Understanding Bowel Obstruction

Summary

This video provides a comprehensive overview of bowel obstruction, covering its causes, symptoms, and management. It highlights the most common causes, such as adhesions, hernias, and tumors, and explains how conditions like closed loop obstruction and volvulus complicate treatment. The video discusses the key clinical signs, including vomiting, abdominal distension, and constipation, as well as diagnostic methods like abdominal X-rays and CT scans. The management involves both conservative and surgical options, with surgery being necessary in severe cases. Key interventions include fluid management, NG tube drainage, and surgical procedures like exploratory surgery and tumor resection.

Takeaways

• 🩺 Bowel obstruction occurs when the passage of food, fluids, and gas through the intestines is blocked, most commonly affecting the small bowel.
• ⚠️ It is a surgical emergency due to the risk of fluid loss, hypovolemia, shock, ischemia, and perforation.
• 💧 Obstruction causes fluid buildup in the intestines, leading to third spacing—where fluid shifts from the intravascular space into the gastrointestinal tract.
• 🏥 The three main causes of bowel obstruction are adhesions, hernias, and tumors, accounting for around 90% of cases.
• 🔄 Other causes include volvulus, diverticular disease, strictures (e.g., from Crohn’s disease), and intussusception in young children.
• 🩹 Adhesions, often from prior surgery, peritonitis, or infection, can kink or squeeze the bowel—most often causing small bowel obstruction.
• 🚨 Closed-loop obstruction involves two points of blockage isolating a section of bowel, which can rapidly lead to ischemia and perforation, requiring emergency surgery.
• 🤢 Typical symptoms include vomiting (often bilious), abdominal distension, diffuse pain, constipation, and lack of flatulence, with tinkling bowel sounds in early cases.
• 🩻 On X-ray, small bowel loops appear with valvulae conniventes (lines across the full width), while large bowel shows haustra (lines only partway across).
• 💉 Initial management follows a ‘drip and suck’ approach: nil by mouth, IV fluids to correct dehydration, and an NG tube for free drainage.
• 🧪 Blood tests check for electrolyte imbalances, metabolic alkalosis, and elevated lactate indicating ischemia; imaging like CT confirms obstruction site and cause.
• 🔧 Surgical intervention (laparoscopy or laparotomy) is used when conservative management fails or in unstable patients, treating the underlying cause such as adhesiolysis, hernia repair, or tumor resection.

Q & A

What is a bowel obstruction?

A bowel obstruction occurs when the passage of food, fluid, and gas through the intestines is blocked. This blockage leads to a buildup of gas and fecal matter, causing symptoms like vomiting, abdominal distension, and pain.

What are the most common causes of bowel obstruction?

The three most common causes of bowel obstruction are adhesions, hernias, and tumors. These account for around 90% of cases, with adhesions and hernias affecting the small bowel more frequently, and tumors typically affecting the large bowel.

How does bowel obstruction lead to hypovolemia?

In bowel obstruction, fluid that should normally be absorbed by the colon accumulates in the gastrointestinal tract due to the blockage. This results in fluid loss from the intravascular space, causing hypovolemia and potentially shock.

What is the significance of third spacing in bowel obstruction?

Third spacing refers to the abnormal loss of fluid into the gastrointestinal tract due to obstruction. This fluid loss contributes to hypovolemia and can lead to shock if not managed appropriately.

What is a closed loop obstruction, and why is it dangerous?

A closed loop obstruction occurs when two points of the bowel are obstructed, trapping a section of the bowel between them. This section becomes isolated and cannot drain, leading to increasing pressure, ischemia, and the potential for perforation, which requires emergency surgery.

What are the key symptoms of bowel obstruction?

The key symptoms of bowel obstruction include vomiting (often green and bilious), abdominal distension, diffuse abdominal pain, absolute constipation, and the absence of flatulence. Early bowel obstruction may also present with tinkling bowel sounds.

How is bowel obstruction diagnosed using abdominal x-ray?

An abdominal x-ray in cases of bowel obstruction typically shows distended loops of bowel. Small bowel loops have a diameter of up to 3 cm, while the large bowel can measure up to 6 cm. The presence of valvulae conniventes (in the small bowel) and haustra (in the large bowel) help differentiate the two.

What is the initial management of bowel obstruction?

The initial management of bowel obstruction follows the ABCDE approach. The patient is made nil by mouth, given intravenous fluids (the 'drip'), and an NG tube is placed for drainage (the 'suck') to relieve pressure and prevent vomiting and aspiration.

When is surgery required for bowel obstruction?

Surgery is required if conservative management fails, especially in cases caused by adhesions, volvulus, or tumors. The surgical approach depends on the underlying cause and may involve laparoscopy or laparotomy, with procedures like adhesiolysis, hernia repair, or tumor resection.

How is bowel ischemia detected in a patient with bowel obstruction?

Bowel ischemia can be indicated by a raised lactate level, which can be measured through a venous blood gas or a laboratory sample. This helps in assessing the severity of the obstruction and the potential for tissue damage.