Lockout Time Research Articles

Clinical observation of preemptive analgesia with gabapentin for adenotonsillectomy in children with obstructive sleep apnea hypopnea syndrome

Objective To evaluate the use of gabapentin in preemptive analgesia for adenotonsillectomy in children with obstructive sleep apnea hypopnea syndrome (OSAS). Methods Eighty OSAHS patients, American Society of Anesthesiologists (ASA)Ⅰ or Ⅱ , undergoing adenotonsillectomy were divided into two groups, according to a random number table:an observation group or a control group, with 40 patients in each group. Patients in the observation group were orally administered with gabapentin 30 mg/kg 3 h before entry in the operation room. In the control group, placebo was given 3 h before entry in the room. All patients received patient controlled intravenous analgesia (PCIA) with fentanyl, where 8 μg/kg fentanyl was diluted to 50 ml. The initial dose was 4 ml, without background dose, and the bolus was 2 ml, with a lockout time of 30 min. The bolus would be adjusted to 3 ml, if analgesia was inadequate 2 h later. Those with vomiting were intravenously injected with 0.1 mg/kg granisetron. The Children's and Infants Postoperative Pain Scale (CHIPPS) scores and the consumption of fentanyl were recorded 1, 2, 4, 8, 16 h and 24 h after surgery. The adverse reactions of both groups were recorded. Results The CHIPPS scores 1, 2, 4, 8, 16 h and 24 h after surgery and fentanyl doses were significantly lower in the observation group than those in the control group (P<0.05). Patients in the observation group reported less incidences of nausea, vomiting, anxiety and itching than the control (P<0.05). Conclusions The use of gabapentin in preemptive analgesia for adenotonsillectomy in children with OSAS can effectively relieve postoperative pain and reduce the consumption of opioids after operation. Key words: Gabapentin; Obstructive sleep apnea hypopnea syndrome; Preemptive analgesia; Postoperative analgesia; Children

Intravenous infusion of dexmedetomidine amplifies thoracic epidural analgesic effect after open thoracotomy: A prospective, double-blind, randomized controlled trial.

Background:The anesthetic-sparing effect of dexmedetomidine has led to its use as a general adjuvant. The present study aimed to determine intravenous infusion of dexmedetomidine to epidural analgesia after open thoracotomy.Methods:Forty-four patients scheduled for admission to the intensive care unit after open thoracotomy were divided into 2 groups. An epidural catheter was placed at T4 to T7. Thirty minutes before the end of thoracotomy, group D was injected with 0.3 μg/kg/h of dexmedetomidine and group C received an equal dose of normal saline. For patient-controlled epidural analgesia (PCEA), 150 mL of levobupivacaine 300 mg was infused at a rate of 1 mL/h, plus a bolus dose of 3 mL with a lockout time of 30 minutes. The primary outcome evaluated was analgesic efficacy using a visual analog scale (VAS) 48 hours postoperatively. Other outcomes included additional analgesic use, total consumed local analgesia via PCEA, sedation score, blood pressure, heart rate, arterial blood gases, patient satisfaction, and adverse effects.Results:The VAS scores in group D were significantly lower than that in group C immediately, 1, 4, 12, 36, and 48 hours after admission to the intensive care unit (P = .016, .009, .015, .002, .001, and .042, respectively). The total dose of additional analgesic was also significantly lower in group D (P = .011). Patient satisfaction was higher in group D (P < .05). There were no significant differences in the other outcomes between groups.Conclusion:Intravenous infusion of dexmedetomidine amplifies thoracic epidural analgesic effect after open thoracotomy.

Patient controlled analgesia (PCA) versus non-PCA intravenous hydromorphone titration for severe cancer pain: A randomized, controlled, multicenter, phase III trial, HMORCT09-1.

TPS11635 Background: The opioid dose for an individual with cancer pain to provide adequate relief of pain with an acceptable degree of side effects is variable. Opioid titration is a process to obtain the tailored dose. Conventional titration is administered by a clinician or nurse. PCA is that patients control cancer pain by self-administration of intravenous opioids using programmable pump. The aim of our study is to evaluate the efficacy of PCA titration versus conventional titration intravenously for severe cancer pain (10-point numerical rating scale, NRS ≥ 7). Injectable Hydromorphone was selected as pharmaceutical analgesics, which works as well as morphine and oxycodone and had similar side effects. Methods: This is currently enrolling patients (n=230) with severe cancer pain during previous 24 hours. Patients are randomized 1:1 and stratified by opioid intolerance or opioid tolerance into PCA or non-PCA titration. PCA titration using programmable pump: bolus hydromorphone at 0.5mg (for opioid intolerance) or hydromorphone dose equivalent to 10% to 20% of the total opioid taken in the previous 24 hours with a lockout time 15 minutes (for opioid tolerance) was administered by the patients educated. No basal infusion was set in the pump. Non-PCA titration administered by a nurse or clinician: Initial hydromorphone doses were same with PCA titration. Reassess pain at 15 minutes. Increased dose of hydromorphone by 50%-100% if pain unchanged or increased, or repeat same dose if pain decreased to NRS 4-6, or continue at current effective dose as needed over initial 24 hours. The primary endpoint is the time needed to successful titration was defined the time from the first dose of hydromorphone after randomization to achieve satisfied pain control. The satisfied pain control was defined NRS pain score ≤ 3 at rest in at least 2 consecutive assessment (15 minutes interval). The time needed to successful titration was extended to achieve satisfied pain control again if NRS pain score ≥ 7 after satisfied pain control within 24 hours. The failure of successful titration was defined that satisfied pain control does not achieve within 24 hours. Secondary endpoints include the percentage of patients titrated successfully, the mean NRS pain score of 24 hours, the total dose of hydromorphone titrated, and adverse events. Clinical trial information: NCT03375515.

Postoperative analgesia after combined thoracoscopic-laparoscopic esophagectomy: a randomized comparison of continuous infusion and intermittent bolus thoracic epidural regimens.

PurposeJudicious postoperative pain management after thoracoscopic–laparoscopic esophagectomy (TLE) facilitates enhanced rehabilitation. Thoracic epidural analgesia (TEA) offers many benefits in esophagectomy, while several complications are associated with the delivery mode by continuous epidural infusion. This study compared the efficiency and safety of intermittent epidural bolus to continuous epidural infusion for pain management after TLE.Patients and methodsSixty patients, aged 18–80 years, with American Society of Anesthesiologists classes I–III and scheduled for TLE with combined general anesthesia and TEA were randomly allocated to two groups. Patients received either a continuous epidural infusion with 0.3% ropivacaine and 1.5 µg/mL fentanyl at 6 mL/h plus a patient-controlled bolus of 3 mL (continuous group) or an intermittent bolus of 6 mL of the same solution on demand with lockout time of 30 minutes (intermittent group). If the patient complained of pain and the visual analog scale score was >4, an intravenous injection of tramadol or dezocine was administered as rescue treatment. The primary outcome variable was the consumption of epidural opioids and local anesthetics for TEA.ResultsTEA for pain management following TLE by intermittent epidural bolus was associated with significantly lower consumption of fentanyl and ropivacaine and lower incidences of breakthrough pain and hypotension than continuous epidural infusion. No significant differences were observed between the two groups in terms of pain score at rest or while coughing, patient satisfaction, or incidence of postoperative complications.ConclusionCompared with continuous epidural infusion, TEA by on-demand intermittent bolus greatly reduced the consumption of local anesthetics and opioids with comparable pain relief and little impairment in hemodynamics when used for pain management after TLE.

RETRACTED ARTICLE: Effect of perioperative infusion of Dexmedetomidine combined with Sufentanil on quality of postoperative analgesia in patients undergoing laparoscopic nephrectomy: a CONSORT-prospective, randomized, controlled trial

BackgroundPostoperative pain is one of the most common symptoms after surgery, which brings physical discomfort to patients. In addition, it may cause a series of complications, and even affect the long-term quality of life. The purpose of this prospective, randomized, double-blinded, controlled trial is to investigate the efficacy and safety of dexmedetomidine combined with sufentanil to attenuate postoperative pain in patients after laparoscopic nephrectomy.MethodsNinety patients undergoing laparoscopic nephrectomy were randomized into three groups: the control (sufentanil 0.02 μg/kg/h, Group C), sufentanil plus low dose of dexmedetomidine (0.02 μg/kg/h each, Group D1), and sufentanil plus high dose of dexmedetomidine (0.04 μg/kg/h, Group D2). The patient-controlled analgesia was programmed to deliver a bolus dose of 0.5 ml, followed by an infusion of 2 ml/h and a lockout time of 10 min. The primary goal was to calculate the cumulative amount of self-administered sufentanil; the secondary goals were to estimate pain intensity using the numerical rating scale (NRS), level of sedation, the first bowel movement, concerning adverse effects as well as duration of postoperative hospital stay.ResultsThe total consumption of sufentanil in group D1 and D2 were significantly lower than in group C during the first 8 h after surgery (P < 0.05), whereas there were no statistically significant differences (P > 0.05) between group D1 and D2. Compared with group C, the NRS scores at rest during first 8 h after surgery were significantly lower in group D1 (P < 0.05). The NRS scores, neither at rest nor with movement, show statistically significant differences between group D1 and D2 at each time point following surgery (P > 0.05). The time to first flatus was shorter in group D1 compared with the control group (P < 0.05). In addition, compared with group C, group D1 and D2 had a shorter time for first defecation (P < 0.05).ConclusionsDexmedetomidine combined with sufentanil showed better postoperative analgesia without adverse effects, as well as facilitated bowel movements for patients undergoing laparoscopic nephrectomy.Trial registrationWe registered this study in a Chinese Clinical Trial Registry (ChiCTR) centre on Dec 23 2015 and received the registration number: ChiCTR-IPR-15007628.

Oxycodone versus sufentanil in adult patient-controlled intravenous analgesia after abdominal surgery: A prospective, randomized, double-blinded, multiple-center clinical trial.

Background:A randomized controlled trial was performed to compare analgesic effects and adverse effects of oxycodone and sufentanil in patient-controlled intravenous analgesia (PCIA) after abdominal surgery under general anesthesia.Methods:Adult patients undergoing elective abdominal surgery were randomly allocated into oxycodone and sufentanil groups according to the randomization sequence. Study personnel, health-care team members, and patients were masked to the group assignment throughout the study period. Oxycodone (0.1 mg/kg for endoscopy; 0.15 mg/kg for laparotomy) or sufentanil (0.1 μg/kg for endoscopy; 0.15 μg/kg for laparotomy) was administrated at the end of surgeries. Postoperative pain was controlled using PCIA. Bolus dose was 2 mg and 2 μg for oxycodone and sufentanil group, respectively. The lockout time was 5 minutes for all patients, and there was no background infusion for oxycodone group, whereas 0.02 μg/kg/h background infusion was administrated in sufentanil group. The primary outcomes were the total analgesic doses in PCIA, effective bolus times, the length of first bolus since patients returning to ward from postanesthesia care unit (PACU), rescue analgesic rate in PACU, numeric rating scales, functional activity scores, and patients’ satisfaction scores.Results:A total of 200 patients were screened, and 175 patients were enrolled. Patients were randomly assigned to oxycodone (n = 87) and sufentanil (n = 88) groups. Both oxycodone and sufentanil PCIA provided adequate postoperative pain relief. Patients in oxycodone group showed a shorter consciousness recovery time after surgery. The major adverse effect in patients from oxycodone group was nausea/vomiting, whereas multiple adverse complications including nausea/vomiting, pruritus, and respiratory depression were observed in patients from sufentanil group. Patients from oxycodone group showed significantly reduced analgesic drug consumption (calculated as equivalent dose of morphine), functional activity scores, and patient satisfaction scores.Discussion:Compared with sufentanil PCIA, oxycodone PCIA showed better analgesic effects, lower incidence of adverse complications, and less analgesic drug consumption during postoperative pain management.

Jinekolojik cerrahide postoperatif uygulanan intravenöz tramadolün ve tramadole deksmedetomidin ilavesinin analjezi ve hemodinamik parametreler üzerine etkileri: Prospektif (çift kör) randomize kontrollü çalışma

Aim: We designed this double-blind study to test and compare the effects of intravenous tramadol and intravenous tramadol plus dexmedetomidine on analgesia and hemodynamic parameters for treatment of postoperative pain in gynecologic surgeries with Pfannenstiel incision. Methods: Sixty patients undergoing total abdominal hysterectomy with Pfannenstiel incision under general anesthesia were randomly allocated into two groups. Group C (Tramadol) and Group D (Tramadol + Dexmedetomidin). The anesthetic technique was standardized. Postoperatively, the patients in both groups received patient controlled analgesia during 24 hours after surgery (tramadol 20 mg bolus for Group C, tramadol 20 mg+dexmedetomidine 10 mg first four hours, then tramadol 20 mg for Group D with a lock-out time of 15 minutes). Postoperative assessment included verbal pain score, sedation score, nausea and vomiting score, consumption of tramadol, hemodynamic parameters and patient’s satisfaction. Results: Postoperative pain scores were significantly lower in Group D compared with Group C and patient-controlled analgesia tramadol use was significantly reduced in Group D. Total PCA tramadol use was decreased by 27% in Group D compared with Group C (p=0.001). Patient satisfaction with pain treatment was significantly improved in Group D compared with Group C (p=0.001). A significant increase in sedation scores at the 1st, 2nd and 4th hours were observed in Group D. Heart rate was lower in Group D at the 1st, 2nd and 4th hours postoperatively (p=0.001, p=0.001 and p=0.01, respectively). Nausea and vomiting score was lower in Group D (p&amp;lt;0.05 for all). Conclusion: The addition of dexmedetomidine to tramadol by patient controlled analgesia method significantly reduces tramadol consumption and increases analgesia level and patient satisfaction in gynecological operations.

Analgesic efficacy of dexmedetomidine used for epidural anesthesia on labor analgesia

Objective: Toinvestigatetheanalgesic effect of dexmedetomidine in epidural anesthesia for labor analgesia. Methods: 150 nulliparous patients were randomly divided into two groups with 75 cases each: ropivacaine group (R) and ropivacaine+dexmedetomidinegroup (R+Y). R group received analgesia with 0.1% ropivacaine and R+Y group received 0.1% ropivacaine and 0.5 μg/ml dexmedetomidine. The background infusion 10 ml/h, bonus 5 ml, lockout time 20 min. Vital signs, VAS of pain, progress of labor, neonatal Apgar score, postpartum haemorrhage amount, side effects and serum level of IL-6 and TNF-α were recorded. Results: Heart rate and mean arterial pressure of two groups were decreased after analgesia, but still in the normal range. The total stage of labor of R group was (608.2 ± 98.4 min) longer than the R+Y group. Two groups of total labor have a significant difference, especially in the first and second labor. The VAS score of the two groups all decreased after analgesia, score of R+Y group was lower than the other. There were no significant differences in the side effects, postpartum haemorrhage amount and neonatal Apgar score between the two groups. The serum level of IL-6 and TNF-α in R+Y group were lower than the R group in childbirth and 24 h after it. Conclusion: Dexmedetomidine used for epidural anesthesia on labor analgesia has high effect and safety. It can promote the progress of labor without severe side effects. Combination of ropivacaine +dexmedetomidine is better medicine mode for labor analgesia.

The application of nalbuphine in patient-controlled intravenous analgesia for patients undergoing subtotal gastrectomy.

The aim of the present study was to investigate the analgesic effect and safety of the application of different doses of nalbuphine in patient-controlled intravenous analgesia (PCIA) for patients undergoing subtotal gastrectomy. A total of 120 patients, who underwent subtotal gastrectomy at our hospital between May, 2015 and January, 2017 under combined spinal epidural combined anesthesia, were selected. The patients received PCIA after surgery. The patients were randomly divided into four groups, including the morphine (MOP group), nalbuphine 60 mg (N60 group), nalbuphine 80 mg (N80 group) and nalbuphine 100 mg (N100 group). The first dose of PCIA treatment was 2 ml, the background dose was 2 ml/h, PCIA dose was 0.5 ml, and the lockout time was 15 min. Postoperative vital signs and adverse reactions (bleeding, fullness and aching of upper abdomen and vomiting) were recorded. The visual analogue scale (VAS) and Ramsay sedation score of patients were evaluated. The number of PCIA and analgesia-related complications during analgesia were recorded. No significant differences in general data were found among the four groups (P>0.05). The VAS score of the three nalbuphine groups was lower than that of the MOP group, but the differences were not significant. All postoperative Ramsay sedation scores of the four groups showed appropriate sedation, but no significant differences were found between the groups. Compared with the MOP group, the use of postoperative PCIA was significantly delayed and the number of PCIA was significantly smaller in the three nalbuphine groups (P<0.05). The results show that the analgesic effect and safety of the use of PCIA for patients undergoing subtotal gastrectomy were satisfactory.

Comparing the Effectiveness of Patient Control Analgesia Pump and Bolus Morphine in Controlling Pain After Cardiopulmonary Bypass Graft Surgery.

BackgroundPostoperative pain is a complex process commonly caused by surgical trauma. It is one of the major concerns of patients undergoing heart surgery. Despite new techniques and modern analgesic treatments, postoperative pain is still one of the most important controversial issues.Methods68 patients scheduled for elective CABG with CPB were included in a prospective, double-blind clinical trial. They were randomly divided into two groups. One group received PCA pump including morphine (group P) with underlying infusion of 0.02 mg/kg/Qh, bolus dose of 1 mg, lockout time of 15 minutes, and a maximum of 4 bolus of 0.02 mg/kg for one hour and the other group received morphine bolus (group B). Three patients were excluded from the study, and 33 and 32 patients participated in the groups P and B, respectively. Variables including age, gender, pump time, aortic clamp time, duration of surgery, complications (nausea and vomiting, GI Bleeding, and hypoxia), level of pain based on VAS, opioid consumption, hemodynamic, and sedation status were measured in both groups.ResultsThere was no significant difference between the groups regarding age, gender, pump time, clamp time, duration of surgery, complication, sedation score, and hemodynamic status in most of the assessment periods. By assessing the pain severity in the groups at different periods, results showed a significant difference between the groups except at enrollment, and a lower severity of pain was noted in the group P compared to the group B. The consumed opioid was significantly higher in the group P than in the group B. However, higher doses of diclofenac and paracetamol were administered in the group B compared to the group P.ConclusionsResults showed that higher morphine would be used in patients with PCA pump after extubation following heart surgery, and this increased dose of opioid was associated with better pain control and lack of complication. Therefore, PCA pump with underlying infusion could be effectively used in patients undergoing CABG that are directly assessed in intensive care unite.

Using simulation modelling to examine the impact of venue lockout and last‐drink policies on drinking‐related harms and costs to licensees

Objective:Many variations of venue lockout and last‐drink policies have been introduced in attempts to reduce drinking‐related harms. We estimate the public health gains and licensee costs of these policies using a computer simulated population of young adults engaging in heavy drinking. Method:Using an agent‐based model we implemented 1 am/2 am/3 am venue lockouts in conjunction with last drinks zero/one/two hours later, or at current closing times. Outcomes included: the number of incidents of verbal aggression in public drinking venues, private venues or on the street; and changed revenue to public venues. Results:The most effective policy in reducing verbal aggression among agents was 1 am lockouts with current closing times. All policies produced substantial reductions in street‐based incidents of verbal aggression among agents (33–81%) due to the smoothing of transport demand. Direct revenue losses were 1–9% for simulated licensees, with later lockout times and longer periods between lockout and last drinks producing smaller revenue losses. Conclusion:Simulation models are useful for exploring consequences of policy change. Our simulation suggests that additional hours between lockout and last drinks could reduce aggression by easing transport demand, while minimising revenue loss to venue owners. Implications for public health:Direct policies to reduce late‐night transport‐related disputes should be considered.

Observation of the analgesic effects of decozine combined with sufentanil on patients after laparoscopic radical gastrectomy

Objective To investigate the analgesic efficacy and safety of decozine combined with sufentanil on patients after laparoscopic radical gastrectomy. Methods Sixty patients undergoing laparoscopic radical gastrectomy, American Society of Anesthesiologists (ASA)Ⅰ~Ⅱ, were selected, and were randomly divided into two groups. All of the patients were treated with intravenous-inhalation combined anesthesia, and was given patient controlled intraveous analgesia (PCIA) when the patient was awoken. PCIA was administered with subsequent bolus of 0.5 ml with lockout time 15 minutes and background infusion of 2 ml/h. A ratio (3 μg/kg) of sufentanil and 0.5 mg palonosetron were mixed in PCIA pump in sufentanil group (S group); and 1.5 μg/kg sufentanil, 0.3 mg/kg dezocine, and 0.5 mg palonosetron in PCIA were mixed in dezocine combined with sufentainl group (DS group), they were diluted to 100 ml with saline. The visual analogue scale (VAS), Bruggrmann comfort scale (BCS), Ramsay and incidence of adverse reactions of two groups were observed in 2 h (T1), 6 h (T2), 12 h (T3), 24 h (T4), 48 h(T5) after operation. Results There was no significant difference of VAS and BCS between two groups at each time point after operation (P>0.05); The Ramsay score of S group was significantly higher than that of DS group at T1, T2, and T3 (P<0.05). The Ramsay scores of two groups at T4, T5 were lower than those of T1, T2, and T3. The incidence of nausea, vomiting of DS group was significantly lower than that of S group (P<0.05). Conclusions Dezocine combined with sufentainl used in PCIA on postoperative gastric cancer patients can obtain satisfactory analgesic effects, but has fewer side effects than single sufentainl. Key words: Cycloparaffins/AD; Sufentanil/AD; Laparoscopy; Gastrectomy; Analgesia

The efficacy of elastomeric patient-control module when connected to a balloon pump for postoperative epidural analgesia: A randomized, noninferiority trial.

When considering the principles of a pain control strategy by patients, reliable administration of additional bolus doses is important for providing the adequate analgesia and improving patient satisfaction. We compared the efficacy of elastomeric patient-control module (PCM) with conventional PCM providing epidural analgesia postoperatively.A noninferiority comparison was used. Eighty-six patients scheduled for open upper abdominal surgery were randomized to use either an elastomeric or conventional PCM connected to balloon pump. After successful epidural catheter insertion at T6–8 level, fentanyl (15–20 μg/kg) in 0.3% ropivacaine 100 mL was administered at basal rate 2 mL/h with bolus 2 mL and lock-out time 15 minutes. The primary outcome was the verbal numerical rating score for pain.The 95% confidence intervals for differences in pain scores during the first 48 hours postoperatively were <1, indicating noninferiority of the elastomeric PCM. The duration of pump reservoir exhaustion was shorter for the elastomeric PCM (mean [SD], 33 hours [8 hours] vs 40 hours [8 hours], P = 0.0003). There were no differences in the frequency of PCM use, additional analgesics, or adverse events between groups.The elastomeric PCM was as effective as conventional PCM with and exhibited a similar safety profile.

Postoperative analgesia after arthroscopic shoulder surgery: A comparison between single-shot interscalene block and single-shot supraclavicular block.

In arthroscopic rotator cuff surgery for postoperative analgesia opioids, nonsteroid analgesics, and local anesthetics can be used. This study aimed to compare the effectiveness, additional analgesic requirements, patients satisfaction, and complications of single-shot interscalene and supraclavicular blocks. After obtaining the ethics committee's approval and informed consent, 50 ASA I-II patients were randomized to either the interscalene (GISB) or supraclavicular (GSCB) group. Preoperatively, patients received an ultrasonography-guided block using 30 ml of 0.5% bupivacaine. In the postoperative period, morphine patient-controlled analgesia was administered as a 0.3-mg/h basal dose and 1-mg bolus dose, with a 20-min lockout time. Postoperative visual analog scale (VAS; 0-10 cm) scores of the patients were evaluated at 4, 8, 12, and 24 h postoperatively; additional analgesic requirements, adverse effects, and complications were recorded. Patient satisfaction (PS) scores were evaluated after 24 h. VAS scores at 4 h were lower in the GSCB group than in the GISB group, and the VAS scores at 8, 12, and 24 h were lower in the GISB group than in the GSCB group, with no statistical significance. Additional analgesic requirements was 28% in the GISB group and 68% in the GSCB group (p < 0.05). Total morphine consumption was lower in the GISB group than in the GSCB group (18.95±9.2 mg vs. 30.6 ± 9.6 mg; p < 0.001). PS scores were higher in the GISB group than in the GSCB group (7.0±1.0 vs. 6.1±0.9; p < 0.01). Adverse effects and complication rates were similar in both the groups. In GISB group, seven patients (28%) had nausea/vomiting, whereas in the GSCB group, 12 patients (48%) had nausea/vomiting. This difference was statistically insignificant. Supraclavicular block can be considered as an alternative to interscalene block for arthroscopic shoulder surgery.

The effect of tramadol plus paracetamol on consumption of morphine after coronary artery bypass grafting

Study of objectiveTo compare the effects of oral tramadol+paracetamol combination on morphine consumption following coronary artery bypass grafting (CABG) in the patient-controlled analgesia (PCA) protocol. DesignA prospective, double-blind, randomized, clinical study. SettingSingle-institution, tertiary hospital. PatientsFifty cardiac surgical patients undergoing primary CABG surgery. InterventionsAfter surgery, the patients were allocated to 1 of 2 groups. Both groups received morphine according to the PCA protocol after arrival to the coronary intensive care unit (bolus 1 mg, lockout time 15 minutes). In addition to morphine administration 2 hours before operation and postoperative 2nd, 6th, 12th, 18th, 24th, 30th, 36th, 42th, and 48th hours, group T received tramadol+paracetamol (Zaldiar; 325 mg paracetamol, 37.5 mg tramadol) and group P received placebo. Sedation levels were measured with the Ramsay Sedation Scale, whereas pain was assessed with the Pain Intensity Score during mechanical ventilation and with the Numeric Rating Scale after extubation. If the Numeric Rating Scale score was ≥3 and Pain Intensity Score was ≥3, 0.05 mg/kg morphine was administered additionally. MeasurementsPreoperative patient characteristics, risk assessment, and intraoperative data were similar between the groups. Main resultsCumulative morphine consumption, number of PCA demand, and boluses were higher in group P (P<.01). The amount of total morphine (in mg) used as a rescue analgesia was also higher in group P (5.06±1.0), compared with group T (2.37±0.52; P<.001). The patients who received rescue doses of morphine were 8 (32%) in group T and 18 (72%) in group P (P<.001). Duration of mechanical ventilation in group P was longer than group T (P<.01). ConclusionTramadol+paracetamol combination along with PCA morphine improves analgesia and reduces morphine requirement up to 50% after CABG, compared with morphine PCA alone.

Continuous Peripheral Nerve Blocks: An Update of the Published Evidence and Comparison With Novel, Alternative Analgesic Modalities.

A continuous peripheral nerve block (CPNB) consists of a percutaneously inserted catheter with its tip adjacent to a target nerve/plexus through which local anesthetic may be administered, providing a prolonged block that may be titrated to the desired effect. In the decades after its first report in 1946, a plethora of data relating to CPNB was published, much of which was examined in a 2011 Anesthesia & Analgesia article. The current update is an evidence-based review of the CPNB literature published in the interim. Novel insertion sites include the adductor canal, interpectoral, quadratus lumborum, lesser palatine, ulnar, superficial, and deep peroneal nerves. Noteworthy new indications include providing analgesia after traumatic rib/femur fracture, manipulation for adhesive capsulitis, and treating abdominal wall pain during pregnancy. The preponderance of recently published evidence suggests benefits nearly exclusively in favor of catheter insertion using ultrasound guidance compared with electrical stimulation, although little new data are available to help guide practitioners regarding the specifics of ultrasound-guided catheter insertion (eg, optimal needle-nerve orientation). After some previous suggestions that automated, repeated bolus doses could provide benefits over a basal infusion, there is a dearth of supporting data published in the past few years. An increasing number of disposable infusion pumps does now allow a similar ability to adjust basal rates, bolus volume, and lockout times compared with their electronic, programmable counterparts, and a promising area of research is communicating with and controlling pumps remotely via the Internet. Large, prospective studies now document the relatively few major complications during ambulatory CPNB, although randomized, controlled studies demonstrating an actual shortening of hospitalization duration are few. Recent evidence suggests that, compared with femoral infusion, adductor canal catheters both induce less quadriceps femoris weakness and improve mobilization/ambulation, although the relative analgesia afforded by each remains in dispute. Newly published data demonstrate that the incidence and/or severity of chronic, persistent postsurgical pain may, at times, be decreased with a short-term postoperative CPNB. Few new CPNB-related complications have been identified, although large, prospective trials provide additional data regarding the incidence of adverse events. Lastly, a number of novel, alternative analgesic modalities are under development/investigation. Four such techniques are described and contrasted with CPNB, including single-injection peripheral nerve blocks with newer adjuvants, liposome bupivacaine used in wound infiltration and peripheral nerve blocks, cryoanalgesia with cryoneurolysis, and percutaneous peripheral nerve stimulation.

Model Predictive Control for Thermostatically Controlled Appliances Providing Balancing Service

This paper studies the modeling and control methods for the provision of ancillary services through aggregating thermostatically controlled appliances (TCAs). A model predictive control (MPC) scheme is presented. Minimum ON/OFF time for protecting the TCA unit is explicitly described in the MPC scheme. A novel method of converting time-integrated interdependent logic conditions, which are for constraining the lockout effect, into inequalities is proposed in this paper. A case study is conducted with realistic data to validate the feasibility of the modeling and control approaches. Parametric studies in terms of temperature deadband width, ambient temperature, and lockout time are conducted to investigate the service quality in different circumstances. The test results reveal that a population of diversified TCAs can become a major source of providing ancillary service. The proposed approach can be specialized to deal with the pure ON/OFF control.

Implementation of Programmed Intermittent Epidural Bolus for the Maintenance of Labor Analgesia.

Programmed intermittent epidural bolus (PIEB) is an exciting new technology that has the potential to improve the maintenance of epidural labor analgesia. PIEB compared with a continuous epidural infusion (CEI) has the potential advantage of greater spread within the epidural space and therefore better sensory blockade. Studies have demonstrated a local anesthetic-sparing effect, fewer instrumental vaginal deliveries, less motor blockade, and improvements in maternal satisfaction with PIEB compared with CEI. However, the optimal PIEB regimen and pump settings remain unknown, and there are a number of logistical issues and practical considerations that should be considered when implementing PIEB. The PIEB bolus size and interval, PIEB start time delay period, and patient-controlled epidural analgesia bolus size and lockout time can influence the efficacy of PIEB used for epidural labor analgesia. Educating all members of the health care team is critical to the success of the technique. This review summarizes the role of PIEB for the maintenance of labor analgesia, outlines implementation strategies, suggests optimal settings, and presents potential limitations of the technique.

Patient-controlled bolus femoral nerve block after knee arthroplasty: quadriceps recovery, analgesia, local anesthetic consumption.

Continuous femoral nerve block (cFNB) induces quadriceps muscle weakness, but patient-controlled femoral nerve block (PCFNB) can provide analgesia with lower consumption of local anesthetics compared to cFNB. We hypothesized that cFNB followed by PCFNB leads to accelerated recovery of quadriceps weakness after total knee arthroplasty compared to cFNB alone. Secondary outcomes were local anesthetic consumption, pain, and mobilization. Fifty-six subjects received post-operative cFNB for 24 h and then randomized to receive either cFNB (basal infusion of 6 ml/h using a dummy bolus button; n = 27) or PCFNB (bolus infusion of 3 ml with a lockout time of 30 min and no basal infusion; n = 29) using 0.08% levobupivacaine for the subsequent 24 h in a double-blind manner (registration: UMIN000010105). Quadriceps strength was assessed using a hand-held dynamometer. The percentage change from baseline was compared between groups. Quadriceps strength at 48 h was 47.3 ± 18.3% in the cFNB group and 49.7 ± 15.7% in the PCFNB group (95% confidence interval -7.0-11.9%, P = 0.61). Local anesthetic consumption during the post-operative period was significantly lower in the PCFNB group compared to the cFNB group (102 ± 10.8 ml vs.146 ± 4.6 ml; P < 0.001). No significant differences were found in any of the other outcomes, including pain scores at rest and during knee rehabilitation. Continuous femoral nerve block followed by PCFNB does not improve quadriceps strength recovery time compared to cFNB alone after total knee arthroplasty, but similar analgesic effects were demonstrated with reduced levobupivacaine consumption.

Effects of intraoperative high-dose vs low-dose remifentanil for postoperative epidural analgesia after gynecological abdominal surgery: a randomized clinical trial

Study objectivesTo evaluate whether intraoperative high-dose remifentanil infusion increased local anesthetic consumption in postoperative epidural analgesia and postoperative pain scores compared with low-dose remifentanil infusion. DesignProspective, randomized controlled study. SettingOperating room, university hospital. PatientsThirty female patients scheduled for elective gynecological abdominal surgery. InterventionsAfter epidural catheter placement and induction of general anesthesia, patients were randomly assigned to 2 anesthetic regimens. In the first group (high-dose remifentanil group), sevoflurane concentration was held constant at 1.2%, and the remifentanil infusion rate was titrated to maintain systolic blood pressure within 20% of baseline. In the second group (low-dose remifentanil group), the remifentanil infusion rate was held constant at 0.1μg/(kg min), and the sevoflurane concentration was titrated to maintain systolic blood pressure within 20% of baseline. As abdominal wall closure began, 6mL of 0.2% ropivacaine was administrated via epidural catheter; a patient-controlled analgesia device was set to deliver 4mL/h of 0.2% ropivacaine with 3μg/mL of fentanyl, with 2-mL incremental doses and a 15-minute lockout time. MeasurementsLocal anesthetic consumption via postoperative epidural catheter and pain intensity with the Prince Henry pain scale were assessed for 48hours after surgery. Main resultsThe mean remifentanil infusion rate was 0.23μg/(kg min) in the high-dose remifentanil group, 2.3 times the rate used in the low-dose remifentanil group. The cumulative amount of local anesthetic used within 48hours of surgery was significant greater in the high-dose remifentanil group than in the low-dose remifentanil group (212±25mL vs. 181±35mL, respectively; P<.05), but postoperative pain scores were similar in each group. ConclusionsIntraoperative high-dose remifentanil infusion increased local anesthetic consumption in postoperative epidural analgesia relative to low-dose remifentanil.