The hemogram is an essential lab test for a patient with appendicitis. The white blood cell count should be elevated as a sign of infection; however, you would not expect that the WBC to be greater than 20,000 in typical appendicitis. The platelet count should be elevated as an acute phase reactant. The haemoglobin and haematocrit may be elevated as a sign that the patient may be dehydrated
Complete Blood Count (Hemogram)[edit | edit source]
The hemogram is an essential lab test for a patient with appendicitis. The white blood cell count should be elevated as a sign of infection; however, you would not expect that the WBC to be greater than 20,000 in typical appendicitis. The platelet count should be elevated as an acute phase reactant. The haemoglobin and haematocrit may be elevated as a sign that the patient may be dehydrated.
| Test | Result | Normal |
|---|---|---|
| WBC | 12,000 | 3,300-8,700 uL |
| Haemoglobin | 14.0 | 12.6-16.1 g/dL |
| Haematocrit | 42.1 | 38-47.7% |
| Platelets | 400,000 | 147,000-347,000 uL |
Basic Metabolic Panel (Chemistry)[edit | edit source]
A basic metabolic panel or a chemistry will guide your preoperative therapies on your patient. The patient must be adequately hydrated with normal electrolytes to tolerate anaesthesia. Most general anaesthetics cause vasodilation so the patient must be well-hydrated to prevent cardiac collapse. Likewise, many general anaesthetics force the extracellular potassium intracellular so the patient must have appropriate electrolytes to prevent cardiac collapse.
| Test | Result | Normal |
|---|---|---|
| Sodium | 145 | 136 – 146 mmol/L |
| Potassium | 3.6 | 3.5 – 5.0 mmol/L |
| Chloride | 102 | 98 – 106 mmol/L |
| Bicarbonate | 26 | 24-31 mmol/L |
| Blood Urea Nitrogen (BUN) | 12 | 6 – 20 mg/dL |
| Creatinine | 1.3 | 0.70-1.20 mg/dL |
| Glucose | 102 | 70-99 mg/dL |
Urine Analysis[edit | edit source]
Because of the localization of pain on physical exam, analysing the patient’s urine is important. You should be weary of your diagnosis of appendicitis if you see:
- positive leukocyte esterase or nitrites which would be concerning for an ascending urinary tract infection
- positive blood which would be concerning for kidney stones
In this patient’s UA, it appears his specific gravity is high which correlates to the dehydration seen in the chemistry.
| Test | Result | Normal |
|---|---|---|
| Colour | Amber | Yellow |
| Specific Gravity | 1.05 | 1.005-1.030 |
| pH | 5.5 | 5.0 – 8.0 |
| Blood | Negative | Negative |
| Protein | Negative | Negative |
| Glucose | Negative | Negative |
| Leukocyte esterase | Negative | Negative |
| Nitrite | Negative | Negative |
Imaging[edit | edit source]
If you are concerned the patient may not have typical appendicitis, then consider ordering imaging. In some facilities, ultrasound imaging and reports and radiology is more accessible.
On ultrasound, direct signs of acute appendicitis include:
- Non-compressiblity of the appendix
- Appendix diameter > 6 mm
- Single wall thickness > 3 mm
- Target Sign – hypoechoic fluid-filled lumen with hyperechoic mucosa/submucosa and hypoechoic muscularis layer
- Appendicolith – hyperechoic with posterior shadowing
If the patient’s body habitus is not amenable to ultrasound, consider a computed tomography scan.
On CT, signs of acute appendicitis include:
- Appendix diameter > 6 mm
- Wall thickening > 2 mm
- Visualizing appendicolith, fat stranding, mesenteric lymph nodes or peri-appendiceal fluid
