Total Anesthetic Dose Research Articles

Dexmedetomidine versus Dexamethasone as Adjuvants to Bupivacaine for Ultrasound Guided Rectus Sheath Block in Pediatric Abdominal Surgery

Background: The use of ultrasound as a guide for regional anesthesia has become common practice and a new challenge to anesthesiologists. Besides its benefits of reduced complications, it also helps in reducing the total anesthetic dose required with higher block success rates. There is also the advantage of direct observation of the pattern of anesthetic spread. Objective: To compare between dexamethasone and dexmedetomidine as adjuvants to bupivacaine in rectus sheath block applied during pediatric abdominal surgeries. Patients and methods: This prospective randomized study was conducted at Mansoura University Children Hospital. We included a total of 60 pediatric patients undergoing elective abdominal surgery. The study was conducted over the period of two years, starting from January 2019 till December 2020. Results: The mean age of the included patients was 4.7, 4.7, and 4.6 in groups C, D, and Z respectively. Operative time and duration of anesthesia did not show any significant difference between the three groups. The duration of analgesia showed a highly significant difference between the three groups. Group Z showed its superiority as it had a mean analgesic duration of 15.3 hours, followed by Group D which had mean value of 13.02 hours. Conclusion: Both dexamethasone and dexmedetomidine were efficient adjuvants to local anesthetics as they were associated with significant prolongation of the duration of analgesia, decrease in postoperative analgesia, and better patient satisfaction compared to bupivacaine alone.

Is there any difference between oral preemptive pregabalin vs. placebo administration on response to EBUS-TBNA under sedation?

Background/aimThe aim of this study is to evaluate the effects of preemptive oral pregabalin on hemodynamic response, anxiety, sedation, and recovery in patients who underwent endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) under sedation with intravenous ketamine-propofol combination.Materials and methodsSixty patients were included in this study, and patients were randomly divided into two equal groups to receive the placebo (Group 1) versus pregabalin 150 mg (Group 2) one hour prior to EBUS- TBNA procedure. Patients received 0.25 mg kg-1 ketamine and 0.25 mg kg-1 propofol mixture (ketofol) for sedation. Timing of the parameters was defined as follows; T0: in hospital ward before pregabalin or placebo administration, T1: premedication, T2: in operating room, T3: before the procedure, T4: initiation, T5: 3 min after induction, T6: 6 min after induction, T7: 9 min after induction, and T8: 12 min after induction. Hemodynamic parameters, severity of coughing, sedation and anxiety scores, and complications were recorded. The level of satisfaction of the bronchoscopist and the patients were evaluated at the end of the procedure. ResultsThe heart rate and mean arterial pressure were significantly higher in Group 1 (P = 0.008, P = 0.04). Total doses of anesthetics, recovery time, and desaturation rate were significantly higher in Group 1 (P = 0.014, P = 0.001, P = 0.045). In Group 2, SpO2 level was significantly higher at various time periods (T1; P = 0.025, T4; P =0.043, T6; P = 0.001, T7; P = 0.003, T8; P < 0.001). The severity of coughing was found significantly lower in Group 2 (T4; P = 0.011, T5; P = 0.01, T6; P = 0.02, T7; P = 0.03, T8; P < 0.01). Anxiety scores were significantly lower in Group 2 (P < 0.001). ConclusionPreemptive oral pregabalin, in addition to sedation with ketamine-propofol combination, was effective in providing limited hemodynamic response, restricted coughing reflex, and lower anxiety during EBUS-TBNA. Besides, with pregabalin usage, decreased anesthetics consumption, lower complication rate, and shorter recovery time might have contributed to safety of the procedure and comfort of the bronchoscopist.

The efficacy of maxillary and mandibular nerve blockade using electrical nerve stimulation for guidance

BackgroundIn oral and maxillofacial surgical procedures, sometimes conventional loco-regional anesthesia techniques could be insufficient in daily clinical practice. The aim of this study was to evaluate the efficacy of analgesia using electrical nerve stimulation (ENS) for maxillary or mandibular nerve blockade, in comparison with conventional loco-regional anesthesia techniques. MethodsThe study comprised 52 patients who were attending the department for advanced surgery of the upper and lower jaw. Patients were randomly divided into 2 groups: ENS and Local group. The predictor variable was the anesthesia technique (ENS and Local groups). The outcome variables were patient assessed pain levels (VAS scores) and total anesthetic dose. ResultsBoth the administered anesthetic dose and patient-assessed pain levels were significantly lower in the ENS group than in the Local group, despite there being no difference in age, sex or any hemodynamic parameters between the groups. ConclusionsMaxillary and mandibular nerve blockade is more efficient with ENS guidance, with lower amounts of anesthetic required, compared to conventional loco-regional anesthesia.

Is I-gel airway a better option to endotracheal tube airway for sevoflurane-fentanyl anesthesia during cardiac surgery?

Background:Anesthetists used lower doses of fentanyl, successfully with hemodynamic control by titrating volatile anesthetic agents or vasodilators for fast-tracking in cardiac surgery.Hypothesis:Lower total doses of anesthetics and fentanyl could be required with hemodynamic control by use of supraglottic devices than endotracheal tube (ETT) and helps in fast-tracking.Design:A prospective randomized observational clinical trial study.Aims:The authors compared the utility of I-gel airway with a conventional ETT during the induction and maintenance of anesthesia with sevoflurane and fentanyl in adults undergoing cardiac surgery.Patients and Methods:A total of 49 adult patients underwent cardiac surgery were randomized into two groups according to the airway management: I-gel group (n = 23) and ETT group (n = 26). Doses of fentanyl and hemodynamic parameters (heart rate [HR], mean arterial pressure [MAP] central venous pressure [CVP], pulmonary artery pressure [PAP], and pulmonary capillary wedge pressure [PCWP]) were recorded preoperative, 5 min following tracheal intubation or I-gel airway insertion, after skin incision, after stenotomy, and after weaning off bypass.Results:None of the patients in the I-gel group required additional doses of fentanyl during the I-gel insertion, compared with 74% of the patients during laryngoscopy and endotracheal insertion in the ETT group, for an average total dose of 22.6 ± 0.6 μg/kg. The MAP and HR did not significantly differ from the baseline values at any point of measurement in either group. Furthermore, CVP, PAP, and PCWP measured during the procedure were significantly lower in I-gel group than ETT group. Extubation required more amount of time in ETT than I- gel group.Conclusion:The I-gel airway is well-tolerated by adult patients undergoing cardiac surgery, and requires lower total doses of anesthetics than endotracheal intubation with hemodynamic control and helps in fast-tracking.

Manyetik rezonans görüntüleme yapılan pediatrik olgularda midazolam-ketamin kombinasyonu ile tiopental’in sedatif etkilerinin karşılaştırılması

Comparison of sedative effects of midazolam-ketamine combination and thiopental in pediatric patients undergoing magnetic resonance imaging Introduction and Aim: Children especially under age 8 cannot lie still enough for magnetic resonance imaging (MRI) or are afraid of noise and narrow spaces so sedation is necessary for high quality imaging. The aim of this study was to compare Midazolam - Ketamine combination and Thiopental sedation for children undergoing MRI. Materials and Methods: Forty randomly selected patients undergoing MRI classified as ASA physical status I and II aged between 0-8 were included in this study after receiving institutional approval from Ethics Committee. The patients were divided into two groups. Group 1 received Midazolam iv 0.1 mg kg + Ketamine iv 2 mg kg followed by an additional dose of Ketamine 0.5 mg kg. Group 2 received Thiopental iv 3 mg kg followed by an additional dose of Thiopental 1 mg kg when needed. University of Michigan Sedation Scale (UMSS) was applied. UMSS score 3 and higher were accepted for effective sedation and the patients underwent MRI. Demographic data induction process recovery and total sedation times MRI quality total anesthetic dose amount systolic and diastolic blood pressure at every 5 minutes from the beginning peak heart rate and saturation values and complications were recorded. Results: There was no significant difference in terms of age and weight between the two groups. The average induction time total sedation time and recovery time of Group 1 was significantly longer than that of Group 2 (p=0.001, p=0.035, p=0.038). There were no significant differences in PHR SBP DBP and SpO2 distributions at all times. Evaluations of the families of Midazolam - Ketamine group's patients were recorded as 19 very satisfied 1 satisfied while evaluations of the families of Thiopental group's patients were recorded as 18 very satisfied 2 satisfied. There was no significant difference between the two groups in terms of imaging quality. No side effects or complications were observed for both groups. Discussion: Thiopental was found to be a safe alternative to Midozolam - Ketamine combination in MRI. High image quality anesthesia induction time and short recovery time make Thiopental a more effective anesthetic agent for MRI.

Effects of lidocaine constant rate infusion on sevoflurane requirement, autonomic responses, and postoperative analgesia in dogs undergoing ovariectomy under opioid-based balanced anesthesia

The effects of constant rate infusion (CRI) of lidocaine on sevoflurane (SEVO) requirements, autonomic responses to noxious stimulation, and postoperative pain relief were evaluated in dogs undergoing opioid-based balanced anesthesia. Twenty-four dogs scheduled for elective ovariectomy were randomly assigned to one of four groups: BC, receiving buprenorphine without lidocaine; FC, receiving fentanyl without lidocaine; BL, receiving buprenorphine and lidocaine; FL, receiving fentanyl and lidocaine. Dogs were anesthetized with intravenous (IV) diazepam and ketamine and anesthesia maintained with SEVO in oxygen/air. Lidocaine (2mg/kg plus 50 μg/kg/min) or saline were infused in groups BL/FL and BC/FC, respectively. After initiation of lidocaine or saline CRI IV buprenorphine (0.02 mg/kg) or fentanyl (4 μg/kg plus 8 μg/kg/h CRI) were administered IV in BC/BL and FC/FL, respectively. Respiratory and hemodynamic variables, drug plasma concentrations, and end-tidal SEVO concentrations (E'SEVO) were measured. Behaviors and pain scores were subjectively assessed 1 and 2h post-extubation. Lidocaine CRI produced median drug plasma concentrations <0.4 μg/mL during peak surgical stimulation. Lidocaine produced a 14% decrease in E'SEVO in the BL (P<0.01) but none in the FL group and no change in cardio-pulmonary responses to surgery or postoperative behaviors and pain scores in any group. Thus, depending on the opioid used, supplementing opioid-based balanced anesthesia with lidocaine (50 μg/kg/min) may not have any or only a minor impact on anesthetic outcome in terms of total anesthetic dose, autonomic responses to visceral nociception, and postoperative analgesia.

Bloqueo paravertebral torácico con punción múltiple en cirugía reconstructiva de la mama

To describe the use of multiple-injection thoracic paravertebral blockade, with intravenous sedation, for anesthesia during reconstructive breast surgery. Descriptive, prospective study in 100 scheduled operations for major reconstructive breast surgery. The paravertebral block was performed by means of 3 injections at the lower edges of the vertebral apophyses at T3-5. We recorded time performing the procedure, latency (time until block onset), dermatomes blocked, degree of effectiveness, conversion to general anesthesia, postoperative complications and pain, and patient satisfaction. Dermatomes T3, T4, and T5 were blocked in 99% of the patients. The block took 7.39 minutes to perform and latency was 7.37 minutes. Postoperative analgesia with anti-inflammatory drugs was adequate for most patients. There were 3 cases of epidural diffusion, 10 patients with hypotension, 12 with postoperative nausea or vomiting, and 3 with symptoms of epidural blockade. Intravascular puncture occurred, without complications, in 3 cases. There were no cases of pneumothorax or intrathecal injection. Ninety-one percent of the patients declared they were satisfied or very satisfied with the technique. Triple-injection paravertebral blocks, in which 3 fractions of the total anesthetic dose are delivered to block dermatomes T3-5 is an effective technique that is easy to perform and leads to few complications. Most patients express a high degree of satisfaction with this anesthetic technique.

SMOKING CESSATION: WHO DESERVES BEHAVIORAL AND PHARMACOLOGICAL ASSISTANCE?

Topical anesthesia for flexible bronchoscopy can be administered via transcricoid injection, nebulizer, or directly through the bronchoscope in a "spray as you go" fashion. We performed a prospective, randomized, double-blind, placebo-controlled trial to evaluate whether nebulized lidocaine provides additional benefit and reduces the total anesthetic dose required during bronchoscopy.Tertiary care university hospital.One hundred fifty patients (93 men; age, 20 to 89 years) undergoing diagnostic flexible bronchoscopy were randomized to receive either 4 mL of 4% lidocaine (160 mg) or 4 mL of saline solution as placebo via nebulization. Combined sedation was achieved using 5 mg of IV hydrocodone and midazolam boluses. Supplemental lidocaine doses and total midazolam required as judged by the bronchoscopist were recorded for each patient. After the procedure, both bronchoscopists and patients charted their perception of cough on a 10-cm visual analog scale (VAS). Similarly, patients recorded their discomfort related to the procedure on a 10-cm VAS.The most common procedures were BAL in 77 cases (51%), transbronchial biopsy in 40 cases (27%), and transbronchial needle aspiration in 34 cases (23%). Outcome parameters, including hemodynamic findings, duration of the procedure, cough scores for physicians and patients, discomfort score for patients, midazolam doses, and supplemental lidocaine doses, were similar in both groups. Mean total lidocaine dose required in the lidocaine group was 318 +/- 41 mg and was significantly higher than the total dose required in the placebo group (157 +/- 44 mg [+/- SD]) [p < 0.001].Additional nebulized lidocaine cannot be recommended for flexible bronchoscopy performed under combined sedation.

Target-Controlled Infusion for Remifentanil in Vascular Patients Improves Hemodynamics and Decreases Remifentanil Requirement

Remifentanil is a potent ultra-short-acting opioid, which permits rapid emergence. However, remifentanil is expensive and may have detrimental effects on hemodynamics in case of overdose. Target-controlled infusion (TCI) permits adapting infusion to pharmacokinetic models. In this prospective randomized study, we compared intra- and postoperative hemodynamics, remifentanil requirement during anesthesia, and postoperative morphine requirement in patients scheduled for carotid surgery, and receiving either continuous IV weight-adjusted infusion of remifentanil (RIVA) or TCI for remifentanil (TCIR). Forty-six patients were enrolled in this study: all were anesthetized by using TCI for propofol. Twenty-three received RIVA (0.5 μg · kg−1 · min−1) for the induction of anesthesia and endotracheal intubation, with the infusion rate decreased to 0.25 μg · kg−1 · min−1 after intubation, then adapted by step of 0.05 μg · kg−1 · min−1 according to hemodynamics. Twenty-three patients received TCIR (Minto model, Rugloop), with an effect-site concentration at 4 ng/mL during induction, then adapted by step of 1 ng/mL according to hemodynamics. All patients received atracurium and a 50% mixture of N2O/O2. Hemodynamic variables were recorded each minute. The number and duration of hemodynamic events were collected, and total doses of anesthetics (remifentanil and propofol) and vasoactive drugs were noted in both groups of patients. Data were analyzed by using unpaired t-tests. RIVA was significantly associated with more frequent episodes of intraoperative hypotension (16 versus 6, P < 0.001) and more frequent episodes of postoperative hypertension and/or tachycardia requiring more frequent administration of β-adrenergic blockers (16 vs 10, P < 0.04) in comparison with TCIR. The need for morphine titration was not significantly different between groups. TCIR led to a significantly smaller requirement of remifentanil (700 ± 290 versus 1390 ± 555 μg, P < 0.001) without difference in propofol requirement. This prospective randomized study demonstrated that, during carotid endarterectomy, in comparison with patients receiving remifentanil using continuous RIVA, TCI results in less hypotensive episodes during the induction of anesthesia, in fewer episodes of tachycardia and/or hypertension and a smaller β-adrenergic blocker requirement during recovery, and a decrease in remifentanil requirement. Recommendations to prefer TCI for remifentanil administration during carotid endarterectomy may be justified.

Continuous intravenous regional anesthesia

This study evaluates the effectiveness of continuous intravenous regional anesthesia for prolonged operations on the upper extremity. The factors evaluated include patient's sex and age, number of procedures performed, tourniquet on and off times, anesthetic doses, adjunctive drugs used, technical complications, and side effects. Seventy-two procedures were done on 34 patients. The first tourniquet time averaged 58 minutes. Off time averaged 10 minutes. Second tourniquet time averaged 33 minutes, and the mean total tourniquet time was 91 minutes. The mean first anesthetic dose was 275 mg. Mean second anesthetic dose was 128 mg. Mean total anesthetic dose was 402 mg. There were two (6%) technical complications and two (6%) patients had side effects. Continuous intravenous regional anesthesia offers the prolonged anesthesia of brachial plexus block or general anesthesia and the safety, reliability, and ease of intravenous regional anesthesia. Continuous intravenous regional anesthesia should be considered an alternative choice of anesthetic method in upper extremity surgery.