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To compare the analgesic profile of remifentanil patient-controlled analgesia (RPCA) and combined spinal-epidural analgesia technique (CSEA) in multiparous women during the entire labour. We hypothesized that CSEA would provide a better and more sustained pain reduction than RPCA.A prospective observational trial under ID NCT02963337 at a university hospital in Slovenia 2017-2018. Analgesic efficacy, satisfaction with pain-relief, adverse effects, labour progress, and outcomes between RPCA (80) and CSEA (81) were compared.CSEA provided significantly lower pain scores during the entire labour. Compared to baseline, significant pain reduction was recorded in both groups after 15 min. No difference was recorded compared to baseline with RPCA and CSEA after 45 and 90 mins, respectively. CSEA provided higher satisfaction than RPCA (5 [5-5] vs 5 [4-5], p0.0001). More patients with CSEA opted for the same technique for the next labour [CSEA; 77 (95%) vs RPCA; 65 (81%), p = 0.003]. No crossovers were observed. RPCA was associated with desaturation (34%), bradypnea (21%) and apnoea (25%), which were transitional and easily managed. None had severe sedation. No differences were recorded in labour progress and outcomes. Apgar scores were reassuring in all neonates (8). None had umbilical artery pH7.0.In multiparas, CSEA provided superior analgesia and satisfaction than RPCA. Nevertheless, RPCA provided a satisfactory experience, suggesting it could be used when neuraxial analgesia is not available, preferred, or contraindicated. In that case, constant presence of midwife is mandatory for management of clinically significant hypoventilation.

Background Glycomer 631 and lactomer 9–1 are absorbable suture materials indicated for soft tissue approximation in non-infected wounds. Pigs are often used as surgical models in translational research; however, reports of tissue reactions to both suture materials in pigs are limited. The aim of this study was to assess clinical and histologic responses of skin incisions closed with a subcuticular technique using glycomer 631 and lactomer 9–1 in pigs. Results Skin incisions on 17 pigs were closed with glycomer 631 and lactomer 9–1, and a clinical reactive score (CRS) including erythema, swelling, discharge and dehiscence was calculated on postoperative days 7 and 14. Subcuticular tissue reaction was assessed histologically on postoperative day 14 (the presence of extravascular neutrophils, macrophages, multinucleated giant cells, lymphocytes, fibroblasts, bacterial colonies and the overall severity of the inflammatory response to the suture material), and the cumulative score of the variables was calculated as an aggregate tissue irritation score (ATIS). Tissue samples were examined for suture extrusion and evaluated microbiologically. The clinical reactive score did not differ between the suture materials. Only one ATIS variable, namely the overall severity of the inflammatory response, was lower (p = 0.029) when glycomer 631 was used. Suture extrusion was found in 10/17 of the incisions closed by glycomer 631 and in 7/13 of the incisions closed by lactomer 9–1. Trueperella pyogenes was isolated from the skin and from the area of tissue reaction in six pigs. Conclusions No difference in CRS between the suture materials was observed, and thus both materials may be used for the subcuticular technique in pigs. Glycomer 631 induced less tissue reaction only in terms of the overall severity of the inflammatory response. Suture extrusion was observed in more than 50% of incisions regardless of the suture material, possibly due to a large amount of suture material in the wound. Trueperella pyogenes was the only pathogen isolated from the tissue surrounding the suture material.

This report describes transurethral catheterization with a Foley catheter in 19 anaesthetized, laterally recumbent female pigs with a chest circumference of 72.1 ± 4.2 cm and weighing approximately 40 kg. Catheterization within five minutes was successful in 78.9% of the pigs. Catheterization depth, measured as the distance between the bladder neck and the mucocutaneous junction of the vulva, was 14.5 ± 1.3 cm and correlated with chest circumference but not body length. Measurement of catheterization depth aids in optimal positioning and may prevent inflation of the Foley catheter in the urethra.

In obesity, the skeletal muscle capillary network regresses and the insulin-mediated capillary recruitment is impaired. However, it has been shown that in the early stage of advanced obesity, an increased functional vascular response can partially compensate for other mechanisms of insulin resistance. The present study aimed to investigate the changes in the capillary network around individual muscle fibres during the early stage of obesity and insulin resistance in mice using 3D analysis. Capillaries and muscle fibres of the gluteus maximus muscles of seven high-fat-diet-induced obese and insulin-resistant mice and seven age-matched lean healthy mice were immunofluorescently labelled in thick transverse muscle sections. Stacks of images were acquired using confocal microscope. Capillary network characteristics were estimated by methods of quantitative image analysis. Muscle fibre typing was performed by histochemical analysis of myosin heavy chain isoforms on thin serial sections of skeletal muscle. Capillary length per muscle fibre length and capillary length per muscle fibre surface were increased by 27% and 23%, respectively, around small muscle fibres in obese mice, while there were no significant comparative differences around large fibres of obese and lean mice. Furthermore, the capillarization was larger around small compared to large fibres and there was a shift toward fast type myosin heavy chain isoforms, with no significant changes in muscle fibre diameters, tortuosity and anisotropy in obese mice. Overall, the results show that obese insulin-resistant mice have selective increase in capillarization around small predominantly intermediate muscle fibres, which is most likely related to the impaired glucose metabolism characteristic of type 2 diabetes.

Background Diabetes mellitus and the associated neuropathic complications have become a steadily increasing global health burden. Diabetic patients are estimated to require surgery at least twice as often as nondiabetic patients. Neuropathy may change the way nerves respond to nerve blocks. There is currently no consensus on whether regional anaesthesia techniques should be adopted in these patients. Long-acting local anaesthetics ( e.g . bupivacaine HCl) or sustained-release formulations of bupivacaine ( e.g . liposomal bupivacaine) could prove neurotoxic in the presence of diabetic neuropathy. The aim of the study was to assess neurotoxicity of liposome bupivacaine in streptozotocin (STZ)-induced diabetic mice after sciatic nerve block using a reduction in fibre density and decreased myelination assessed by G-ratio as an indicator of local anaesthetic neurotoxicity. Results Prior to performing sciatic nerve block, higher levels of fasting glucose were recorded in diabetic mice compared to nondiabetic mice ( P < 0.001). Likewise, significant differences were noted in the tail flick and plantar test thermal latencies between the groups ( P < 0.001) which confirmed the presence of peripheral sensory neuropathy in diabetic mice. In both, diabetic and nondiabetic mice, sciatic nerve block with 0.25% bupivacaine HCl resulted in a significantly greater G-ratio (axon diameter/large fibre diameter) and an axon diameter compared to nerves treated with 1.3% liposomal bupivacaine or saline (0.9% sodium chloride) ( P < 0.01 ). Moreover, sciatic nerve block with 0.25% bupivacaine HCl resulted in higher fibre density and large fibre and axon diameters compared to the control (untreated) sciatic nerves in both STZ-induced diabetic ( P < 0.05 ) and nondiabetic mice ( P < 0.01 ). No evidence of acute or chronic inflammation was observed in any of the treatment groups. Conclusions Under the conditions of this study, sciatic nerve block with bupivacaine HCl, but not liposome bupivacaine or saline, resulted in histomorphometric indices of neurotoxicity. The presence of diabetes did not appear to affect the severity of the histologic findings.

In the present study, we developed a simple and rapid analytical method for the quantification of bupivacaine hydrochloride in human biopsy samples of adipose, muscle, neural, connective and cartilage tissue using liquid chromatography-mass spectrometry. Anesthetics were extracted from the tissue samples using 0.1% formic acid in acetonitrile for protein denaturation and hexane for removal of lipophilic impurities. Analytes were separated adequately on Phenomenex Luna Omega polar C18 column using a gradient mobile phase 0.1% formic acid in water and 0.1% formic acid in acetonitrile. The lower limits of quantification were ≤ 97 ng g-1 tissue for all studied tissues. Intra-day recoveries were between 48.2% and 82.1% with relative standard deviations (RSDs) between 1.47% and 14.28%, whereas inter-day recoveries were between 52.2% and 77.6% with RSDs between 2.98% and 14.79%. The calibration curve showed a linear fit with R2 higher than 0.99 in the concentration range from 0.16 to 100 μg g-1 . Lidocaine hydrochloride was tested as internal standard because its recoveries and matrix effects were comparable to bupivacaine hydrochloride. Post-analytical corrections of measured bupivacaine tissue concentrations can accordingly be made based on recovery of lidocaine as internal standard, with recoveries between 51.2% and 86.9% and RSDs between 1.99% and 16.88%. The developed method could be used to study time-dependent spread of bupivacaine locally or to more distant locations across tissue barriers.

Background Reducing pain and minimising opioids after caesarean section are crucial to enhancing maternal recovery and promoting mother-newborn interaction. Various techniques have been implemented to improve analgesia. We compared the analgesic efficacy of posteromedial quadratus lumborum block with that of wound infiltration following elective caesarean section. Objective We hypothesised that within a multimodal analgesia approach, posteromedial quadratus lumborum block would, due to its potential to relieve visceral pain, result in a 15% reduction in 24-h postoperative opioid consumption compared with wound infiltration. Design A double-blind, randomised, placebo-controlled clinical study. Setting A single-centre study between August 2019 and May 2020. Patients One hundred and sixteen women were randomly allocated into two groups. In the quadratus lumborum group, 20 ml 0.9% saline was injected into the surgical wound followed by bilateral posteromedial quadratus lumborum block using 20 ml 0.25% levobupivacaine per side. In the wound infiltration group, 20 ml of 0.25% levobupivacaine was injected into the surgical wound followed by a bilateral posteromedial quadratus lumborum injection with 20 ml 0.9% saline per side. Main outcome measures The primary outcome was opioid (piritramide) consumption at 24 h. Secondary outcomes were piritramide consumption at 48 h, time-to-first analgesic request, pain scores at rest and with movement, surgery-to-first-ambulation time, surgery-to-breastfeeding time, sedation, pruritus and complications. Results Piritramide consumption in 24 h was significantly lower with posteromedial quadratus lumborum block (1.5 ± 1.8 mg) than with wound infiltration (2.2 ± 1.7 mg) (P = 0.04), mean difference of -0.7 mg, (95% CI -1.3 to -0.03). In those who required piritramide, time-to-first analgesic request was significantly longer with posteromedial quadratus lumborum block 11 [7 to 14] h, than with wound infiltration 7 [5 to 11] h (P = 0.02). Pain scores were low, with no differences recorded at rest and with movement. There were no differences in time-to-ambulation and time-to-breastfeed between the groups. Conclusion As a component of multimodal postcaesarean section analgesia, posteromedial quadratus lumborum block was associated with lower 24-h opioid consumption compared with wound infiltration. Trial registration ClinicalTrials.gov identifier: NCT04000308.

Objective To determine whether vitamin C in the first three days postpartum reduces pulmonary oedema (PE) assessed by lung ultrasound in patients with severe preeclampsia. Design Randomised, placebo-controlled, double-blind trial. Setting Tertiary perinatal centre. Population Consecutively admitted patients with singleton pregnancies complicated by severe preeclampsia. Methods Thirty-four patients received vitamin C (1.5 g/6 h) (n = 17) or placebo (n = 17) at days 1, 2, and 3 postdelivery. Mann-Whitney-U test was used to compare vitamin C vs placebo groups. A p ≤ 0.05 was considered statistically significant. Main outcome measures Lung ultrasound was performed once daily in the first three days following delivery. Echo Comet Score (ECS) on day 1 postdelivery was the primary outcome studied and was obtained using the 28-rib interspaces technique. ECS on days 2 and 3 postdelivery were secondary outcomes. Results There was no significant difference in ECS on day 1 (median 23 (inter-quartile range (IQR) 21–61) vs 18 (IQR 8–35); p = 0.31). All ultrasound examinations on day 1 were performed within six hours from delivery. On days 2 and 3, ECS was significantly lower in vitamin C group compared to placebo (8 (IQR 3–14) vs 35 (IQR 15–78); p = 0.03 and 5 (IQR 3–10) vs 18 (IQR 18–44); p = 0.04, respectively). Conclusion A single dose of intravenous vitamin C did not reduce PE in postpartum patients with severe preeclampsia on day 1 after delivery. Repeated doses, however, seem to have a delayed effect with a reduction in PE detected on ultrasound on days 2 and 3 following delivery. Trial registration This trial is registered at ClinicalTrials.gov: ID NCT03451266 ( https://clinicaltrials.gov/ct2/show/NCT03451266?term=NCT03451266&draw=2&rank=1 ).

In the obese, the evidence for the choice of the optimal emergency front-of-neck access technique is very limited and conflicting. We compared cannula and scalpel-bougie emergency front-of-neck access techniques in an anaesthetised porcine model with thick pretracheal tissue. Cannula and scalpel-bougie cricothyroidotomy techniques were performed in 11 and 12 anaesthetised pigs, respectively. Following successful tracheal access, oxygenation was commenced and continued for 5 min using Rapid-O2 device for cannula and circle breathing system for scalpel-bougie study groups. The primary outcome was a successful rescue oxygenation determined by maintenance of arterial oxygen saturation >90% 5 min after the beginning of oxygenation. Secondary outcomes included success rate of airway device placement, time to successful airway device placement, and trauma to the neck and airway. The success rate of rescue oxygenation was 18% after cannula, and 83% after scalpel-bougie technique (P = 0.003). The success rate of airway device placement was 73% with cannula and 92% with scalpel-bougie technique (P = 0.317). Median (inter-quartile-range) times to successful airway device placement were 108 (30-256) and 90 (63-188) seconds (P = 0.762) for cannula and scalpel-bougie emergency front-of-neck access, respectively. Proportion of animals with iatrogenic trauma additional to the procedure itself was 27% for cannula and 75% for scalpel-bougie technique (P = 0.039). Thus, in the porcine model of obesity, the scalpel-bougie technique was more successful in establishing and maintaining rescue oxygenation than cannula-based technique; however, it was associated with a higher risk of severe trauma.

Background : Remifentanil has a suitable pharmacological profile for labour analgesia. Fast set up, onset, and limited time efficacy may render it useful in multiparas with a faster labour progression. The objective of this prospective, non-randomized trial was to compare the pain relief for vaginal delivery between remifentanil patient-controlled analgesia (RPCA) with that of combined spinal-epidural analgesia (CSEA) in multiparas. Methods : After making an informed choice of either RPCA or CSEA, 162 multiparous women in the active phase of first-stage labour were enrolled in this study. The primary outcome was pain intensity measured during the whole period of labour using an 11-point numerical rating scale. The secondary outcomes were satisfaction with pain-relief, adverse effects, labour progress and outcomes. Results : CSEA provided lower pain scores and a higher satisfaction rate than RPCA [3.9 (0.36) vs 2.6 (1.1), P

The general microscopic characteristics of nerves are described in several textbooks of histology, but the specific microanatomies of most nerves that can be blocked by anesthesiologists are usually less well known. Our objective was to evaluate the 3D reconstruction of nerve fascicles from optical projection tomography images (OPT) and the ability to undertake an internal navigation exploring the morphology in detail, more specifically the fascicular interconnections. Median and lingual nerve samples were obtained from five euthanized piglets. OPT images of the samples were acquired and 3D reconstruction was performed. The OPT technique revealed the inner structure of the nerves at high resolution, including large and small fascicles, perineurium, interfascicular tissue, and epineurium. The fascicles were loosely packed inside the median nerve and more densely so in the lingual nerve. Analysis of the 3D models demonstrated that the nerve fascicles can show six general spatial patterns. Fascicular interconnections were clearly identified. The 3D reconstruction of nerve fascicles from OPT images opens a new path for research into the microstructure of the inner contents of fascicular nerve groups and their spatial disposition within the nerve including their interconnections. These techniques enable 3D images of partial areas of nerves to be produced and could became an excellent tool for obtaining data concerning the 3D microanatomy of nerves, essential for better interpretation of ultrasound images in clinical practice and thus avoiding possible neurological complications. Clin. Anat. 31:424-431, 2018. © 2017 Wiley Periodicals, Inc.

Background The combined spinal-epidural analgesia (CSEA) proved useful in multiparous women on account of faster onset and better analgesia in the first 30 minutes compared to standard epidural analgesia. Remifentanil has a suitable pharmacological profile for labour analgesia. Fast set up, onset, and limited time efficacy may render it useful in multiparous women with a faster labour progression.Methods The prospective observational study was performed in multiparous women in their active phase of the first stage labour after their informed choice of either RPCA (n=80) or CSEA (n=82). The primary outcome was pain-relief assessed on a 11-point numerical rating scale. The secondary outcomes were with pain-relief satisfaction, adverse effects, labour progress and labour outcomes.Results CSEA provided significantly lower pain scores and a higher satisfaction rate compared to RPCA [3.9 (0.36) vs 2.6 (1.1), P

There are concerns that drugs administered to the mother may affect the new-born through placental transfer. In order to avoid the potential for neonatal depression, general anaesthesia is usually induced with thiopental and succinylcholine with maintenance of anaesthesia using nitrous oxide (N2O) and low concentrations of inhalation agents. A single induction dose of thiopental rapidly redistributes and quickly appears in the umbilical venous blood after injection with a mean foeto/maternal (F/M) ratio of 0.4–1.1, which requires the introduction of volatile anaesthetic to prevent awareness. The latter may be associated with neonatal depression and uterine atony in a dose-dependent manner particularly when the induction-delivery (I-D) time interval exceeds 8 min. High lipid solubility and low molecular weight of volatile anaesthetics facilitate their rapid transfer across the placenta. When administered for caesarean section, N2O results in F/M ratio of 0.83, isoflurane of 0.71 and sevoflurane of 0.31.1 When placental transfer of different anaesthetic drugs were compared between different foetal perfusion states, lower placental transfer of drugs were observed during foetal hypoperfusion suggesting that the maintenance of volatile anaesthetics at a marginally low concentration may not be necessary when foetal distress is observed during emergency caesarean delivery because their placental transfer decreases with decreasing placental perfusion.2 Propofol with a dose of 2–2.5 mg/kg allows rapid and smooth induction of anaesthesia when used for caesarean section. It readily crosses the placenta after both bolus induction and intravenous maintenance anaesthesia with F/M ratio between 0.65–0.85. Propofol plasma level in the neonate depends on the maternal dose and I-D interval. Higher bolus dosages >2.5 mg/kg were associated with depressed newborns, while lower doses 2 mg/kg did not induce neonatal depression as measured by Apgar scores and neurobehavioral scores.3 Although opioids are not drugs of choice in induction of general anaesthesia during caesarean section, fentanyl is administered in special cases potentially resulting in low Apgar scores and respiratory depression necessitating tracheal intubation of the newborn, as well as low neurobehavioral scores due to a potential accumulation in the breast milk. Muscle relaxants are fully ionised, quaternary ammonium salts, which do not rapidly cross the placenta; however, single doses of muscle relaxants can result in detectable foetal blood concentrations. After a standard induction dose, succinyholine is not detected in umbilical venous blood at deliver; doses larger than 300 mg are required before the drug can be detected. The administration of nondepolarizing muscle relaxants results in low F/M ratio, for instance, 0.16 for rocuronium.4 Meperidine injection used for labour analgesia results in rapid placental transfer of 90 sec. F/M ratio may exceed 1 after 2–3 hours. Maternal levels fall more rapidly than foetal levels because of the mother’s greater capacity to metabolise the drug. The same time interval is associated with the greatest likelihood of neonatal depression, in part because of the active metabolite normeperidine. As maternal levels fall, the meperidine and normeperidine will transfer from the foetus back to the mother, correlating well with the clinically observed decrease in neonatal sedation 4 hours after maternal administration.4 Remifentanil is an ultra-short acting systemic opioid with a fast onset of action (30–60 sec), peak analgesic effect of 2.5 min and a high metabolic rate (context-sensitive half-time 3–4 min) with no accumulation with a repeated or long-term use. Although it crosses the placenta, it is metabolised and redistributed quickly by the foetus. When remifentanil was used for patient controlled intravenous labour analgesia no adverse neonatal outcome was observed in a wide range of the doses.5 However, when remifentanil was used for induction of general anaesthesia for caesarean section, thoracic rigidity, negative effect on Apgar scores and neonatal ventilation were encountered pointing to the importance of providing enough time between remifentanil infusion stopping and cord clamping (at least 5–10 minutes) to allow the drug clearance from the foetal blood.6 Opioids used for epidural analgesia reach peak concentration in maternal plasma within 10–15 min. The highly lipofilic drugs such as fentanyl diffuse readily across the placental membrane in non-ionised and nonprotein bound forms approaching transplacental equilibrium in a single circulation. Despite that, the combined spinal epidural analgesia for labour using 0.1% bupivacaine with 2 µg fentanyl/ml epidurally for periods up to 15 h is unlikely to result in significant drug accumulation in either the mother or the neonate. On the contrary, after an epidural bolus of 150–200 µg fentanyl, respiratory depression needed resuscitation was observed in some neonates. Relative short acting local anaesthetic such as lignocaine, when given at a rate necessary to maintain epidural analgesia, can achieve plasma concentrations approaching the toxic range. Such drugs may therefore depress newborn neurobehavioural scores. This is not the case with bupivacaine which, in normal dose for caesarean section or labour, is not associated with maternal toxicity or adverse neonatal effects.7 In conclusion, the rate of the drug placental transfer is governed by the concentration gradient of the free nonionised drug and by the maternal and foetal placental blood flows, and it is influenced by pH gradient and the protein binding on either side of the placenta. However, additional caution should be taken with a repeated or long time use of the drugs. References Pournajafiana A, Rokhtabnak F, Kholdbarin A, Ghodrati M, Ghavam S. Comparison of remifentanil and fentanyl regarding hemodynamic changes due to endotracheal intubation in preeclamptic parturient candidate for cesarean delivery. Anesth Pain Med 2012;2:90–93. Satoh D, Iwatsuki N, Naito M, Sato M, Hashimoto Y. Compariosn of the placental transfer of halothane, emflurane, sevoflurane, and isoflurane during caesarean section. J Anesth 1995;9:220–223. Taiwan J. Obstet Gynecol 2017;56:521–526. Chestnut DH, Wong CA, Tsen L, Ngan Kee W, Beilin Y, Mhyre JM. Chestnut’s obstetric anesthesia principles and practice 5th ed. Elsevier, Saunders, 2014. Anesthesiology 1998;88(6):1467–1474. Anesth Analg 2017;124(4):1029–1031. Fernando R, Bonello E, Gill P, et al. Neonatal walfare and placental transfer of fentanyl and bupivacaine during ambulatory combined spinal epidural analgesia for labour. Anaesthesia 1997;52:517–524.

Background and aims To assess the neurotoxicity of liposome bupivacaine after the sciatic nerve block in streptozotocin (STZ)-induced diabetic mice. Methods 18 streptozotocin-induced diabetic and 18 non-diabetic female mice were included in the study. Once peripheral neuropathy was confirmed using tail flick and paw withdrawal tests, peripheral sciatic nerve block was performed. Application of 1.3% liposome bupivacaine, 0.25% bupivacaine hydrochloride (HCl) and 0.9% NaCl was achieved percutaneously, introducing the needle posteromedial to the great trochanter and injecting solutions at the moment the tip of the needle hit the bone. Seven days after the nerve block the sciatic nerves were harvested. Neurotoxicity was assessed using high-resolution light microscopy and morphometric analysis using Ellipse program. Results In both diabetic and nondiabetic mice, the G-ratio and axon diameter of 0.25% bupivacaine HCl treated sciatic nerves were significantly increased compared to 0.9% NaCl and 1.3% liposome bupivacaine. the 0.25% bupivacaine HCl treated sciatic nerves showed a decrease in fiber density and an increase in large fiber and axon diameters compared to untreated sciatic nerves in both diabetic and nondiabetic mice. No evidence of acute or chronic inflammation in any of the treatment groups was observed. Conclusions Under the conditions of our study, application of bupivacaine HCl, but not liposome bupivacaine or NaCl results in histomorphometric indices of neurotoxicity in diabetic mice. the presence of diabetes did not appear to increase the severity of the histologic findings.

Epidural analgesia (EA) is the gold standard for pain relief during labour and delivery. In spite of its efficacy and increased use there has been significant controversy regarding its impact on labour outcomes. the current evidence suggests that EA does not increase the overall rate of caesarean delivery,1 however, its impact on operative vaginal delivery and neonatal outcome is still not that clear. 2 3 Characteristics such as multiple birth, preterm labour, foetal presentation, spontaneous versus induced labour, and previous uterine surgeries may impact labour progress and maternal as well as neonatal outcome. Many of these characteristics have not been adequately accounted for in randomized trials published to date, since smaller sub-groups of labours (e.g. breech or twin labour) have not been adequately represented in these trials due to their relatively small contribution to the overall number of deliveries.4–7 Ten-Group Classification System (TGCS) was first described in 2001 and originally utilized to assess caesarean delivery rates.8 the TGSC is structured to make it relevant to clinicians and labouring women, and to provide a common language for discussion on safety, quality of care and perinatal audit.9 the TGCS has been endorsed by the World Health Organization and the International Federation of Gynecology and Obstetrics and is increasingly used by labour and delivery units to report their caesarean delivery rates.10–13 It was also recommended that other events and outcomes surrounding labour and delivery are analysed using this classification.11–13 This manuscript presents the data recently published in IJOA showing the effects of EA on labour and delivery outcomes in Slovenia using the Slovenian National Perinatal Information System (NPIS) data for the period 2007 through 2014.14 the TGCS (table 1) was used to assess the difference in caesarean deliveries and operative vaginal deliveries between women with or without EA during labour. Two hundred seven thousand five hundred deliveries fulfilled inclusion criteria. table 2 presents numbers of deliveries in women who did and did not receive EA according to the TGCS labour types. Basic maternal (age, BMI) and neonatal (birth weight, occipito-posterior presentation) characteristics that could act as confounders in the analysis of incidences of caesarean and/or operative vaginal delivery rates are also presented for each of the groups. Statistically significant differences in maternal age, BMI, birthweight and rates of occipito-posterior presentation were found in most groups 1 to 5 (table 1). table 3 shows count and percentages of caesarean deliveries and operative vaginal deliveries in the group of women who received EA during labour vs. those who did not. the caesarean delivery rates were lower among women with EA versus women without EA in all the TGCS groups except in group 3 (multiparous term women with singleton foetuses in cephalic presentation in spontaneous labour) in which caesarean delivery rates were very low irrespective of analgesic technique, group 9 (abnormal lies) in which caesarean delivery rates were high irrespective of analgesic technique, and group 1 (nulliparous term women with singleton foetuses in cephalic presentation in spontaneous labour). In group 1 EA was associated with significantly higher caesarean delivery rates in contrast to other groups. the potential association between EA and caesarean delivery is complex and difficult to study in observational studies. This may also explain the conflicting results of several studies published on this topic to date.1 EA as an effective analgesic method may have a beneficial effect on labour progression and therefore lower the risk of dystocia and, consequently, caesarean delivery. the seemingly consistent association between EA and lower caesarean rates in most groups of labouring women seems to support this hypothesis. on the other hand, the request for EA may be a marker of dysfunctional (prolonged or obstructed) labour, since women with complicated labours are more likely to require more efficient analgesia. the higher caesarean delivery rates in group 1 may be the result of such an association.3 Future studies on the characteristics of nulliparous women requesting EA should be performed to elucidate this, since preventing cesarean delivery in this group of women is a very important goal.15 The rate of operative vaginal delivery was higher in women with EA in groups 1 to 5 (table 1). An association between EA and higher operative vaginal delivery rates was observed in most TGCS labour types, and this in accordance with several previously published studies that showed an overall increase in operative vaginal delivery rates with EA.3 4 15 This may be, in part, explained by a higher incidence of occipito-posterior presentation possibly due to the then EA practice of delivering either single boluses or constant infusions alone or combined with patient controlled boluses of higher local anaesthetic concentrations without fentanyl with a consequently higher potential of motor blockade during the study period.3 15 It also has to be noted that obstetricians were not blinded to the type of analgesia present and may be more likely to perform an operative vaginal delivery in women with EA. Moreover, higher neonatal birth weights observed in EA groups may also have contributed to higher operative vaginal delivery rates associated with EA. In conclusion, when looking for associations between the use of EA and different rates of labour interventions, the TGCS groups should be taken into consideration. Epidural analgesia was associated with a higher caesarean delivery rate in nulliparous term women with singleton foetuses in cephalic presentation in spontaneous labour (group 1), and with higher vacuum delivery rates in most TGCS groups. References Cambic CR, Wong CA. Labour analgesia and obstetric outcomes. BJA 2010;105:i50–i60. Hawkins JL. Epidural analgesia for labour and delivery. N Engl J Med 2010;362:1503–10. Bergant J, Sirc T, Lucovnik M, Verdenik I, Stopar Pintaric T. Perinatal analgesia and labour outcomes in Slovenia: a retrospective analysis of births between 2003 and 2013. Zdrav Vestn 2016;85:83–91. Anim-Somuah M, Smyth R, Howell C. Epidural versus non-epidural or no analgesia in labour. Cochrane Database Syst Rev 2005;4:CD000331. Howell CJ, Chalmers I. a review of prospectively controlled comparisons of epidural with non-epidural forms of pain relief during labour. Int J Obstet Anesth 1992;1:93–110. Paech MJ. the King Edward Memorial Hospital 1,000 mother survey of methods of pain relief in labour. Anaesth Intens Care 1991;19:393–9. Ramin SM, Gambling DR, Lucas MJ, Sharma SK, Sidawi JE, Leveno KJ. Randomized trial of epidural versus intravenous analgesia during labour. Obstet Gynecol 1995;86:783–9. Robson MS. Classification of cesarean sections. Fetal Matern Med Rev 2001;12:23–39. Robson M. The Ten Group Classification System (TGCS) - a common starting point for more detailed analysis. BJOG 2015;122:701. Brennan DJ, Robson MS, Murphy M, O’Herlihy C. Comparative analysis of international cesarean delivery rates using 10-group classification identifies significant variation in spontaneous labour. Am J Obstet Gynecol 2009;201:308 e1–8. Homer CS, Kurinczuk JJ, Spark P, Brocklehurst P, Knight M. a novel use of a classification system to audit severe maternal morbidity. Midwifery 2010;26:532–6. Betran AP, Torloni MR, Zhang JJ, Gulmezoglu AM, Section WHOWGoC. WHO Statement on Cesarean Section Rates. BJOG 2016;123:667–70. Rossen J, Lucovnik M, Eggebo TM, Tul N, Murphy M, Vistad I, Robson M. a method to assess obstetric outcomes using the 10-Group Classification System: a quantitative descriptive study. BMJ Open 2017;7:e016192. Lucovnik M, Blajic I, Verdenik I, Mirkovic T, Stopar Pintaric T. Impact of epidural analgesia on cesarean and operative vaginal delivery rates classified by the Ten Groups Classification System. Int J Obstet Anesth 2018; 34:37–41. Spong CY, Berghella V, Wenstrom KD, Mercer BM, Saade GR. Preventing the first cesarean delivery. Obstet Gynecol 2012;120:1181–93. Anim-Somuah M, Smyth RMD, Jones L. Epidural versus non-epidural or no analgesia in labour. Cochrane Database of Syst Rev 2011;12:CD000331. Robson M, Hartigan L, Murphy M. Methods of achieving and maintaining an appropriate cesarean section rate. Best Pract Res Clin Obstet Gynaecol 2013;27:297–308.

Marija Damjanovska,1 Tatjana Stopar Pintaric,1,2 Erika Cvetko,2 Kamen Vlassakov3 1Clinical Department of Anesthesiology and Intensive Therapy, University Medical Centre Ljubljana, Ljubljana, Slovenia; 2Institute of Anatomy, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia; 3Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA Purpose: The ultrasound-guided retrolaminar block is one of the newer and simpler alternatives to the traditional, often technically challenging, paravertebral (PV) block. Its feasibility, safety, and efficacy have already been clinically demonstrated in patients with multiple rib fractures using higher volumes of local anesthetic, when compared with the traditional approach. The primary aim of this observational anatomical study was to assess the spread of local anesthetic from the retrolaminar injection point to the PV space and its volume dependence. Second, we assessed the incidence of epidural and contralateral PV spread in the both groups.Methods: Ten fresh porcine cadavers were randomized into 2 groups (n=5 each) to receive ultrasound-guided retrolaminar injections at Th4-Th5 level with either 10 mL (low-volume group) or 30 mL (high-volume group) of 2% lidocaine and methylene blue mixture. After the procedure, the cadavers were dissected and frozen. Cross-section cuts (~1 cm thick) were performed to evaluate the injectate spread.Results: In the high-volume group, injectate spread from the retrolaminar to the PV space was observed in all specimens (5 out of 5; 100%), while in the low-volume group, no apparent spread to the PV space was found (0 out of 5; 0%). No epidural or contralateral PV spread was observed in any of the specimens.Conclusion: Following ultrasound-guided retrolaminar injections in fresh porcine cadavers, injectate spread from the retrolaminar tissue plane to the PV space is strongly volume dependent, suggesting that, clinically, high local anesthetic volumes maybe critical for achieving regional anesthesia and analgesia consistent with traditional PV blockade. Keywords: paravertebral space, vertebral lamina, local anesthetic, injections&nbsp

Airway anesthesia is pivotal for successful awake intubation provided either topically or by blocks. Airway blocks are considered technically more difficult to perform and carry a higher risk of complications. However, in experienced hands, they can be useful as they provide excellent intubating conditions. For complete upper airway anesthesia, bilateral glossopharyngeal and superior laryngeal nerve blocks with translaryngeal injection are required. Superior laryngeal nerve block and translaryngeal injection can be performed easily, safely and with a high success rate in patients with normal anatomy. In those with difficult landmarks, ultrasound can be of assistance. For the superior laryngeal nerve block, other targets than the nerve itself must be established to make the technique consistently successful, easy to teach, learn and perform. The same applies to the translaryngeal injection, where the use of ultrasound is necessary for correct midline identification. Intraoral glossopharyngeal nerve block is also safe and easy to perform, but associated with long lasting discomfort. Bilateral extraoral peristyloid approach should be discouraged since inadvertent blocks of the closely adjacent vagus nerve cannot be prevented in this location. A safe and easy method of blocking the distal portions of the glossopharyngeal nerve for awake intubation is therefore required.

Introduction: Despite advanced therapies for pulmonary arterial hypertension (PAH), maternal mortality in women with PAH and their offspring remains high (30-56% and 11-28%) and is especially high during the post-partum period1,2. Case report: 39-years-old woman was presented in 24th week of pregnancy with moderate dyspnea and cyanosis without peripheral edema. ECG showed right ventricular strain and NT-proBNP was 1300 ng/L. Echocardiogram showed severe precapillary pulmonary hypertension with systolic pulmonary pressure (PAP) 103 mmHg, reduced stroke volume (SVI 29 ml/m2), normal cardiac output (CI 2.6 L/min/m2) and mildly reduced systolic function of the right ventricle (FAC 30%, PMI TDI 0.8) with normal central venous pressure (CVP) 3 mmHg. Right heart catheterization confirmed echocardiographic hemodynamic measurements (mean pulmonary pressure 61 mmHg, pulmonary vascular resistance (PVR) 9.4 WU) and the vasoreactivity test was negative. Epoprostenol was initiated, titrated up to 22 ng/kg/min and on 30th week planned caesarean section was performed with NO inhalations, noradrenalin and dobutamine. Fortunately, standby supportive therapy - ECMO and high urgency lung transplantation, was not needed. The baby did well. The patient was extubated on the same day and sildenafil was added. The patient was discharged after 4 weeks. After 2 months epoprostenol was switched to treprostinil up to 26 ng/kg/min and macitentan was added. NT-proBNP stabilized at 170 ng/L. Echocardiography was performed weekly to monitor CI, CVP and right systolic function indexes. Favorable echocardiographic dynamics after therapy were observed: mean PAP 60 mmHg to 45-50 mmHg, PVR from 10 WU to 7 WU, stroke volume normalized and CVP remained normal. However, right ventricular systolic function improved but did not normalize (Table 1). In conclusion, with complete echocardiographic hemodynamic assessment and thorough clinical assessment high-risk pregnancies in patients with severe PAH can be managed. In addition, FAC, MPI TDI, 3D ejection fraction and RV free strain better assess right ventricular systolic function than TAPSE.

Background and objectives: Glossopharyngeal nerve (GPN) blocks are usually performed by topical, intraoral, or peristyloid approaches, which carry significant complication risks due to the proximity of important neurovascular structures. This study presents a proof of concept for a new ultrasound (US)-guided technique, which would block the GPN distally, in the parapharyngeal space, away from the immediate vicinity of high-risk collateral structures. Methods: Five cadaver heads were dissected, and the location of the GPN was explored bilaterally. In 40 healthy volunteers (20 men and 20 women; median age, 35.5 years [range, 24-69 years]) parapharyngeal sonograms were obtained, saved, and analyzed. To assess the technical feasibility of a distal GPN block in the parapharyngeal space, unilateral US-guided dye injections were performed in 3 fresh cadavers, followed by dissections. Results: The GPN was consistently identified between the stylopharyngeal and middle pharyngeal constrictor muscles in all cadaver specimens. The median distance between the GPN and the ipsilateral greater horn of the hyoid bone was 2.4 cm (range, 2.3-2.7 cm) on the right and 2.6 cm (range, 2.3-2.9 cm) on the left. The mean skin-to pharyngeal wall distances in the volunteers were 2.03 (SD, 0.41) cm on the right and 2.02 (SD, 0.45) cm on the left. The mean hyoid bone-to-pharyngeal wall distances were 2.04 (SD, 0.35) cm (right) and 2.07 (SD, 0.35) cm (left). The fresh cadaver dissections demonstrated dye deposition adjacent to the GPN in the parapharyngeal space in all specimens. Conclusions: Based on our anatomical results in cadavers and healthy volunteers, we submit that successful and safe blockade of the distal GPN at the pharyngeal wall level is technically feasible under US guidance.

Background: Effective labour analgesia is important for the mother and the newborn although it might have adverse effects on the labour outcome. Due to our limited data, the slovene obstetricians, when counselling prospective mothers, mainly rely on foreign data the findings of which are difficult to interpret because of differences in labour management between countries. The aim of this retrospective analysis is to evaluate the effects of labour analgesia on the obstetric outcome in slovene maternity units.Methods: A retrospective study using data from the National perinatal information system was done, and 168863 deliveries were analysed. All singletons (cefalic presentation and gestational age of 37 weeks 0/7 and more) from all 14 Slovenian maternity wards, born from 1st Jan 2003 to 31th Dec 2012 were included. Stillbirths, children with congenital abnormalities and elective caesarean sections were excluded. Univariate analysis and multivariate logistic regression were used to examine the impact of risk factors on birth outcomes.Results: Multivariate logistic regression showed that epidural and intravenous analgesia compared to the absence of analgesia present a higer risk factor for labour duration above 7 hours (OR 5.1; 95 % CI 4.8–5.4 for epidural analgesia), (OR 1.8; 95 % CI 1.8–1.9 for intravenous analgesia) and for vacuum extraction of the fetus (OR 4.0; 95 % CI 3.7–4.4 for epidural analgesia), (OR 1.7; 95 % CI 1.6–1.8 for intravenous analgesia). Only epidural analgesia increases the risk for occipitoposterior presentation (OR 1.8; 95 % CI 1.7–2.0). The risk for caesarean section decreases with intravenous (OR 0.4; 95 % CI 0.4–0.5) as well as with epidural analgesia (OR 0.6; 95 % CI 0.5–0.6). Neither intravenous nor epidural analgesia incure any risk factor for low Apgar score (< 6) (OR 1.0; 95 % CI 0.8–1.1 for intravenous analgesia) (OR 0.9; 95 % CI 0.7–1.2 for epidural analgesia) or pathological cardiotocogram (OR 1.0; 95 % CI 0.9–1.0 for intravenous analgesia) (OR 1.0; 95 % CI 0.9–1.1 for epidural analgesia).Conclusions: Intravenous and epidural analgesia affected the course and outcome of labour. Mothers under epidural anagesia had a higher risk of labour longer than 7 hours, incidence of occipitoposterior presentation and vaccum extraction of fetus. Pain control during labour reduced the risk of caesarean section and had no adverse effects on the neonate.

To compare the effects of paravertebral analgesia with levobupivacaine or bupivacaine on intra- and postoperative pain for thoracic surgery.A prospective, randomized, and double-blinded study.A university hospital.Forty patients undergoing thoracic surgery.Patients received paravertebral catheterization and a bolus (14-20 mL) of 0.5% bupivacaine (n = 20) or 0.5% levobupivacaine (n = 20) with morphine, 60 μg/kg, before the induction of general anesthesia that consisted of a propofol infusion. A paravertebral continuous infusion (0.05 mL/kg/h) of 0.25% bupivacaine or 0.25% levobupivacaine, 100 mL, with added morphine, 10 mg, and clonidine, 0.15 mg, was started at the end of surgery for 72 hours postoperatively. Postoperative rescue diclofenac analgesia was available if required.The primary outcome was intraoperative fentanyl consumption. Static and dynamic pain scores measured by a visual analog scale were assessed regularly. Intraoperative fentanyl consumption was significantly lower in the levobupivacaine group compared with the bupivacaine group (p = 0.001). On all 3 postoperative days, static pain scores were significantly lower in the levobupivacaine group compared with the bupivacaine group (p0.05). Dynamic pain scores were significantly lower in the levobupivacaine group compared with the bupivacaine group during the 2 postoperative days (p0.05). A smaller proportion of patients in the levobupivacaine group used rescue analgesia (p0.005).Paravertebral analgesia with levobupivacaine resulted in less intraoperative fentanyl consumption, lower static (3 days) and dynamic (2 days) pain scores, and less rescue analgesia than analgesia with bupivacaine.

Study objective The objective was to present a proof of concept for a simple and consistently successful ultrasonograpy (US)-guided technique to block the internal branch of the superior laryngeal nerve (iSLN). Design This was a volunteer and cadaver anatomy study. Setting The setting was an anesthesiology department and an anatomy laboratory at a medical school Measurements H13-6 MHz US scans were performed in 40 healthy volunteers positioned supine and with extended necks. The goals were to identify the thyrohyoid membrane, measure its depth (in centimeters) using the shortest vertical distance from the skin, and record the scanning time (in seconds) needed to obtain the optimal image. Anatomical dissection was performed with an operating microscope bilaterally on 5 adult cadaver heads, fixed in formalin, to expose the point of iSLN penetration through the thyrohyoid membrane. The distance between the greater horn of the hyoid bone and the nerve entry point into the thyrohyoid membrane was measured. Ultrasonography-guided in-plane injections were performed unilaterally with 22-gauge 50-mm nerve block needles in 3 fresh cadavers with 2-mL lidocaine/methylene blue mixture deposited under direct vision just superficial to the thyrohyoid membrane to evaluate technical feasibility and injectate spread. Main results Anatomically, the iSLN was identified in all formalin-preserved cadavers, with hyoid bone greater horn to nerve-membrane interface distances measuring 1.0-2.4 cm (mean, 2.0 cm; SD, 0.5). Sonographically, the iSLN was not visualized, whereas the hyoid bone and the thyrohyoid membrane were visualized in all volunteers. The mean distance from skin to thyrohyoid membrane was 1.69 cm (SD, 0.38). The mean time needed to scan was 15 seconds (SD, 2.3). After US-guided injection, the dye deposition was observed around the iSLN in all cadaver specimens. Conclusions A simpler and consistently reproducible US-guided iSLN block is feasible using the thyrohyoid membrane as target plane for local anesthetic injection. Clinical trials are needed to determine its effectiveness and safety, needle entry point, trajectory, and local anesthetic volume.

BACKGROUND Ultrasound gel nerve inflammation has been reported. We evaluated the extent and nature of inflammation after gel injection with endotoxin (positive), saline, or dry needle puncture (negative) controls after peripheral blocks in piglets. METHODS Selected nerves of 12 piglets were localized by landmarks and nerve stimulator. Forty-eight hours after injection, specimens were examined for immunohistochemical cell differentiation/quantification and cytokine expression by using quantitative polymerase chain reaction. RESULTS Both gel and endotoxin injections resulted in a significantly higher density of inflammatory cells (lymphocytes/granulocytes) as compared with needle insertions and/or saline injections (both P < 0.001). Cytokines were not detected in any of the specimens. CONCLUSIONS Perineural gel injections cause significant inflammation. The lack of cytokines suggests injectate-related changes rather than mechanical trauma.

Background Ultrasound-guided neuraxial anesthesia requires the application of ultrasound gel between the transducer and the skin to avoid signal drop-off. As the needle is inserted, the gel may be introduced intrathecally. The purpose of this study was to examine the evidence of an inflammatory response in the subarachnoid space after intrathecal gel introduction. Methods Twelve piglets were sedated with azaperone 0.5 mg/kg intramuscularly and anesthetized via face mask (2%–4% isoflurane in 50% air-oxygen mixture). After collection of cerebrospinal fluid by lumbar puncture with a 22-gauge needle (baseline), 0.2 mL of ultrasound gel mixed with 1 mL of saline was injected intrathecally into 9 piglets (gel group). In 3 piglets (control group), 1 mL of saline was administered. Behavioral and neurologic assessments were recorded on a 4-grade scale. Following the preinjection and postinjection cerebrospinal fluid collection, the piglets were killed, and samples of spinal cord with meninges were excised. Five cross sections (1 mm apart) were processed using immunohistochemistry. Results After anesthesia, all piglets displayed short-lived mild (grade 1) motor and behavioral deficits. Mean ± SD protein concentrations in the gel and baseline samples were 14.1 ± 3.0 and 1.3 ± 0.5 g/L, respectively (P = 0.001). No differences were found in protein concentration between baseline (1.8 ± 0.7 g/L) and control samples (2.8 ± 0.8 g/L) (P = 0.4). In the gel group, numerous immunopositive cells were found in the pia, arachnoid, and inner layer of dura. Conclusion Subarachnoid injection of ultrasound gel in piglets results in an inflammatory response within neuraxial space.

Background and Objectives Anesthesia and analgesia with paravertebral block are reportedly variable. Existence of an endothoracic fascia has been proposed as one of the possible mechanisms leading to variability. We undertook an electron-microscopy imaging study to investigate the endothoracic fascia in the thoracic paravertebral space (TPS) in rats. Methods Male Wistar rats were studied in accordance with the principles of laboratory animal care. After the rats were euthanized in a CO2 chamber, the thoracic paravertebral tissues were removed en bloc and cut into consecutive transverse sections of approximately 3 mm. Stereomicroscopy and electron-microscopy assessments were performed by 2 independent observers. Results The endothoracic fascia was consistently identified in all specimens. The fascia was located between the parietal pleura and the innermost intercostal muscles or ribs. Its thickness ranged from 15 to 27 μm (mean, 20 ± 3 μm). The endothoracic fascia divided the TPS in 2 compartments: one, extrapleural and anterolateral (EPC); another, subendothoracic and posteromedial (SETC). The spinal nerves with their ganglia were found within SETC, whereas the sympathetic ganglia were consistently located within the EPC. Conclusions The endothoracic fascia in rats appears to divide the TPS into EPC and SETC. These anatomic characteristics may have implications in thoracic paravertebral blockade.

Background: Epidural analgesia can result in perioperative hypotension in patients having thoracotomy. This randomized prospective study assessed the effects of epidural and paravertebral analgesia on hemodynamics during thoracotomy. Methods: Thirty-two patients were randomized to receive either epidural analgesia (n = 16, 0.25% levobupivacaine and 30 μg/kg morphine) or paravertebral block (n = 16; 0.5% levobupivacaine and 30 μg/kg morphine). Oxygen delivery, stroke volume and systemic vascular resistance indices, heart rate, and mean arterial pressure measurements were performed before administration of local anesthetic, after induction of general anesthesia, institution of 1-lung ventilation, first skin incision, retractor placement, lung-inflation maneuver, and at last skin suture. The primary end point was the volume of the colloid infusion necessary to maintain oxygen delivery index of 500 mL/min per squared meter or higher. Postoperative analgesia was provided immediately after surgery by an infusion of 0.125% levobupivacaine and 20 μg/mL morphine in epidural/paravertebral infusion. Pain, rescue-analgesia consumption, arterial pressure, and heart rate were recorded at 6, 24, and 48 hrs after surgery. Administration of anesthesia and data collection were done by research staff blinded to the regional analgesia technique. Results: The groups did not differ significantly in heart rate, mean arterial blood pressure, or systemic vascular resistance indices. However, to maintain the targeted oxygen delivery index, a greater volume of colloid infusion and phenylephrine were required, respectively, in the epidural than in the paravertebral group (554 ± 50 vs 196 ± 75 mL, P = 0.04; and 40 ± 10 vs 17 ± 4 μg, P = 0.04). Pain intensity before and after respiratory physiotherapy as well as 24 hr rescue piritramide consumption was similar in the epidural (4.1 ± 3.1 mg) and the paravertebral (2.5 ± 1.5 mg) groups (P = 0.14). Systolic blood pressure after 24 and 48 hrs was lower in the epidural group. Conclusions: Under the conditions of our study, continuous paravertebral block resulted in similar analgesia but greater hemodynamic stability than epidural analgesia in patients having thoracotomy. Paravertebral block also required smaller volume of colloids and vasopressors to maintain the target oxygen delivery index (DO2I).

Background Minimally invasive parathyroidectomy (MIP) can be performed under cervical plexus block (CPB). Superficial CPB has been reported to be easier to perform with similar efficacy and less anesthesia-related complications than combined deep and superficial CPB. In this study, we compared the efficacy of superficial and combined (deep and superficial) CPB in patients undergoing MIP. Methods Forty-two patients with primary hyperparathyroidism due to a solitary adenoma were randomized to receive either a superficial (group superficial, n = 20) or a combined deep and superficial CPB (group combined, n = 22) using 0.35 mL/kg of 0.5% levobupivacaine. The primary end-point was the amount of supplemental fentanyl required to complete surgery. Results There were no differences in onset of block, pain scores during surgery, or time to first analgesic request between groups. Fentanyl consumption was similar in both groups, i.e., 50 (0-200) microg in group superficial and 50 (0-100) microg in group combined (P = 0.60). Six patients [1 in group superficial (5%) and 5 in group combined (22.7%)] were converted to general anesthesia for surgically required bilateral neck dissection (P = 0.18). General anesthesia for block failure was reported in three superficial (15%) and two combined group patients (9%) (P = 0.99). In group combined, only one patient (4.5%) showed diaphragmatic paresis after the block (P = 0.99). Conclusion Superficial CPB is an alternative to combined block for MIP.

Study Objective To evaluate the pharmacokinetic profile of 0.35 mL/kg of 0.5% levobupivacaine during superficial and combined (deep and superficial) cervical plexus block (CPB) in patients undergoing minimally invasive parathyroidectomy. Design Prospective randomized study. Setting Operating theater of a university hospital. Patients 12 ASA physical status II and III patients (11 women and 1 man), scheduled for minimally invasive parathyroidectomy. Interventions Seven and 5 patients were randomly assigned to receive either superficial or combined CPB, respectively. The superficial CPB was performed with an injection of 0.35 mL/kg of 0.5% levobupivacaine subcutaneously along the posterior border of the sternocleidomastoid muscle and deeper on its medial surface. The combined CPB was initiated by the deep block at the C3 level vertebra by injecting 0.2 mL/kg of 0.5% levobupivacaine, followed by the superficial block with an injection of the remaining 0.15 mL/kg. After completion of the block, venous blood was sampled at the intervals of 5, 10, 15, 20, 30, 45, and 60 minutes. Measurements and Main Results Venous plasma concentrations were measured using gas chromatography-mass spectroscopy. Mean ± SD of maximal concentrations of levobupivacaine was 0.58 ± 0.41 mg/L in group superficial and 0.52 ± 0.28 mg/L in group combined ( P = 0.71). The median (range) time required to reach the maximal concentrations was 30 minutes (20-30 min) in group superficial and 20 minutes (15-30 min) in group combined ( P = 0.45). The areas under the drug concentration/time curve (AUC 10-60 ) were also similar in both groups. No signs of central nervous system or cardiovascular toxicity or other untoward events were observed in any patient. Conclusion With the given dose regimen, levobupivacaine plasma concentrations were within safe ranges.