Fig. 9.1
Colonic bleeding in colonoscopy
High-risk patients may be referred to appropriate institutes.
Low-risk patients may be discharged earlier.
Management
Endoscopy can be used as a potential therapeutic tool in selected cases.
Therapeutic procedures include injection therapy, sclerotherapy, endoscopic clip application, argon beam cauterization, golden probe application, detorsion, tube placement, percutaneous endoscopic gastrostomy, and transcolonic and transrectal abscess drainage.
Indications
Hemorrhage
Large bowel obstruction
Foreign body extraction
Treatment of anastomotic failure
Contraindications
Absolute
Suspicion of perforation
Noncompliant patient
Shock
Respiratory distress
Clear indication for exploratory laparotomy: diffuse peritonitis
Relative
Coagulopathy (if life-threatening entity in which a diagnostic and/or therapeutic endoscopy is considered to be critical)
Patients who have had a gastrointestinal tract surgery (low-pressure endoscopy after the fifth to seventh postoperative day)
Pregnancy
Patient preparation
Major limiting factor in emergency colonoscopy: lack of mechanical bowel preparation.
It is wise to avoid oral laxatives for mechanical bowel preparation in critically ill patients and in patients who may not tolerate dehydration: enemas should be preferred over oral laxatives in these patients.
Of note, polyethylene glycol (Golytely) is a fast-acting (4 h) oral solution and is responsible for relatively mild fluid-electrolyte disturbance.
Particular to emergency colonoscopy.
Likelihood of overlooking colonic lesions is considerably high, and it is usually not possible to advance the colonoscope into the cecum; therefore, the endoscopist should focus on identifying the emergency pathology instead of exploring the whole colon and should then carry out an elective colonoscopy to exclude additional pathologies.
Avoid administration of sedatives and analgesics as much as possible. Short-acting agents, such as propofol and fentanyl, should be preferred in exceptional situations, particularly if physical examination is thought to be crucial for follow-up of the patient.
Staff and equipment.
Staff trained in emergency endoscopy.
Adequate equipment for excessive irrigation.
Complications
Higher incidence of complications in emergency endoscopy (0.9 %) when compared to elective endoscopy (0.1–0.3 %)
Types
Cardiopulmonary complications (responsible for 50 % of deaths)
Infection
Hemorrhage
Perforation
9.2 Lower Gastrointestinal Bleeding
Definition, incidence, and population
i.
Lower intestinal hemorrhage is defined as bleeding in the bowel distal to the ligament of Treitz and usually manifests with maroon stools or bright red blood per rectum.
ii.
Incidence (not exactly known) but assumed to be 20–30/100,000 population.
i.
Twenty-five percent of all gastrointestinal bleedings.
ii.
Male predominance.
iii.
The rate of hospitalization also increases >200-fold between the third and ninth decade of life related to the increased incidence of diverticulosis and malignancy.
iii.
Rarely massive (defined as exsanguinating or hemodynamically significant bleeding that persists and requires at least four units of blood over a period of 24 h).
1.
Most episodes are self-limiting and not hemodynamically significant and never have the precise site and cause established.
2.
However, older population (>65-year-old patients) and the patients with comorbidities warrant hospitalization because of high morbidity and mortality rates (10–20 %).
3.
Up to 80 % of patients will stop bleeding spontaneously, and the recurrence rate reaches as high as 25 %.
4.
Identification of the bleeding source remains a diagnostic challenge. Approximately 10 % of all patients will never have a source identified, and up to 40 % of patients with LGIB have more than one potential bleeding source.
iv.
Causes.
1.
Diverticula of the sigmoid colon and angiodysplasia are the two most common causes of major acute LGIB.
(a)
Bleeding from diverticula occurs more often in elderly patients, particularly in those taking NSAIDs or anticoagulants.
(b)
Bleeding from angiodysplasia can be massive and recurrent.
2.
Ischemic colitis.
(a)
Seen in the elderly
(b)
Rarely presents with massive bleeding
3.
Rectal cancer.
(a)
Bleeds overtly.
(b)
Often the patient may have a history of tenesmus and of episodic minor bleeding with the stools for some time.
4.
Inflammatory bowel disease.
(a)
Almost never the first symptom of the disease
i.
Often preceded by diarrhea
(b)
Rarely massive
5.
Proctitis and especially radiation proctitis and internal hemorrhoids may bleed significantly.
Immediate management
i.
Initiate ABC rules as for all patients in the emergency setting. The goal is to determine hemodynamic stability.
ii.
Appropriate laboratory values should be ordered including a complete blood count, coagulation profiles, and blood gases. An initial type and screen should be completed in anticipation that blood transfusion may be required.
iii.
Determine whether the source of bleeding is upper or lower gastrointestinal tract.
1.
Digital rectal examination
2.
Insertion of nasogastric tube
(a)
To rule out upper gastrointestinal bleeding and evacuate the gastric contents
(b)
Upper gastrointestinal endoscopy
iv.
Recommended to carry out colonoscopy immediately in patients with third and fourth degree hypovolemia and within 12–24 h in patients with first and second degree hypovolemia (Fig. 9.1).
1.
Early colonoscopy is superior to delayed colonoscopy in means of identifying the lesion, reduction of rebleeding rate, reduction of morbidity and mortality rates, and decreasing the necessity of blood transfusion and surgical intervention.
2.
Mechanical bowel preparation is usually not necessary because of the purgative effect of intraluminal blood.
3.
Therapeutic interventions during colonoscopy are required only in 20 % of patients with lower gastrointestinal bleeding.
9.3 Other Diagnostic Modalities in LGIB
Radionuclide scintigraphy
i.
Involves either technetium-99m (Tc-99m) sulfur colloid or Tc-99m-labeled red blood cells to localize bleeding from a gastrointestinal source.
ii.
Scintigraphy can identify bleeding as low as 0.1 ml/min and has been advocated as a safe, noninvasive, and accurate method identifying all types of gastrointestinal bleeding.
iii.
No need for bowel preparation and repeat scans can be easily performed in cases of recurrent bleeding although limited by the half-life of the radiotracer used.
iv.
Scintigraphy is now used at most institutions as a screening tool to determine the group of patients who would be optimal candidates for interventional angiography.
v.
Negative scans may also be useful for screening as they are also associated with a low likelihood of requiring surgical intervention.
Angiography
i.
This method allows for accurate localization of the source of bleeding at rates as low as 0.5 ml/min.
ii.
Can be therapeutic by injecting vasopressin or by performing embolizations of bleeding vessels.
Multi-Detector Row Helical Computed Tomography (MDCT)
i.
Allows for identification of extravasation of intraluminal contrast before it is diluted by intestinal contents.
ii.
This modality has been used increasingly in the diagnosis of vascular diseases as it is capable of more precise imaging and 3-D formatting of vascular structures.
iii.
MDCT demonstrates acute lower GI bleeding rates as low as 0.2 ml/min, lower than that for angiography and comparable to radionuclide scanning.
iv.
Overall rates of detection and localization range around 30 % and is comparable to angiography.
v.
MDCT may be a more reliable method of screening when compared to RBC scintigraphy.
Others
i.
Push enteroscopy and capsule endoscopy have been investigated for the diagnosis of LGIB.
ii.
Push enteroscopy uses a longer, thinner endoscope to examine the small bowel but only reaches approximately 160 cm past the ligament of Treitz, leaving most of the small bowel unexamined.
iii.
Wireless technology have paved the way for capsule endoscopy, a pill-sized capsule that the patient swallows and travels the entire length of the GI tract by peristalsis. It is noninvasive and causes no patient discomfort.
9.4 Several Types of Possible Therapeutic Colonoscopic Interventions
Injection therapy:
i.
Different types of liquid material can be injected around the bleeding lesion with an endoscopic needle
1.
Arrest of bleeding depends on two principles:
(a)
Compression of bleeding vessels by mass effect
(b)
Biochemical effects
2.
The most common biochemicals used are:
(a)
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Epinephrine.
i.
The most preferred agent used worldwide
ii.
Injection of a 1:10,000 solution into four quadrants around the bleeding lesionRelated posts:
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