Anthropometric approximation of body weight in unresponsive stroke patients.
OBJECTIVE
Thrombolysis of acute ischaemic stroke is based strictly on body weight to ensure efficacy and to prevent bleeding complications. Many candidate stroke patients are unable to communicate their body weight, and there is often neither the means nor the time to weigh the patient. Instead, weight is estimated visually by the attending physician, but this is known to be inaccurate.


METHODS
Based on a large general population sample of nearly 7000 subjects, we constructed approximation formulae for estimating body weight from simple anthropometric measurements (body height, and waist and hip circumference). These formulae were validated in a sample of 178 consecutive inpatients admitted to our stroke unit, and their accuracy was compared with the best visual estimation of two experienced physicians.


RESULTS
The simplest formula gave the most accurate approximation (mean absolute difference 3.1 (2.6) kg), which was considerably better than the best visual estimation (physician 1: 6.5 (5.2) kg; physician 2: 7.4 (5.7) kg). It reduced the proportion of weight approximations mismatched by >10% from 31.5% and 40.4% (physicians 1 and 2, respectively) to 6.2% (anthropometric approximation). Only the patient's own estimation was more accurate (mean absolute difference 2.7 (2.4) kg).


CONCLUSIONS
By using an approximation formula based on simple anthropometric measurements (body height, and waist and hip circumference), it is possible to obtain a quick and accurate approximation of body weight. In situations where the exact weight of unresponsive patients cannot be ascertained quickly, we recommend using this approximation method rather than visual estimation.
Lorenz
M W
MW
Johann Wolfgang Goethe University, Department for Neurology, Schleusenweg 2-16, D-60528 Frankfurt/Main, Germany. matthias.lorenz@em.uni-frankfurt.de
Graf
M
M
Henke
C
C
Hermans
M
M
Ziemann
U
U
Sitzer
M
M
Foerch
C
C
D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D000886:Anthropometry / Q000379:methods*; D001835:Body Weight; D001921:Brain / Q000098:blood supply; D002545:Brain Ischemia / Q000150:complications* / Q000175:diagnosis* / Q000188:drug therapy; D002340:Carotid Artery Diseases / Q000150:complications / Q000175:diagnosis; D002560:Cerebrovascular Circulation / Q000502:physiology; D003627:Data Interpretation, Statistical; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D014474:Unconsciousness / Q000209:etiology*
D005343:Fibrinolytic Agents