Tuesday, November 13, 2007

Gastrointesntinal Emergencies - A guide for medical students

This notes is not meant to be exhaustive. Look at some of the links below that I have posted. There are excellent articles out there for you to download FOC!

Key Points

History:

A. Relation between abdominal Pain and Vomiting

Generally,

Pain → vomiting = surgical process

Example:

Epigastric pain that is relieved by vomiting suggests intragastric pathology or gastric outlet obstruction

Vomiting → pain = nonsurgical condition

However, this is just a guide, not a rule

B. Pain out of proportion

If patient complained of severe abdominal pain but you find relatively void of physicial findings (“pain out of proportion”) – especially in the elderly, with risk factors like atherosclerotic disease, atrial fibrillation, coronary heart disease, must think of mesenteric ischemia.

C. Duration of pain

Does The Duration Of Abdominal Pain Help In Categorizing Cause?

- Severe abdominal pain that persists for 6 or more hours is likely to be caused by surgically processes.

- Patients with pain of more than 48 hours' duration have a significantly lower incidence of surgical disease than do patients with pain of shorter duration.

D. Pitfalls In Evaluating Elderly Patients With Acute Abdominal Pain

Advanced age - blunt manifestations of acute abdomen

- Pain - less severe

- Fever - less pronounced

- Signs of peritoneal inflammation - diminished or absent

- Elevation of the white blood cell (WBC) count - less sensitive.

Examination

A. Tests For Peritoneal Irritation

Rebound tenderness

Cough test

Heel-drop jarring (Markle) test

- Highly sensitive test for peritoneal irritation

- Patient asked to stand, rise up on tiptoe with knees straight, and forcibly drop down on both heels with an audible thump.

- Among patients with appendicitis, 74% sensitive, compared with 64% for the standard rebound test

o Markle GB: Heel-drop jarring test for appendicitis [letter]. Arch Surg 120:243, 1985.

Obstipation

What is the significance?

Obstipation - the inability to pass either stool or flatus for more than 8 hours despite a perceived need is highly suggestive of intestinal obstruction

Can we give opioids in acute abdomen witb uncertain cause?

- For fear of masking vital symptoms or physical findings, old, conventional surgical wisdom proscribes the use of narcotic analgesics until a firm diagnosis is established.

- Increasingly, however, studies have demonstrated that pain medication may be given to selected patients with stable vital signs because the analgesic effect may be reversed readily at any time by the administration of naloxone.

§ Pace and Burke, in a prospective, double-blind study of 71 patients with acute abdominal pain, found that pain control with morphine had no deleterious effect on preoperative diagnostic accuracy.

- Although inconclusive, a growing body of data suggests that evaluation of acute abdominal disease may be facilitated when severe pain has been controlled and the patient can cooperate more fully.

§ McHale PM, LoVecchio F: Narcotic analgesia in the acute abdomen-A review of prospective trials. Eur J Emerg Med 8:131-136, 2001.

§ Pace S, Burke TF: Intravenous morphine for early pain relief in patients with acute abdominal pain. Acad Emerg Med 3:1086-1092, 1996.

Plain X-ray Films Useful?

Plain films of the abdomen have the highest yield when used in the evaluation of patients with suspected bowel obstruction, intussusception, ileus, and free air secondary to a perforated viscus.

They have much less utility in detecting intraabdominal mass, renal calculi, diverticulitis, gallbladder disease, and abdominal aortic aneurysms

The supine view of the abdomen is the most informative and worthwhile abdominal film. The upright film is superior for visualizing air-fluid levels associated with ileus, obstruction, or biliary air.

The erect chest radiograph is most sensitive for detection of free intraperitoneal air and may show basal pneumonia, ruptured esophagus, elevated hemidiaphragm, air-fluid levels associated with subdiaphragmatic or hepatic abscess, pleural effusion, and pneumothorax.

Air Fluid Pockets

Are air-fluid pocketss within the intestine always abnormal? No

1. The number of pockets:

A study of 300 normal patients by Gammill and Nice shows that although the average number of air-fluid levels was four per patient, some have up to 20 air fluid pockets.

(To remember: if >3, consider might be abnormal (although as said above, it can be up to 20!)

2. The size of pockets

Although typically less than 2.5 cm in length, some were 10 cm.

Easy to remember:

Consider abnormal if (remember 3,6,9):

In Small bowels >3 cm

In Large bowerls >6 cm

In caecum >9cm

Remember the number 3 for small bowels:

>3 cm dilatation

> 3 air pockets

> 3 mm wall thickness

Links:

To know more about Markle test and cough sign: click: http://www.postgradmed.com/pearls.htm

To download a free article on acute intestinal obstruction and acute abdomen (excellent article!!), click:
http://www.fleshandbones.com/readingroom/pdf/233.pdf

To know more about the dilemma in diagnosing causes of acute abdomen in emergency department, click here:
http://www.emedmag.com/html/pre/cov/covers/011502.asp

Two excellent articles in Student BMJ:
1. on acute abdomen, click here:
http://student.bmj.com/issues/00/03/education/56.ph

2. on abdominal radiograph, click here to download a series of articles in pdf:

To download a FREE powerpoint presentation on acute abdomen, click here:
http://www.edu.rcsed.ac.uk/pps/pps83.pps

1 comment:

jason said...

Thanks! KS. Just found your informative blog site.
Guess i will visit from time to time, high time for me catch up a bit.. urg.. ok, a lot. So, i will get CME point by reading right! Ha ha, just joking!

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