title: Relationship of abdominal circumference and trunk length with spinal anesthesia level in the term parturient.
abstract: BACKGROUND
  We hypothesized that body shape metrics influence the anatomy of spinal canal and intraabdominal pressure in three dimensions. We explored the effects of abdominal circumference, trunk length, and their combination on the level of spinal anesthesia in the term parturient in this study.
  
  
  METHODS
  Thirty term parturients, ASA class I-II, from 20 to 41 years of age, scheduled for cesarean section were enrolled in this observational study. Abdominal circumference (AC) and trunk length (TL) were recorded preoperatively. Spinal anesthesia was performed with 10 mg 0.5% hyperbaric bupivacaine at the L4-L5 intervertebral space in all parturients. Correlation between maximal sensory spinal anesthesia level and physical parameters was analyzed with Spearman rank correlation coefficients. The calculated r value was compared with r = 0 with p < 0.05 as the significant level. The prediction power of these physical parameters for spinal level was evaluated by prediction probability.
  
  
  RESULTS
  The parameter TL/AC2 was statistically correlated with maximal sensory level (Spearman correlation coefficient, -0.45 with p < 0.02). The prediction probability of TL/AC2 for the dermatomal level was P K = 0.685. If the dermatomal levels were lumped as higher (above T2) and lower (below T3) levels, the prediction probability of TL/AC2 was as high as P K = 0.856.
  
  
  CONCLUSIONS
  TL/AC2, which simulated the ratio of the long axis and transection area of the abdomen, was correlated with maximal spinal level, and parturients with low TL/AC2 values tended to have higher dermatomal levels during spinal anesthesia.
authors.affiliation: Department of Anesthesiology, Lin-Shin Hospital, No 36, Sec. 3, Hueijhong Rd., Taichung 408, Taiwan.
authors.forename: Yi-Hui
authors.initials: YH
authors.lastname: Lee
authors.forename: Yi-Chia
authors.initials: YC
authors.lastname: Wang
authors.forename: Man-Ling
authors.initials: ML
authors.lastname: Wang
authors.forename: Pei-Lin
authors.initials: PL
authors.lastname: Lin
authors.forename: Chi-Hsiang
authors.initials: CH
authors.lastname: Huang
authors.forename: Hui-Hsun
authors.initials: HH
authors.lastname: Huang
mesh_terms: D000328:Adult; D000773:Anesthesia, Obstetrical / Q000379:methods*; D000775:Anesthesia, Spinal / Q000379:methods*; D000779:Anesthetics, Local / Q000627:therapeutic use*; D002045:Bupivacaine / Q000627:therapeutic use*; D002585:Cesarean Section / Q000379:methods; D005260:Female; D006801:Humans; D011247:Pregnancy; D018709:Statistics, Nonparametric; D055815:Young Adult
chemical_list: D000779:Anesthetics, Local; D002045:Bupivacaine