Evaluation of a new training device to simulate the epidural and subarachnoid spaces for neuraxial anesthesia techniques.

BACKGROUND: We are introducing a new epidural/spinal simulation unit to be used either as a part-task trainer to teach and learn regional anesthesia techniques or to be inserted in the manikin's back to allow reliable advanced simulation scenarios. The aim of this study was to determine if it may be a useful tool for training novice anesthesiologists in these procedures according to the evaluation performed by experienced anesthetists. METHODS: Experienced anesthetists performed an epidural followed by a lumbar puncture procedure on the simulator model. Various aspects of both epidural and lumbar puncture insertions were scored for likeness to a real patient using a Likert scale. RESULTS: Experienced anesthetists found the simulator to be life-like for almost all the aspects of epidural or spinal insertion and that the overall impression was that the simulator could provide a useful tool for training of epidural and spinal techniques. Almost all the examiners appreciated that this device contained layers representing the anatomical boundaries of each compartment, and the module can be added blood or sponge to the epidural compartment or water to the spinal compartment to challenge the trainee with more difficult procedure such as inadvertent dural or vascular puncture or difficult catheter insertion. CONCLUSION: This device to be inserted in a full scale manikin may be a promising tool for training of neuraxial procedures. It could be also an essential component of more complex high fidelity scenarios when neuraxial anesthesia is one of the major learning goals.

Effect of µ-opioid receptor A118G polymorphism on the ED50 of epidural sufentanil for labor analgesia.

BACKGROUND: A common polymorphism of the µ-opioid receptor gene (OPRM1, p.118A/G), which has been shown to effect the response to neuraxial opioids, occurs in 30% of Caucasian women. This double-blind up-down sequential allocation study was designed to examine the effect of p.118A/G on the ED50 of epidural sufentanil for labor analgesia. METHODS: Nulliparous women were recruited at 35 weeks of gestation (n=77) and genotyped for p.118A/G. Those subsequently requesting epidural labor analgesia were enrolled. Each woman received epidural sufentanil diluted with 0.9% saline to a volume of 5 mL. The initial sufentanil dose was 21 µg, with subsequent doses determined by the response of the previous patient (testing interval 1 µg). Efficacy was accepted if the visual analogue score decreased to <10mm on a 100-mm scale within 30 min of drug administration. RESULTS: Twenty patients were excluded, leaving 57 women from whom data were analyzed: 33 in Group A (wild-type A118 homozygotes) and 24 in Group G (heterozygotes and homozygotes G118). The ED50 for epidural sufentanil was 25.2 µg in Group A (95% CI 23.2-26.4) and 20.2 µg in Group G (95% CI 14.2-23.6) (P=0.03). The potency ratio for epidural sufentanil in Group G compared to Group A was 1.25 (95% CI 1.00-1.64). CONCLUSION: Women carrying the variant allele of p.118A/G of OPRM1 (G118) had a lower ED50 for epidural sufentanil given for early labor analgesia than women homozygous for the wild-type allele.

Multidimensional evaluation of pain during early and late labor: a comparison of nulliparous and multiparous women.

BACKGROUND: Labor pain has a sensory and an affective component. This study was undertaken to evaluate whether the quality and intensity of the cognitive descriptors of labor pain may be influenced by parity and stage of labor. METHODS: One hundred and eighty-four parturients were divided into four groups according to parity (nulliparous and multiparous women) and stage of labor (early and late) and were given a modified version of the short-form McGill Pain Questionnaire that included the 23 most frequently reported labor pain descriptors. In addition, parturients were asked to report intensity of pain on a visual analogue pain scale and using the present pain intensity index. RESULTS: The most frequent descriptors used were cramping, pulling, hot, stinging, aching, heavy, tiring, exhausting and unbearable. The descriptors, "tiring" and "exhausting", were used primarily by nulliparous women (P <0.001). The intensity of "cramping", "stinging" and "aching" was greater in nulliparous women (P <0.0001) and the intensity of "heavy", "stinging", and "aching" increased as labor progressed in both groups (P <0.001). Mean intensity of pain increased as cervical dilation increased in both nulliparous and multiparous women. The visual analogue pain scale and present pain intensity index were strongly correlated (tau=0.63; P <0.0001). Low fetal station was associated with greater pain scores in nulliparous women (P<0.026). CONCLUSIONS: Affective and cognitive components of labor pain are frequently communicated with a restricted number of pain descriptors and may be affected by obstetric variables. An understanding of labor pain in a multidimensional framework provides the basis for a woman-centered approach to labor pain management.

Expectant fathers' experience during labor with or without epidural analgesia.

BACKGROUND: For men the worst aspect of childbirth is witnessing their partner in pain. The aim of this study was to investigate fathers' attitudes towards labor and delivery with and without epidural analgesia. METHOD: The study was performed using a questionnaire that included yes/no, multiple choice or 6-point ordinal scale answers. Expectant fathers whose partners were nullipara between 36 and 38 weeks of gestation were recruited and the questionnaires were administered on the day after the birth. To investigate paternal anxiety during labor, the State part of the State-Trait Anxiety Inventory was used. RESULTS: The questionnaire was completed by 243 fathers. Sixty percent (145) of the parturients received epidural analgesia and 40% (98) did not. Paternal characteristics were comparable. Fathers whose partners did not receive epidural analgesia felt their presence as troublesome and unnecessary (P<0.001). The presence of maternal epidural analgesia increased threefold paternal feelings of helpfulness and was associated with a greater involvement (P<0.001) and less anxiety and stress (P<0.001). Median (range) State-Trait Anxiety Inventory score was respectively 75 (50-80) and 30 (20-60) in fathers whose partners did not or did receive epidural analgesia (P<0.0001). Maternal analgesia greatly increased paternal satisfaction (P<0.0001). CONCLUSION: Epidural analgesia reduces paternal anxiety and stress and increases paternal involvement, participation and satisfaction with the experience of childbirth.