considerations for anaesthesia

Anaesthetic assessment

A full anaesthetic review and appropriate investigations should be carried out for all patients as normal, but with particular emphasis on the following:

• (i)History: Attention should be paid to the child's nutritional status, symptoms of reflux, and current medications. Patients on regular steroids will usually require a dose of hydrocortisone at induction. Those on immunosuppressant drugs are at risk of neutropenia; where this is the case, consider if the procedure is still in their best interests, and, if so, then antibiotic prophylaxis may be indicated. Antibiotics may also be indicated in patients who have an indwelling central venous catheter (e.g. a peripherally inserted central catheter or Hickman line), as there is a risk of bacterial translocation. Local guidelines should be in place.
• (ii)Examination: Children having bowel preparation not infrequently vomit and have diarrhoea. Look for evidence of dehydration. Those most at risk should have been given i.v. fluids as a preventative measure, but some children may require initiation of, or additional, fluid therapy before anaesthesia.
• (iii)Investigations: Consider preprocedural blood tests in patients taking immunosuppressant drugs, those on PN, those at risk of electrolyte disturbance (particularly renal, cardiac, or endocrine patients), and those having more aggressive bowel preparation regimens. Children having Klean-Prep (macrogol 3350) or similar have a 15% incidence of hypokalaemia and daily electrolyte supplementation is required.

Anaesthetic technique

There are many ways to anaesthetise children for endoscopy. A technique in which spontaneous ventilation is maintained may be preferred by the endoscopist, as some find that abdominal muscle tone can help guide the endoscope during colonoscopy; this can be particularly helpful in children with constipation, as the colon can be large and floppy, making navigation potentially very challenging. Commonly used techniques include the following:

• (i)I.V. sedation: In many countries, i.v. sedation for endoscopy is routinely given by non-anaesthetists, and many drug combinations have been described. Guidelines from the National Institute for Health and Care Excellence recommend midazolam alone for an OGD, and a combination of midazolam and fentanyl (or similar opioid) for a colonoscopy.¹¹ These guidelines also highlight the importance of deep sedation being administered by an appropriately trained healthcare professional whose only role is to administer sedation, monitor the child, and respond accordingly. A recent review of published evidence regarding sedation techniques for paediatric endoscopy found that combinations of midazolam and either fentanyl or meperidine resulted in a greater need for restraint and an increased incidence of the procedure being abandoned than when TIVA with propofol was used (see below for a description of this technique).¹² It was also found that the available data for both ketamine-based sedation and sedation with midazolam alone were too limited for a proper assessment of effectiveness or safety. A retrospective review of more than 10 000 OGDs in children in the USA found that, when compared with general anaesthesia, i.v. sedation was independently associated with a five-fold risk of a cardiopulmonary complication.¹³ General anaesthesia is now the norm in the United Kingdom.
• (ii)Laryngeal mask airway: It is possible to perform an OGD with a laryngeal mask in situ, and this is the usual practice in some departments. A standard i-gel® (Intersurgical, Wokingham, UK) works well for this, although a smaller size than normal will usually be required. Interestingly, a laryngeal mask has recently been released that has a dedicated channel for the endoscope (LMA® Gastro™ Airway; Teleflex Medical, Athlone, Ireland); however, the smallest size is a 3 and it is not licenced for use in children.
• (iii)Native airway technique: Anaesthesia with spontaneous breathing, but without an airway adjunct can be achieved in selected patients using TIVA with propofol. Oxygen is delivered via nasal cannulae that have an integral sampling port, so allowing for capnography. TIVA can be used for induction of anaesthesia or started after a gaseous induction. This is described in more detail in a recent article on TIVA in children in this journal.¹⁴ Both manual and target-controlled infusion (TCI) models are available for children; however, TCI has the advantage of being more easily titratable and is recommended.¹⁵ Adjuncts that can be used to facilitate the native airway technique include opioids (typically remifentanil, alfentanil, or fentanyl), local anaesthetic throat spray, or i.v. lidocaine.

The main problem with this technique is the risk of either apnoea or laryngospasm, particularly during an OGD.¹⁶ Reasons include the potent stimulus of the procedure, whilst the application of 100% oxygen and positive end-expiratory pressure is impossible. Close coordination with the endoscopist is important to ensure the procedure does not start until an appropriate depth of anaesthesia has been achieved. The endoscopist must also be ready to remove the endoscope rapidly if required in the event of apnoea, laryngospasm, or oxygen desaturation. Lateral positioning improves airway patency and may reduce the triggering of laryngospasm by secretions.¹⁷ As for any anaesthetic, standard monitoring should be used and emergency equipment should be prepared with suction apparatus close to hand.

The advantages of TIVA with propofol over volatile agents include a lower risk of nausea and vomiting, and a lower risk of emergence delirium (and possibly also of post-hospitalisation behavioural change).¹⁸ Children undergoing endoscopy often have multiple food allergies, including to egg and soya. It is now thought to be safe to give propofol to these children, with the possible exception of those with a history of anaphylaxis to egg.¹⁹

• (iv)
  Tracheal intubation: It must be recognised when the aforementioned techniques are not suitable for a particular patient, in which case tracheal intubation is advised. Indications for intubation include the following:

  • (a)
    A patient weighing <10 kg or aged less than 1 yr
  • (b)
    Difficult airway or known airway problems, including snoring/obstructive sleep apnoea
  • (c)
    Significant cardiac or respiratory co-morbidity
  • (d)
    GI conditions that increase the risk of aspiration (e.g. significant GORD, CIPO, oesophageal stricture, or achalasia; the last two can both result in food residue being retained above the level of obstruction)
  • (e)
    Specific procedures, such as PEG insertion/removal/change or enteroscopy

Good intubating conditions and safe tracheal intubation can be achieved in children without using neuromuscular blocking agents (NMBAs); effective methods include giving propofol, alfentanil, or remifentanil after a gaseous induction, or using an i.v. induction with propofol in combination with either remifentanil or alfentanil.²⁰ Avoiding the use of an NMBA can allow the early resumption of spontaneous breathing and may also facilitate early extubation after short procedures (where the duration of action of the NMBA exceeds the procedure time). A commonly used alternative would be to use rocuronium for intubation, followed at the end of the procedure by sugammadex to achieve rapid reversal of neuromuscular block and extubation.

Postprocedure

Even with meticulous suction by the endoscopist, all patients will have some intraluminal gas left behind after the procedure. This is still true for an OGD, despite it being easy to empty the stomach at the end of the procedure, as some gas will enter and remain in the small bowel. In most patients, this is of no consequence; however, infants and small children can end up with significant diaphragmatic splinting. Patients with underlying respiratory or cardiovascular disease may not tolerate even the modest amounts of intraluminal gas. These patients should be managed using tracheal intubation; gentle pressure on the abdomen at the end of the procedure can help the expulsion of some of the gas before extubation of the trachea.

Most patients should be pain free afterwards, although those with a history of abdominal pain may be uncomfortable because of residual intraluminal gas. Any patient in significant pain in recovery needs to be examined and bowel perforation excluded.

Declaration of interest

The authors declare that they have no conflicts of interest.

MCQs

The associated MCQs (to support CME/CPD activity) will be accessible at www.bjaed.org/cme/home by subscribers to BJA Education.

Acknowledgement

The authors would like to thank Ian Steele for his help with sourcing the images.

Biographies

Katherine Railton FRCA is a locum consultant paediatric anaesthetist at Great Ormond Street Hospital for Children. She has a special interest in patient safety, clinical governance, and service improvement.

Keith Lindley PhD MRCPCH is a consultant paediatric gastroenterologist at Great Ormond Street Hospital for Children. He has a special interest in neurogastroenterology and motility.

Hugo Wellesley FRCA MA is a consultant paediatric anaesthetist at Great Ormond Street Hospital for Children. His clinical interests include anaesthesia for paediatric endoscopy, and he is also a member of the hospital's Clinical Ethics Committee.

Matrix codes: 1H02, 2A03, 3D00