The incidence of dry chlorhexidine gluconate transfer from skin to surgical gloves: a simulation and in vitro study.

BACKGROUND: To prevent alcohol-based chlorhexidine from reaching the cerebrospinal fluid, it is recommended that the antiseptic solution be allowed to dry before skin palpation or puncture. However, no guidelines specify a drying time interval. Manufacturers recommend 3 min of air drying, based upon the isopropyl alcohol component. Therefore, to fill this knowledge gap, we designed a simulation study to investigate the incidence of primary chlorhexidine transfer from skin to gloves following three drying time intervals. We also investigated the incidence of secondary chlorhexidine transfer from gloves to another surface following one drying time interval. METHODS: An alcohol-based chlorhexidine antiseptic solution with dye, ChloraPrep®, was applied to the skin of the lumbar region of 20 volunteers. Cotton-tipped applicators wrapped in material from gloves were taken from the application area at 3, 4, 5, and 10 min following application. Transfer of chlorhexidine from skin to gloves, and gloves to another medium, was assessed through a chemical assay that produced a color change when chlorhexidine was present on the sample. RESULTS: The incidence of primary chlorhexidine transfer from skin to gloves at 3, 4 and 10 min following application was 99.5%, 99.4%, and 99.6%, respectively. The incidence of secondary chlorhexidine transfer from gloves to another surface was 68.9%. CONCLUSION: Gloves are routinely contaminated with chlorhexidine during central neuraxial blockade. The high incidence of secondary transfer in our simulation suggests a pathway by which chlorhexidine may gain access to the neuraxial space.

Determination of ChloraPrep® drying time before neuraxial anesthesia in elective cesarean delivery. A prospective observational study.

BACKGROUND: ChloraPrep® is a skin antiseptic commonly used before neuraxial anesthesia. It is believed that skin must be allowed to dry to prevent nerve damage by seeding ChloraPrep® solution into the neuraxis. We aimed to determine ChloraPrep® drying time in pregnant women before initiation of neuraxial anesthesia. METHODS: In 18 parturients undergoing elective cesarean delivery the skin 'wetness' after standardized ChloraPrep® application was prospectively assessed by blotting the skin with tissue paper and observing for residual orange tint. The isopropyl alcohol drying time was indirectly assessed by measuring the alcohol vapor concentration above the skin with a volatile organic compound analyzer. The primary outcome was the time measured from the end of skin preparation until tissue paper was no longer stained with orange tint. The secondary outcome was the time measured from the end of skin preparation until an abrupt reduction of isopropyl alcohol vapor concentration indicating that no further significant evaporation of alcohol was occurring. RESULTS: The mean ChloraPrep® drying time assessed by blotting the skin with tissue paper was 123 s (SD 32 s, 95% CI 107 to 140 s, range 85-195 s). The estimated isopropyl alcohol drying time was 82 s (95% CI 77.4 to 86.3 s). CONCLUSION: Our results suggest that ChloraPrep® drying time may be longer than the current manufacturer-recommended guideline of three minutes. The amount of ChloraPrep® used, application methods, patient characteristics, and environmental factors could influence the drying time.

Novel 3D ultrasound system for midline single-operator epidurals: a feasibility study on a porcine model.

BACKGROUND: We developed a real-time 3D ultrasound thick slice rendering technique and innovative Epiguide needle-guide as an adjunct to single-operator midline epidural needle insertions. Study goals were to determine feasibility of the technique in a porcine model and compare the visibility of standard and echogenic needles. METHODS: Thirty-four lumbar needle insertions were performed on six intact porcine spines ex vivo. Ultrasound scanning identified the insertion site and, using an Epiguide, the needle was guided into the epidural space through the ligamentum flavum in the midline plane, watched in real-time on the 3D ultrasound. Entry into the epidural space was judged by a loss-of-resistance technique. Needle visibility was rated by the anesthesiologist performing the technique using a 4-point scale; (0=cannot see, 1=poor, 2=satisfactory, 3=excellent), and later by an independent assessor viewing screenshots. The procedure was repeated at all lumbar levels using either the standard or echogenic needle. RESULTS: Successful loss-of-resistance to fluid was achieved in 76% of needle insertions; needle visibility with echogenic needles (94.2% rated satisfactory/excellent) was significantly better than with standard needles (29.4% satisfactory/excellent, P<0.0001). Successful loss-of-resistance was 93% when mean needle visibility was rated as 'excellent'. Inter-observer agreement between assessors was 'near-perfect' (weighted kappa=0.83). CONCLUSION: It is feasible to perform 3D ultrasound-guided real-time single-operator midline epidural insertions, in a porcine model. Echogenic needles were found to consistently improve needle visibility; and improved needle visibility tended to increase successful entry into epidural space.

A randomized controlled trial comparing Ametop™ with placebo for reducing pain associated with local anesthetic skin infiltration before neuraxial anesthesia in parturients.

BACKGROUND: Between 10-22% of the general population experience needle phobia. Needle phobic parturients are at increased risk of adverse outcomes. We assessed the efficacy of topical Ametop™ (tetracaine 4%) gel in reducing the pain associated with local anesthetic skin infiltration before neuraxial block in non-laboring women. METHODS: This was a prospective, randomized, double-blind, placebo-controlled study. Ametop™ or placebo was applied to the skin of the lower back at least 20min before neuraxial block using a standardized technique with 1% lidocaine skin infiltration. The primary outcome was numeric pain score (0-10) 30s after lidocaine infiltration. Groups were compared using Welch's t-test. RESULTS: Thirty-six subjects in each group were analyzed. There was a statistically significant difference in the mean (standard deviation) pain score between the Ametop™ and the placebo groups: 2.36±1.80 and 3.51±2.22, respectively (P=0.019). There were no significant adverse events. CONCLUSION: The mean numeric pain score in the Ametop™ group was 33% lower compared to the placebo group. Topical Ametop™ gel applied at least 20min before local anesthetic infiltration of the skin prior to neuraxial block in elective cesarean delivery may be a useful adjunct in needle phobic women.

Speed of spinal vs general anaesthesia for category-1 caesarean section: a simulation and clinical observation-based study.

Controversy exists as to whether effective spinal anaesthesia can be achieved as quickly as general anaesthesia for a category-1 caesarean section. Sixteen consultants and three fellows in obstetric anaesthesia were timed performing spinal and general anaesthesia for category-1 caesarean section on a simulator. The simulation time commenced upon entry of the anaesthetist into the operating theatre and finished for the spinal anaesthetic at the end of intrathecal injection and for the general anaesthetic when the anaesthetist was happy for surgery to start. In the second clinical part of the study, the time from intrathecal administration to 'adequate surgical anaesthesia' (defined as adequate for start of a category-1 caesarean section) was estimated in 100 elective (category-4) caesarean sections. The median (IQR [range]) times (min:s) for spinal procedure, onset of spinal block and general anaesthesia were 2:56 (2:32-3:32 [1:22-3:50]), 5:56 (4:23-7:39 [2:9-13:32]) and 1:56 (1:39-2:9 [1:13-3:12]), respectively. The limiting factor in urgent spinal anaesthesia is the unpredictable time needed for adequate surgical block to develop.

Inadequate pain relief with labor epidurals: a multivariate analysis of associated factors.

BACKGROUND: Labor epidural analgesia providing inadequate pain relief may cause maternal dissatisfaction and may fail to produce effective anesthesia when topped up for operative delivery. This study looked at factors associated with inadequate labor epidural analgesia. METHODS: Data were prospectively collected from 275 parturients receiving labor epidural analgesia. Pain was assessed 30 min after epidural insertion using a verbal pain scale of 0 to 100. A score of 10 or more was considered to represent inadequate pain relief. Sixteen factors chosen by experienced obstetric anesthesiologists for their association with inadequate labor epidural analgesia were studied. RESULTS: Fifteen parturients were excluded. Forty-four of the remainder (16.9%) experienced inadequate pain relief. Multiparity, history of a previous failure of epidural analgesia, the use of air for loss of resistance, cervical dilatation >7 cm at insertion all had a statistically significant association with inadequate epidural analgesia (P<0.05). Logistic regression showed that cervical dilatation >7 cm, a history of opioid tolerance, a previous failed epidural and insertion of the epidural by a trainee anesthesiologist increased the odds ratio for inadequate pain relief. CONCLUSIONS: The final model correctly classified 93% of the epidurals that provided effective analgesia but classified only 9.3% of those providing inadequate pain relief. This information can be used to develop a predictive score and change practice resulting in fewer inadequate epidurals.

Anaesthetic management of a craniopagus conjoined twin delivery.

We report the successful caesarean delivery of craniopagus conjoined twins in a 21-year-old using a neuraxial technique. Early diagnosis at 19(+5) weeks of gestation enabled thorough multidisciplinary antepartum planning. The multidisciplinary approach aimed to reduce maternal and fetal morbidity. Teams involved in the delivery included the specialities of obstetrics, neonatology, anaesthesia, paediatric neurosurgery and radiology. The delivery was complicated by an anterior placenta. The obstetricians used a J-shaped incision avoiding the placenta and making space for the fetal heads at delivery. Regional anaesthesia was used successfully in this case; although plans had been made should the mother need general anaesthesia intra-operatively. At delivery there were 17 members of the multidisciplinary team present in the operating theatre. They were from five specialities from two separate hospitals. We discuss the anaesthetic considerations for the delivery of conjoined twins and the multidisciplinary approach used in this case.

Anesthesia for the parturient with pseudoxanthoma elasticum.

We present our experience in the anesthetic management of two parturients with pseudoxanthoma elasticum. The first had an epidural catheter inserted for labor analgesia and ultimately had a forceps delivery. The second had a cesarean section under epidural anesthesia and had a complicated postoperative course. There were no untoward effects of regional anesthesia in either of these two women. The anesthetic implications for parturients with pseudoxanthoma elasticum are discussed.

[Heart involvement in systemic scleroderma]. / Postizení srdce u systémové sklerodermie.

Systemic scleroderma is a general disease of the connective tissue which may affect practically any organ. The authors describe the case of a man where in the course of the disease affection of the heart with symptoms of severe cardiac failure became the dominating symptom.

Effect of the localization of recording electrode on the auditory brain stem responses in healthy subjects.

In a group of 24 healthy people acoustic brain stem responses (ABR) were simultaneously recorded from different regions of the scalp. Evaluation of latencies and amplitudes individual ABR waves has shown that their average latency is longer and the amplitude is higher in records from electrodes above the right half of the scalp, regardless of which ear was stimulated.