Manual Boluses Research Articles

Exploration of the optimal programmed intermittent epidural bolus volume with the dural puncture epidural technique for labour analgesia: a biased-coin up-and-down sequential allocation study.

To determine the optimal programmed intermittent epidural bolus (PIEB) volume for providing effective analgesia in 90% of patients (EV90) during the first stage of labour using the dural puncture epidural (DPE) technique to initiate labour analgesia. We conducted a biased-coin up-and-down sequential allocation study. We included 40 nulliparous women requiring epidural labour analgesia. We used a 25G Whitacre spinal needle to puncture the dural mater and then administered a loading dose of 12mL of ropivacaine 0.1% and sufentanil 0.3μg·mL-1. Subsequently, the PIEB pump delivered boluses with an identical solution at a fixed 40-min interval, starting 1hr after epidural initiation. The bolus volume for the first patient was 7mL and was adjusted for subsequent patients according to the study protocol (bolus volume, 7-12mL). The primary endpoint was effective analgesia, indicated by no need for patient-controlled or manual boluses within 6hr after analgesia initiation or until complete cervical dilation, whichever came first. Outcome evaluators assessed the patients' pain ratings, Bromage scores, sensory blockade level, and maternal blood pressure hourly. Using the truncated Dixon and Mood method, the estimated EV90 was 9.2mL (95% confidence interval [CI], 8.5 to 9.9) whereas the isotonic regression method yielded a value of 8.8mL (95% CI, 8.6 to 9.8). None of the patients experienced a motor block. Two patients experienced hypotension without the need for vasopressors. The estimated PIEB EV90 for ropivacaine 0.1% and sufentanil 0.3μg·mL-1 approached 9mL when DPE was combined with a fixed 40-min interval. ChiCTR.org.cn ( ChiCTR2300067281 ); first submitted 3 January 2023.

Serial manual bolus irrigation leads to critical intrarenal pressures during flexible ureterorenoscopy - time to abandon this manoeuvre.

To characterise the effect of solitary and serial manual bolus irrigations on intrarenal pressures (IRPs) and observe the clinical consequences. A pressure guidewire was used for IRP measurement during routine flexible ureterorenoscopy for management of renal stone disease, including manual bolus irrigation when required to maintain vision. The fluid bolus was either as a solitary manual bolus or a series of manual boluses in quick succession. The pre-bolus, maximal and difference between IRPs were calculated. A total of 50 procedures in 46 patients were analysed. In all, 68 solitary manual boluses and 38 serial manual boluses were observed to have been undertaken during these procedures. After a solitary manual bolus, the median (standard deviation [SD], range) increase in IRP was 22.4 (34.0, 0.1-160.8) mmHg, and the mean (SD, range) maximum IRP was 46.1 (41.7, 15.8-190.0) mmHg, with elevated IRPs persisting for a median (range) duration of 19 (4-66) s. After serial manual boluses, the median (SD, range) rise in IRP was 58.4 (64.7, 10.2-242.84) mmHg and the mean (SD, range) maximum IRP reached was 100.8 (69.7, 34.3-303.5) mmHg. The elevated IRPs endured for a median (range) of 42 (9-121 s; P < 0.01 in all comparisons), suggesting a much greater elevation of IRP with instances where serial bolus irrigation was undertaken. Manual bolus irrigation, both solitary but particularly serial boluses, produces significant rises in IRP and could logically result in pyelovenous backflow and sepsis. We suggest that this manoeuvre should be avoided to reduce complications during ureterorenoscopy.

High-Volume Patient-Controlled Epidural Versus Programmed Intermittent Epidural Bolus for Labor Analgesia: A Randomized Controlled Study

(Anaesthesia. 2023;78(9):1129–1138) Neuraxial labor analgesia is a well-established and effective method for managing pain during labor. The initiation of analgesia through epidural or combined spinal-epidural methods can be followed by various maintenance techniques, including continuous epidural infusion, manual intermittent boluses, patient-controlled epidural analgesia (PCEA), programmed intermittent epidural bolus (PIEB), or a combination of these approaches. Adding PCEA to a continuous infusion was long-favored, demonstrating benefits such as reduced breakthrough pain incidents, lower local anesthetic consumption without compromising efficacy, and heightened patient satisfaction compared with continuous epidural infusion.

Comparison of the dural puncture epidural and the standard epidural techniques in patients having labor analgesia maintained using programmed epidural boluses: a prospective double-blinded randomized clinical trial

BackgroundThe dural puncture epidural technique has been shown in some studies to improve the onset and quality of the initiation of labor analgesia compared with the standard epidural technique. However,...

Optimum programmed intermittent epidural bolus interval time of ropivacaine 0.0625% with dexmedetomidine 0.4μg/ml at a fixed volume of 10mL: a randomized controlled trial.

The aim of our study was to administer adequate local anesthetic in programmed intermittent epidural bolus (PIEB) to avoid breakthrough pain and decrease the use of manual and PCEA boluses. We, therefore, conducted this study to determine the effective PIEB interval time between boluses of ropivacaine 0.0625% with dexmedetomidine 0.4μg/ml at a fixed volume of 10mL in 90% of subjects (EI90), without the use of patient-controlled epidural analgesia (PCEA). A total of 80 subjects were included in the final statistical analysis from 23 August 2022 to 22 November 2022. The subjects were randomly assigned to one of four different PIEB time intervals: 40, 50, 60, and 70min (groups 40, 50, 60, and 70), respectively. The primary outcome was the effective epidural labor analgesia, defined as no use of PCEA bolus or a manual bolus until the end of the first stage of labor or within 6hours after loading dose administration. The PIEB EI90 (95% CI) between boluses of ropivacaine 0.0625% with dexmedetomidine 0.4μg/ml at a fixed volume of 10mL was estimated using probit regression. The effective PIEB interval time between boluses of ropivacaine 0.0625% with dexmedetomidine 0.4μg/ml at a fixed volume of 10mL in 90% of subjects without the use of PCEA was 45.4 (35.5-50.5) minutes using probit regression. No statistical differences were found in the proportion of subjects with Bromage score > 0, hypotension, pruritus, nausea, and vomiting between groups. However, the highest sensory block (pinprick) in the 40-min group was significantly higher than that in the other groups. The estimated value for EI90 for PIEB between boluses of ropivacaine 0.0625% with dexmedetomidine 0.4μg/ml at a fixed volume of 10mL using probit regression was 45.4 (35.5-50.5) minutes. Furthermore, future studies are warranted to be established to determine the optimal parameters for different regimens in clinical practice.

Study protocol for a randomised open-label clinical trial examining the safety and efficacy of the Android Artificial Pancreas System (AAPS) with advanced bolus-free features in adults with type 1 diabetes: the ‘CLOSE IT’ (Closed Loop Open SourcE In Type 1 diabetes) trial

IntroductionMultiple automated insulin delivery (AID) systems have become commercially available following randomised controlled trials demonstrating benefits in people with type 1 diabetes (T1D). However, their real-world utility may be undermined...

A randomized comparative study of patient-controlled epidural analgesia with manual standard intermittent bolus for labor analgesia

Background: Patient-controlled epidural analgesia (PCEA) pump has proven to reduce the incidence of unscheduled clinician interventions and total dose of local anesthetic administered for labor pain. Aims and Objectives: The aim of the study was to compare the quality of analgesia, maternal satisfaction, amount of rescue analgesia needed, and neonatal outcome between clinician delivered manual bolus doses and PCEA pumps for epidural labor analgesia. Materials and Methods: 60 parturients of the American Society of Anesthesiologists II scheduled for normal vaginal delivery were randomly divided into two groups, Group A (PCEA) and Group B (Manual bolus). Both groups received an initial epidural bolus of 10 mL of 0.125% Inj. Bupivacaine+20 mcg injection fentanyl. Group A (PCEA) patients received a basal infusion of 5 mL/h with self-administered bolus of 2 mL with a lockout interval of 15 min. Group B patients were provided with a bolus of 10 mL of the same solution manually after every hour. Patients of both groups were given manual rescue boluses for distressing pain (visual analog scale [VAS] &gt;5). Results: Mean VAS score in Group A was 2.97±0.73; and in Group B, it was 3.03±0.56 (P&gt;0.05). Total bupivacaine use and mean duration of second stage of labor in both groups was found comparable. Mean top-up requirement of local anesthetics was significantly high in Group B. Maternal satisfaction was also higher in PCEA group. Conclusion: As PCEA pump provides continuous infusion of local anesthetics, there was lesser requirement of top ups of bupivacaine and higher maternal satisfaction score in PCEA group than manual bolus group.

Combined Programmed Intermittent Bolus and Patient-Controlled Bolus Is a More Favorable Setting for Epidural Pain Relief Than Continuous Infusion.

Epidural analgesia is a suitable and effective treatment for labor pain. However, the preferable modality setting for delivery remains debatable. This study adopted a programmed intermittent epidural bolus (PIEB) setting in conjunction with a patient-controlled epidural analgesia (PCEA) setting to improve the quality of labor analgesia and reduce the number of medical staff. We conducted a prospective observational analysis of primigravida parturients scheduled for spontaneous labor, which required epidural analgesia for painless labor. A total of 483 healthy primigravida parturients with singleton pregnancies were included in this cohort; 135 nulliparous patients were assigned to the continuous infusion setting (CEI) group and 348 to the PIEB + PCEA group. Compared to the CEI setting, the PIEB + PCEA setting significantly reduced the manual rescue by the clinician, extended the time required for the first manual rescue dose, and acclaimed good maternal satisfaction. The use of the CEI mode increased for poor performance requiring more than two rescues with an odds ratio of 2.635 by a binary logistic regression analysis. Using the PIEB + PCEA setting as the maintenance infusion had a longer duration for the first requested manual rescue, fewer manual rescue boluses, excellent satisfaction, and no significant increase in adverse events compared to the CEI setting.

Safety of User-Initiated Intensification of Insulin Delivery Using Cambridge Hybrid Closed-Loop Algorithm.

Many hybrid closed-loop (HCL) systems struggle to manage unusually high glucose levels as experienced with intercurrent illness or pre-menstrually. Manual correction boluses may be needed, increasing hypoglycemia risk with overcorrection. The Cambridge HCL system includes a user-initiated algorithm intensification mode ("Boost"), activation of which increases automated insulin delivery by approximately 35%, while remaining glucose-responsive. In this analysis, we assessed the safety of "Boost" mode. We retrospectively analyzed data from closed-loop studies involving young children (1-7 years, n = 24), children and adolescents (10-17 years, n = 19), adults (≥24 years, n = 13), and older adults (≥60 years, n = 20) with type 1 diabetes. Outcomes were calculated per participant for days with ≥30 minutes of "Boost" use versus days with no "Boost" use. Participants with <10 "Boost" days were excluded. The main outcome was time spent in hypoglycemia <70 and <54 mg/dL. Eight weeks of data for 76 participants were analyzed. There was no difference in time spent <70 and <54 mg/dL between "Boost" days and "non-Boost" days; mean difference: -0.10% (95% confidence interval [CI] -0.28 to 0.07; P = .249) time <70 mg/dL, and 0.03 (-0.04 to 0.09; P = .416) time < 54 mg/dL. Time in significant hyperglycemia >300 mg/dL was 1.39 percentage points (1.01 to 1.77; P < .001) higher on "Boost" days, with higher mean glucose and lower time in target range (P < .001). Use of an algorithm intensification mode in HCL therapy is safe across all age groups with type 1 diabetes. The higher time in hyperglycemia observed on "Boost" days suggests that users are more likely to use algorithm intensification on days with extreme hyperglycemic excursions.

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.

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. 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. 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. 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.

A randomized comparative study of 0.1% levobupivacaine with fentanyl vs 0.1% ropivacaine with fentanyl

Background: Pregnant women experience severe labor pain which is the leading cause of stress and anxiety. The present study compared 0.1% ropivacaine and 0.1% levobupivacaine with 2 µg/ml fentanyl as a patient controlled epidural analgesia. Materials and Methods: 30 labouring parturients were divided into 2 groups of 15 each. Group I patients received 0.1% ropivacaine with 2 µg/ml fentanyl and group II patients received 0.1% levobupivacaine with 2 µg/ml fentanyl as epidural solutions via PCEA pump infusions. Results: Mode of delivery found to be caesarean seen in 5 in group I and 7 in group II, instrument‑assisted vaginal delivery seen 8 in group I and 6 in group II and normal vaginal delivery seen 7 in group I and 7 in group II. The difference was non- significant (P> 0.05). Demand boluses per hour was 0.08 in group I and 0.36 in group II, mean total number of manual rescue boluses was 1.02 in group I and 0.61 in group II and first requirement of manual rescue bolus was 3.10 in group I and 2.60 in group II. The difference was significant (P< 0.05). Conclusion: Both bupivacaine and ropivacaine produced equivalent analgesia with fentanyl for labor.

A comparison of maternal fear of childbirth, labor pain intensity and intrapartum analgesic consumption between primiparas and multiparas: A cross-sectional study

ObjectivesTo describe and compare fear of childbirth and in-labor pain intensity between primiparas and multiparas and explore the association between the amount of actual pain relief and fear of childbirth. MethodsA convenience sampling method was used. A total of 260 women undergoing spontaneous or induced labor, including 97 primiparas and 163 multiparas, were recruited in a large academic specialized hospital in Guangzhou, China, from February 2018 to August 2019. The clinical data of maternal and neonatal were extracted from a structured electronic medical record system. Other demographic information, such as employment and family monthly income, was collected by a questionnaire. The Numeric Rating Scale (NRS) and the Chinese version of the Childbirth Attitude Questionnaire (C-CAQ) were applied to assess maternal in-labor pain intensity and fear of childbirth. The analgesic consumption and the frequency of manual boluses as rescue analgesia were stored and collected from the analgesia pump. ResultsEighty-two (84.5%) primiparas and ninety-nine (60.7%) multiparas received epidural analgesia (P < 0.001). In the epidural subgroup, the primiparous average fear of childbirth (36.46 ± 10.93) was higher than that of the multiparas (32.06 ± 10.23) (P = 0.007). However, multiparas reported more intense in-labor pain [8.0 (8.0, 9.0) vs. 8.0 (7.0, 8.0)], had more successful manual boluses per hour [2.68 (1.65, 3.85) vs. 1.77 (0.90, 2.47)], more hourly analgesic consumption [23.00 (16.00, 28.25) vs. 17.24 (11.52, 21.36) mL] and more average analgesic consumption [0.35 (0.24, 0.45) vs. 0.26 (0.19, 0.35) mL/(h·kg)] than the primiparas (P < 0.05). Spearman’s correlation analysis showed that the maximum in-labor pain was weakly positively correlated with fear of childbirth (r = 0.09) (P < 0.05), hourly analgesic consumption (r = 0.16) (P < 0.01) and average analgesic consumption (r = 0.17) (P < 0.05). No statistically significant association was uncovered between analgesic consumption and maternal fear of childbirth. ConclusionsFear of childbirth is a potential predictor of labor pain intensity. Further study is needed to explore its role and value in pain management during delivery. Parity is not a determinant of pain relief use and should not be a preconceived preference of obstetric care team members to determine the distribution of epidural analgesia, especially when analgesia resources are insufficient.

Pain management during labor: use of intermittent drug delivery devices for improvement of obstetric and neonatal outcome and reduction of healthcare burden: A large non-inferiority randomized clinical trial

BackgroundAutomated continuous epidural administration of local anesthetics provides a more stable analgesic block with decreasing of healthcare staff compared to manual boluses administration (TOP-UP) but is associated to high rate of operative vaginal delivery. We hypothesized that the use of programmed intermittent automated boluses (PIEB) is able to provide a good quality of analgesia and decreasing of anesthesiologic workload without increasing the rate of instrumental vaginal birth in comparison with TOP-UP technique. Laboring nulliparous woman aged between 18 and 46 years were randomized to epidural analgesia with 0.0625% levobupivacaine and sufentanil administered by PIEB or by TOP-UP techniques. Primary outcome was instrumental vaginal delivery rate and secondary outcomes were quality of analgesia, total and time-related drugs doses used, motor block, newborn outcome, and anesthesiologic workload.ResultsSix hundred twenty-nine were randomized, and 628 were included in the intention-to-treat analysis. The rate of instrumental vaginal delivery was similar in the PIEB and TOP-UP groups (13.2% vs 9.7%, OR 1.4 95% CI 0.8 to 2.5; p 0.21). There was no difference between groups regarding mode of delivery (cesarean section vs vaginal birth), newborn outcome, and motor block. Patients in the PIEB group received more total and time-related drugs doses and a better quality of analgesia. Anesthesiological workload was significantly reduced in the PIEB group.ConclusionsOur study demonstrated that epidural anesthesia with programmed intermittent epidural boluses by an automated device provides an effective and safe management of labor analgesia with improvement of pain control and sparing of man workload compared to manual top-up protocols.

Computer-assisted Anesthesia Care: Avoiding the Highway to HAL

Computer-assisted Anesthesia Care: Avoiding the Highway to HAL

The Study of Postoperative Recall in Patients under Total Intravenous Anesthesia

Background:The incidence of postoperative recall under total intravenous anesthesia (TIVA) is not yet fully established. Avoidance of inhalational agent is a known risk factor for awareness. In addition, lack of reliable technique to monitor drug concentration needed for adequate depth of anesthesia makes TIVA challenging. Hence, we intend to evaluate our standard anesthesia practice for postoperative recall.Methodology:This questionnaire-based observational study was done over the period of 2 years. We enrolled 1080 adult (American Society of Anesthesiologists physical status Class I or II) patients undergoing TIVA for Endoscopic retrograde cholangiopancreatography (ERCP). All patients received fentanyl, midazolam and propofol-based anesthesia. Manual boluses of propofol were given to achieve adequate sedation. (Ramsay sedation scale of 5) in accordance with clinical signs as judged by the primary anesthesiologist. Postoperatively within 12–24 h, patients were assessed for recall using Brice questionnaire. Primary outcome was number of patients reporting postoperative recall in the Brice interview. Secondary outcome was the incidence of dreaming.Results:On postoperative interview, none of the patients reported awareness. 12.5% of patients had dreams which were pleasant. None of the dreams was unpleasant. The worst thing about surgery was pain.Conclusion:Our study suggests that if adequate doses of propofol are adhered to and necessary action is taken against responses indicating wakefulness, postoperative recall under TIVA is an uncommon occurrence.

Programmed intermittent epidural boluses (pieb) for labor analgesia: study of the sensor block and effects on maternal motor function

Background. Programmed intermittent epidural boluses (PIEB) technique is a promising approach that demonstrates certain advantages over traditional techniques of epidural analgesia. We compared the dynamics of the sensory block of PIEB + parturient-controlled epidural analgesia (PCEA) with continuous epidural infusion (CEI) + PCEA for maintenance labor analgesia and the incidence of motor block (MB) in women who received PIEB or traditional techniques.&#x0D; Methods. A total of 165 subjects were studied. All parturients were divided into five groups: manual boluses, PCEA, PCEA + CEI, PIEB + PCEA; levobupivacaine 0.25 mg/mL; 1.25 mg/mL; 0.625 mg/mL. The level of the MB was evaluated by the classic Bromage scale (0-1-2-3). The level of the sensor block was evaluated by the pin-prick test.&#x0D; Results. MB was reported in 80% in group 1 120 min after analgesia, 78% and 52% in groups 2 and 3 at the 150th min (p 0.001); in group 4, the MB frequency was 6% 15 min after the start and was increasing to 40% at full cervical dilation (p 0.001). In group 5, the relative MB frequency did not exceed 10% at the 120th min and was 0% at full cervical dilation (p 0.00001). The results indicate that in the PIEB group, the level of sensory block in patients was higher 15 min after the start of analgesia and remained so until the end of the observation period [median PIEB Th5 versus Th8 in the CEI group, (p 0.0004)].&#x0D; Conclusions. PIEB + PCEA technique maintained a consistently high level of sensor block throughout the study compared to PCEA + CEI, which ensured effective analgesia in the first and second stages of labor with minimal MB.

Hybrid closed-loop therapy: Where are we in 2021?

Hybrid closed-loop systems are characterized by the coexistence of algorithm-driven automated insulin delivery combined with manual mealtime boluses. Used correctly, these insulin delivery systems offer better glucose control and reduced risk of hypoglycaemia and represent the most advanced form of insulin delivery available for people with type 1 diabetes. The aim of this paper was to compare the currently available commercial hybrid closed-loop systems in the UK: the Medtronic 670G/780G, Tandem t:slim X2 Control IQ and CamAPS FX systems. The Medtronic 670G/780G systems use Guardian 3 sensor (7-day use, two to four calibrations per day), while Tandem and CamAPS systems use the calibration-free Dexcom G6 sensor (10 days). The CamAPS system is available as an android app, whereas the other two systems have the algorithm embedded in the insulin pump. During pivotal studies, depending on the study population and baseline glycated haemoglobin level, these systems achieve a time spent in the target range 3.9 to 10 mmol/L (70 to 180 mg/dL) of 65% to 76% with low burden of hypoglycaemia. All three systems allow a higher glucose target for announced exercise, while the Tandem system offers an additional night-time tighter target. The CamAPS system offers fully customizable glucose targets and is the only system licensed for use during pregnancy. Additional education is required for both users and healthcare professionals to harness the best performance from these systems as well as to troubleshoot when "automode exits" occur. We provide consensus recommendations to develop pragmatic pathways to guide patients, clinicians and commissioners in making informed decisions on the appropriate use of the diabetes technology.

The Labor Analgesia Requirements in Nulliparous Women Randomized to Epidural Catheter Placement in a High or Low Intervertebral Space.

We hypothesized that an epidural catheter placed in a lower vertebral interspace will require less medication for labor analgesia. Nulliparous women requesting neuraxial labor analgesia were randomized to epidural catheter placement at the ultrasound-confirmed L1-2 or L4-5 interspace. Patient-controlled epidural analgesia and breakthrough manual epidural boluses of 10 mL of 0.125% bupivacaine with 50 µg of fentanyl or 8 mL of 2% lidocaine were utilized. Abdominal and perineal pain scores were assessed at 30 and 60 minutes after standardized initiation of epidural analgesia. Pain scores during pushing were assessed after delivery. The primary outcome was the proportion of patients requiring manual boluses and was compared using a χ test. Secondarily, we analyzed the number of boluses given in early (up to 4 hours before delivery) versus late labor using χ tests and the pain scores using Mann-Whitney U tests, with adjustment of P values for multiple testing. We analyzed 148 patients. Overall, the percentage of patients in the low versus high groups who required manual boluses was 46% vs 51% (P = 1.0). For the 56 patients in each group who delivered vaginally, 22 (52%) vs 20 (48%) manual boluses were given to the low epidural group in early versus late labor, compared to 9 (20%) vs 36 (80%) in the high epidural group (P = .014). There was no statistical difference in patient-controlled epidural analgesia requirements or patient satisfaction. Comparing the low versus high groups, the median (interquartile range) pain scores were: 3 (1, 6) vs 0 (0, 2) (P = .013) at 30 minutes and 1 (1, 3) vs 0 (0, 1) (P = .013) at 60 minutes for abdominal pain; 0 (0, 2) vs 1 (1, 3) (P = .36) and 0 (0, 1) vs 1 (1, 3) (P = .014) at these same time points for perineal pain; and 1 (0, 5) vs 0 (0, 3) (P = .9) for abdominal and 2 (0, 5) vs 4 (1, 8) (P = .025) for perineal pain during pushing. The percentage of patients who underwent instrumental delivery was 15% vs 5% (P = .06) for the low versus high group. An L4-5 epidural catheter initially provides less relief of abdominal pain but more relief of perineal labor pain. Patients with an L4-5 catheter require more manual boluses during early labor but less during late labor. The possible association of low epidural catheters with instrumental delivery merits further investigation.

Manual Closed-Loop Insulin Delivery Using a Saddle Point Model Predictive Control Algorithm: Results of a Crossover Randomized Overnight Study.

The purpose was to assess the efficacy of a new closed-loop algorithm (Saddle Point Model Predictive Control, SP-MPC) in achieving nocturnal normoglycemia while reducing the risk of hypoglycemia in patients with type 1 diabetes. In this randomized crossover study, 10 adult patients (mean hemoglobin A1c 7.35 ± 1.04%) were assigned to be treated overnight by open loop using sensor-augmented pump therapy (open-loop SAP) or manual closed-loop delivery. During closed loop, insulin doses were calculated using the SP-MPC algorithm and administered as manual boluses every 15 minutes from 9:00 pm to 8:00 am. Patients consumed a self-selected meal (65-125 g of carbohydrates) at 7:00 pm accompanied by their usual prandial bolus. Blood glucose was measured every 30 minutes. The primary endpoints were the time spent in target (70-145 mg/dl) and time spent below 70 mg/dl from 11:00 pm to 8:00 am. Time spent in target did not differ between closed-loop and open-loop SAP. The number of hypoglycemic events (<70 mg/dl) was reduced 2.8-fold in closed loop (n = 5, median = 0/patient/hour; interquartile range: 0-0.11) as compared to open-loop SAP (n = 14, median = 0.22/patient/hour, 0.02-0.22) ( P = .02). The area under the curve for sensor glucose values >145 mg/dl was significantly lower during closed-loop than during open-loop SAP ( P = .03) as well as HBGI ( P = .02). This pilot study suggests that the use of the SP-MPC algorithm may improve mean overnight glucose control and reduce the number of hypoglycemic events as compared to SAP therapy.

Programmed Intermittent Epidural Boluses for Maintenance of Labor Analgesia: An Impact Study

(IJOA. 2016;26:32–38) Maintenance of epidural labor analgesia has evolved from manual boluses to continuous infusions to patient-controlled boluses. Patient-controlled epidural analgesia (PCEA) in the presence or absence of a background continuous epidural infusion (CEI) is a common technique for providing labor analgesia. Programmed intermittent epidural bolus (PIEB) is an automated technique that provides fixed boluses of local anesthetic with or without opioid at scheduled intervals. It can be used as an alternative to CEI alone or CEI with PCEA. This current study aimed to compare PIEB+PCEA administration to CEI+PCEA administration for labor analgesia. The hypothesis was that PIEB would reduce the number of patients requiring clinician boluses compared to CEI.