Fetal Growth Biometry as Predictors of Shoulder Dystocia in a Low-Risk Obstetrical Population

OBJECTIVE

 This study aimed to evaluate fetal biometrics as predictors of shoulder dystocia (SD) in a low-risk obstetrical population.

STUDY DESIGN

 Participants were enrolled as part of a U.S.-based prospective cohort study of fetal growth in low-risk singleton gestations (n = 2,802). Eligible women had liveborn singletons ≥2,500 g delivered vaginally. Sociodemographic, anthropometric, and pregnancy outcome data were abstracted by research staff. The diagnosis of SD was based on the recorded clinical impression of the delivering physician. Simple logistic regression models were used to examine associations between fetal biometrics and SD. Fetal biometric cut points, selected by Youden's J and clinical determination, were identified to optimize predictive capability. A final model for SD prediction was constructed using backward selection. Our dataset was randomly divided into training (60%) and test (40%) datasets for model building and internal validation.

RESULTS

 A total of 1,691 women (98.7%) had an uncomplicated vaginal delivery, while 23 (1.3%) experienced SD. There were no differences in sociodemographic or maternal anthropometrics between groups. Epidural anesthesia use was significantly more common (100 vs. 82.4%; p = 0.03) among women who experienced SD compared with those who did not. Amniotic fluid maximal vertical pocket was also significantly greater among SD cases (5.8 ± 1.7 vs. 5.1 ± 1.5 cm; odds ratio = 1.32 [95% confidence interval: 1.03,1.69]). Several fetal biometric measures were significantly associated with SD when dichotomized based on clinically selected cut-off points. A final prediction model was internally valid with an area under the curve of 0.90 (95% confidence interval: 0.81, 0.99). At a model probability of 1%, sensitivity (71.4%), specificity (77.5%), positive (3.5%), and negative predictive values (99.6%) did not indicate the ability of the model to predict SD in a clinically meaningful way.

CONCLUSION

 Other than epidural anesthesia use, neither sociodemographic nor maternal anthropometrics were significantly associated with SD in this low-risk population. Both individually and in combination, fetal biometrics had limited ability to predict SD and lack clinical usefulness.

KEY POINTS

· SD unpredictable in low-risk women.. · Fetal biometry does not reliably predict SD.. · Epidural use associated with increased SD risk.. · SD prediction models clinically inefficient..

Race-Based Variation in the Utilization of Epidural Analgesia in Addition to General Anesthesia for Open Abdominal Aortic Aneurysm Repair in the United States

BACKGROUND

Epidural analgesia (EA) is recommended along with general anesthesia (GA) for patients undergoing open abdominal aortic aneurysm repair (AAA) and is known to be associated with improved postoperative outcomes. This study evaluates inequities in using this superior analgesic approach and further assesses the disparities at patient and hospital levels.

METHODS

A retrospective analysis was performed using the Vascular Quality Initiative database of adult patients undergoing elective open AAA repair between 2003 and 2022. Patients were grouped and analyzed based on anesthesia utilization, that is, EA + GA (Group I) and GA only (Group II). Study groups were further stratified by race, and outcomes were studied. Univariate and multivariate analyses were performed to study the impact of race on the utilization of EA with GA. A subgroup analysis was also carried out to learn the EA analgesia utilization in hospitals performing open AAA with the least to most non-White patients.

RESULTS

A total of 8,940 patients were included in the study, of which EA + GA (Group I) comprised n = 4,247 (47.5%) patients, and GA (Group II) had n = 4,693 (52.5%) patients. Based on multivariate regression analysis, the odds ratio of non-White patients receiving both EA and GA for open AAA repair compared to White patients was 0.76 (95% confidence interval: 0.53-0.72, P < 0.001). Of the patients who received both EA + GA, non-White race was associated with increased length of intensive care unit stay and a longer total length of hospital stay compared to White patients. Hospitals with the lowest quintile of minorities had the highest utilization of EA + GA for all patients compared to the highest quintile.

CONCLUSIONS

Non-White patients are less likely to receive the EA + GA than White patients while undergoing elective open AAA repair, demonstrating a potential disparity. Also, this disparity persists at the hospital level, with hospitals with most non-White patients having the least EA utilization, pointing toward system-wide disparities.

The 90% effective dose of intrathecal hyperbaric bupivacaine for Cesarean delivery under combined spinal-epidural anesthesia in parturients with super obesity: an up-down sequential allocation study

PURPOSE

To determine the 90% effective dose (ED90) of intrathecal hyperbaric bupivacaine for Cesarean delivery under combined spinal-epidural anesthesia (CSE) in parturients with super obesity (body mass index [BMI] ≥ 50 kg·m-2).

METHODS

We enrolled parturients with BMI ≥ 50 kg·m-2 with term, singleton vertex pregnancies undergoing elective Cesarean delivery under CSE. An independent statistician generated the 0.75% hyperbaric bupivacaine dosing regimen in increments of 0.75 mg using a biased-coin up-down sequential allocation technique. This was combined with 15 μg fentanyl, 150 μg morphine, and normal saline to a volume of 2.05 mL. The initial and maximum doses were 9.75 mg and 12 mg, respectively. Participants, clinical team, and outcome assessors were blinded to the dose. The primary outcome was block success, defined as T6 block to pinprick within ten minutes and no intraoperative analgesic supplementation within 90 min of spinal injection. We determined the ED90 using logistic regression.

RESULTS

We enrolled 45 parturients and included 42 in the analysis. All doses achieved a T6 level within ten minutes, and the primary outcome occurred in 0/1 (0%) of the 9.75-mg doses, 2/3 (67%) of the 10.5-mg doses, 21/27 (78%) of the 11.25-mg doses, and 11/11 (100%) of the 12-mg doses. The ED90 of hyperbaric bupivacaine was 11.56 mg (95% confidence interval, 11.16 to 11.99). Four parturients (9.5%) had sensory level higher than T2, but none was symptomatic or required general anesthesia.

CONCLUSION

The estimated ED90 of hyperbaric bupivacaine with fentanyl and morphine in parturients with super obesity undergoing Cesarean delivery under CSE was approximately 11.5 mg.

STUDY REGISTRATION

ClinicalTrials.gov (NCT03781388); first submitted 18 December 2018.

Application of OFA-based ERAS for video-assisted thoracoscopic surgery in elderly patients with airway stenosis: A case report

BACKGROUND

Thoracic surgery without general anesthesia can be traced back to the First World War, and thoracic epidural block was used to complete the operation due to a large number of patients with gunshot wounds who needed emergency thoracic surgery. By reducing the intraoperative opioid dose, intraoperative and postoperative opioid-related adverse events such as respiratory depression, nausea and vomiting, delirium, hyperalgesia, and other side effects can be reduced to the benefit of patients.

METHODS

A 72-year-old male patient was admitted to the hospital with a 5-day history of multifocal pain throughout the body caused by a fall. The injury was not treated at that time, and the pain gradually increased, accompanied by cough with difficulty expelling sputum.

DIAGNOSES

Left lung contusion; traumatic pneumonia; multiple left rib fractures; left fluid pneumothorax; thyroid tumor of unknown nature, possibly malignant. Grade I tracheal stenosis; Sequelae of cerebral infarction. Because of goiter and severe tracheal compression, the patient was not intubated and received deopiated general anesthesia combined with epidural anesthesia to preserve spontaneous breathing.

OUTCOMES

At the end of the video-assisted thoracoscopic exploration, the patient was immediately conscious and returned directly to the ward 6 min later. The patient was able to move freely after surgery and eat normally within 6 h of surgery. The postoperative visual analog scale score was 2 points, and there were no anesthetic complications during the follow-up.

CONCLUSION

The opioid-free anesthesia strategy of tubeless general anesthesia, allowing spontaneous breathing combined with epidural anesthesia in elderly patients with tracheal stenosis undergoing video-assisted thoracoscopic surgery can not only avoid accidents and injuries caused by tracheal intubation and mechanical ventilation, but can also significantly reduce postoperative respiratory complications, optimize postoperative analgesia, and help achieve enhanced recovery after surgery.

Primary failure of thoracic epidural analgesia: revisited

Primary failure of thoracic epidural analgesia (TEA) remains an important clinical problem, whose incidence can exceed 20% in teaching centers. Since loss-of-resistance (LOR) constitutes the most popular method to identify the thoracic epidural space, the etiology of primary TEA failure can often be attributed to LOR's low specificity. Interspinous ligamentous cysts, non-fused ligamenta flava, paravertebral muscles, intermuscular planes, and thoracic paravertebral spaces can all result in non-epidural LORs. Fluoroscopy, epidural waveform analysis, electrical stimulation, and ultrasonography have been proposed as confirmatory modalities for LOR.The current evidence derived from randomized trials suggests that fluoroscopy, epidural waveform analysis, and possibly electrical stimulation, could decrease the primary TEA failure to 2%. In contrast, preprocedural ultrasound scanning provides no incremental benefit when compared with conventional LOR. In the hands of experienced operators, real-time ultrasound guidance of the epidural needle has been demonstrated to provide comparable efficacy and efficiency to fluoroscopy.Further research is required to determine the most cost-effective confirmatory modality as well as the best adjuncts for novice operators and for patients with challenging anatomy. Moreover, future trials should elucidate if fluoroscopy and electrical stimulation could potentially decrease the secondary failure rate of TEA, and if a combination of confirmatory modalities could outperform individual ones.

Comparison of epidural infusion versus intrathecal morphine block as part of enhanced recovery after open pancreatoduodenectomy

BACKGROUND AND OBJECTIVES

The accepted approach to pain management following open pancreatoduodenectomy (PD) remains controversial, with the most recent enhanced recovery after surgery (ERAS) protocols recommending epidural anesthesia (EA). Few studies have investigated intrathecal (IT) morphine, combined with transversus abdominis plane (TAP) blocks. We aim to compare the different approaches to pain management for open PD.

METHODS

Patients who underwent open PD at our institution from 2020 to 2022 were included in the study. Patient characteristics, pain management, and postoperative outcomes between EA, IT morphine with TAP blocks, and TAP blocks only were compared using univariate analysis.

RESULTS

Fifty patients were included in the study (58% male, median age 66 years [interquartile range, IQR: 58-73]). Most patients received IT morphine (N = 24, 48%) or EA (N = 18, 36%). The TAP block-only group required higher doses of postoperative narcotics while hospitalized (p = 0.004) and at discharge (p = 0.017). The IT morphine patients had a shorter median time to Foley removal (p = 0.007). Postoperative pain scores, non-opioid administration, postoperative bolus requirements, postoperative outcomes, and length of stay were similar between pain modalities.

CONCLUSIONS

IT morphine and EA showed comparable efficacy with superior results compared to TAP blocks alone. Integration of IT morphine into PD ERAS protocols should be considered.

A Case Report of Fluoroscopically Guided Epidural Catheter Placement in a Parturient with History of Tethered Cord, Super-Morbid Obesity, and Risk for Difficult Airway

Tethered cord syndrome results from adherence of the conus medullaris to the sacrum and may be associated with high complication rates from neuraxial anesthesia. We present the case of a 32-year-old gravida 2 para 0 patient with a history of lipomyelomeningocele (one of several types of spina bifida) and tethered cord status post repair, residual low-lying conus medullaris, supermorbid obesity (body mass index of 58), and Mallampati IV airway, who underwent successful fluoroscopically guided epidural catheter placement for vaginal delivery. Risks and benefits of epidural catheter utilization and methods of placement are reviewed.

[Anaesthesia for Emergent Caesarean Section: A Population-based Study on Icelandic and Migrant Women during 2007-2018]

INTRODUCTION

General anaesthesia for emergent caesarean section, though uncommon, is vital in expediting deliveries. Studies indicate higher complication risks among pregnant migrant women. This research investigates if migrant women in Iceland are more likely to undergo general anaesthesia for emergent caesarean section compared to their Icelandic counterparts.

MATERIALS AND METHODS

This population-based cohort study analysed 4,415 emergency caesarean sections in Iceland between 2007 and 2018, sourced from the National Birth Registry. Participants were categorized by citizenship, with migrants further stratified by their country's Human Development Index (HDI). NCSP-IS and ICD-10 codes indexed diseases, interventions, and complications. The impact of variables was assessed through multiple logistic regression analysis.

RESULTS

Migrant women received general anaesthesia in 16.1% of cases, slightly surpassing Icelandic women's 14.6%. Adjusting for risk factors showed no increased risk for migrant women. However, they had a higher likelihood of urgent caesarean sections (OR 1.45, 95% CI 1.08-1.94, p=0.015), a known risk factor for general anaesthesia, despite fewer comorbidities. Adjusting for confounders revealed reduced odds with a history of previous caesarean section (aOR 0.73, 95% CI 0.59-0.89, p=0.003) and placement of epidural anaesthesia in the delivery room (aOR 0.49, 95% CI 0.40-0.60, p< 0.001).

CONCLUSIONS

Migrant women in Iceland do not face increased risks of general anaesthesia for emergent caesarean sections. However, their elevated risk of urgent caesarean sections suggests potential challenges, including language barriers or inadequate antenatal care. Early information dissemination and targeted interventions may mitigate these risks in this vulnerable community.

Epidural versus general anesthesia for laparo-endoscopic single-site cholecystectomy: a randomized controlled trial

INTRODUCTION

This study compares outcomes after LESS cholecystectomy utilizing epidural versus general anesthesia.

METHODS

Patients undergoing LESS Cholecystectomy were randomized into receiving epidural or general anesthesia by protocol. Patients used a Visual Analog Scale to rate pain from 0 (no pain) to 10 (severe pain). Data presented as median (mean ± standard deviation).

RESULTS

75 patients underwent LESS cholecystectomy with general anesthesia [32 patients (22% men) after five patients withdrew consent] or epidural anesthesia [23 patients (22% men) after 15 patients withdrew consent]. Respectively, they were of age 38 years (41 ± 15.1) and 47 years (48 ± 13.9), BMI 29 (28 ± 4.9) kg/m2 and 28 (28 ± 3.8) kg/m2, and ASA 2 (2 ± 0.5) and 2 (2 ± 0.3) (p > 0.05 for all). LOS for patients receiving general vs. epidural anesthesia was 72 min (122 ± 104.4) vs. 95 min (113 ± 77.5) (p = 0.25). On POD 0, patients receiving general anesthesia rated pain as 4 (4 ± 2.9) vs. 0 (1 ± 2.2) for epidural anesthesia (p = 0.02). On POD 1, they rated pain as 6 (5 ± 2.3) vs. 6 (6 ± 2.9) (p = 0.68). On POD 6, patients rated pain as 3 (3 ± 2.7) vs. 4 (3 ± 2.2) (p = 1.00). For patient satisfaction with incisional scars for those receiving general vs. epidural anesthesia, patients rated their scars to be 10 (8 ± 3.6) vs. 10 (9 ± 1.2) (p = 0.21). Total costs for the hospital using general vs. epidural anesthesia were found $6,909 (7,167 ± 2,083.8) vs. $6,225 (5,848 ± 1530.1) (p = 0.014), respectively. Patients self-assessed satisfaction on a scale of 1 (worst) to 5 (best) as a 5 (5 ± 0).

CONCLUSIONS

Patients undergoing LESS cholecystectomy with general vs. epidural anesthesia had similar demographics, LOS, and pain scores. Patients that received epidural anesthesia reported less pain and incurred less cost. Utilization of epidural anesthesia in lieu of general anesthesia for LESS cholecystectomy is safe, reduces pain, and offers potential cost savings.

Safety and effcacy of remimazolam tosilate for sedation during combined spinal-epidural anesthesia for orthopedic procedures: a randomized controlled trial

OBJECTIVE

The objective of this study was to assess the efficacy and safety of Remimazolam in the context of combined spinal-epidural anesthesia for sedation during orthopedic surgery.

METHODS

This randomized controlled trial enrolled patients scheduled for orthopedic surgery under combined spinal-epidural anesthesia (N = 80), who were randomly allocated to receive either dexmedetomidine (Group-D) or remimazolam (Group-R). The target sedation range aimed for a Ramsay score of 2-5 or a BIS value of 60-80 to evaluate the effectiveness and safety of remimazolam during sedation.

RESULTS

The time taken to achieve the desired level of sedation was significantly shorter in the remimazolam group compared to the dexmedetomidine group (3.69 ± 0.75 vs. 9.59 ± 1.03; P < 0.0001). Patients in the remimazolam group exhibited quicker recovery, fewer intraoperative adverse events, more consistent vital signs, and greater satisfaction at various time points throughout the surgery.

CONCLUSION

This preliminary study demonstrates that remimazolam tosilate serves as a safe and effective sedative for orthopedic surgery performed under combined spinal-epidural anesthesia, in comparison with dexmedetomidine.

Enhancing epidural needle guidance using a polarization-sensitive optical coherence tomography probe with convolutional neural networks

Epidural anesthesia helps manage pain during different surgeries. Nonetheless, the precise placement of the epidural needle remains a challenge. In this study, we developed a probe based on polarization-sensitive optical coherence tomography (PS-OCT) to enhance the epidural anesthesia needle placement. The probe was tested on six porcine spinal samples. The multimodal imaging guidance used the OCT intensity mode and three distinct PS-OCT modes: (1) phase retardation, (2) optic axis, and (3) degree of polarization uniformity (DOPU). Each mode enabled the classification of different epidural tissues through distinct imaging characteristics. To further streamline the tissue recognition procedure, convolutional neural network (CNN) were used to autonomously identify the tissue types within the probe's field of view. ResNet50 models were developed for all four imaging modes. DOPU imaging was found to provide the highest cross-testing accuracy of 91.53%. These results showed the improved precision by PS-OCT in guiding epidural anesthesia needle placement.

Perinatal outcome of emergency cesarean section under neuraxial anesthesia versus general anesthesia: a seven-year retrospective analysis

OBJECTIVE

An emergency cesarean section (CS), which is extremely life-threatening to the mother or fetus, seems to be performed within an adequate time horizon to avoid negative fetal-maternal denouement. An effective and vigilant technique for anesthesia remains vital for emergency cesarean delivery. Therefore, this study aimed to validate the impact of various anesthesia tactics on maternal and neonatal outcomes.

METHOD

This was a retrospective cohort study of parturient patients who were selected for emergency CS with the assistance of general or neuraxial anesthesia between January 2015 and July 2021 at our institution. The 5-min Apgar score was documented as the primary outcome. Secondary outcomes, including the 1 min Apgar score, decision-to-delivery interval (DDI), onset of anesthesia to incision interval (OAII), decision to incision interval (DII), duration of operation, length of hospitalization, height and weight of the newborn, use of vasopressors, blood loss, neonatal resuscitation rate, admission to neonatal intensive care unit (NICU), duration of NICU and complications, were also measured.

RESULTS

Of the 539 patients included in the analysis, 337 CSs were performed under general anesthesia (GA), 137 under epidural anesthesia (EA) and 65 under combined spinal-epidural anesthesia (CSEA). The Apgar scores at 1 min and 5 min in newborns receiving GA were lower than those receiving intraspinal anesthesia, and no difference was found between those receiving EA and those receiving CSEA. The DDI of parturients under GA, EA, and CSE were 7[6,7], 6[6,7], and 14[11.5,20.5], respectively. The DDI and DII of GA and EA were shorter than those of CSE, and the DDI and DII were similar between GA and EA. Compared to that in the GA group, the OAII in the intraspinal anesthesia group was significantly greater. GA administration correlated with more frequent resuscitative interventions, increased admission rates to NICU, and a greater incidence of neonatal respiratory distress syndrome (NRDS). Nevertheless, the duration of NICU stay and the incidence rates of neonatal hypoxic ischemic encephalopathy (HIE) and pneumonia did not significantly differ based on the type of anesthesia performed.

CONCLUSION

Compared with general anesthesia, epidural anesthesia may not be associated with a negative impact on neonatal or maternal outcomes and could be utilized as an alternative to general anesthesia in our selected patient population following emergency cesarean section; In addition, a comparably short DDI was achieved for emergency cesarean delivery under epidural anesthesia when compared to general anesthesia in our study. However, the possibility that selection bias related to the retrospective study design may have influenced the results cannot be excluded.

Comparison of the incidence of intravascular injection using the Tuohy and Quincke needles during ultrasound-guided caudal epidural block: a prospective randomized controlled study

INTRODUCTION

Intravascular injection of a local anesthetic can lead to life-threatening complications, such as deficits in neurological function after caudal epidural block. This study aimed to determine whether the intravascular injection rate of the Tuohy needle is lower than that of the Quincke needle during an ultrasound-guided caudal block.

METHODS

Two-hundred and thirty patients were randomized into the Quincke (n=115) and the Tuohy (n=115) needle groups. The randomly selected needle was introduced at a 45° angle until it penetrated the sacrococcygeal ligament under ultrasound guidance, and intravenous injections were analyzed using contrast-dyed digital subtraction angiography. The relationship between the incidence of intravascular injection and independent variables, including needle type, patient demographics, history of lumbosacral surgery, use of anticoagulants, anatomic variables of the sacrum, presence of bony contact during the procedure, and the number of needle repositioning under ultrasound guidance, were examined.

RESULTS

Intravascular uptake of contrast medium was surveyed in 25/230 (10.9%) caudal blocks using digital subtraction angiography (DSA). The incidence of intravascular uptake was 13.9% (16/115) using the Quincke needle and 7.8% (9/115) using the Tuohy needle (p=0.14). Although the needle tip type was not associated with the rate of intravascular injection, the occurrence of bony contact during the procedure demonstrated a relationship with the intravenous injection (p<0.01).

CONCLUSIONS

The overall incidence of inadvertent intravascular injections during ultrasound-guided caudal block confirmed using DSA was 10.9%. Tuohy needles did not reduce intravascular injection rates during the ultrasound-guided caudal block.

TRIAL REGISTRATION NUMBER

NCT05504590.

Two-stage laparoscopic transversus abdominis plane block as an equivalent alternative to thoracic epidural anaesthesia in bowel resection-an explorative cohort study

PURPOSE

We evaluated the effect of the two-stage laparoscopic transversus abdominis plane block (TS-L-TAPB) in comparison to thoracic epidural anaesthesia (TEA) and a one-stage L-TAPB (OS-L-TAPB) in patients who underwent elective laparoscopic bowel resection.

METHODS

We compared a TS-L-TAPB (266 mg bupivacaine), which was performed bilaterally at the beginning and end of surgery, with two retrospective cohorts. These were patients who had undergone a TEA (ropivacaine/sufentanil) or an OS-L-TAPB (200 mg ropivacaine) at the beginning of surgery. Oral and i.v. opiate requirements were documented over the first 3 postoperative days (POD).

RESULTS

Patients were divided into three groups TEA (n = 23), OS-L-TAPB (n = 75), and TS-L-TAPB (n = 49). By the evening of the third POD, patients with a TEA had a higher cumulative opiate requirement with a median of 45.625 mg [0; 202.5] than patients in the OS-L-TAPB group at 10 mg [0; 245.625] and the TS-L-TAPB group at 5.625 mg [0; 215.625] (p = 0.1438). One hour after arrival in the recovery room, significantly more patients in the TEA group (100%) did not need oral and i.v. opioids than in the TS-L-TAPB (78%) and OS-L-TAPB groups (68%) (p = 0.0067).This was without clinical relevance however as the median in all groups was 0 mg. On the third POD, patients in the TEA group had a significantly higher median oral and i.v. opioid dose at 40 mg [0; 80] than the TS-L-TAPB and OS-L-TAPB groups, both at 0 mg [0; 80] (p = 0.0009).

CONCLUSION

The TS-L-TAP showed statistically significant and clinically meaningful benefits over TEA and OS-L-TAP in reducing postoperative opiate requirements.

Regional anesthesia might reduce recurrence and metastasis rates in adult patients with cancers after surgery: a meta-analysis

BACKGROUND

The influence of anesthesia techniques on cancer recurrence and metastasis following oncological surgery is a topic of growing interest. This meta-analysis investigates the potential effects of regional anesthesia (RA), either independently or combined with general anesthesia (GA), on these outcomes.

METHODS

We performed an extensive search across PubMed, Embase, and the Cochrane Library databases. The primary outcome was cancer recurrence, while the secondary outcomes were local recurrence and distant metastasis. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated by utilizing random-effects models. The Newcastle-Ottawa Scale (NOS) was used for quality assessment of observational studies, the Cochrane Risk of Bias Tool for Randomized Trials (Rob 2.0) was used for randomized controlled trials, and all the outcomes were assessed by using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE).

RESULTS

This study included 32 studies comprising 24,724 cancer patients. RA, either alone or in combination with GA, was significantly associated with reduced cancer recurrence compared to GA alone (OR = 0.82; 95% CI = 0.72 to 0.94; p < 0.01). This association remained significant for prostate cancer patients in subgroup analyses (OR = 0.71; 95% CI = 0.51 to 0.98; p = 0.04) and in the context of epidural anesthesia combined with GA. However, there were no significant associations noted for local recurrence or distant metastasis.

CONCLUSIONS

This meta-analysis provides evidence that RA, used alone or adjunctively with GA, is associated with a lower risk of cancer recurrence, particularly in patients with prostate cancer. However, no significant effects were observed on local recurrence or distant metastasis. Further prospective studies should be conducted to clarify this important issue.

The impact of sufentanil versus remifentanil on surgical site wound healing in caesarean section primiparas undergoing epidural anaesthesia: A systematic meta-analysis

Caesarean section (C-section) is a prevalent obstetric surgical procedure, with the choice of analgesic agents playing a pivotal role in postoperative recovery. This systematic meta-analysis aimed to compare the effects of sufentanil (ST) and remifentanil (RT) on postoperative wound healing in caesarean section primiparas undergoing epidural anaesthesia. A comprehensive search was conducted across multiple databases, adhering to PRISMA guidelines, yielding eight randomized controlled trials (RCTs) for inclusion. The primary outcome was wound healing assessment using the REEDA (redness, edema, ecchymosis, discharge, approximation) scale on the third, fifth and tenth postoperative days. The meta-analysis encompassed 691 primiparas. A significant difference in wound healing was observed between ST and RT on the third (I2  = 99%; Random: SMD: 6.75, 95% CIs: 3.11-10.39, p < 0.01) and fifth days (I2  = 99%; Random: SMD: 3.63, 95% CIs: 1.56-5.70, p < 0.01) postcaesarean section. However, no significant difference was noted on the tenth day (I2  = 5%; Random: SMD: 0.00, 95% CIs: -0.45-0.45, p = 0.35). Sufentanil and remifentanil exhibit differential effects on early postoperative wound healing in caesarean section primiparas undergoing epidural anaesthesia. While both opioids are effective analgesics, sufentanil demonstrates a more pronounced impact on wound healing during the immediate postoperative days. Clinicians should consider these findings when selecting an opioid for pain management in this patient population.

Administration of combined spinal epidural anesthesia with ultrasound-assisted positioning in obese patients undergoing open hysterectomy: A randomized controlled trial

BACKGROUND

Administration of combined spinal epidural anesthesia (CSEA) with traditional landmark-guided positioning can be challenging in patients with high body mass index (BMI). The popularization of ultrasound technology may effectively solve these problems. However, reports on the administration of CSEA ultrasound-assisted positioning in obese populations are relatively limited and have made inconsistent conclusions. We aimed to investigate the ability of ultrasound-assisted positioning to improve the success rate of CSEA in obese patients.

METHODS

Overall, 118 adult women with a BMI ≥ 30 kg/m2 who scheduled to undergo open hysterectomy and received CSEA were recruited. Finally, 108 patients were enrolled and randomly assigned to 2 groups: the ultrasound-assisted positioning group (group A) and traditional landmark-guided positioning group (group B). Ultrasound-assisted or landmark-guided positioning was employed to locate the puncture interspace before anesthesia. The primary outcomes were the success rate of first attempt and number of attempts. The secondary outcomes were the patient positioning accuracy, positioning time, CSEA operation time, patient-satisfaction scores, anesthesia characteristics, and complications of CSEA.

RESULTS

The success rate of patient first puncture attempt in group A was significantly higher than that in group B (78.4% vs 52.9%, P = .007). The total number of punctures was lower in group A than that in groups B (average rank 44.54 vs 58.46, P = .005). Using ultrasound positioning as the gold standard, the accuracy of landmark-guided location was only 67%. Positioning time in croup A was longer in group A than that in group B (P = .004), while CSEA operation time spent in Group A was less than that in Group B (P < .001). Patient satisfaction score in group A was significantly higher than that in group B (P = .002). The successful puncture interspace in group A were more likely at L3-4 than that in group B (P = .02).

CONCLUSION

The success rate of first puncture attempt and positioning accuracy in CSEA with ultrasound-assisted is significantly higher than those based on landmark-guided location in obese patients.

A longitudinal study of the association of epidural anesthesia and low-dose synthetic oxytocin regimens with breast milk supply and breastfeeding rates

Breastfeeding is known to improve maternal and child health. However, epidural anesthesia (EDA) and synthetic oxytocin (synOT) are suggested to have negative effects on breastfeeding. In this study, we aimed to determine the effects of intrapartum synOT and EDA on breast milk supply, breastfeeding rates, and maternal salivary oxytocin levels. Women were recruited during pregnancy or after birth at a single hospital. Data were collected at 3 days postpartum (T1), 1 month postpartum (T2), and 4 months postpartum (T3) on 83 low-risk primiparous women who planned to breastfeed for at least 12 weeks postpartum to avoid dropouts from early discontinuance of breastfeeding. Women with cesarean section, twin pregnancy, premature neonates, and an Apgar score of < 7 at 5 min were excluded. Participants recorded their 24-h milk supply by test weights at 3 days and 1 month postpartum. Additionally, they filled out questionnaires assessing their breastfeeding level and lactogenesis stage II initiation. Salivary oxytocin levels were obtained at 3 days postpartum. Women who delivered using EDA had lower salivary oxytocin levels (P = .055, d = .442), breast milk supply in early postpartum (P = .025, d = .520) and at 1 month postpartum (P = .036, d = .483), and breastfeeding rates at 4 months postpartum (P = .037, V = .236) than women who did not deliver using EDA. There was no association between breastfeeding and the use of intrapartum synOT. In conclusion, this study showed that women who delivered using EDA had lower breast milk supply in the early postpartum period and breastfeeding rates at 4 months postpartum. It also revealed that using synOT at low doses during labor did not affect breastfeeding. Thus, women who deliver using EDA need support for increased breast milk supply in the early postpartum period.Trial registration: UMIN000037783 (Clinical Trials Registry of University Hospital Information Network).

Effects of epidural anesthesia on the prognosis of ovarian cancer-a systematic review and meta-analysis

INTRODUCTION

The global low survival rate among ovarian cancer patients has resulted in significant social and economic burdens. Nevertheless, previous studies have produced mixed results when exploring the link between anesthetic techniques and the prognosis of ovarian cancer. The study aims to compare the effect of epidural anesthesia with general anesthesia on survival time after cytoreductive surgery in patients with ovarian cancer.

METHODS

The PubMed (National Library of Medicine), Cochrane library, Web of science, Embase, CNKI (China National Knowledge Internet), Wanfang Med Online (China database), were systematically searched from inception to May, 2023, using the Medical Subject Headings [MeSH] of "Ovarian Neoplasm" and "Anesthesia, Epidural" and free words to identify systematic reviews or meta-analyses. The research methodology involved analyzing randomized controlled trials (RCTs), as well as prospective or retrospective cohort studies, which compared the long-term prognosis of patients with ovarian cancer under general anesthesia combined with epidural anesthesia (GEA) versus general anesthesia alone (GA). The Newcastle Ottawa Scale (NOS) was used to assess methodological quality and bias. Data extraction and assessment of study quality were conducted by two independent reviewers. A meta-analysis was then performed to calculate hazard ratios (HRs) and corresponding 95% confidence intervals (CIs). Overall survival (OS) was defined as the primary outcome, time to tumor recurrence (TTR) was the secondary outcome. Epidural anesthesia could be used intraoperatively and immediately postoperatively (EIP), or postoperatively only (EP). GEA includes EIP and EP.

RESULTS

In total, 8 retrospective cohort studies with 2036 participants met the inclusion criteria. The pooled results demonstrated that GEA could extend OS (HR 0.75, 95% CI 0.67-0.84, I2 = 0%, P < 0.05, fixed-effect model) when compared with GA in ovarian cancer patients undergoing cytoreductive surgery, but not TTR (sensitivity analysis revealed substantial heterogeneity among the included studies). The result of analyzing a total of 1490 patients in 4 studies was that EIP had a better prognosis on OS than GA (HR 0.68, 95%CI 0.55-0.85, I2 = 61%, P < 0.05, random-effect model). However, EP had no advantage in TTR (sensitivity analysis revealed it was unstable outcome). Ovarian cancer FIGO(International Federation of Gynecology and Obstetrics) stage III, stage IV compared to stage I on OS was statistically significant, HRs respectively are 3.67 (95%CI 2.25-5.98), I2 = 0%, fixed-effect model, P < 0.05, and 7.43 (95%CI 3.67-15.03), I2 = 31%, fixed-effect model, P < 0.05, but there was no statistically significant difference between stage II and stage I, HR 2.00, 95%CI0.98-4.09, I2 = 0%, fixed-effect model, P > 0.05. 1-10 mm tumor residuals shorten TTR compared with 0 residuals, HR 1.75, 95% CI1.50-2.04, I2 = 0%, fixed-effect model, P < 0.05.

CONCLUSIONS

It is hard to conclude that postoperative epidural analgesia offers greater benefits than GA. However, general anesthesia combined with epidural anesthesia (EIP) can improve overall survival in ovarian cancer patients, allowing the anesthesiologist to use anesthesia techniques to provide a favorable prognosis for the ovarian cancer patient. Tumor staging and the extent of cell reduction are also critical factors that significantly influence the long-prognosis of ovarian cancer patients.

Application of Cervical Epidural Anesthesia and Analgesia to the Patient With 90% Burnt Surface Area

Patients with an extremely large, burnt surface area have a high mortality rate. The follow-up, treatment, and intraoperative anesthesia practices of these patients in the ICU pose serious challenges. In this case, the experience of anesthesia and analgesia using cervical epidural anesthesia, which is not frequently used in anesthesia routine, applied to a patient with a 90% burnt surface area is shared. It was aimed to evaluate the contribution of effective non-opioid analgesia, early mobilization, and nutrition applied to the patient's recovery.

Anesthesiology resident preferences regarding learning to perform epidural anesthesia procedures in obstetrics: a qualitative phenomenological study

BACKGROUND

Learning to perform neuraxial techniques in obstetrics is considered one of the most difficult skills for anesthesiology trainees to acquire and no consensus exists regarding the best practices for teaching these procedures. Utilizing a qualitative, phenomenological approach, we aimed to explore what trainees perceive as the best approaches to teaching epidural anesthesia techniques; identify how these perceptions align or differ from those of faculty anesthesiologists; and examine how these approaches fit into the cognitive apprenticeship framework, which describes a process of reflection on how learning occurs in the authentic environment.

METHODS

Semi-scripted interviews were conducted with 10 residents and three faculty members from the division of obstetric anesthesiology at an academic center. Interviews were transcribed, de-identified, fragmented, and coded. A thematic analysis was conducted, and codes re-organized into the cognitive apprenticeship framework of (1) content, (2) method (including subcategories modeling, coaching, scaffolding, articulation, reflection, and exploration), (3) sequence, and (4) sociology (including situated learning and culture of expert practice).

RESULTS

Trainees valued a staged approach to learning epidural techniques, independent trouble-shooting, graded independence, focused feedback, and a calm instructor. The challenges of learning and teaching epidural techniques identified by trainees and instructors included the tactile nature of the procedure, teaching on awake, non-sedated patients, limited teaching time, and creating an environment of psychological safety.

CONCLUSION

Trainee and instructor preferences for teaching epidural procedures in obstetrics aligned with the cognitive apprenticeship framework. These concepts may be applied to curriculum design, evaluation, feedback, self-assessment and faculty development.

Research and application of a teaching platform for combined spinal-epidural anesthesia based on virtual reality and haptic feedback technology

BACKGROUND

Intraspinal anesthesia poses significant teaching challenges and inadequate teaching resources, which ultimately limit students' opportunities for practice. To address this issue, we aimed to develop a virtual platform for combined spinal-epidural anesthesia that merges virtual reality technology with haptic feedback technology, while assessing its educational impact and learning outcomes.

METHODS

We utilized MIMICS, 3Ds MAX, and UNITY 3D software to perform 3D reconstruction based on lumbar CT/MRI data from a standard male volunteer. The haptic coefficients were configured on each layer by 20 experienced anesthesiologists in accordance with the Geomagic Touch X force feedback device. A total of 20 anesthesiology interns completed 30 virtual puncture training sessions. Two experienced anesthetists evaluated the efficacy of the platform and the level of mastery achieved using the Global Rating Scale (GRS) and a Checklist score, respectively. Finally, a questionnaire survey was conducted to gather feedback on the virtual platform.

RESULTS

After the 10th session, the puncture time stabilized at 2.4 min. As the number of sessions increased, the Global Rating Scale (GRS) score stabilized by the 8th session, and the Checklist scores tended to stabilize by the 10th session. Results from questionnaires indicated that over half of the anesthesiology interns (70%) believed that the platform, which exhibited strong repeatability, improved their anatomical recognition and provided a strong sense of breakthrough in identifying the ligamentum flavum. The majority of them (80%) expressed satisfaction with the virtual platform.

CONCLUSIONS

The platform effectively facilitated the acquisition of basic and accurate puncture skills on a virtual patient.

Regional Anesthesia for Neonates

Pain management in neonates and infants has many unique and important facets, particularly in former preterm infants. Untreated pain and surgical stress in neonates are associated with myriad negative sequelae, including deleterious inflammatory, autonomic, hormonal, metabolic, and neurologic effects. Meanwhile, opioid side effects are also very impactful and affect multiple systems and pathways, particularly in the neonatal and infant population. Regional anesthesia presents a unique opportunity to provide highly effective analgesia; prevent deleterious signaling cascade pathways within the endocrine, immune, and nervous systems from occurring; and create conditions to facilitate reduced reliance on opioids and other analgesics. In some cases, clinicians can completely avoid general anesthesia and systemic anesthetics. This review will discuss some of the unique aspects of pain management in neonates and infants and provide an overview of the different regional anesthetic options available, namely, spinal anesthesia, epidural anesthesia, and peripheral nerve blocks.

Effect of alternatively designed hospital birthing rooms on the rate of vaginal births: Multicentre randomised controlled trial Be-Up

BACKGROUND

There is limited research into the effects of the birth environment on birth outcomes.

AIM

To investigate the effect of a hospital birthing room designed to encourage mobility, self-determination and uptake of upright maternal positions in labour on the rate of vaginal births.

METHODS

The multicentre randomised controlled trial Be-Up, conducted from April 2018 to May 2021 in 22 hospitals in Germany, included 3719 pregnant women with a singleton pregnancy in cephalic position at term. In the intervention birthing room, the bed was removed or covered in a corner of the room and materials were provided to promote upright maternal positions, physical mobility and self-determination. No changes were made in the control birthing room. The primary outcome was probability of vaginal births; secondary outcomes were episiotomy, perineal tears degree 3 and 4, epidural anaesthesia, "critical outcome of newborns at term", and maternal self-determination (LAS).

ANALYSIS

intention-to-treat.

FINDINGS

The rate of vaginal births was 89.1 % (95 % CI 87.5-90.4%; n = 1836) in the intervention group and 88.5 % (95 % CI 87.0-89.9 %; n = 1863) in the control group. The risk difference in the probability of vaginal birth was + 0.54 % (95 % CI - 1.49 % to 2.57 %), the odds ratio was 1.06 (95 % CI 0.86-1.30). Neither the secondary endpoints nor serious adverse events showed significant differences. Regardless of group assignment, there was a significant association between upright maternal body position and maternal self-determination.

CONCLUSION

The increased vaginal birth rates in both comparison groups can be explained by the high motivation of the women and the staff.

Necessity of routine perioperative epidural catheter placement in laparoscopic colorectal resections: a retrospective data analysis

PURPOSE

Whether epidural anesthesia leads to further improvement in the postoperative course of colorectal procedures is under discussion. The aim of this study was to evaluate the effects of minimally invasive colorectal oncological interventions without epidural anesthesia (EDA).

METHODS

This retrospective data analysis included the clinical data of all patients who underwent minimally invasive oncological colorectal resection at our clinic between January 2013 and April 2019. Of 385 patients who met the inclusion criteria, 183 (group I; 47.5% of 385) received EDA, and 202 (group II; 52.5% of 385) received transversus abdominis plane block instead. The relevant target parameters were evaluated and compared between the groups. The postoperative complications were graded according to the Clavien-Dindo classification.

RESULTS

The patients in group I (n=183; women, 77; men, 106; age 66.8 years) were younger (p=0.0035), received a urinary catheter more often (99.5% versus [vs.] 28.2% p<0.001), required longer, more frequent arterenol treatment (1.1 vs. 0.6 days; p<0.001), and had a longer intermediate care unit stay than those in group II (2.8 vs. 1.1 days; p<0.001). Postoperative pain levels were not significantly different between the groups (p=0.078). The patients in group I were able to ambulate later than those in group II (4 vs. 2 days; p<0.001). The difference in the postoperative day of the first defecation was not significant between the groups (p=0.236). The incidence of postoperative complications such as bleeding (p=0.396), anastomotic leaks (p=0.113), and wound infections (p=0.641) did not differ between the groups. The patients in group I had significantly longer hospital stays than those in group II (12.2 vs. 9.4 days; p<0.001).

CONCLUSION

EDA can be safely omitted from elective minimally invasive colorectal resections, and its omission is not accompanied by any relevant disadvantages to the patient.

Continuous nerve block versus thoracic epidural analgesia for post-operative pain of pectus excavatum repair: a systematic review and meta-analysis

Surgery to repair pectus excavatum (PE) is often associated with severe postoperative pain, which can impact the length of hospital stay (LOS). While thoracic epidural analgesia (TEA) has traditionally been used for pain management in PE, its placement can sometimes result in severe neurological complications. Recently, paravertebral block (PVB) and erector spinae plane block (ESPB) have been recommended for many other chest and abdominal surgeries. However, due to the more severe and prolonged pain associated with PE repair, it is still unclear whether continuous administration of these blocks is as effective as TEA. Therefore, we conducted this systematic review and meta-analysis to demonstrate the equivalence of continuous PVB and ESPB to TEA.

Remimazolam dosing for intraoperative sedation in elderly patients undergoing hip replacement with combined spinal-epidural anesthesia

OBJECTIVE

The aim of the study was to investigate the 50% and 95% effective doses (ED50 and ED95) of remimazolam for intraoperative sedation in elderly patients undergoing hip replacement with combined spinal-epidural anesthesia (CSEA).

PATIENTS AND METHODS

We retrospectively analyzed the clinical data of 50 patients who underwent hip replacement with CSEA in our hospital from October 2021 to June 2022. There were 29 males and 21 females, aged 60-80 years old, with body mass indexes (BMI) ranging from 18 to 24 kg/m2, and American Society of Anesthesiologists (ASA) classifications of I or II. The modified Dixon sequential method was used to determine the dose of remimazolam for each patient. Each patient's initial dose was 0.1 mg/kg/h, and the dose gradient was 0.01 mg/kg/h. The bispectral index (BIS) and the modified observer's assessment of alertness/sedation score (MOAA/S) were used to evaluate the sedation of the patient. An MOAA/S score ≤3 and a BIS <85 at three or more time points during surgery indicated the sedation was satisfactory. The induction dose of the next patient was adjusted by 0.01 mg/kg/h based on the level of sedation achieved, and the study was terminated after eight crossovers.

RESULTS

The ED50 and ED95 of remimazolam for sedation of elderly patients undergoing hip replacement with CSEA are 0.212 mg/kg/h (95% CI: 0.121-0.231 mg/kg/h) and 0.288 mg/kg/h (95% CI: 0.254-0.884 mg/kg/h), respectively. Two patients experienced transient bradycardia, five experienced hypoxemia, three experienced postoperative nausea, and three experienced postoperative delirium. No patients experienced adverse reactions such as injection pain, hypotension, vomiting, delayed awakening, or emergence agitation.

CONCLUSIONS

The ED50 and ED95 of remimazolam for sedation of elderly patients undergoing hip replacement with CSEA are 0.212 mg/kg/h and 0.288 mg/kg/h, respectively.

Tissue Classification During Needle Insertion Using Self-Supervised Contrastive Learning and Optical Coherence Tomography

Needle positioning is essential for various medical applications such as epidural anaesthesia. Physicians rely on their instincts while navigating the needle in epidural spaces. Thereby, identifying the tissue structures may be helpful to the physician as they can provide additional feedback in the needle insertion process. To this end, we propose a deep neural network that classifies the tissues from the phase and intensity data of complex OCT signals acquired at the needle tip. We investigate the performance of the deep neural network in a limited labelled dataset scenario and propose a novel contrastive pretraining strategy that learns invariant representation for phase and intensity data. We show that with 10% of the training set, our proposed pretraining strategy helps the model achieve an F1 score of 0.84±0.10 whereas the model achieves an F1 score of 0.60±0.07 without it. Further, we analyse the importance of phase and intensity individually towards tissue classification.

Effect of ropivacaine combined with sufentanil epidural anesthesia in abdominal surgery

To explore and analyze the effect of ropivacaine plus sufentanil for epidural anesthesia during abdominal surgery, a total of 120 patients who underwent abdominal surgery at our institution between May 2019 and November 2020 were recruited and randomly assigned at a 1:1 ratio to receive either ropivacaine alone for epidural anesthesia (control group) or ropivacaine plus sufentanil (observation group). The total anesthesia effect in the observation group was significantly higher than that in the control group (96.66% vs 78.33%) (P<0.05). The combined anesthesia resulted in significantly lower visual analogue scale (VAS) scores (1.51±0.84, 1.63±0.56, 1.69±0.63, 1.54±0.42) in patients at 4h, 8h, 16h and 24h postoperatively versus ropivacaine alone (2.35±0.88, 2.49±0. 69, 2.47±0.78, 2.39±0.58) (P<0.05). The Ramsay sedation score (RSS) scores (1.98±0.81, 2.44±0.62, 2.18±0.62, 2.51±0.37) of the observation group at 4h, 8h, 16h and 24h after operation were significantly lower than those of the control group (1.42±0.52, 1.73±0.71, 1.47±0.66, 1.68±0.62) (P<0.05). Patients receiving ropivacaine plus sufentanil were associated with a lower incidence of adverse reactions than those given ropivacaine only (5.00% vs 30.00%) (P<0.05). In abdominal surgery, ropivacaine plus sufentanil epidural anesthesia resulted in reduced postoperative pain, enhanced sedative effects and a lower risk of adverse reactions versus ropivacaine alone.

Application of high-flow nasal cannula oxygen therapy in patient with pulmonary edema following cesarean-section under combined spinal-epidural anesthesia: A case report

BACKGROUND

High-flow nasal cannula (HFNC), which overcomes the disadvantages of the existing low flow mask, is an efficient method that can immediately provide a high volume of heated oxygen to the patient.[1] Therefore, this case reports a case in which HFNC was applied to a pregnant with acute respiratory failure.

CASE

A 37-year-old woman pregnant (GA 30 + 5 weeks) with twin was diagnosed with preeclampsia. It was decided to perform an emergency Cesarean-section under combined spinal-epidural technique worsening respiratory failure. After delivery, maternal dyspnea was not alleviated applying of O28 L/min via facial mask. Thus, high-flow nasal cannula (HFNC) oxygen therapy was applied (60 L/min, partial pressure of oxygen (FiO2) 80%) and SpO2 subsequently rose to 98% and the patient's dyspnea was resolved.

CONCLUSIONS

HFNC is a safe device that can effectively provide oxygen to pregnant with acute respiratory failure.

The Effect of Adolescent Idiopathic Scoliosis on Natural Delivery and Epidural Use in Pregnant Females: A Matched Cohort Study

STUDY DESIGN

Retrospective matched cohort study.

OBJECTIVE

The aim of this study was to determine whether females with idiopathic scoliosis (IS), both with and without spine fusion, experience different rates of cesarean section (CS) and epidural anesthesia (EA) than females without scoliosis.

SUMMARY OF BACKGROUND DATA

IS is a common spine condition with a higher prevalence in females. It is unclear whether females with scoliosis, treated nonoperatively or operatively, have different rates of cesarean delivery or EA.

MATERIALS AND METHODS

Patients with IS who delivered in our integrated health care system during a 6-year period were identified (N = 1810). They were matched with a group without scoliosis who delivered during the same period (N = 1810). Rates and relative risk (RR) of CS and EA between cohorts and subgroups were calculated.

RESULTS

The scoliosis cohort had significantly higher rates and RR of EA ( P = 0.002 and P = 0.004, respectively). Scoliosis patients treated nonoperatively had an 8% greater RR of EA ( P = 0.004) and had a significantly lower rate of CS (23.2% vs . 26%, P = 0.048) compared with the control group. Among only scoliosis patients, those treated with spine fusion had a 38% decreased RR of EA ( P < 0.001). Distal fusion level did not seem to influence the RR of EA or CS.

CONCLUSIONS

Females with scoliosis were significantly more likely to receive EA at delivery compared with females without scoliosis. Rates and RR of cesarean delivery were not significantly lower among women with scoliosis, but females treated nonoperatively for scoliosis had a significantly lower CS rate than those without scoliosis. Females treated with spine fusion for scoliosis were far less likely to receive EA than both females without scoliosis and females with scoliosis treated nonoperatively.

Direct Comparison of Peak Bulk Flow Rate of Programmable Intermittent Epidural Bolus and Manual Epidural Bolus Using a Closed-End Multiorifice Catheter: An Experimental Study

BACKGROUND

The programmable intermittent epidural bolus (PIEB) has been popularized as the optimal delivery technique for labor analgesia. Suggested advantages of this method are less local anesthetic consumption, improved maternal satisfaction, potentially shorter duration of labor, and decreased workload requirements for the anesthesia providers. However, a manual bolus is still routinely used for breakthrough pain when the PIEB is underperforming.

METHODS

We conducted a laboratory-based study to quantify the flow through a multiorifice epidural catheter using the PIEB setting on an epidural pump compared to the manual epidural bolus. Four syringe volumes, 3, 5, 10, and 20 mL, were selected for this experiment. The flow in a manual bolus was also studied with and without the presence of an epidural catheter filter. A generalized estimating equation analysis was done to compare data between the groups.

RESULTS

Regardless of the syringe size, there was a several-fold increase in flow when a manual bolus was used compared to a pump-administered dose, with the highest difference in the peak flow rate observed in 3-mL boluses with up to a 12-fold difference, while the difference was, at most, 7-fold in 5-mL and 10-mL boluses. Manual boluses without a filter achieve a mean peak flow rate higher than manual boluses with a filter.

CONCLUSIONS

Our study found that manual boluses produced a higher flow rate compared to the CADD-Solis epidural pump (Smiths Medical). This study also found that the placement of a particulate filter reduces the flow rates generated while bolusing. Bulk flow rate is directly correlated with induced pressure and solution spread. Because higher bolus pressure has been shown to provide a more efficient distribution of local anesthetic and more efficient pain relief, these results may have impactful clinical significance and will pave the way for future studies.