Plasma creatine kinase indicates major amputation or limb preservation in acute lower limb ischemia.
OBJECTIVE
Acutely ischemic limbs are often of uncertain viability. To assist operative management, this study determined prospectively which indicators on admission were the best predictors of major amputation and, conversely, limb preservation.


METHODS
Data were collected on admission. Presenting complaint, history, clinical assessment, and blood test results, including creatine kinase (CK), were recorded. Surgical procedures were noted-in particular, the presence or absence of major amputation by death or discharge. The setting was a tertiary vascular referral center in a university teaching hospital. Subjects included all patients referred as emergency cases to the vascular unit over an 18-month period who were admitted for inpatient management with acute lower limb ischemia. The main outcome measure was major amputation.


RESULTS
A total of 97 patients with acute ischemia were studied prospectively (51 men and 46 women). Twenty-one patients (21.6%) underwent major amputation. Previous vascular surgery (P = .012), mottling (P = .001), sensory loss (P = .003), motor loss (P = .001), muscle tenderness (P < .001), absent ankle Doppler signals (P = .008), neutrophilia (P = .011), and increased CK (P < .001) were significantly associated with major amputation. If CK was normal, the risk of major amputation was 4.6% (95% confidence interval, 0.0%-9.7%). If CK was increased, the risk was 56.2% (95% CI, 39.1%-73.4%).


CONCLUSIONS
Specific clinical findings were significantly associated with major amputation. Of these, only CK had a positive predictive value greater than 50%. Plasma CK can assist operative management of acute lower limb ischemia by quantifying prospectively the risk of major amputation or limb preservation on admission.
Currie
Ian S
IS
Department of Vascular Surgery, Royal Infirmary of Edinburgh, Little France Crescent, Edinburgh, United Kingdom. Ian.Currie@dial.pipex.com <Ian.Currie@dial.pipex.com>
Wakelin
Sonia J
SJ
Lee
Amanda J
AJ
Chalmers
Roderick T
RT
D000208:Acute Disease; D000368:Aged; D000671:Amputation, Surgical / Q000706:statistics & numerical data*; D003402:Creatine Kinase / Q000097:blood*; D005260:Female; D006801:Humans; D007511:Ischemia / Q000097:blood* / Q000453:epidemiology / Q000601:surgery*; D023821:Limb Salvage / Q000706:statistics & numerical data*; D035002:Lower Extremity / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D010343:Patient Admission / Q000706:statistics & numerical data; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D012372:ROC Curve; D018570:Risk Assessment; D012606:Scotland / Q000453:epidemiology; D012680:Sensitivity and Specificity
D003402:Creatine Kinase