Fiona Hibberts, MSc, BSc, RN, is colorectal nurse specialist, Department of Colorectal Surgery, St Thomas’ Hospital, London; Elizabeth Barnes, BA, RN, is palliative nurse specialist, Leighton Hospital, Crewe; Fiona Hibberts, MSc, BSc, RN, is colorectal nurse specialist, Department of Colorectal Surgery, St Thomas’ Hospital, London.
Endoscopic retrograde cholangio pancreatography (ERCP) allows a detailed examination of the bile ducts, the pancreatic duct and the gallbladder using a combination of endoscopic and radiographic techniques. Patients undergo ERCP for diagnostic or therapeutic reasons.
Anatomy and physiology
The liver secretes 500-1000ml of bile daily. This consists of water, mineral salts, mucus, bilirubin (bile pigment), bile salts and cholesterol. Bile drains from the liver down the hepatic ducts, along the cystic duct and into the gallbladder, which absorbs water from the bile so that it is 10-15 times more concentrated than liver bile. Stored bile is then released into the common bile duct, which joins with the main pancreatic duct and opens into the duodenum. Bile and pancreatic enzymes emulsify fats and aid their digestion.
Chemical imbalances in bile draining from the liver may cause gallstones. These may cause minimal, intermittent or complete obstruction to the flow of bile from the gallbladder into the duodenum. A tumour arising from the bile ducts, the head of the pancreas or the ampulla of vater, can also have this effect.
An obstruction to bile flow results in jaundice - an excessive amount of bilirubin in the blood. Jaundice may cause yellowing of the skin and sclera of the eye. Itching of the skin may occur due to bile salts, and urine may become dark as bilirubin - excreted into the blood stream rather than the bowel - is expelled. Steatorrhea (pale, fatty, and foul-smelling faeces) occurs because fats are not being absorbed in the small intestine.
Contraindications for ERCP
ERCP should not be undertaken, except in life-threatening situations, in patients who have severe cardiorespiratory disease as endoscopy or sedation may exacerbate these conditions (Siegel, 1992). ERCP may also be contraindicated for anatomical reasons, for example in patients who have oesophageal or duodenal stricture or where previous surgery limits access.
Patients should be given a full explanation of ERCP and the chance to ask questions before written consent is obtained. Many prefer to ask nursing staff questions, so a good knowledge of the procedure and the ability to explain it clearly are essential (White, 1990).
Patients should be nil by mouth for at least four hours prior to ERCP, to allow a clear passage for the endoscope and to prevent aspiration of stomach contents while under sedation.
Temperature, pulse and blood pressure should be recorded for comparative purposes postprocedure. Assessment should establish whether the patient has any known allergies. A significant number of drugs are used during ERCP and drug sensitivities must be known. The patient should also be asked about any previous exposure to X-ray dyes. Sensitivity to intravenous contrast medium, however, may not preclude ERCP as the volume entering the bloodstream is much smaller (White, 1990). Blood tests should be carried out to assess:
- Renal function - patients can be predisposed to renal failure due to obstructive jaundice, sepsis and acute pancreatitis. This risk is aggravated by dehydration;
- Full blood count - anaemia may increase the risk of hypoxia during sedation and endoscopy. It is important to check for signs of neutropenia especially in patients undergoing chemotherapy. This is the single most important predisposing factor to infection in a person with cancer;
- Clotting - bile is necessary in the small intestine for absorption of vitamin K - a fat-soluble vitamin essential for the synthesis of prothrombin in the liver and for other blood-clotting proteins. If the patient has an obstruction of the bile duct, clotting ability may be reduced;
- Blood group and save - in case of haemorrhage (Bassett, 1997);
- Prophylactic antibiotics - intravenous or oral - are valuable for preventing sepsis in patients undergoing ERCP (Martin et al, 1998). The IV line should ideally be established in the right arm, as the patient will lie partially on the left arm (Cotton and Williams, 1996);
- ERCP must be carried out under sedation as it takes longer and is more uncomfortable than endoscopy, especially during therapeutic procedures such as stent insertion and stone extraction (Martin et al, 1998). It is important that patients remain still, relaxed and comfortable.
The long, flexible endoscope is inserted via the mouth to the back of the throat, down the oesophagus, through the stomach and into the first portion of the duodenum. Once the ampulla of vater is identified, a cannula is passed down the endoscope, through the ampulla and into the pancreatic/bile ducts. Contrast dye is then injected and X-rays are taken.
If there is no abnormality, the endoscope is removed. If gallstones are seen, the opening of the bile duct can be enlarged by diathermy (sphincterotomy). Gallstones are then removed or pass harmlessly into the duodenum.
If narrowing of the bile duct is found, a short plastic tube (stent) can be inserted via the endoscope. The stent opens up the duct and allows bile to drain.
If the suspected cause of the narrowing is a cancer and the patient is to be considered for surgery with curative intent, a biopsy should not be taken. A negative result will not change the management of the patient, as a duct stricture seen on a computerised tomography scan usually indicates a cancer (Martin et al, 1998). There is also concern about tumour spread during a biopsy (Cotton and Williams, 1996). Biliary brush cytology can be carried out by passing a fine cytology brush down the endoscope. However, this can be insensitive and a negative result has little value.
Complications following ERCP
Abnormal changes to blood pressure, pulse, respiration rate and temperature, abdominal pain or changes to the patient’s level of consciousness indicate the possibility of a complication.
- Sepsis - after ERCP this can be linked to the handling of an obstructed bile duct. The risk is reduced by administration of IV antibiotics immediately preceding ERCP (Lail and Cotton, 1990). In the event of a rise in temperature, a fall in blood pressure, and an increase in pulse and respiration rate, the medical team should check the patient’s blood, take blood cultures and initiate an antibiotic regime for bile duct sepsis;
- Acute pancreatitis - this inflammatory response can cause the patient increasing abdominal pain, which may be accompanied by nausea and vomiting. Bowel sounds may be diminished or absent. Blood pressure, pulse and respiration rate may be raised while temperature may be only minimally elevated. Post-ERCP pancreatitis is usually mild but may require hospitalisation for two or three days (Wilkinson, 1990). Treatment includes nil by mouth, IV hydration, IV antibiotics and pain management (not morphine as this causes sphincter of Oddi spasm, which is thought to make the pain worse). Severe acute pancreatitis with necrosis of the pancreas and/or development of a pseudocyst can also occur after ERCP;
- Haemorrhage - can occur immediately following sphincterotomy or as late as 12-24 hours postprocedure. The patient should be observed for abdominal distension and increasing pain. Treatment aims to prevent hypovolaemic shock, and may include transfusion, embolisation under X-ray guidance or, in the most severe cases, surgical resection (Saeed et al, 1989);
- Perforation - occurs in about one per cent of patients following a sphincterotomy (Lail and Cotton, 1990). A symptom is severe abdominal pain. It is usually diagnosed after a plain abdominal X-ray showing free air in the abdomen. Treatment involves nil by mouth with a nasogastric tube, IV fluids and IV antibiotics. Surgical intervention may be required in severe cases.
Complications post-ERCP are relatively uncommon but can be life-threatening and must be identified early. Nurses should have clear patient information regarding:
- Recovery from sedation;
- Procedure performed;
- Findings and any therapeutic interventions;
- Medications administered;
- The need for antibiotics post-procedure;
- Response and any complications that occurred.
Temperature, blood pressure, pulse and respiration should be recorded half-hourly initially and reduced as vital signs stabilise. The patient should also be monitored for respiratory depression and altered level of consciousness associated with sedation and analgesia.
If ERCP was diagnostic the patient should remain nil by mouth until fully alert and the gag reflex has returned. Oral intake can then recommence beginning with cool water. If the procedure was therapeutic individual advice as to when to recommence oral intake should be sought.
Patient information and education
Patients should be given verbal and written information following ERCP. They should contact the hospital if they develop a temperature, rigor, abdominal pain or distension. A 24-hour contact number should be provided. Patients leaving hospital should be accompanied by another adult and advised not to drive or operate machinery for 24 hours.
Before discharge the side-effects of sedation and the findings and implications of the ERCP should be explained to patients and their relatives. Patients should understand that follow-up may be necessary and should be aware of their plan of care. Good nursing aftercare and information minimise the risks to patients.