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Objective Pain severity and opioid requirements in the postoperative period show substantial and clinically significant inter-patient variation due mainly to factors such as age, surgery type, and duration. Genetic factors have not been adequately assessed except for the neuronal OPRM1 rs1799971 and COMT rs4680, whereas the contribution of innate immune signaling pathway genetics has seldom been investigated. Setting Hospital surgical ward. Subjects Women (107 Indian, 184 Malay, and 750 Han Chinese) undergoing total hysterectomy surgery. Methods Morphine consumption, preoperative pain, and postoperative pain were evaluated in relation to genetic variability comprising 19 single-nucleotide polymorphisms (SNPs) in 14 genes involved in glial activation, inflammatory signaling, and neuronal regulation, plus OPRM1 (1 SNP) and COMT (3 SNPs). Results Pre- and postoperative pain and age were associated with increased and decreased morphine consumption, respectively. In Chinese patients, only 8% of the variability in consumption could be explained by these nongenetic and genetic (BDNF, IL1B, IL6R, CRP, OPRM1, COMT, MYD88) factors. However, in Indian patients, 41% of morphine consumption variability could be explained by age (explaining Conclusions This is the highest known value reported for genetic contributions (38%) to morphine use in the acute postoperative pain setting. Our findings highlight the need to incorporate both genetic and nongenetic factors and consider ethnicity-dependent and nonadditive genotypic models in the assessment of factors that contribute to variability in opioid use.

Background During spinal anaesthesia for caesarean section, haemodynamic instability may lead to maternal and foetal complications. We developed a novel advanced double intravenous vasopressor automated system (ADIVA) by using a continuous blood pressure and heart rate monitor. Treatment of hypotension was based on three criteria: the drug (phenylephrine or ephedrine) according to the heart rate; the dose of vasopressor determined by the degree of hypotension; a fast or slow bolus of vasopressor administered depending on whether there was a negative or positive gradient of SBP changes, respectively. Objective The aim of this pilot study was to investigate the feasibility of the ADIVA algorithm. Design A prospective pilot study. Setting Single obstetrics and gynaecology centre in Singapore. Patients Women undergoing elective caesarean delivery under spinal anaesthesia. Intervention Automated administration of ephedrine or phenylephrine based on changes in blood pressure and heart rate (via the ADIVA algorithm) detected on continuous noninvasive haemodynamic monitoring using noninvasive continuous haemodynamic monitor (Nexfin). Main outcome measures The primary outcome was the incidence of hypotension, defined as SBP less than 80% of baseline. The secondary outcome measures were reactive hypertension, total vasopressor requirement, maternal and neonatal outcomes and system performance. Results Forty-five women were recruited. Thirty-one women (69.9%) had at least one reading of hypotension. SBP was within ±20% of the baseline in a mean ± SD of 79.7 ± 17.6% of measurements. Forty-four (97.8%) women required phenylephrine before delivery, while 15 (33.3%) required ephedrine. No rescue medications were required. Three women (6.7%) had nausea and two (4.4%) vomiting. All neonates had APGAR scores of 9 at 5 min. Conclusion The ADIVA system, with noninvasive continuous haemodynamic monitoring, was able to maintain maternal SBP within ±20% of baseline for the vast majority of the measurements. This system had good maternal and foetal outcomes with minimal intervention from the attending anaesthetist. Trial registration NCT03620942.

Unless prevented, hypotension occurs in up to 80% of normotensive women undergoing spinal anaesthesia for caesarean delivery. Renin-angiotensin-aldosterone system genetic polymorphisms have been associated with hypertensive disease, but few studies investigated effects on blood pressure regulation under spinal anaesthesia. We postulated that these polymorphisms increased vasodilation and maternal hypotension during spinal anaesthesia.A retrospective secondary analysis of data from four prospective trials with similar inclusion/exclusion criteria evaluating phenylephrine/ephedrine delivery systems during spinal anaesthesia for elective caesarean delivery. Angiotensin type-1 receptor (AT1R) (A1166C), angiotensin-converting enzyme (ACE) (I/D), and aldosterone synthase CYP11B2 (C344T) polymorphisms were identified from stored specimens. The associations between the polymorphisms and hypotension (systolic blood pressure80% of baseline), and vasopressor use, were determined by univariable and multivariable regression.Of 556 patients, 378 (68.0%) had hypotension. The AC/CC genotypes of AT1R (A1166C) were associated with hypotension by univariable analysis (OR 2.70, 95% CI 1.38 to 5.28, P=0.004]) and multivariable analysis (OR 3.65, [95% CI 1.68 to 7.94, P=0.004]) after adjustment for age, race, intravenous fluid volume, and block height. No difference in vasopressor use or adverse maternal or fetal outcomes were noted. Baseline characteristics were similar, with the exception of higher baseline blood pressure, block height, and intravenous fluid volume in the hypotensive group. There was no significant association between ACE and CYP11B2 polymorphisms and hypotension.AC/CC genotypes of AT1R (A1166C) polymorphism were associated with maternal hypotension under spinal anaesthesia for caesarean delivery. An association with cardiovascular indices and high-risk parturients should be examined.

Background Although cesarean delivery is one of the most commonly performed surgical procedures, robust data regarding post-cesarean pain is still lacking. Recent studies showed an association between pain upon local anesthetic (LA) injection for spinal anesthesia, or the use of a "three simple questions", and acute post-cesarean pain. Nevertheless, these assessments have yet to be validated further, despite their relative ease of use. We aimed to assess the association between pain score upon LA injection with acute post-cesarean pain after 24 hours at rest (primary outcome) and sub-acute post-cesarean pain lasting for 4 weeks or more (secondary outcome). Methods Women undergoing cesarean delivery under spinal anesthesia were given pre-operative questionnaires on pain and psychological vulnerability. We also assessed the pain score upon LA injection and mechanical temporal summation. Univariate and multivariable logistic regressions were performed. Results The incidence of moderate-to-severe acute post-cesarean pain at 24 hours was 21.0% (95% CI=16.6-27.6%) (48 of 217 patients). Pain score upon LA injection was not significantly associated with acute post-cesarean pain after 24 hours at rest (unadjusted OR=1.10, 95% CI=0.95-1.27, P=0.21). However, pain score upon LA injection was significantly associated with sub-acute post-cesarean pain (adjusted OR=1.29, 95% CI=1.07-1.55, P=0.0089) with significant covariate of increased pre-operative central sensitization inventory (CSI) scores (adjusted OR=1.05, 95% CI=1.01-1.09, P=0.0111; area under the curve (AUC)=0.691). Conclusion There was no association between increased pain score upon LA injection and acute post-cesarean pain, but it was associated with sub-acute post-cesarean pain. Further work is needed to define pain score upon LA injection as a convenient pragmatic measure of risk stratifying patients predisposed to sub-acute post-cesarean pain.

Purpose Hysterectomy is associated with a high incidence of chronic post-hysterectomy pain (CPHP). Pain catastrophizing, a negative cognitive-affective response to pain, is associated with various pain disorders but its role in CPHP is unclear. We aimed to determine the association of high preoperative pain catastrophizing with CPHP development and functional impairment 4 months after surgery. Patients and methods Secondary analysis of a prospective cohort study of women undergoing abdominal/laparoscopic hysterectomy to investigate the association between high pain catastrophizing (pain catastrophizing scale, PCS≥20) with CPHP and associated functional impairment (defined as impairment with standing for ≥30 minutes, sitting for ≥30 minutes, or walking up or down stairs). CPHP and functional impairment were assessed via 4- and 6-month phone surveys. Results Of 216 patients, 72 (33.3%) had high PCS, with mean (SD) of 30.0 (7.9). In contrast, 144 (66.7%) patients had low PCS, with mean (SD) of 9.0 (4.7). At 4 months, 26/63 (41.3%) patients in the high PCS group developed CPHP, compared to 24/109 (22.0%) in the low PCS group. At 6 months, 14/53 (26.4%) high PCS patients developed CPHP, compared to 10/97 (10.3%) patients with low PCS. High PCS was independently associated with CPHP at 4 months (OR 2.49 [95% CI 1.27 to 4.89], p=0.0082) and 6 months (OR 3.12 [95% CI 1.28 to 7.64], p=0.0126) but was not associated with functional impairment. High PCS≥20, presence of evoked mechanical temporal summation (MTS), and history of abdominal/pelvic surgery predict CPHP at 4 months with area under the curve (AUC) of 0.69. Similarly, PCS≥20 and increasing MTS magnitude predicted CPHP at 6 months with AUC of 0.76. Conclusion High PCS was independently associated with CPHP. Future studies should identify other CPHP associated factors to formulate a risk-prediction model and investigate the effectiveness of early intervention for pain catastrophizers in improving pain-related outcomes.

Purpose Postnatal depression (PND) is associated with maternal morbidity and socioeconomic burden. Recent studies have shown an association between pain catastrophizing, increased labor pain, and subsequent adverse postnatal adjustment; however, little is known on its role in PND development. We aimed to investigate the association between pain catastrophizing and probable PND. Methods Parturients planning to undergo epidural labor analgesia were recruited. Predelivery questionnaires, including the Pain Catastrophizing Scale (PCS) and Edinburgh Postnatal Depression Scale (EPDS), were administered during early labor. A phone survey at 5- 9 weeks postdelivery was conducted to determine postdelivery EPDS and Spielberger's State-Trait-Anxiety Inventory scores. The primary outcome was a binary variable of postdelivery EPDS with cutoff of ≥10, whereas the secondary outcome was a continuous variable on increases in EPDS score. Results Probable PND (EPDS ≥10) occurred in 10.5% (95% CI 8.0%-13.5%, 55 of 525) of women who underwent epidural labor analgesia. We found that high pain catastrophizing (PCS ≥25) was associated with increased postdelivery EPDS scores (adjusted β estimate 0.36, 95% CI 0.15-0.57; p=0.0008), but did not meet significance for increased risk of probable PND (p=0.1770). Additionally, presence of breakthrough pain during epidural analgesia (adjusted β estimate 0.24, 95% CI 0.02-0.46; p=0.0306) and lower BMI at term (adjusted β estimate -0.04, 95% CI -0.07 to -0.01; p=0.0055) were associated with increased postdelivery EPDS scores. Conclusion No significant association was found between high pain catastrophizing and probable PND; however, high predelivery pain catastrophizing, presence of breakthrough pain during epidural analgesia, and lower BMI at term were associated with increased postdelivery EPDS scores. Further research will be needed to validate this association in the context of the risk of PND development.

Background Single nucleotide polymorphisms (SNPs) of the voltage-gated sodium channel alpha subunit gene (SCN9A) have been associated with pain in various settings. The aim of this study was to investigate the association of the SNPs to evaluate the influence of common gene variants on chronic postoperative pain (CPSP) and other related pain variables in a cohort of patients who underwent a scheduled hysterectomy. Methods DNA samples from a cohort of 1,075 patients who underwent a scheduled total hysterectomy in our hospital were genotyped for three common SCN9A SNPs using TaqMan assays. Multivariate logistic regression models were used to quantify the association between independent covariates such as pain threshold, pain endurance, pain scores, morphine use, and the presence of chronic pain. Results Frequencies of the minor alleles were different between the different ethnic groups. There was a statistically significant association of rs16851799 with morphine consumption and self-reported postoperative pain for the 1,038 subjects genotyped, with the TT genotype reporting higher pain and using more morphine. For the subpopulation of 446 subjects with chronic pain data, there was a similar association with self-reported postoperative pain and tolerance of pressure pain. Univariate analysis also showed a statistically significant association of rs16851799 with CPSP, whereas multivariable analysis revealed a similar association of rs4387806 with this outcome. There were three haplotypes with different relative frequencies for the CPSP and non-CPSP groups. Conclusions Our results showed that SCN9A polymorphisms could play a role in acute pain perception and the susceptibility to chronic pain.

Purpose Pre-operative association factors (pain and psychological vulnerability) could significantly contribute to post-Cesarean pain; however, limited information is available on the development of postnatal depression (PND). We aimed to investigate the development of PND and its association with pain vulnerability and psychological vulnerability factors. Patients and methods Women undergoing Cesarean delivery under spinal anesthesia were given pre-operative questionnaires, psychological and pain assessments including pain on local anesthetic injection during spinal anesthesia and mechanical temporal summation. Post-operative assessments were administered at 6 to 10 weeks post-Cesarean delivery via follow-up survey to assess post-Cesarean psychological and pain outcomes. Results PND occurred in 21.1% (43 of 205) of patients who underwent elective Cesarean delivery. An increased pre-operative pain score with movement (Odds ratio (OR) 1.65, 95% CI 1.12-2.44, p = 0.0110), anxiety about upcoming surgery (OR 1.02, 95% CI 1.00-1.04, p = 0.0429), higher pre-operative Hospital Anxiety and Depression Scale (HADS) subscale on anxiety (OR 1.25, 95% CI 1.07-1.45, p = 0.0041) and higher pre-operative central sensitization inventory (CSI) scores (OR 1.05, 95% CI 1.01-1.09, p = 0.0156) were independently associated with an increased risk of PND. Anticipated pain medication needs were associated with reduced risk of PND (OR 0.48, 95% CI 0.29-0.79, p = 0.0038) (Receiver operating characteristic (ROC) = 0.8177). Conclusion Higher pre-operative anxiety, pain score, central sensitization and lower anticipated pain medication needs were associated with increased risks of PND. Further work using larger sample size will be needed to validate the model in predicting PND development after Cesarean delivery.

Summary: The COVID-19 pandemic has had a substantial and global impact on health care, and has greatly accelerated the adoption of digital technology. One of these emerging digital technologies, blockchain, has unique characteristics (eg, immutability, decentralisation, and transparency) that can be useful in multiple domains (eg, management of electronic medical records and access rights, and mobile health). We conducted a systematic review of COVID-19-related and non-COVID-19-related applications of blockchain in health care. We identified relevant reports published in MEDLINE, SpringerLink, Institute of Electrical and Electronics Engineers Xplore, ScienceDirect, arXiv, and Google Scholar up to July 29, 2021. Articles that included both clinical and technical designs, with or without prototype development, were included. A total of 85 375 articles were evaluated, with 415 full length reports (37 related to COVID-19 and 378 not related to COVID-19) eventually included in the final analysis. The main COVID-19-related applications reported were pandemic control and surveillance, immunity or vaccine passport monitoring, and contact tracing. The top three non-COVID-19-related applications were management of electronic medical records, internet of things (eg, remote monitoring or mobile health), and supply chain monitoring. Most reports detailed technical performance of the blockchain prototype platforms (277 [66·7%] of 415), whereas nine (2·2%) studies showed real-world clinical application and adoption. The remaining studies (129 [31·1%] of 415) were themselves of a technical design only. The most common platforms used were Ethereum and Hyperledger. Blockchain technology has numerous potential COVID-19-related and non-COVID-19-related applications in health care. However, much of the current research remains at the technical stage, with few providing actual clinical applications, highlighting the need to translate foundational blockchain technology into clinical use.

Purpose Epidural analgesia provides safe and effective labor pain relief. However, labor episodic pain can occur during epidural analgesia, requiring epidural top-ups, and may result in decreased patient satisfaction. The primary aim of our study was to investigate the factors associated with labor episodic pain during epidural analgesia. Patients and methods Electronic and hardcopy records of labor deliveries between January 2012 and December 2015 were reviewed at KK Women's and Children's Hospital, Singapore. The primary outcome was the prevalence of episodic pain. Demographic, clinical and anesthetic data were retrieved. Univariate and multivariate logistic regression analyses were used to identify associated risk factors for labor episodic pain experienced by parturients while receiving epidural analgesia. Model performance was assessed by area under the curve (AUC) from the receiver operating characteristic curve. Results The prevalence of labor episodic pain was 14.2% (2,951 of 20,798 parturients). The risk factors associated with labor episodic pain, which are given here as factor (OR, 95% CI), are the following: need for epidural resiting (11.4, 7.53-17.28), higher pain scores intrapartum (1.34, 1.32-1.36), higher Bromage scores (1.12, 1.02-1.22), the need for instrumental delivery (1.32, 1.16-1.52), the need for cesarean delivery (1.41, 1.26-1.59), the presence of venous puncture (1.29, 1.03-1.62), the presence of dural puncture (14.28, 5.92-34.43), the presence of high block (6.05, 1.39-26.35), the need for a urinary catheter (1.17, 1.17-1.34), larger volumes of local anesthetics used (1.01, 1.01-1.01) and higher body mass index (1.01, 1.01-1.02), and decreased maternal satisfaction (0.97, 0.97-0.98). The AUC was 0.80. Conclusion Knowledge of these factors may allow for future interventions in management to prevent labor episodic pain. Further research is needed to validate these association factors.

Background Ultrasonography for neuraxial anesthesia is increasingly being used to identify spinal structures and the identification of correct point of needle insertion to improve procedural success, in particular in obesity. We developed an ultrasound-guided automated spinal landmark identification program to assist anesthetists on spinal needle insertion point with a graphical user interface for spinal anesthesia. Methods Forty-eight obese patients requiring spinal anesthesia for Cesarean section were recruited in this prospective cohort study. We utilized a developed machine learning algorithm to determine the needle insertion point using automated spinal landmark ultrasound imaging of the lumbar spine identifying the L3/4 interspinous space (longitudinal view) and the posterior complex of dura mater (transverse view). The demographic and clinical characteristics were also recorded. Results The first attempt success rate for spinal anesthesia was 79.1% (38/48) (95%CI 65.0 - 89.5%), followed by successful second attempt of 12.5% (6/48), third attempt of 4.2% (2/48) and 4th attempt (4.2% or 2/48). The scanning duration of L3/4 interspinous space and the posterior complex were 21.0 [IQR: 17.0, 32.0] secs and 11.0 [IQR: 5.0, 22.0] secs respectively. There is good correlation between the program recorded depth of the skin to posterior complex and clinician measured depth (r = 0.915). Conclusions The automated spinal landmark identification program is able to provide assistance to needle insertion point identification in obese patients. There is good correlation between program recorded and clinician measured depth of the skin to posterior complex of dura mater. Future research may involve imaging algorithm improvement to assist with needle insertion guidance during neuraxial anesthesia. Trial registration This study was registered on clinicaltrials.gov registry (NCT03687411) on 22 Aug 2018.

BackgroundPre-operative anxiety is common and is associated with negative surgical outcomes. Virtual reality (VR) is a promising new technology that offers opportunities to modulate patient experience and cognition and has been shown to be associated with lower levels of anxiety. In this study, we investigated changes in pre-operative anxiety levels before and after using VR in patients undergoing minor gynecological surgery.MethodsPatients who underwent elective minor gynecological surgeries in KK Women’s and Children’s hospital, Singapore were recruited. The VR intervention consisted of 10-min exposure via a headset loaded with sceneries, background meditation music and breathing exercises. For the primary outcome of pre-operative anxiety, patients were assessed at pre- and post-intervention using the Hospital Anxiety and Depression Scale (HADS). Secondary outcomes of self-reported satisfaction scores and EuroQol 5-dimension 3-level (EQ-5D-3L) were also collected.ResultsData analysis from 108 patients revealed that HADS anxiety scores were significantly reduced from 7.2 ± 3.3 pre-intervention to 4.6 ± 3.0 post-intervention (p p p = 0.025), ‘pain/discomfort’ (p = 0.008) and ‘anxiety/ depression’ (p ConclusionsFor patients undergoing minor gynecological procedures, the VR intervention brought about a significant reduction in pre-operative anxiety. This finding may be clinically important to benefit patients with high pre-operative anxiety without the use of anxiolytics.Trial registrationThis study was registered onclinicaltrials.govregistry (NCT03685422) on 26 Sep 2018.

Introduction Risk-prediction models for breakthrough pain facilitate interventions to forestall inadequate labour analgesia, but limited work has used machine learning to identify predictive factors. We compared the performance of machine learning and regression techniques in identifying parturients at increased risk of breakthrough pain during labour epidural analgesia. Methods A single-centre retrospective study involved parturients receiving patient-controlled epidural analgesia. The primary outcome was breakthrough pain. We randomly selected 80% of the cohort (training cohort) to develop three prediction models using random forest, XGBoost, and logistic regression, followed by validation against the remaining 20% of the cohort (validation cohort). Area-under-the-receiver operating characteristic curve (AUC), sensitivity, specificity, and positive and negative predictive values (PPV and NPV) were used to assess model performance. Results Data from 20 716 parturients were analysed. The incidence of breakthrough pain was 14.2%. Of 31 candidate variables, random forest, XGBoost and logistic regression models included 30, 23, and 15 variables, respectively. Unintended venous puncture, post-neuraxial analgesia highest pain score, number of dinoprostone suppositories, neuraxial technique, number of neuraxial attempts, depth to epidural space, body mass index, pre-neuraxial analgesia oxytocin infusion rate, maternal age, pre-neuraxial analgesia cervical dilation, anaesthesiologist rank, and multiparity, were identified in all three models. All three models performed similarly, with AUC 0.763–0.772, sensitivity 67.0–69.4%, specificity 70.9–76.2%, PPV 28.3–31.8%, and NPV 93.3–93.5%. Conclusions Machine learning did not improve the prediction of breakthrough pain compared with multivariable regression. Larger population-wide studies are needed to improve predictive ability.

Introduction Epidural re-siting is one of the significant events during labour epidural analgesia that may result in decreased patient satisfaction. The aim of our study was to investigate the incidence of and factors associated with epidural re-siting in parturients using epidural analgesia, with an emphasis on those with breakthrough pain. Methods A retrospective cohort study of 10 170 parturients who received labour epidural analgesia. The primary outcome was the incidence of epidural re-siting (binary data). Univariate and multivariate logistic regression analysis were performed to find associated risk factors for re-siting. Results Less than 1% (0.85%, 86/10 170) of the women in the study had their epidural re-sited. Amongst the subset of women with breakthrough pain, the incidence of epidural re-siting was higher (4.7%, 68/1 454). Most of the women who had their epidural re-sited had experienced breakthrough pain (79%, 68/86). Amongst all parturients, the presence of breakthrough pain (OR=21.31), hypotension (OR=4.18) and venous puncture (OR=2.74) were significantly associated with re-siting. Amongst the parturients with breakthrough pain who required epidural re-siting, lower cervical dilatation (OR=0.81), higher number of episodes of breakthrough pain (OR=1.83) and patchy block (OR=4.37) were significantly associated with re-siting. The areas-under-curves of two multivariate models were 0.894 and 0.806 respectively. Conclusion In our institution, the incidence of epidural catheter re-siting was low in all patients. However, the majority of patients whose catheters were re-sited had exhibited breakthrough pain. The risk factors associated with the need for re-siting of catheters in all patients differed from those who had breakthrough pain.

Ban Leong Sng,1,2 Yin Ying Ching,3 Nian-Lin R Han,4 Farida Binte Ithnin,1 Rehena Sultana,5 Pryseley Nkouibert Assam,6 Alex Tiong Heng Sia1,2 1Department of Women’s Anaesthesia, KK Women’s and Children’s Hospital, Singapore, Singapore; 2Duke-NUS Medical School, Singapore, Singapore; 3Ministry of Health Holdings, Singapore, Singapore; 4Division of Clinical Support Services, KK Women’s and Children’s Hospital, Singapore, Singapore; 5Centre for Quantitative Medicine, Duke-NUS Medical School, Singapore, Singapore; 6Singapore Clinical Research Institute, Singapore, Singapore Abstract: Chronic pain has major adverse effects on health-related quality of life and contributes to significant socioeconomic burden. Hysterectomy is a very common gynecological surgery, resulting in chronic post-hysterectomy pain (CPHP), an important pain syndrome. We conducted a prospective cohort study in 216 Asian women who underwent abdominal or laparoscopic hysterectomy for benign conditions. Demographic, psychological, and perioperative data were recorded. Postoperative 4- and 6-month phone surveys were conducted to assess the presence of CPHP and functional impairment. The incidence rates of CPHP at 4 and 6 months were 32% (56/175) and 15.7% (25/159), respectively. Women with CPHP at 4 and 6 months had pain that interfered with their activities of daily living. Independent association factors for CPHP at 4 months were higher mechanical temporal summation score, higher intraoperative morphine consumption, higher pain score in the recovery room, higher pain score during coughing and itching at 24 hours postoperatively, and preoperative pain in the lower abdominal region. Independent association factors for CPHP at 6 months were preoperative pain during sexual intercourse, higher mechanical temporal summation score, and higher morphine consumption during postoperative 24 and 48 hours. In a majority of cases, CPHP resolved with time, but may have significant impact on activities of daily living. Keywords: chronic pain, hysterectomy, mechanical temporal summation score, postsurgical pain, central sensitization, morphine

Background The Supreme™ laryngeal mask airway (SLMA) is a single-use LMA with double lumen design that allows separation of the respiratory and the alimentary tract, hence potentially reducing the gastric volume and risk of aspiration. The purpose of this prospective cohort study is to evaluate the the role of the SLMA as an airway technique for women undergoing category 2 and 3 Cesarean delivery under general anesthesia. Methods We recruited 584 parturients who underwent category 2 or 3 Cesarean delivery under general anesthesia, in which 193 parturients underwent category 2 and 391 parturients underwent category 3 Cesarean delivery. The primary outcome was insertion success rate at 1st attempt in SLMA insertion. The secondary outcomes included anaesthetic, obstetric outcomes and maternal side effects associated with airway device. Results The 1st attempt insertion success rate was 98.3%, while the overall insertion success rate was 100%. The mean (Standard deviation) time to effective ventilation was 15.6 (4.4) seconds. Orogastric tube insertion was successful at the 1st attempt in all parturients. There was no clinical evidence of aspiration or regurgitation. No episodes of hypoxemia, laryngospasm or bronchospasm were observed intra-operatively. The incidence of complications was low and with good maternal satisfaction reported. Conclusions The SLMA could be an alternative effective airway in category 2 and 3 parturients emergency Cesarean Delivery under general anesthesia in a carefully-selected obstetric population. Trial registration Clinical Trials Registration: Clinicaltrials.gov Registration NCT02026882 . Registered on December 31, 2013.

Both isobaric and hyperbaric bupivacaine have been used for spinal anaesthesia for elective caesarean section, but it is not clear if one is better than the other. The primary objective of this systematic review was to determine the effectiveness and safety of hyperbaric bupivacaine compared with isobaric bupivacaine administered during spinal anaesthesia for elective caesarean section. We included 10 studies with 614 subjects in the analysis. There was no evidence of differences either in the risk of conversion to general anaesthesia, with a relative risk (95%CI) of 0.33 (0.09-1.17) (very low quality of evidence), or in the need for supplemental analgesia, the relative risk (95%CI) being 0.61 (0.26-1.41) (very low quality of evidence). There was also no evidence of a difference in the use of ephedrine, the amount of ephedrine used, nausea and vomiting, or headache. Hyperbaric bupivacaine took less time to reach a sensory block height of T4, with a mean difference (95%CI) of -1.06 min (-1.80 to -0.31). Due to the rarity of some outcomes, dose variability, use of adjuvant drugs and spinal technique used, future clinical trials should look into using adequate sample size to investigate the primary outcome of the need for supplemental analgesia.

Intravenous remifentanil patient-controlled analgesia can be used during labour as an alternative to epidural analgesia. Adverse effects of opioids, including hypoxia and bradycardia, may lead to maternal morbidity and mortality. We devised an interactive feedback system based on a clinical proportional algorithm, to continuously monitor for adverse effects to enhance safety and better titrate analgesia. This vital signs-controlled, patient-assisted intravenous analgesia with remifentanil used a prototype delivery system linked to a pulse oximeter that evaluated maternal oxygen saturation and heart rate continuously. With this system, we detected oxygen saturation < 95% for more than 60 s in 15 of 29 subjects (52%); and heart rate < 60 min-1 for more than 60 s in 7 of 29 subjects (24%) during use. The system automatically responded appropriately by reducing the dosages and temporarily halting remifentanil administration, thus averting further hypoxia and bradycardia.

Neuraxial analgesia is considered the gold standard in labour analgesia, providing the most effective pain relief during childbirth. Improvements have enhanced the efficacy and safety of epidural analgesia through better drugs, techniques and delivery systems. This review describes the history of epidural labour analgesia and recent improvements in labour epidural analgesia. We discuss the role of the combined spinal epidural technique, low-concentration local anaesthetic-opioid epidural solutions, patient-controlled epidural analgesia, and programmed intermittent or automated mandatory boluses in the maintenance of epidural labour analgesia. We also review the newer interactive techniques for drug delivery, such as computer-integrated patient-controlled epidural analgesia and variable frequency automated mandatory bolus. Finally, we discuss future clinical research developments, including the use of data analytics and long-term outcomes associated with childbirth pain management.

Persistent childbirth pain (pelvic, perineal, and abdominal pain lasting ≥2 months) affects up to 20% of women, with adverse impact on quality of life.[1][1] Despite increasing associations between analgesic and psychological risk factors with persistent pain,[1 2][1] their association with

Background We developed a Vital-signs-integrated Patient-assisted Intravenous opioid Analgesia (VPIA) analgesic infusion pump, a closed-loop vital signs monitoring and drug delivery system which embodies in a novel algorithm that takes into account patients’ vital signs (oxygen saturation, heart rate). The system aims to allow responsive titration of personalized pain relief to optimise pain relief and reduce the risk of respiratory depression. Moreover, the system will be important to enable continuous monitoring of patients during delivery of opioid analgesia.Methods Nineteen patients who underwent elective gynecological surgery with postoperative patient controlled analgesia (PCA) with morphine were recruited. The subjects were followed up from their admission to the recovery room/ ward for up to 24 hours until assessment of patient satisfaction on the VPIA analgesic infusion pump.Results The primary outcome measure of incidence of oxygen desaturation showed all patients had at least one episode of oxygen desaturation (

Background We developed a Vital-signs-integrated Patient-assisted Intravenous opioid Analgesia (VPIA) analgesic infusion pump, a closed-loop vital signs monitoring and drug delivery system which embodies in a novel algorithm that takes into account patients’ vital signs (oxygen saturation, heart rate). The system aims to allow responsive titration of personalized pain relief to optimise pain relief and reduce the risk of respiratory depression. Moreover, the system will be important to enable continuous monitoring of patients during delivery of opioid analgesia. Methods Nineteen patients who underwent elective gynecological surgery with postoperative patient controlled analgesia (PCA) with morphine were recruited. The subjects were followed up from their admission to the recovery room/ ward for up to 24 hours until assessment of patient satisfaction on the VPIA analgesic infusion pump. Results The primary outcome measure of incidence of oxygen desaturation showed all patients had at least one episode of oxygen desaturation (

Obstetric dfficult airway is a leading cause of maternal morbidity and mortality. The laryngeal mask airway (LMA) is often used as a rescue airway device after failed intubation, however, little is known about predictors of difficult LMA insertion, particularly in obstetrics. Since Mallampati scores of III/IV has been associated with difficult tracheal intubation, our present study aims to investigate if Mallampati score (MP) could predict airway outcomes for LMA use in obstetrics. This prospective cohort study was performed at a single-center: Quanzhou Women’s and Children’s Hospital, Fujian Province, China. Five hundred and eighty-four parturients undergoing elective cesarean section under general anesthesia were recruited. The primary outcome was time to effective ventilation, and secondary outcomes included first attempt insertion success, seal pressure, ventilation and hemodynamic parameters, occurrence of clinical aspiration, and maternal and fetal outcomes. The parturients were classified into two groups based on MP of III/IV (High MP: 61) versus I/II (Low MP: 523). BMI was higher in the High MP group than in the Low MP group (mean (SD) 29.3 (7.0) vs 26.8 (3.1), p

Neuraxial techniques are the current gold standard for labour analgesia, but are associated with up to 25% incidence of breakthrough pain. In this review, we aim to update clinicians on the latest research pertaining to the optimization of neuraxial labour analgesia.Attempts to improve the efficacy and reliability of epidural analgesia while minimizing adverse effects have resulted in the rising popularity of combined spinal epidural and the dural puncture epidural (DPE). Recent studies have focused on determining the safety, efficacy, and optimization of the DPE technique.Another research focus is on the development of individualized therapy in which patients may titrate their own labour analgesia according to their varying requirements, possibly augmented with computer-aided feedback systems and automated mandatory bolus techniques that automatically adjust drug delivery to the patients' analgesic requirements. The addition of a risk-stratification model based on maternal, anaesthetic, and obstetric factors will facilitate early institution of individualized therapy to forestall breakthrough pain in higher risk patients.Recent advances in combined spinal epidural, DPE, automated mandatory bolus, and individualized therapies have advanced our goal of providing effective labour analgesia that is titrated to changing analgesic requirements during labour and delivery and reducing breakthrough pain.

Mun-Fai Loke,1 Heming Wei,1 Junjie Yeo,2 Ban-Leong Sng,3 Alex T Sia,3 Ene-Choo Tan1 1Research Laboratory, KK Women’s & Children’s Hospital, Singapore, Singapore; 2Duke-NUS Medical School, Singapore, Singapore; 3Department of Women’s Anaesthesia, KK Women’s & Children’s Hospital, Singapore, SingaporeCorrespondence: Ene-Choo TanKK Research Centre, KK Women’s and Children’s Hospital, Singapore 229899, SingaporeTel +65 6 394 3792Fax +65 6 394 1618Email tan.ene.choo@kkh.com.sgPurpose: Most of the genetic variants that are reported to be associated with common pain phenotypes and analgesic use are common polymorphisms. The objective of our study was to identify new variants and investigate less common genetic variants that are usually not included in either small single-gene studies or high-throughput genotyping arrays.Patients and methods: From a cohort of 1075 patients who underwent a scheduled total abdominal hysterectomy, 92 who had higher self-rated pain scores and used more morphine were selected for the re-sequencing of 105 genes.Results: We identified over 2400 variants in 104 genes. Most were intronic with frequencies >5%. There were 181 novel variants, of which 30 were located in exons: 17 nonsynonymous, 10 synonymous, 2 non-coding RNA, and 1 stop-gain. For known variants that are rare (population frequency

Background Neuraxial procedures are commonly performed for therapeutic and diagnostic indications. Currently, they are typically performed via palpation-guided surface landmark. We devised a novel intelligent image processing system that identifies spinal landmarks using ultrasound images. Our primary aim was to evaluate the first attempt success rate of spinal anesthesia using landmarks obtained from the automated spinal landmark identification technique. Methods In this prospective cohort study, we recruited 100 patients who required spinal anesthesia for surgical procedures. The video from ultrasound scan image of the L3/4 interspinous space in the longitudinal view and the posterior complex in the transverse view were recorded. The demographic and clinical characteristics were collected and analyzed based on the success rates of the spinal insertion. Results Success rate (95%CI) for dural puncture at first attempt was 92.0% (85.0–95.9%). Median time to detection of posterior complex was 45.0 [IQR: 21.9, 77.3] secs. There is good correlation observed between the program-recorded depth and the clinician-measured depth to the posterior complex (r = 0.94). Conclusions The high success rate and short time taken to obtain the surface landmark with this novel automated ultrasound guided technique could be useful to clinicians to utilise ultrasound guided neuraxial techniques with confidence to identify the anatomical landmarks on the ultrasound scans. Future research would be to define the use in more complex patients during the administration of neuraxial blocks. Trial registration This study was retrospectively registered on clinicaltrials.gov registry (NCT03535155) on 24 May 2018.

Purpose Epidural analgesia provides safe and effective labor pain relief. However, labor episodic pain can occur during epidural analgesia, requiring epidural top-ups, and may result in decreased patient satisfaction. The primary aim of our study was to investigate the factors associated with labor episodic pain during epidural analgesia. Patients and methods Electronic and hardcopy records of labor deliveries between January 2012 and December 2015 were reviewed at KK Women’s and Children’s Hospital, Singapore. The primary outcome was the prevalence of episodic pain. Demographic, clinical and anesthetic data were retrieved. Univariate and multivariate logistic regression analyses were used to identify associated risk factors for labor episodic pain experienced by parturients while receiving epidural analgesia. Model performance was assessed by area under the curve (AUC) from the receiver operating characteristic curve. Results The prevalence of labor episodic pain was 14.2% (2,951 of 20,798 parturients). The risk factors associated with labor episodic pain, which are given here as factor (OR, 95% CI), are the following: need for epidural resiting (11.4, 7.53–17.28), higher pain scores intrapartum (1.34, 1.32–1.36), higher Bromage scores (1.12, 1.02–1.22), the need for instrumental delivery (1.32, 1.16–1.52), the need for cesarean delivery (1.41, 1.26–1.59), the presence of venous puncture (1.29, 1.03–1.62), the presence of dural puncture (14.28, 5.92–34.43), the presence of high block (6.05, 1.39–26.35), the need for a urinary catheter (1.17, 1.17–1.34), larger volumes of local anesthetics used (1.01, 1.01–1.01) and higher body mass index (1.01, 1.01–1.02), and decreased maternal satisfaction (0.97, 0.97–0.98). The AUC was 0.80. Conclusion Knowledge of these factors may allow for future interventions in management to prevent labor episodic pain. Further research is needed to validate these association factors.

Although several genetic factors have been associated with postsurgical morphine requirements, those involving the innate immune system and cytokines have not been well investigated. The aim of this study was to investigate the contribution of genetic variability in innate immune signalling pathways to variability in morphine dosage after elective caesarean section under spinal anaesthesia in 133 Indian, 230 Malay, and 598 Han Chinese women previously studied. Twenty single nucleotide polymorphisms in 14 genes involved in glial activation (TLR2, TLR4, MYD88, MD2), inflammatory signalling (IL2, IL6, IL10, IL1B, IL6R, TNFA, TGFB1, CRP, CASP1), and neuronal regulation (BDNF) were newly investigated, in addition to OPRM1, COMT, and ABCB1 genetic variability identified previously. Postsurgical patient-controlled analgesia morphine use (mg/24 hours) was binned into 6 normally distributed groups and scored 0 to 5 to facilitate step-down multiple linear regression analysis of genetic predictors, controlling for ethnicity and nongenetic variables. Ethnicity, OPRM1 rs1799971 (increased), TLR2 rs3804100 (decreased), and an interaction between ethnicity and IL1B rs1143634 (increased), predicted 9.8% of variability in morphine use scores in the entire cohort. In the Indian cohort, 14.5% of the variance in morphine use score was explained by IL1B rs1143634 (increased) and TGFB1 rs1800469 (decreased). In Chinese patients, the incidence of postsurgical pain was significantly higher in variant COMT rs4680 genotypes (P = 0.0007) but not in the Malay or Indian cohorts. Innate immune genetics may contribute to variability in postsurgical opioid requirements in an ethnicity-dependent manner.

Background Epidural catheter re-siting in parturients receiving labour epidural analgesia is distressing to the parturient and places them at increased complications from a repeat procedure. The aim of this study was to develop and validate a clinical risk factor model to predict the incidence of epidural catheter re-siting in labour analgesia. Methods The data from parturients that received labour epidural analgesia in our centre during 2014–2015 was used to develop a predictive model for epidural catheter re-siting during labour analgesia. Multivariate logistic regression analysis was used to identify factors that were predictive of epidural catheter re-siting. The forward, backward and stepwise variable selection methods were applied to build a predictive model, which was internally validated. The final multivariate model was externally validated with the data collected from 10,170 parturients during 2012–2013 in our centre. Results Ninety-three (0.88%) parturients in 2014–2015 required re-siting of their epidural catheter. The training data set included 7439 paturients in 2014–2015. A higher incidence of breakthrough pain (OR = 4.42), increasing age (OR = 1.07), an increased pain score post-epidural catheter insertion (OR = 1.35) and problems such as inability to obtain cerebrospinal fluid in combined spinal epidural technique (OR = 2.06) and venous puncture (OR = 1.70) were found to be significantly predictive of epidural catheter re-siting, while spontaneous onset of labour (OR = 0.31) was found to be protective. The predictive model was validated internally on a further 3189 paturients from the data of 2014–2015 and externally on 10,170 paturients from the data of 2012–2013. Predictive accuracy of the model based on C-statistic were 0.89 (0.86, 0.93) and 0.92 (0.88, 0.97) for training and internal validation data respectively. Similarly, predictive accuracy in terms of C-statistic was 0.89 (0.86, 0.92) based on 2012–2013 data. Conclusion Our predictive model of epidural re-siting in parturients receiving labour epidural analgesia could provide timely identification of high-risk paturients required epidural re-siting.