Scoring Systems

Question 1

MELD score

Answer 1

MELD =

3.8*log_e(serum bilirubin [mg/dL])

+ 11.2*log_e(INR)

+ 9.6*log_e(serum creatinine [mg/dL]) + 6.4

[UpToDate: The MELD equation that has been used by for prioritizing allocation of deceased donor livers for transplantation. With this model, scores can range from negative values to infinity. However, to avoid confusion, UNOS modified the MELD scoring system to eliminate negative values by setting to 1.0 any measured laboratory values that were less than 1.0. Thus, patients with the combination of an INR of ≤1, serum creatinine ≤1 mg/dL, and serum bilirubin ≤1 mg/dL will receive the minimum score of 6 MELD points. In addition, UNOS set an upper limit for the MELD score at 40 points.

In an effort to avoid an unfair advantage for patients with intrinsic renal disease, the maximum serum creatinine level was set to 4.0 mg/dL, which is also the value that is automatically assigned to patients who have received hemodialysis at least twice, or continuous venovenous hemodialysis for 24 hours, in the preceding week. There is currently no modification in the score for patients receiving anticoagulation.]

Question 2

Childs Pugh score

Answer 2

Question 3

Caprini score

Answer 3

The most widely tested surgical risk assessment model (the Modified Caprini Risk Assessment Model, Caprini score) has been slightly modified for use in the 2012 ACCP Guidelines.

Very low risk patients — Very low risk patients have been defined as those undergoing general and abdominal-pelvic surgery with a Caprini score of zero, and those undergoing plastic and reconstructive surgery with a Caprini score of zero to two. Their estimated baseline risk of VTE in the absence of prophylaxis is estimated to be less than 0.5%.

A prospective observational cohort study using the American College of Surgeons National Surgical Quality Improvement Program was used to identify independent predictors of 30-day VTE events requiring treatment following outpatient or same-day surgery. The 30-day incidence of VTE for the 173,501 subjects in the derivation cohort was 0.15%, and was 0.06% and 1.18% among those in the lowest and highest risk categories, respectively. Results of this study must be interpreted in context; it was unable to provide details on the use of VTE prophylaxis or common VTE risk factors, such as personal or family history of VTE. Nine independent risk factors were identified, including age 40 to 59 years, age ≥60 years, current pregnancy, active cancer, increased body mass index, operative time ≥120 minutes, arthroscopic surgery, saphenofemoral junction surgery, and venous surgery not involving the great saphenous vein. Even the highest risk patients using this outpatient model fit in the “low risk” surgical group, despite the fact that some of the identified risk factors may place a given patient in the highest Caprini risk group.

Low risk patients — Low risk surgical patients have been defined as those undergoing general and abdominal-pelvic surgery with a Caprini score of 1 to 2, or those undergoing plastic and reconstructive surgery with a Caprini score of 3 to 4. Their estimated baseline risk of VTE in the absence of prophylaxis is estimated to be approximately 1.5%.

In most cases, low risk surgical patients are those undergoing minor elective abdominal or thoracic surgery. However, in some settings the risk of VTE remains uncertain, and there have not been good randomized clinical trials demonstrating effectiveness of any particular form of VTE prophylaxis. These include vascular surgery, laparoscopic surgery, knee arthroscopy in the absence of more complicated surgery, elective spine surgery (eg, spinal fusion), shoulder and elbow surgery, isolated lower extremity fractures, Achilles tendon rupture repair, and podiatric surgery.

Moderate risk patients — Moderate risk surgical patients have been defined as those undergoing general and abdominal-pelvic surgery with a Caprini score of 3 to 4, or those undergoing plastic and reconstructive surgery with a Caprini score of 5 to 6. Their estimated baseline risk of VTE in the absence of prophylaxis is estimated to be approximately 3%.

Patients undergoing general gynecologic, urologic, thoracic, ankle fracture, or neurosurgical procedures usually fall into the moderate risk category.

High risk patients — High risk surgical patients have been defined as those undergoing general and abdominal-pelvic surgery with a Caprini score of 5 or more, or those undergoing plastic and reconstructive surgery with a Caprini score of 7 to 8. Their estimated baseline risk of VTE in the absence of prophylaxis is estimated to be approximately 6%. Examples of patients in the high risk group are those undergoing hip or knee arthroplasty, pelvic or hip fracture surgery, colorectal surgery, major trauma, spinal cord injury, or cancer surgery

Question 4

CHADS2 score

Answer 4

Question 5

Modified Alvarado score

Answer 5

• Migratory right lower quadrant pain (1 point)
• Anorexia (1 point)
• Nausea or vomiting (1 point)
• Tenderness in the right lower quadrant (2 points)
• Rebound tenderness in the right lower quadrant (1 point)
• Fever >37.5°C (>99.5°F) (1 point)
• Leukocytosis of WBC count >10 x 109/L (2 points)

The Alvarado score can be used to identify patients with a very low likelihood of acute appendicitis so as to triage them to evaluation for other causes of abdominal pain. Patients with a high Alvarado score should be further evaluated with imaging prior to treatment.

While several scoring systems have been proposed to standardize the clinical and laboratory assessment for acute appendicitis, the modified Alvarado score is the most widely used

The score is obtained by summing the components. Higher values indicate higher probability of appendicitis. The maximum total score is 9. The original Alvarado score included left shift as an additional factor, resulting in a total score of 10.

Scores of <4 and <5 have both been assessed as a cutoff for low risk of acute appendicitis in the literature and have resulted in an overall similarly low likelihood of acute appendicitis with either cutoff score. For the purposes of triage, the score of <4 is selected for its potential to rule out appendicitis with greater certainty, given reported variability in the prevalence of acute appendicitis in patients with a score of 4. Initial triage in the diagnostic workup of appendicitis using Alvarado score is as follows:

• Patients with a score of 0 to 3 are unlikely to have appendicitis and should be evaluated for other possible diagnoses.
• Patients with a score of ≥4 should be evaluated further for appendicitis. Surgical evaluation and imaging, if readily available, should be pursued.

A low Alvarado score (<4) has more diagnostic utility to “rule out” appendicitis than a high score (≥7) does to “rule in” the diagnosis. The accuracy of the score in women of reproductive age is equivalent to that in all adults. In a systematic review of 42 retrospective and prospective studies that included over 8300 patients with suspected acute appendicitis and/or right lower quadrant pain, overall 99% of patients with acute appendicitis had a score of >4. In contrast, a high score (≥7) alone had poor diagnostic utility, as the overall specificity was 81%

Question 6

Pediatric appendicitis score

Answer 6

Question 7

ABCD2 score

Answer 7

Question 8

Khorana score

Answer 8

Question 9

Hinchey classification system

Answer 9

Classification of acute diverticulitis

• Stage I – Pericolic or mesenteric abscess
• Stage II – Walled-off pelvic abscess
• Stage III – Generalized purulent peritonitis
• Stage IV – Generalized fecal peritonitis

Diffuse contamination (Hinchey III or IV) — Hinchey III or IV diverticulitis is characterized by generalized purulent or fecal peritonitis, for which a primary anastomosis is contraindicated. The preferred surgical treatment is a Hartmann’s procedure with end colostomy.

Localized contamination (Hinchey I or II) — Hinchey I or II diverticulitis is characterized by one or more localized abscesses in the pericolonic, mesenteric, or pelvic locations. Patients with Hinchey I or II diverticulitis can usually tolerate a preoperative bowel preparation. Thus, if the abscess can be resected with the colonic segment, a primary anastomosis can be performed in these patients.

If there are concerns about either contamination or inflammation involving the surrounding tissue (eg, with a large pelvic abscess), a primary anastomosis can be performed while protected by a diverting ostomy (eg, loop ileostomy or colostomy). Compared with an end colostomy, a protective loop ostomy is easier to reverse at a later time.

Minimal contamination (elective surgery) — Elective surgery is typically performed six or more weeks after an episode of acute diverticulitis when all infection and inflammation have resolved. Thus, a primary anastomosis without protective ostomy (ie, a one-stage procedure) is standard.

Question 10

The Los Angeles classification

Answer 10

The Los Angeles classification is the most thoroughly evaluated classification for esophagitis and is the most widely used. The Los Angeles classification grades esophagitis severity by the extent of mucosal abnormality, with complications recorded separately. In this grading scheme, a mucosal break refers to an area of slough adjacent to more normal mucosa in the squamous epithelium with or without overlying exudate.

• Grade A – one or more mucosal breaks each ≤5 mm in length
• Grade B – at least one mucosal break >5 mm long, but not continuous between the tops of adjacent mucosal folds
• Grade C – at least one mucosal break that is continuous between the tops of adjacent mucosal folds, but which is not circumferential
• Grade D – mucosal break that involves at least three-fourths of the luminal circumference

Question 11

Trans-Atlantic Inter-Society Consensus (TASC) classification

Answer 11

Arterial lesions can be classified by Trans-Atlantic Inter-Society Consensus (TASC II) as Type A, B, C, or D according to anatomic distribution, number and nature of lesions (stenosis, occlusion), and according to the overall success rates of treating the lesion using endovascular or surgical means. Most patients with peripheral artery disease have more than one lesion, at more than one level, so the classification scheme is limited in focusing on singular patterns. The original TASC I classification included classifications for aortoiliac, femoropopliteal, and tibial vessel runoff. Tibial disease was omitted from TASC II. A new tibial classification system has been proposed by selected, former TASC steering committee members; this proposed system considers tibial stenosis length, lesion number, presence of occlusion, density of calcification, and nonvisualization of collaterals [2,3]. However, this tibial classification system is not widely used and has not yet been validated.

Type A lesions — Type A lesions are relatively short and focal, and generally have excellent results with endovascular therapy.

• Aortoiliac – Unilateral or bilateral stenosis of the common iliac artery; unilateral or bilateral single short (≤3 cm) stenosis of the external iliac artery
• Femoropopliteal – Single stenosis ≤10 cm in length; Single occlusion ≤5 cm in length

Type B lesions — Type B lesions have good results using endovascular methods, which are preferred, unless open revascularization is required for another lesion in the same anatomic area.

• Aortoiliac – Short (≤3 cm) stenosis of the infrarenal aorta; unilateral common iliac artery occlusion; single or multiple stenoses totaling 3 to 10 cm of the external iliac artery not extending into the common femoral artery; unilateral external iliac artery occlusion not involving the origins of the internal iliac artery or common femoral artery
• Femoropopliteal – Multiple lesions (stenoses or occlusions), each ≤5 cm; stenosis or occlusion ≤15 cm not involving the infra-geniculate popliteal artery; Single or multiple lesions in the absence of continuous tibial vessels to improve inflow for a distal bypass; heavily calcified occlusion ≤5 cm in length; single popliteal stenosis

Type C lesions — Type C lesions have better long-term results with open revascularization such that endovascular techniques should be used if the patient is at high risk for open surgical repair.

• Aortoiliac – Bilateral common iliac artery occlusions; bilateral external iliac artery stenosis 3 to 10 cm not extending into the common femoral artery; unilateral external iliac artery stenosis extending into the common femoral artery; unilateral external iliac artery occlusion of the origins of the internal iliac and/or common femoral artery; heavily calcified unilateral external iliac artery occlusion with or without involvement of the origins of the internal iliac and/or common femoral artery
• Femoropopliteal – Multiple stenoses or occlusion totaling >15 cm with or without heavy calcification; recurrent stenoses or occlusion that need treatment after two endovascular interventions

Type D lesions — Type D lesions have poor results with endovascular treatment, and thus, surgery is the primary treatment for low-to-moderate risk patients.

• Aortoiliac – Infrarenal aortoiliac occlusion; diffuse disease of the aorta and both iliac arteries requiring treatment; diffuse multiple stenoses of the unilateral common and iliac artery, and common femoral artery; unilateral occlusions of the common iliac and external iliac arteries; bilateral occlusions of external iliac arteries; iliac stenoses in patients with abdominal aortic aneurysm (that require treatment and are not amenable to endograft placement) or other lesions requiring open aortic or iliac surgery
• Femoropopliteal – Chronic total occlusion of the common femoral artery or superficial femoral artery (>20 cm, involving the popliteal artery); chronic total occlusion of the popliteal artery and proximal trifurcation vessels.