LBO Flashcards
(133 cards)
1
Q
A
2
Q
Q: What are the two types of intestinal obstruction?
A
A: Dynamic (mechanical) and adynamic (pseudo-obstruction).
3
Q
Q: What is the most common cause of large intestinal obstruction in the United States?
A
A: Colorectal cancer.
4
Q
Q: What is a more common cause of large intestinal obstruction in Russia, Eastern Europe, and Africa?
A
A: Colonic volvulus.
5
Q
Q: What are some extrinsic causes of colonic obstruction?
A
A: Adhesions, hernia, endometriosis, neoplasms.
6
Q
Q: What are some intramural causes of colonic obstruction?
A
A: Colonic neoplasms, colonic volvulus, diverticulitis, strictures, Crohn’s colitis.
7
Q
Q: What are some intraluminal causes of colonic obstruction?
A
A: Intussusception, colonic polyp, fecal impaction, inspissated barium, foreign bodies, Ogilvie’s syndrome.
8
Q
Q: What is the hallmark of large intestinal obstruction?
A
A: The sequential occurrence of colicky/crampy abdominal pain, constipation, significant abdominal distention, and vomiting.
9
Q
Q: What is the onset of large intestinal obstruction?
A
A: Sudden and progressive.
10
Q
Q: How is the pain described in large intestinal obstruction?
A
A: Worsening, coming every 10-15 minutes, crampy, and colicky.
11
Q
Q: What happens to the pain if gangrene occurs?
A
A: It becomes continuous.
12
Q
Q: What is the status of feces and flatus in large intestinal obstruction?
A
A: None.
13
Q
Q: What is the level of dehydration in large intestinal obstruction?
A
A: Severe.
14
Q
Q: How does abdominal distension present in large intestinal obstruction?
A
A: Initially peripherally located, becomes global later.
15
Q
Q: How common are nausea, anorexia, and vomiting in large intestinal obstruction?
A
A: Not common, very late.
16
Q
Q: What is the prognosis for septic shock in the context of large intestinal obstruction?
A
A: Frequently fatal.
17
Q
Q: What type of onset of symptoms makes volvulus a more likely diagnosis?
A
A: Abrupt onset of symptoms.
18
Q
Q: What history may imply diverticula or carcinoma in large intestinal obstruction?
A
A: History of chronic constipation, change in caliber of stools, long-term cathartic use, and straining at stool.
19
Q
Q: What are the vital signs like in large intestinal obstruction?
A
A: They remain stable until late.
20
Q
Q: What signs indicate dehydration in the context of gangrenous intestines?
A
A: Dehydration shows gangrenous intestines, but does not fulfill both some and severe criteria.
21
Q
Q: What abdominal examination findings are typical in large intestinal obstruction?
A
A: Distension, tenderness or guarding, and a mass may represent a palpable tumor.
22
Q
Q: What abdominal sound may be heard in a hyper-tympanitic abdomen?
A
A: Visible or palpable colonic loops.
23
Q
Q: What are signs of mild dehydration?
A
A: Irritability, eagerness to drink, tenting skin pinch, and sunken eyes.
24
Q
Q: What are signs of severe dehydration?
A
A: Lethargy, not eager to drink, tenting skin pinch, and sunken eyes; may include weak pulse and cold extremities.
25
Q: What bowel sound patterns are present in large intestinal obstruction?
A: Hypoactive bowel sounds below the obstruction and hyperactive above the obstruction.
26
Q: What is typically found upon rectal examination in large intestinal obstruction?
A: Usually empty and ballooned; blood may suggest carcinoma.
27
Q: What may be palpable in rectal cancer during examination?
A: A mass may be palpable.
28
Q: What does a mass in the Pouch of Douglas suggest?
A: It may suggest carcinomatosis peritonei.
29
Q: What is the primary fluid management for large intestinal obstruction?
A: Large amounts of crystalloids.
30
Q: What should be avoided when managing patients with cardiovascular risk?
A: Overloading with fluids.
31
Q: What may be required in severe cases of large intestinal obstruction?
A: Blood transfusion.
32
Q: Which electrolyte abnormalities need correction in large intestinal obstruction?
A: Especially sodium (Na+) and potassium (K+).
33
Q: Why catheterize a patient with large intestinal obstruction?
A: To monitor urine output.
34
Q: When is a central venous line indicated?
A: In the elderly and seriously ill patients.
35
Q: What is the purpose of nasogastric suction?
A: Relieves distension, improves breathing, facilitates operation, sucks out toxic intestinal contents, and reduces the risk of aspiration.
36
Q: What type of antibiotics are given preoperatively?
A: Peri-operative antibiotics against Gram-negative bacteria, anaerobes, and Gram-positive bacteria.
37
Q: What additional support may be provided during management?
A: Nasal oxygen.
38
Q: What is volvulus?
A: An abnormal twisting of an air-filled segment of bowel on its mesentery, along its longitudinal axis.
39
Q: What percentage of all large bowel obstructions does volvulus account for in the USA?
A: 1-5%.
40
Q: What percentage of large intestinal obstructions does volvulus account for in the developing world?
A: 50%.
41
Q: What percentage of large intestinal obstructions does volvulus account for in countries of the volvulus belt?
A: 80-100%.
42
Q: What is the most common site for volvulus in the colon?
A: Sigmoid colon (~80%).
43
Q: What percentage of volvulus cases occur in the cecum?
A: ~15%.
44
Q: What percentage of volvulus cases are found in the transverse colon?
A: ~3%.
45
Q: What percentage of volvulus cases are located at the splenic flexure?
A: ~2%.
46
Q: In which direction does volvulus classically occur?
A: Anti-clockwise direction.
47
Q: Where is the site of torsion in relation to the anal verge?
A: Approximately 15 cm above the anal verge.
48
Q: What are the consequences of the twist in volvulus?
A: Closed loop obstruction and gangrene.
49
Q: What percentage of volvulus cases have a torsion degree of 180°?
A: 35%.
50
Q: What percentage of volvulus cases have a torsion degree of 540°?
A: 10%.
51
Q: What percentage of volvulus cases have a torsion degree of 360°?
A: 50%.
52
Q: What is a volvulus?
A: A twisting or axial rotation of a portion of bowel about its mesentery.
53
Q: What happens when torsion exceeds 180°?
A: It causes obstruction to the lumen.
54
Q: What occurs if torsion exceeds 360°?
A: It causes vascular occlusion in the mesentery.
55
Q: How many turns of rotation are required to cause vascular obstruction and gangrene?
A: One and a half turns of rotation.
56
Q: Where can perforation occur due to volvulus?
A: Either at the root or at the summit of the sigmoid loop.
57
Q: What are the two types of volvuli?
A: Primary and secondary.
58
Q: What causes primary volvulus?
A: Congenital malrotation of the gut, abnormal mesenteric attachments, or congenital bands.
59
Q: What are examples of primary volvulus?
A: Volvulus neonatorum, caecal volvulus, and sigmoid volvulus.
60
Q: What is the more common type of volvulus?
A: Secondary volvulus.
61
Q: What causes secondary volvulus?
A: Rotation of a segment of bowel around an acquired adhesion or stoma.
62
Q: What is one prerequisite for sigmoid volvulus?
A: Redundancy of the sigmoid colon.
63
Q: What anatomical feature contributes to sigmoid volvulus?
A: Narrowing of the base of the sigmoid mesocolon.
64
Q: How does the length of the sigmoid mesocolon affect volvulus?
A: A long sigmoid mesocolon is a prerequisite.
65
Q: What type of force is involved in sigmoid volvulus?
A: A torque force to the sigmoid colon.
66
Q: What is a predisposing factor for sigmoid volvulus?
A: Band of adhesions.
67
Q: How does peridiverticulitis contribute to volvulus?
A: It is a predisposing factor.
68
Q: What condition related to the colon can predispose to sigmoid volvulus?
A: Overloaded redundant pelvic colon.
69
Q: How does the length of the pelvic mesocolon affect volvulus risk?
A: A long pelvic mesocolon is a predisposing factor.
70
Q: What anatomical feature of the sigmoid mesocolon can increase volvulus risk?
A: Narrow attachment of the sigmoid mesocolon.
71
Q: What percentage of all large bowel obstructions (LBO) does sigmoid volvulus account for in the developing world?
A: 80%.
72
Q: What is a common demographic for patients with sigmoid volvulus in the developing world?
A: Young male patients.
73
Q: What dietary factor is commonly associated with sigmoid volvulus?
A: High fiber diet.
74
Q: What anatomical feature is often present in patients with sigmoid volvulus?
A: Anatomical redundant sigmoid colon.
75
Q: What percentage of all large bowel obstructions (LBO) does sigmoid volvulus account for in the developed world?
A: 1-5%.
76
Q: What is the common demographic for patients with sigmoid volvulus in the developed world?
A: Old frail female patients.
77
Q: What is a common history associated with these patients?
A: Long history of constipation.
78
Q: What anatomical change leads to sigmoid volvulus in the developed world?
A: Secondary sigmoid elongation.
79
Q: What percentage of volvulus cases are sub-acute type (recurrent)?
A: 85-90%.
80
Q: What percentage of volvulus cases are acute type?
A: 10-15%.
81
Q: How do patients typically progress with sub-acute volvulus?
A: Slow and recurrent.
82
Q: What type of obstruction is associated with acute volvulus?
A: Complete obstruction.
83
Q: What is a common risk associated with sub-acute volvulus?
A: Fluid loss.
84
Q: How does the bowel wall appear in sub-acute volvulus?
A: Thickened and hypertrophied.
85
Q: What is the condition of the bowel wall in acute volvulus?
A: Normal or attenuated with normal vessels.
86
Q: How does the mesocolon appear in sub-acute volvulus?
A: Thick with increased vascularity.
87
Q: How does the mesocolon appear in acute volvulus?
A: Normal.
88
Q: What age group is more commonly affected by sub-acute volvulus?
A: Older patients.
89
Q: What age group is more commonly affected by acute volvulus?
A: Young patients.
90
Q: What is a common complication of acute volvulus?
A: Gangrene.
91
Q: Where does pain typically start in patients with volvulus?
A: Initially left-sided, eventually all over.
92
Q: What is a key symptom related to bowel movements in volvulus?
A: Absolute constipation (obstipation—no feces, no flatus).
93
Q: How does abdominal distension present in volvulus?
A: Enormous distension starting from the left iliac fossa, extending to the whole abdomen (tympanic abdomen).
94
Q: What late symptoms may occur in volvulus patients?
A: Late vomiting and eventually dehydration.
95
Q: What additional features may develop in advanced cases of volvulus?
A: Features of peritonitis.
96
Q: What other symptoms can occur with volvulus?
A: Hiccough and retching.
97
Q: What is a diagnostic feature of the abdomen in volvulus?
A: A tyre-like feel of the abdomen.
98
Q: What occurs in the colon during volvulus?
A: Enormous distension of the colon.
99
Q: What complication can occur when the ileum encircles the sigmoid volvulus?
A: Compound volvulus, causing ileosigmoid knotting.
100
Q: What happens to the knotted small bowel in ileosigmoid knotting?
A: It can become gangrenous.
101
Q: What percentage of cases can be diagnosed with a plain X-ray?
A: 70-80%.
102
Q: What does the Ω sign (omega sign) indicate in X-ray for volvulus?
A: A single, grossly distended loop of colon arising from the pelvis and extending towards the diaphragm.
103
Q: What are the alternate names for the coffee-bean sign?
A: Bent-inner tube sign.
104
Q: How can sigmoid volvulus be differentiated from cecal or transverse colon volvulus on X-ray?
A: Sigmoid volvulus shows a characteristic bent inner tube or coffee bean appearance.
105
Q: Where does the convexity of the loop appear in sigmoid volvulus on X-ray?
A: In the right upper quadrant (opposite the site of obstruction).
106
Q: What is a key symptom indicating gangrenous volvulus?
A: Severe continuous abdominal pain.
107
Q: What physical exam finding may be present in gangrenous volvulus?
A: Rebound tenderness.
108
Q: What cardiovascular change may occur in patients with gangrenous volvulus?
A: Tachycardia.
109
Q: What laboratory finding is associated with gangrenous volvulus?
A: Leukocytosis.
110
Q: What is cecal volvulus?
A: Axial rotation of the terminal ileum, cecum, and ascending colon with twisting of the associated mesentery.
111
Q: How common is cecal volvulus?
A: Relatively rare (<2% of all cases).
112
Q: In which demographic is cecal volvulus more common?
A: More common in women.
113
Q: What are some risk factors for cecal volvulus?
A: Previous surgery, pregnancy, malrotation, obstructing lesions of the left colon.
114
Q: What anatomical issue contributes to cecal volvulus?
A: Nonfixation of the right colon.
115
Q: Around which blood vessels does rotation typically occur in cecal volvulus?
A: Ileocolic blood vessels.
116
Q: What percentage of cecum cases may fold upon itself (cecal bascule)?
A: 10% to 30%.
117
Q: What is the onset of abdominal pain in cecal volvulus?
A: Sudden onset of abdominal pain.
118
Q: How does abdominal distension present in cecal volvulus?
A: Distension with asymmetric distension of the abdomen.
119
Q: What palpable mass may be felt in cecal volvulus?
A: Tympanitic mass in either the left upper quadrant or midabdomen.
120
Q: What does a plain film reveal in cases of cecal volvulus?
A: A dilated cecum that is usually displaced to the left side of the abdomen.
121
Q: What characteristic shape is seen on plain X-rays in cecal volvulus?
A: A kidney-shaped, air-filled structure.
122
Q: Where is the kidney-shaped structure located on X-ray in cases of cecal volvulus?
A: In the left upper quadrant (opposite the site of obstruction).
123
Q: What occurs when loops of ileum wrap around the sigmoid?
A: They form a 'knot' leading to double loop obstruction and gangrene.
124
Q: In which type of patient might this condition occur?
A: In a 2-week-old neonate.
125
Q: How do patients typically present with this condition?
A: With a dramatic combined large and small bowel obstruction.
126
Q: What are the two anatomic factors contributing to this condition?
A: Long ileal mesentery with absence of fat, and a long sigmoid colon with a narrow pedicle.
127
Q: What dietary factor may exacerbate this condition?
A: High bulk diet in an empty small intestine.
128
Q: What other factors can contribute to this condition?
A: Relaxed anterior abdominal wall, occurrence in the early morning, and during pregnancy.
129
Q: What percentage of cases are diagnosed pre-operatively?
A: Less than 20%.
130
Q: What is the useful triad for diagnosis?
A: Clinical features of small bowel obstruction, radiologic features of large bowel obstruction, inability to insert a rectal tube or sigmoidoscope.
131
Q: What is the most common cause of mortality in this condition?
A: Sepsis + multi-organ failure (MOF).
132
Q: What is the mortality rate for gangrenous ileosigmoid knotting (ISK)?
A: 20-100%.
133
Q: What is the mortality rate for non-gangrenous ileosigmoid knotting (ISK)?
A: 6.8-8%.
