[Validation of a scale for the assessment of paravertebral muscle contraction during lumbar puncture].
OBJECTIVE
This study aimed at validating a scale to quantify the intensity of paravertebral muscle contraction during lumbar punctures, to be used in further studies on the effects of local anesthetic infiltration.


METHODS
This study involved 31 physicians, from two different Anesthesiology training centers located in two Brazilian cities, 12 of which were from institution 1 and 19 from institution 2. Eight participants were first-year residents, 6 were second-year residents and 17 were instructors. Participants were invited to watch 23 movies, repeated in 3 randomized electronically generated samples. Movies presented skin stimulation with 25, 27 and 29 G Quincke needles during lumbar puncture and puncture simulations (syringe tip touch). Patients authorized shooting and showing the movies. Physicians evaluated paravertebral muscles contraction according to the following scale: 0 - no sign of muscle contraction; 1 - mild muscular contraction without lumbar spine movement; 2 - muscles contraction with moderate lumbar spine movement; 3 - muscle contraction with movement precluding needle progression. Modes of the three samples were considered for each movie score calculation. Reliability analysis consisted of calculation of Cronbach's alpha, and intercoder reliability was evaluated by Krippendorff's alpha coefficient.


RESULTS
Cronbach's alpha was 0.98. Median (25th - 75th percentiles) of Krippendorff's alpha coefficients was 0.81 (0.78 - 0.84).


CONCLUSIONS
High internal and intercoder reliability found in this study suggests that the scale may be used in future studies to quantify paravertebral muscle contraction during lumbar puncture.
Alencar
Tiago Gayer de
TG
CET, SBA, Hospital de Clínicas, UFPR, Curitiba, PR, Brazil. alencartiago@yahoo.com.br
Almeida
Gustavo Paiva
GP
Boos
Gustavo Luchi
GL
Tambara
Elizabeth Milla
EM
Oliveira Filho
Getúlio Rodrigues de
GR