Surgical Emergencies
Question 160 of 180
A 75 year old man is brought to the Emergency Department by his family. He has not opened his bowels for 3 days and has started vomiting. An abdominal x-ray is shown, what is the diagnosis?
Answer:
A colonic volvulus is identified in 75% of x-rays; a characteristic coffee-bean shape is seen. A sigmoid volvulus is demonstrated by a dilated inverted U-shaped loop of colon projected towards the right side of abdomen; opposing colonic walls produce radio-opaque line; proximal large and small bowel dilation may also be evident.Colonic Volvulus
Surgical Emergencies
Last Updated: 8th September 2021
Pathophysiology
Colonic volvulus arises following axial rotation of the colon on its mesenteric attachments: the sigmoid colon is the most frequently affected segment (76%), then the caecum (22%). Rotation can be clockwise or anti-clockwise. Once the volvulus has a 360° twist, then a closed loop obstruction is produced. Fluid and electrolyte shifts result from fluid secretion into the closed loop producing an increase in pressure and tension on the colonic wall that will eventually impair colonic blood supply. This results in ischaemia, necrosis, and perforation.
Risk factors
- Older age
- Institutionalisation
- Mental illness
- Chronic constipation
- Megacolon
- High-fibre diet
- Previous abdominal surgery
- Laxative abuse
- Diabetes
Clinical features
- Colicky abdominal pain
- Inability to pass faeces or flatus
- Nausea and vomiting (late sign)
- Abdominal distension
- Abdominal tenderness
- Tympanic abdomen
- Abnormal bowel sounds
Investigations
- Abdominal x-ray
- Colonic volvulus is identified in 75% of x-rays; characteristic coffee-bean shape seen with the "apex" locating the origin of volvulus (e.g. sigmoid, caecal)
- Sigmoid volvulus: dilated inverted U-shaped loop of colon projected towards the right side of abdomen; opposing colonic walls produce radio-opaque line; proximal large and small bowel dilation may also be evident.
- Caecal volvulus: dilated right colon rotates to the left side and dilated small bowel may also be present.
Management
- Sigmoid volvulus
- Urgent intervention is required due to risk of perforation from either ischaemia of the affected segment or obstruction.
- Flexible or rigid sigmoidoscopy with the insertion of a rectal tube may relieve obstruction and should be performed immediately after diagnosis, ensuring the affected segment is viable. The rectal tube is fixed and left in situ for 24 hours, and a repeat abdominal x-ray is requested to ensure decompression has been successful.
- Where peritonitis or mucosal gangrene has been identified, emergency midline laparotomy is required.
- Caecal volvulus
- Laparotomy is the primary treatment. However, given the difficulty in diagnosis, the finding is often made at laparotomy.
- Colonoscopic and percutaneous decompression has been attempted, but is reserved for patients who are not candidates for surgery. Nonetheless, attempted decompression may only delay surgical intervention.
Complications
- Intestinal perforation
- Intestinal ischaemia +/- necrosis
- Peritonitis
- Sepsis
- Intra-abdominal abscess
- Fluid and electrolyte imbalance
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- Biochemistry
- Blood Gases
- Haematology
| Biochemistry | Normal Value |
|---|---|
| Sodium | 135 – 145 mmol/l |
| Potassium | 3.0 – 4.5 mmol/l |
| Urea | 2.5 – 7.5 mmol/l |
| Glucose | 3.5 – 5.0 mmol/l |
| Creatinine | 35 – 135 μmol/l |
| Alanine Aminotransferase (ALT) | 5 – 35 U/l |
| Gamma-glutamyl Transferase (GGT) | < 65 U/l |
| Alkaline Phosphatase (ALP) | 30 – 135 U/l |
| Aspartate Aminotransferase (AST) | < 40 U/l |
| Total Protein | 60 – 80 g/l |
| Albumin | 35 – 50 g/l |
| Globulin | 2.4 – 3.5 g/dl |
| Amylase | < 70 U/l |
| Total Bilirubin | 3 – 17 μmol/l |
| Calcium | 2.1 – 2.5 mmol/l |
| Chloride | 95 – 105 mmol/l |
| Phosphate | 0.8 – 1.4 mmol/l |
| Haematology | Normal Value |
|---|---|
| Haemoglobin | 11.5 – 16.6 g/dl |
| White Blood Cells | 4.0 – 11.0 x 109/l |
| Platelets | 150 – 450 x 109/l |
| MCV | 80 – 96 fl |
| MCHC | 32 – 36 g/dl |
| Neutrophils | 2.0 – 7.5 x 109/l |
| Lymphocytes | 1.5 – 4.0 x 109/l |
| Monocytes | 0.3 – 1.0 x 109/l |
| Eosinophils | 0.1 – 0.5 x 109/l |
| Basophils | < 0.2 x 109/l |
| Reticulocytes | < 2% |
| Haematocrit | 0.35 – 0.49 |
| Red Cell Distribution Width | 11 – 15% |
| Blood Gases | Normal Value |
|---|---|
| pH | 7.35 – 7.45 |
| pO2 | 11 – 14 kPa |
| pCO2 | 4.5 – 6.0 kPa |
| Base Excess | -2 – +2 mmol/l |
| Bicarbonate | 24 – 30 mmol/l |
| Lactate | < 2 mmol/l |
