Intermittent Bolus Technique Research Articles

Comparative evaluation of continuous infusion versus programmed intermittent bolus techniques in erector spinae plane block in modified radical mastectomy - A preliminary randomised controlled trial.

Single-shot erector spinae plane block (ESPB) provides excellent analgesia in mastectomy in the immediate post-operative period but is not sufficient to maintain for prolonged duration. This study compares the efficacy of programmed intermittent bolus (PIB) versus continuous infusion (CI) techniques after ESPB by placing a catheter for mastectomy. After ethical approval and patient consent, ESPB was performed at the T4 level in 50 patients with an initial bolus of 20 mL 0.375% ropivacaine and a catheter placed 30 min before surgery. In the postoperative period, they were randomised to Group I - intermittent bolus of 20 mL 0.2% ropivacaine every 4 h for 24 h and Group C - continuous infusion of 0.2% ropivacaine at 5 mL/h for 24 h. The primary outcome was the 24-h fentanyl consumption by patient-controlled analgesia device. Data was analysed using Stata 14.0. Group I patients had reduced post-operative fentanyl consumption {mean [standard deviation (SD)]: 166 (139.17) µg vs 332 (247.96) µg, P = 0.002} and lower median NRS scores (1 h: 3 vs 5), (2 h: 3 vs 5), (4 h: 3 vs 5), (6 h: 4 vs 5) with a higher mean (SD) Quality of Recovery-15 score {134.4 (8.53) vs 127 (12.89), P = 0.020} compared to Group C, respectively. The 24-h dermatomal sensory coverage was more comprehensive in Group I compared to Group C. The PIB technique after ESPB provides decreased postoperative opioid consumption, better post-operative analgesia and quality of recovery compared to the CI technique in patients undergoing mastectomy.

Randomized Assessment of the Optimal Time Interval Between Programmed Intermittent Epidural Boluses When Combined With the Dural Puncture Epidural Technique for Labor Analgesia

(Anesth Analg. 2023;136:532–539) Neuraxial labor analgesia has advanced to include the dural puncture epidural (DPE) and the programmed intermittent epidural bolus (PIEB) techniques. This study aimed to test the appropriate interval for effective analgesia when the DPE technique is followed by the PIEB technique. This study used fixed volumes of PIEB at 10 mL of ropivacaine 0.1% and 0.5 mg/mL of sufentanil.

Effect of programmed intermittent epidural bolus protocol on physician-administered rescue boluses of labor analgesia

Background Prior studies have shown that programmed intermittent epidural bolus (PIEB) techniques, with or without patient-controlled epidural analgesia (PCEA) boluses, provide better pain relief, reduced motor block, and better patient satisfaction compared to continuous epidural infusion (CEI) techniques. We hypothesized that patients who had labor epidural analgesia (LEA) maintained with PIEB and PCEA would be less likely to receive a physician-administered rescue analgesia bolus compared to patients who had CEI and PCEA. Methods We searched our electronic medical record for patients who had CEI and PCEA from August 1, 2021 to December 31, 2021 and for patients who had PIEB and PCEA from August 2, 2022 to December 31, 2022. Results A total of 792 and 665 patients had maintenance of LEA with CEI/PCEA and PIEB/PCEA, respectively. A multivariate logistic regression was performed and, after adjusting for variables of interest, patients who had PIEB and PCEA were less likely to receive one or more physician-administered rescue analgesia boluses (odds ratio 0.504; 95% confidence interval 0.392, 0.649; P < 0.001) compared to patients who had CEI and PCEA. Conclusion PIEB/PCEA was associated with fewer physician-administered boluses of rescue analgesia compared to CEI/PCEA when used for LEA.

Determination of the Optimal Volume of Programmed Intermittent Epidural Bolus When Combined With the Dural Puncture Epidural Technique for Labor Analgesia: A Random-Allocation Graded Dose-Response Study.

The dural puncture epidural (DPE) and the programmed intermittent epidural bolus (PIEB) techniques are recent innovations for labor analgesia. The optimal volume of PIEB during traditional epidural analgesia has been investigated previously but it is unknown whether these findings are applicable to DPE. This study aimed to determine the optimal volume of PIEB for effective labor analgesia after initiation of analgesia using DPE. Parturients requesting labor analgesia received dural puncture with a 25-gauge Whitacre spinal needle and then had analgesia initiated with 15 mL of ropivacaine 0.1% with sufentanil 0.5 μg/mL. Analgesia was maintained using the same solution delivered by PIEB with boluses given at a fixed interval of 40 minutes starting 1 hour after the completion of the initial epidural dose. Parturients were randomized to 1 of 4 PIEB volume groups: 6, 8, 10, or 12 mL. Effective analgesia was defined as no requirement for a patient-controlled or manual epidural bolus for 6 hours after the completion of the initial epidural dose or until full cervical dilation. The PIEB volumes for effective analgesia in 50% of parturients (EV50) and 90% of parturients (EV90) were determined using probit regression. The proportions of parturients with effective labor analgesia were 32%, 64%, 76%, and 96% in the 6-, 8-, 10-, and 12-mL groups, respectively. The estimated values for EV50 and EV90 were 7.1 (95% confidence interval [CI], 5.9-7.9) mL and 11.3 (95% CI, 9.9-15.2) mL, respectively. There were no differences in side effects, including hypotension, nausea and vomiting, and fetal heart rate (FHR) abnormalities among groups. Under the conditions of the study, after initiation of analgesia using DPE, the EV90 of PIEB for effective labor analgesia using ropivacaine 0.1% with sufentanil 0.5 μg/mL was approximately 11.3 mL.

Intermittent epidural boluses vs continuous epidural infusion for labour analgesia: which is superior?

Epidurals are considered the gold standard for labour analgesia. The possibility of newer pumps reducing staff workload has reignited interest in the advantages of the intermittent bolus technique, but is this superior to a continuous epidural infusion?

Levobupivacaine Consumption in Automated Intermittent Bolus in Ultrasound Guided Subparaneural Sciatic Nerve Catheters: A Prospective Double-Blind Randomized Trial

PurposeContinuous sciatic nerve blocks have proven benefits for postoperative analgesia after foot surgery. However, the optimal mode of administration remains a point of debate. Ultrasound guided subparaneural injection accelerates onset time and increases duration after a single shot sciatic nerve block. This double blind prospective randomized trial compares the 48-hour local anesthetic (LA) dose consumption of an automated intermittent bolus technique to a continuous infusion regimen in a subparaneural sciatic nerve catheter after hallux valgus surgery.Patients and MethodsPatients scheduled for hallux valgus surgery were randomized to receive either a continuous infusion of levobupivacaine 0.125% at 5mL/h (group A) or an intermittent automated bolus of 9.8 mL every 2 hours with a background of 0.1 mL/h (group B), both with a PCA bolus of 6 mL and lockout of 30 minutes. The 48 hour LA consumption, PCA boluses, Numeric Rating Scale (NRS), satisfaction and return of normal sensation were recorded.ResultsSixteen patients were excluded because of protocol violation or technical problems and 42 patients remained for analysis. The 48 hour ropivacaine consumption was higher in group A (293 ±60 mL) than group B (257±33 mL). The median and highest NRS scores and patient satisfaction were not statistically different between groups. Normal sensation returned after 75 ± 22 hours (group A) and 70 ± 17 hours (group B).ConclusionProgrammed bolus administration in subparaneural sciatic nerve catheters reduces LA consumption 48 hours after surgery with equal analgesia and patient satisfaction. Return of sensation is variable and can last more than 75 hours.

Efficacy of fentanyl versus sufentanil for labour analgesia and its comparative evaluation with intramuscular tramadol

Introduction: Knowledge about relative merits and demerits of different techniques of administration of drugs through epidural route is needed for optimum management of labour pain. Primary objective of this study is to assess the efficacy of fentanyl and sufentanil for labour analgesia in comparison with intramuscular tramadol. Materials and Methods: This prospective randomized control study included 90 primigravida parturients who were randomly allocated to three groups of 30 each; Fentanyl group (group BF) received 50 mg of epidural fentanyl with 10 ml of 0.125% bupivacaine, Sufentanil group (group BS) received 10mg epidural sufentanil with 10 ml of 0.125% bupivacaine and Tramadol group (group T), the control group received 100mg intramuscular tramadol with 50 mg repeat dose after 4 hours. Results: Epidural groups were comparable in their visual analogue scale (VAS) score satisfaction score, characteristics of sensory and motor blockade, mode of delivery, side effects, haemodynamic stability and neonatal outcome. Value of VAS did not exceed 3 in the epidural group during the entire study period. Onset of analgesia was early with sufentanil (10.52.1 mins, p used was also less (44.16 mg, p =0.002). Higher VAS scores (>4), delayed onset and decreased total duration of labour was seen in tramadol group. Epidural and tramadol group were comparable in mode of delivery and neonatal outcome. Conclusion: Quality of epidural analgesia with either fentanyl or sufentanil using intermittent bolus technique was comparable. Duration of first and second stage of labour was significantly prolonged in parturients receiving labour epidural analgesia. Keywords: Bupivacaine, Fentanyl, Sufentanil, Labour, Analgesia.

Intermittent bolus versus continuous infusion techniques for local anesthetic delivery in peripheral and truncal nerve analgesia: the current state of evidence

Manually delivered intermittent bolus (MIB) and programmable intermittent bolus (PIB), alternatives to continuous infusion (CI), involve administering a set volume of solution at a set interval of time. The benefits...

Neuraxial labor analgesia: a focused narrative review of the 2017 literature.

Neuraxial labor analgesia remains the most effective and one of the most commonly utilized methods for pain relief during labor. This narrative review article is a summary of the literature published in 2017 on neuraxial analgesia for labor. From a total of 41 identified articles, 13 were included in the review. The topics have been structured into three categories: initiation of neuraxial analgesia, maintenance of neuraxial analgesia, and neuraxial analgesia and obstetric outcomes. Maintenance regimens, such as program intermittent epidural bolus (PIEB) techniques, remain a focus of extensive research with the potential to optimize analgesia for each individual patient. In a similar way, the dural puncture epidural technique could improve the quality of labor analgesia with fewer side effects compared with standard epidural and combined spinal epidural (CSE) techniques. Finally, the increased use of modern technology using portable ultrasound devices with automated imaging software to facilitate epidural catheter placement may offer potential advantages to the obstetric anesthesiologist, especially when dealing with technically difficult cases. Recent advances, as well as refinements, of current neuraxial analgesia techniques could improve women's experience of labor.

Programmed intermittent peripheral nerve local anesthetic bolus compared with continuous infusions for postoperative analgesia: A systematic review and meta-analysis

Study objective and backgroundThe role of the programmed intermittent bolus (PIB) technique for infusion of local anesthetics in continuous peripheral nerve blockade (CPNB) remains to be elucidated. Randomized controlled trials (RCTs) on PIB versus continuous infusion for CPNB have demonstrated conflicting results and no systematic review or meta-analysis currently exists. We aimed to delineate via systematic review with meta-analysis if there is any analgesic benefit to performing PIB versus continuous infusion for CPNB. DesignWe conducted a systematic review and random-effects meta-analysis of RCTs. Data sourcesWe searched Medline, Embase, and the Cochrane Library without language restriction from inception to 2-May-2017. Eligibility criteriaIncluded RCTs had to compare PIB to continuous infusion in adult surgical patients receiving any upper or lower limb CPNB for postoperative analgesia. VAS pain scores were the primary outcome. The Cochrane Risk of Bias Tool with GRADE methodology was utilized to assess evidence quality. ResultsNine RCTs (448 patients) met the inclusion criteria. Two studies performed upper limb blocks and the rest lower limb blocks. Five RCTs activated the CPNB with long-acting local anesthetic and only five used multi-modal analgesia. PIB modestly reduced VAS pain scores at 6h (−14.2mm; 95%CI −23.5mm to −5.0mm; I2=82.5%; p=0.003) and 12h (−9.9mm; 95%CI −14.4mm to −5.4mm; I2=12.4%; p<0.001), but not at later time points. There were no other meaningful differences in the rest of the outcomes, apart from more residual motor block with PIB (OR 4.27; 95% CI 1.08–16.9; p=0.04; NNTH=8). GRADE scoring ranged from low to very low. ConclusionsThe existing evidence demonstrates that PIB does not meaningfully reduce VAS pain scores in CPNB. This systematic review provides important information about the limitations of existing studies. Future studies should reflect contemporary practice and focus on more painful operations.

Continuous transversus abdominis plane block vs intermittent bolus for analgesia after abdominal surgery: a randomized trial

BackgroundContinuous and intermittent bolus techniques of transversus abdominis plane (TAP) blocks have been used for analgesia after abdominal surgery. Although both are effective, there are no studies comparing them. The aim of this study is to compare analgesia and cost-effectiveness between these groups.MethodsAfter obtaining ethical approval, 20 American Society of Anesthesiologists ASA grade I to III patients undergoing elective abdominal surgery were recruited with 10 patients allocated to each arm. Bilateral ultrasound-guided TAP blocks were performed with an initial bolus of 0.5% ropivacaine 20 mL per side, followed by catheter insertion. After surgery, the continuous infusion group received 0.2% ropivacaine 8 mL/hour on each side and the intermittent bolus group received doses of 0.2% ropivacaine 20 mL per side every 8 hours for 48 hours. Both groups received intravenous fentanyl patient-controlled analgesia and regular oral paracetamol. Parameters recorded included numerical rating scores for pain and post-operative analgesic consumption at baseline (time 0) and at 1 hour, 1 day and 2 days post-operatively. The duration of catheter insertion, complications, patient satisfaction and information regarding costs were also recorded. Patient satisfaction was assessed utilizing a 4-point “Likert” scale on day 2 and on day 30. Pain and Likert scores were analysed by non-parametric sum rank test and all two-sampled t-tests assumed unequal variances.ResultsThere was no difference between duration of TAP block, anesthetic and surgical technique and length of stay (p=0.23). Primary outcomes: pain scores at rest and cough were not significantly different (p=0.20) between the groups. Satisfaction scores were similar at day 2 and 30 (p=0.77). However, the bolus group was more cost-effective (AU$347.98 vs AU$429.43).ConclusionContinuous or bolus TAP blocks are effective analgesic techniques in abdominal surgery, with bolus technique being more economical.

Total intravenous anaesthesia with propofol in minor gynaecological procedures: target-controlled infusion compared with manually–delivered intermittent bolus technique

Total intravenous anaesthesia with propofol in minor gynaecological procedures: target-controlled infusion compared with manually–delivered intermittent bolus technique

Comparison between Intermittent Propofol Bolus Techniques and Target-Controlled Infusion in Patients Underwent Gastrointestinal Endoscopy

Background : Nowadays, the use of propofol for sedation during gastrointestinal endoscopic procedure has become more popular, either by intermittent-bolus (IB) technique or target-controlled infusion (TCI). The aim of this study was to compare the outcomes of both techniques including the total consumption of propofol, consumption per minute, total cost, side effects and its recovery time. Method : This study was a single-blinded randomized clinical trial conducted at Digestive Endoscopy Center, Cipto Mangunkusumo Hospital, Jakarta between October and November 2013. There were fifty patients with pre-operative American Society of Anesthesiologist (ASA) Physical Status Classification I-III, aged 18-65 years, body mass index 18-30 kg/m2 who were randomized to obtain sedation with IB propofol or TCI after having a premedication with 1 μg/kgBW fentanyl. The outcomes including the duration of sedation, total dose, propofol consumption per minute, the total cost, the incidence of hypotension, the incidence of desaturation, and recovery time were then evaluated using SPSS version 21.0. Results : Duration of procedure between two groups was not significantly different (p = 0.718). Total dose of propofol, its consumption per minute and total cost were higher in TCI group (p = 0.010; p = 0.004; p = 0.001). The incidence of hypotension, desaturation and recovery time were not significantly different (p = 0.248; p = 0.609; p = 0.33) in both groups. Conclusion : IB technique is more efficient in terms of total propofol dose, consumption per minute and total cost compared to the TCI technique. The incidences of hypotension, desaturation and recovery time profiles were comparable between the two groups. Keywords: gastrointestinal endoscopy, intermittent bolus, propofol, sedation, TCI

Propofol sedation for flexible bronchoscopy: a randomised, noninferiority trial

Propofol has been established as a reliable method for sedation in flexible bronchoscopy. There are no data comparing propofol administered as intravenous boluses versus continuous infusion. 702 consecutive patients undergoing flexible bronchoscopy were randomly allocated to receive intravenous propofol using either an intermittent bolus technique or a continuous infusion. The primary end-point was the number of adverse events assessed at the end of flexible bronchoscopy and at 24 h. The number of any adverse event was similar in both randomised groups (219 versus 211, p=0.810). There were complications in eight cases (seven major bleedings, one respiratory failure). As compared with the bolus group, the amount of propofol required was significantly higher in the infusion group (226 ± 147 mg versus 308 ± 204.8 mg, p<0.0001). In a multivariate regression model, this difference remained significant independent of the duration and the interventions performed during the procedure. The duration of bronchoscopy was significantly longer in the infusion group (median 14 (interquartile range 9-24) versus 17 (12-27) min, p<0.0001). Propofol continuous infusion is as safe as bolus administration; however, it is associated with higher propofol requirements and a longer duration of the bronchoscopy.

The efficacy of automated intermittent boluses for continuous femoral nerve block: a prospective, randomized comparison to continuous infusions

Study ObjectiveTo determine whether an automated intermittent bolus technique provides enhanced analgesia compared with a continuous infusion for femoral nerve block. DesignProspective, single-blinded, randomized controlled trial (ClinicalTrials.gov Identifier: NCT01226927). SettingPerioperative areas and orthopedic surgical ward of a university hospital. Patients45 ASA physical status 1, 2, and 3 patients undergoing unilateral primary total knee arthroplasty. InterventionsAll patients received single-injection sciatic and femoral nerve blocks plus femoral nerve catheter placement for postoperative analgesia. Patients were randomly assigned to an automated intermittent bolus (5 mL every 30 min with 0.1 mL/hr basal rate) or a continuous infusion (10.1 mL/hr) delivery method of 0.2% ropivacaine. MeasurementsConsumption of intravenous patient-controlled analgesia (IV-PCA) and visual analog scale (VAS) pain scores were assessed postoperatively at set intervals until the morning of postoperative day (POD) 2. Main ResultsThe mean (SEM) cumulative IV-PCA dose (mg of hydromorphone) for the 36-hour postoperative interval measured was 12.9 ± 2.32 in the continuous infusion rate group (n = 20) and 7.8 ± 1.02 in the intermittent bolus group [n = 21, t(39) = 2.04, P = 0.048; a 39 ± 14% difference in total usage]. Pain scores were statistically significantly lower in the intermittent bolus group in the afternoon of POD 1 (t(39) = 2.47, P = 0.018), but were otherwise similar. ConclusionsAn automated intermittent bolus infusion technique for femoral nerve catheters is associated with clinically and statistically significantly less IV-PCA use (ie, an opioid-sparing effect) than a continuous infusion technique.

Radiofrequency Ablation: Effect of Tumor- and Organ-specific Pharmacologic Modulation of Arterial and Portal Venous Blood Flow on Coagulation Diameter in an N1-S1 Tumor Model

PurposeTo investigate inherent differences in vasculature of tumors versus normal parenchyma and efficacy of radiofrequency (RF) ablation with glucagon, adenosine, and a combination of the two compared with normal saline solution (NS) controls in an N1-S1 tumor model implanted in Sprague–Dawley rat livers. Materials and MethodsA total of 17 tumors were established in the left lobes of rats. Tumor perfusion relative to surrounding liver parenchyma was evaluated with contrast-enhanced ultrasound with intermittent-bolus technique before and after administration of glucagon, adenosine, a combination of the two, or NS. Tumors were ablated with a 22-gauge RF probe with 1 cm of exposed tip at 80 °C for 2 min. Tumor size, zone of necrosis, and viable tumor were measured in tumors after 2,3,5-triphenyltetrazolium chloride staining. Results were compared with degree of tumor perfusion. ResultsThe normalized tumor perfusion ratio did not significantly change with administration of NS (1.38% ± 3.93). Vasomodulation resulted in significant decreases in normalized tumor perfusion ratio: 66.22% ± 24.57 (P < .01) with glucagon, 71.45% ± 22.72 (P < .01) with adenosine, and 74.98% ± 16.58 (P < .01) with glucagon plus adenosine. After tumor ablation, there was an increase in size of the ablated area by 100%–165% in the three treatment groups compared with NS controls. Differences among treatment groups were not statistically significant. ConclusionsTumor blood flow may be significantly altered by using systemic injection of appropriate medications. This tumor- and organ-specific approach to tumor vasomodulation may be used to enhance current therapeutic options.

Low Dose Epidural Analgesia During Labor: Comparison Between Patient Controlled Epidural Analgesia with Basal Continuous Infusion and Intermittent Bolus Technique

To compare the efficacy and safety of patient controlled epidural analgesiawithbasal continuous infusion versus intermittent bolus for labor analgesia using fentanyl and bupivacaine. In this prospective study, 60 parturients having singleton term uncomplicated pregnancy in early active labor were included. 30 parturients were allocated to receive patient controlled epidural analgesia+basal continuous infusion (Group-A) and 30 received intermittent bolus on demand (Group-B). Efficacy of technique was assessed in terms of quality of analgesia on 0-10cm verbal analogue scale. Effect on labor was assessed by duration of labor, mode of delivery, and parturient's satisfaction. Neonatal outcome was measured by Apgar score. Data were expressed as mean±SD and analysed using Student 't' test and chi square test where appropriate. P<0.05 was considered statistically significant. Analgesic efficacy of both the groups was comparable. Maternal satisfaction was better in group A than in group B but the results did not achieve statistical significance. Effect on labor and neonatal outcome were comparable. Both the techniques appear to be safe for the mother and neonate with excellent analgesic efficacy. In a busy obstetric unit with increased demand of epidural analgesia, patient controlled epidural analgesia with basal continuous infusion may be preferred.

Cardiac Output Assessed by Invasive and Minimally Invasive Techniques

Cardiac output (CO) measurement has long been considered essential to the assessment and guidance of therapeutic decisions in critically ill patients and for patients undergoing certain high-risk surgeries. Despite controversies, complications and inherent errors in measurement, pulmonary artery catheter (PAC) continuous and intermittent bolus techniques of CO measurement continue to be the gold standard. Newer techniques provide less invasive alternatives; however, currently available monitors are unable to provide central circulation pressures or true mixed venous saturations. Esophageal Doppler and pulse contour monitors can predict fluid responsiveness and have been shown to decrease postoperative morbidity. Many minimally invasive techniques continue to suffer from decreased accuracy and reliability under periods of hemodynamic instability, and so few have reached the level of interchangeability with the PAC.

The Art and Science of Propofol-Remifentanil Infusions for Office-Based Open Airway Anesthesia

This clinically-oriented presentation introduces the art of administering a propofol and low dose remifentanil admixture by microbolus and continuous infusion to achieve a dose-dependent choice of moderate sedation, deep sedation or general anesthesia. As midazolam has largely replaced diazepam, and propofol / methohexital; now remifentanil replaces fentanyl to segue a new era in the practice of anesthesia for the office-based, operator anesthetist. Current interest in this drug parallels similar phenomena witnessed in other countries. Long-standing and time honored “intermittent bolus techniques” with slower acting drugs will now be viewed as both cumbersome and obsolete.

The Art and Science of Propofol-Remifentanil Infusions for Office-Based Open Airway Anesthesia

This in-depth and clinically oriented presentation introduces the art of administering a propofol-remifentanil admixture by continuous infusion to achieve a dose-dependent choiceof moderate sedation, deep sedation or general anesthesia. As midazolam has largely replaced diazepam, and propofol/methohexital, now remifentanil replaces fentanyl to segue a new era in the practice of anesthesia for the office-based, operator anesthetist. Current interest in this drug parallels similar phenomena witnessed in other countries. Long-standing and time honored “intermittent bolus techniques” with slower acting drugs will now be viewed as both cumbersome and obsolete.