Remifentanil Propofol Research Articles

The Effects of Ketamine-Propofol and Remifentanil-Propofol Combinations on Integrated Pulmonary Index During Sedation in Gastrointestinal System Endoscopy.

Different sedo-analgesia and monitoring methods are used during endoscopic procedures. And yet, there is no consensus on optimal sedating agents. In this study, the main aim is to compare ketamine-propofol and remifentanil propofol sedo-analgesia protocols by monitoring integrated pulmonary index (IPI). The study population is divided into two groups: Group ketamine received 0.25 mg/kg ketamine and 0.75 mg/kg propofol at the beginning of anesthesia. 1 mcg/kg of remifentanil and 0.75 mg/kg propofol were administered to group remifentanil patients at the induction of anesthesia. Anesthesia maintenance was provided by titration of drug doses according to the Ramsey sedation scale. Measurements were taken at four different points in time: just before anesthesia was induced, five minutes after sedation was induced, ten minutes later, and five minutes after the treatment was finished. There was no significant difference in respiratory parameters such as respiratory rate, SPO2, and EtCO2 measured in the T1 time period between the groups. In the T2 time period, a significant difference was found between the groups in the integrated pulmonary index (IPI), sPO2, respiratory rate, and systolic pressure parameters were found to be significantly higher in group ketamine. T3 time period results were higher in these three parameters: IPI, sPO2, and respiration rate. In the T2, T3, T4 time periods, there was a difference between the groups in the respiration count parameter and it was found to be higher in group ketamine. Although it causes slight prolongation in recovery, ketamine is a safe and effective drug that can be used during endoscopic procedures.

Assessing the effect of using remifentanil–propofol mixture versus propofol alone on the movement of paediatric patients undergoing lumbar puncture: a single-centre experience

Assessing the effect of using remifentanil–propofol mixture versus propofol alone on the movement of paediatric patients undergoing lumbar puncture: a single-centre experience

Carbon footprint of inhalational and total intravenous anaesthesia for paediatric anaesthesia: a modelling study

BackgroundTackling the climate emergency is now a key target for the healthcare sector. Avoiding inhalational anaesthesia is often cited as an important element of reducing anaesthesia-related emissions. However, evidence supporting this is based on adult practice. The aim of this study was to identify the difference in carbon footprint of inhalational and i.v. anaesthesia when used in children. MethodsWe used mathematical simulation models to compare general anaesthetic techniques in children weighing 5–50 kg for TIVA, i.v. induction then inhalational maintenance, inhalational induction then i.v. maintenance, and inhalational induction and maintenance. We simulated inhalational induction with sevoflurane alone, and co-induction with sevoflurane and nitrous oxide, and both remifentanil–propofol and propofol-only i.v. anaesthesia. For each technique, we drew on previously published life-cycle data to calculate carbon dioxide equivalents for anaesthetic durations up to 480 min. ResultsTIVA with propofol and remifentanil had a smaller carbon footprint over a typical anaesthetic duration of 60 min (1.26 kg carbon dioxide equivalents [CO2e] for a 20 kg child) than i.v. induction followed by inhalational maintenance (2.58 kg CO2e) or inhalational induction and maintenance (2.98 kg CO2e). Inhalational induction followed by i.v. maintenance only had a lower carbon footprint than inhalational induction and maintenance when used in longer procedures (>77 min for children 5–20 kg; >105 min for children 30–50 kg). ConclusionsIn a simulation study, i.v. anaesthesia had climate benefits in paediatric anaesthesia. However, when used after inhalational induction, benefits were only achieved in longer procedures. These findings provide evidence-based guidance for reducing the environmental impact of paediatric anaesthesia, but these will require confirmation using real-world data.

Rapid sequence induction with a “modified timing principle” of rocuronium provides excellent intubating conditions: A randomised trial

The present study was designed to compare the intubating conditions of rocuronium giving by “a modified timing principle” in rapid induction and intubation (RSII) with that of the gold standard, succinylcholine. One hundred and twenty-four patients were randomly divided into rocuronium group (group R, n = 62) or succinylcholine group (group S, n = 62). In group R, after rocuronium 0.6 mg kg−1 was given, anaesthesia was induced with propofol 2 mg kg−1 and remifentanil 2 μg kg−1, and tracheal intubation was performed 60 sec after rocuronium administration. In group S, succinylcholine 1.5 mg kg−1 was given after patient lost consciousness induced by the same regimen of group R, and tracheal intubation was performed 60 sec after succinylcholine administration. Our primary endpoint was the intubating conditions. The numbers of patients with excellent and good intubating conditions in group R were 90.0% and 6.7%, respectively, which were comparable with those in group S (91.7% and 5.0% respectively). The apnoea time in group S (79.7 ± 5.1 sec) was longer than that of group R (56.6 ± 4.6 sec) (p = 0.0063). The average BIS values at the time of intubation in group R (64.1 ± 4.1) was higher than that of group S (43.2 ± 5.5) (p = 0.018). In the context of a RSII with lidocaine–remifentanil–propofol, the application of this “modified timing principle” with rocuronium 0.6 mg kg−1 could provide comparable intubating conditions with those achieved by succinylcholine 1.5 mg kg−1. Additionally, this modified timing principle with rocuronium was associated with shorter apnoea time.

The effect of concentration, reconstitution solution and pH on the stability of a remifentanil hydrochloride and propofol admixture for simultaneous co-infusion

BackgroundThere are scenarios where pre-mixing and infusing analgesic and anaesthetic agents as a single intravenous (IV) solution is highly desirable; however, it is important to ensure the agents are compatible when mixed. As such, the long-term stability of a remifentanil-propofol mixture, and means of improving this, were assessed across a range of remifentanil concentrations, diluents, and time points.MethodsRemifentanil was reconstituted with ultrapure water, 0.9% saline, 20% saline, or 8.4% sodium bicarbonate solution (the latter two chosen for their pH characteristics, rather than their use in pharmaceutical reconstitution) and then mixed with propofol (1%) or further diluted with water to derive concentrations of 10–50 μg mL− 1. Remifentanil and propofol concentrations were determined initially and then periodically for up to 24 h using high performance liquid chromatography (HPLC). Mass spectrometry (MS) was used to detect degradation products in solutions containing 30 μg mL− 1 of remifentanil. Statistical analysis was performed using ANOVA and Student’s t-test, with a significance value of 0.05.ResultsIsolated remifentanil (pH < 4) and propofol (pH 7.35) did not degrade significantly when reconstituted with water or saline solution over 24 h, while remifentanil reconstituted with sodium bicarbonate degraded significantly (P < 0.001, pH 8.65). Mixing with propofol substantially increased the pH of the mixture and resulted in significant remifentanil degradation for all reconstitution solutions used, while propofol remained stable (pH 6.50). The amount of degradation product detected in samples containing isolated remifentanil and a mixture of the drugs was proportional to the remifentanil degradation observed.ConclusionsRemifentanil stability is affected by both the reconstitution solution used and when mixed with propofol, with pH appearing to be a contributing factor to degradation. If the pH of the solution and concentration of remifentanil are correctly controlled, e.g. through the use of a more acidic diluent, an admixture of remifentanil and propofol may be useful clinically.

A Comparison of Two Proportions of Remifentanil–Propofol Mixture Administered with Target-Controlled Infusion for Patients Undergoing Colonoscopy

Background: Previous studies have demonstrated the feasibility of a remifentanil–propofol (RP) mixture use in sedation for medical examinations. However, delivery of an RP mixture by target-controlled infusion (TCI) for colonoscopy has not been described. Here, we investigate the appropriate proportion of RP mixed regimens, prepared in two different ratios for colonoscopy. Methods: A retrospective study including patients who received a colonoscopy between May 2018 and January 2019 was conducted. Group 1 and Group 2 were, respectively, administered a mixture of RP at concentrations of 2.5 μg/mL-10 mg/mL and 5.0 μg/mL-10 mg/mL by adjusting a TCI pump with Schneider model to keep the Observer's Assessment of Alertness/Sedation scale between 1 and 2. The primary outcome was to determine the appropriate proportion of RP for the procedure in terms of hemodynamic conditions and adverse events. The secondary endpoints included the total dosage of anesthetics and total times of TCI pump adjustments. Results: A total of 120 patients in Group 1 and 116 patients in Group 2 were eligible for analysis. Several parameters were significantly different between Group 1 and Group 2, with Group 1 having a higher respiratory rate, a lower end-tidal carbon dioxide pressure, fewer patients with hypotension (mean arterial pressure

Low-dose S+ ketamine in target-controlled intravenous anaesthesia with remifentanil and propofol for open gynaecological surgery: A randomised controlled trial.

Background and Aims:Using remifentanil–propofol target-controlled infusion (TCI) in open gynaecological surgeries could be associated with opioid-induced hyperalgesia postoperatively. This study's aim was to investigate the effect of low-dose S-ketamine compared with control on cumulative morphine consumption 24 h postoperatively in women undergoing open abdominal hysterectomy with remifentanil–propofol TCI technique.Methods:Ninety female patients above 21 years old who underwent elective open abdominal hysterectomy under general anaesthesia with remifentanil–propofol TCI were recruited. They were randomised to receive either normal saline as control (n = 44) or 0.25 mg/kg intravenous boluses of S-ketamine before skin incision and after complete removal of uterus (n = 45). The primary outcome measure was cumulative morphine consumption measured over 24 h postoperatively. The secondary outcome measures were incidences of opioid-related and psychotomimetic side effects, pain and level of sedation scores.Results:The cumulative 24-h morphine consumption postoperatively (P = 0.0547) did not differ between both the groups. S-ketamine group had slower emergence from general anaesthesia (P = 0.0308) and lower pain scores (P = 0.0359) 15 min postoperatively. Sedation level, common opioid-related side effects (nausea, vomiting, pruritus), respiratory depression and psychotomimetic side effects were similar between both the study groups.Conclusion:Low-dose S-ketamine did not reduce the total cumulative morphine consumption in patients undergoing major open gynaecological surgeries with remifentanil–propofol TCI.

Efficacy and Safety of Sufentanil-Propofol Versus Remifentanil-Propofol as Anesthesia in Patients Undergoing Craniotomy: A Meta-Analysis

In this study, we aimed to evaluate the efficacy and safety of sufentanil-propofol (SF) versus remifentanil-propofol (RF) as maintenance therapy for anesthesia in patients undergoing craniotomy. Randomized controlled studies on SF and RF as anesthesia for craniotomy were searched in electronic databases such as PubMed, Web of Science, Cochrane Library, Embase, CNKI, and Wanfang Data. All studies were published up to December 31, 2017. The primary outcomes were wake-up time, extubation time, and pain score. The secondary outcomes were heart rate, mean arterial pressure (MAP), and adverse reactions. In this meta-analysis, 14 studies involving 927 patients were investigated. Compared with the SF group, RF could significantly reduce the wake-up time and extubation time after craniotomy (P= 0.02, standardized mean difference [SMD], 1.19; 95% confidence interval [CI], 0.21-2.18; P= 0.0001; SMD, 1.87; 95% CI, 0.90-2.83, respectively). Meanwhile, SF had better efficacy to alleviate postoperative pain than RF (P= 0.001; SMD, 2.10; 95% CI,-3.37 to-0.82). However, there were no obvious differences in improving heart rate and MAP between the 2 groups (P= 0.46; SMD, 0.17; 95% CI,-0.28 to 0.62; P=0.43; SMD, 0.16; 95% CI,-0.54 to 0.23, respectively). Moreover, there were no significant differences in the incidents of nausea and vomiting, shivering, fidgeting, and respiratory depression between the SF and RF groups. RF as anesthesia for craniotomy had better effects in reducing the time of postoperative wake-up and extubation and significantly alleviating pain. Moreover, there were no significant differences in the incidence of adverse reactions between the 2 groups. The findings will prove beneficial for the rational use of clinical anesthetic drugs in the future.

The clinical observation of propofol with remifentanil anesthesia on the effection of upper gastrointestinal peristalsis in painless gastroscopy

Objective To discuss the application effect of joint remifentanil propofol anesthesia on upper gastrointestinal peristalsis in the painless gastroscopy. Methods 130 patients who taken painless gastroscopy were choosed,and using the random number table method,they were divided into the observation group and control group.Propofol anesthesia was used in the control group,joint remifentanil anesthesia was used in the observation group,and the anesthetic effect were recorded. Results In the observation group group,the excellent rate of anesthesia was 93.85%,the control group was 80.00%,there was statistically significant difference between the two groups(χ2= 5.481,P< 0.05).The propofol dosage in the observation group was(1.73±0.24)mg/kg,patients awake time was(5.91±1.03)min,and departure from the hospital time was(14.58±2.79)min,while in the control group,the propofol dosage was(3.06±0.57)mg/kg,patients awake time was(9.44±1.87)min,and departure from the hospital time was(22.05±4.86)min,there were statistically significant difference between the two groups(t = 17.337,13.330,10.747,all P<0.05).24 cases of observation group of patients with mild 36 cases,moderate,severe in 5 cases;23 cases of control group in patients with mild and moderate 27 cases,15 cases were severe,there was statistically significant difference between the two groups(χ2= 5.376,P< 0.05). Conclusion Joint remifentanil propofol used in painless gastroscopy of anesthesia is better than only propofol anesthesia,and with little impact on patients with upper gastrointestinal system,it can reduce the dosage of propofol,shorten the patient awake time and time of departure from the hospital,so it is worth popularization and application in clinic. Key words: Gastroscopy; Propofol; Remifentanil

Dexmedetomidine vs remifentanil intravenous anaesthesia and spontaneous ventilation for airway foreign body removal in children

To compare the safety and efficacy of dexmedetomidine/propofol (DP)-total i.v. anaesthesia (TIVA) vs remifentanil/propofol (RP)-TIVA, both with spontaneous breathing, during airway foreign body (FB) removal in children. Seventy-seven children undergoing rigid bronchoscopy for FB removal were randomly allocated to receive either RP-TIVA and spontaneous ventilation (Group RP, n=38) or DP-TIVA and spontaneous ventilation (Group DP, n=39). Heart rate, arterial pressure, pulse oxygen saturation (Sp(O2)), respiratory rate, end-tidal CO2 (E'(CO2)), and induction time were recorded. Adverse events, the intervention for these events, and postoperative care duration were also assessed. The mean induction times were comparable between the two groups (Group RP 12.2 min vs Group DP 13.1 min, P>0.05). At the end of the procedure, the mean (E'(CO2)) was higher in Group RP (Group RP 6.8 kPa vs Group DP 5.8 kPa, P<0.001), and respiratory rate was lower in Group RP (Group RP 20.4 vs Group DP 35.8, P<0.001). Additionally, the perioperative haemodynamic profile was more stable in Group DP than that in Group RP. The incidence rate of breath-holding and intervention were comparable between the two groups. In the post-anaesthesia care unit (PACU), no hypoxaemia was observed, and emergence time increased in Group DP (Group DP 65.1 min vs Group RP 23.8 min, P<0.0001). The incidence of cough in PACU was higher in Group RP (Group RP 55.3% vs Group DP 10.3%, P<0.0001). Compared with RP-TIVA, DP-TIVA provided more stable respiratory and haemodynamic profiles, but required a longer recovery time. Clinical trial registration China Clinical Research Information Service, ChiCTR-TRC-13003018.

Comparación del tiempo de despertar y tiempo de descarga entre dos técnicas de anestesia total intravenosa: remifentanilo vs fentanilo

IntroductionDespite the widespread use of Propofol–opioid combinations for induction and maintenance of adequate anesthesia and analgesia, there are no studies comparing the use of manual Total Intravenous Anesthesia with Remifentanil–Propofol (manual infusion) versus Fen-tanyl–Propofol (Stangraf by controlled). ObjectiveTo compare emergence and discharge times between two Total Intravenous Techniques used at Occidente de Kennedy Hospital, one based on Propofol and Remifentanil (manual infusion) and the other based on Stangraf-controlled Propofol and Fentanyl. MethodAnalytical observational study for the comparison of two groups of subjects, one exposed to Remifentanil plus Propofol and the other exposed to Fentanyl plus Propofol, comprising 43 patients taken to surgery under Total Intravenous Anesthesia at Occidente de Kennedy Hospital. Data were analyzed using the Shapiro–Wilks, Student t and Mann–Whitney U tests and the Spearman and Pearson correlation coefficients, using Windows SPSS, version 20. A p value <0.05 was accepted as statistically significant. ResultsIn comparing the two techniques, no statistically significant time differences were found. The mean emergence time was 10.1 min for Fentanyl and 10.2 min for Remifentanil. The discharge time for Fentanyl was 11.9 min and 11.5 min for Remifentanil. ConclusionsThe Stangraf-guided use of Fentanyl–Propofol combination is equivalent to the use of Remifentanil–Propofol (manual infusion) in terms of emergence and discharge times. Additional studies are required in order to confirm these findings.Palabras clave: Fentanilo; Propofol; Anestesia; Analgesia; Analgésicos opioidesKeywords: Fentanyl; Propofol; Anesthesia; Analgesia; Analgesics, Opioid

Comparison of emergence and discharge times between two Total Intravenous Anesthesia techniques: Remifentanil and Fentanyl

IntroductionDespite the widespread use of Propofol–opioid combinations for induction and maintenance of adequate anesthesia and analgesia, there are no studies comparing the use of manual Total Intravenous Anesthesia with Remifentanil–Propofol versus Fentanyl–Propofol. ObjectiveTo compare emergence and discharge times between two Total Intravenous Techniques used at Occidente de Kennedy Hospital, one based on Propofol and Remifentanil (manual infusion) and the other based on Stangraf-controlled Propofol and Fentanyl. MethodAnalytical observational study for the comparison of two groups of subjects, one exposed to Remifentanil plus Propofol and the other exposed to Fentanyl plus Propofol, comprising 43 patients taken to surgery under Total Intravenous Anesthesia at Occidente de Kennedy Hospital. Data were analyzed using the Shapiro–Wilks, Student t and Mann–Whitney U tests and the Spearman and Pearson correlation coefficients, using Windows SPSS, version 20. A p value <0.05 was accepted as statistically significant. ResultsIn comparing the two techniques, no statistically significant time differences were found. The mean emergence time was 10.1min for Fentanyl and 10.2min for Remifentanil. The discharge time for Fentanyl was 11.9min and 11.5min for Remifentanil. ConclusionsThe Stangraf-guided use of Fentanyl–Propofol combination is equivalent to the use of Remifentanil–Propofol (manual infusion) in terms of emergence and discharge times. Additional studies are required in order to confirm these findings.

Asleep–awake–asleep technique in children during strabismus surgery under sufentanil balanced anesthesia

Both over- and undercorrection can occur in up to 10-15% of strabismus surgeries. Use of adjustable suture technique and an intraoperative awake test may decrease the incidence of over- or undercorrection. In this study, we investigated the ability to provide optimal conditions for intraoperative awake strabismus suture adjustment in children by means of target-controlled infusions (TCI) of propofol and remifentanil propofol compared with propofol and sufentanil. Forty-six ASA I-II patients undergoing strabismus surgery with intraoperative awakening were randomly assigned to anesthesia by TCI of propofol + sufentanil group (group SF) or propofol + remifentanil spontaneous breathing. Propofol was discontinued, and concentrations of the opioid TCIs were reduced to enable awake assessment of the mobility and position of the eye. Changes in intraocular pressure, respiratory function, hemodynamics, awakening time, and awaking quality were compared between the two groups. The degrees of sedation and analgesia were evaluated through the assessment of alertness and sedation scores (OAA/S) and visual analog scale scores (VAS). There was no significant difference in intraocular pressure at three sampling points between two groups (P > 0.05). The heart rate (HR) and mean arterial blood pressure (MAP) in group SF were significantly lower than group RF during laryngeal mask insertion (P < 0.05) as well as during the wake-up test (P < 0.05). Spontaneous breathing was maintained in all patients, and there was no significant difference in RR and Sp02 at T1-T11 between the groups (P > 0.05). There was no significant difference in the target effect-site concentration of propofol at T1-T10 between the groups (P > 0.05). The wake-up times in group SF were significantly longer than in group RF (P < 0.05). In contrast, the quality of wake-up test and the degree of consciousness after the patients were awakened were significantly better (19 good and 4 satisfactory vs 15 good, 2 satisfactory, and 6 poor) in SF group than RF group. The VAS was significantly lower at T6-T9 in SF group than in RF group (P < 0.05). The incidence of untoward events during and after surgery, such as respiratory depression and apnea, oculocardiac reflex, coughing, groan and nausea, and vomiting was not significantly different between the groups (P > 0.05). Propofol combined with sufentanil or remifentanil can be suitable for planned intraoperative awakening for an adjustable suture technique in pediatric patients during strabismus surgery. Remifentanil has quicker wake-up time; however, sufentanil demonstrated an advantage in terms of better analgesia, more stable hemodynamics, and improved qualify of awakening.

Nitrous oxide (N2O) reduces postoperative opioid-induced hyperalgesia after remifentanil–propofol anaesthesia in humans

The aim of this study was to test if intraoperative administration of N(2)O during propofol-remifentanil anaesthesia prevented the onset of postoperative opioid-induced hyperalgesia (OIH). Fifty adult ASA I-II patients undergoing elective open septorhinoplasty under general anaesthesia were studied. Anaesthesia was with propofol, adjusted to bispectral index (40-50), and remifentanil (0.30 μg kg(-1) min(-1)). Patients were assigned to one of the two groups: with N(2)O (70%) and without N(2)O (100% oxygen). Mechanical pain thresholds were measured before surgery and 2 and 12-18 h after surgery. Pain measurements were performed on the arm using hand-held von Frey filaments. A non-parametric analysis of variance was used in the von Frey data analysis. P<0.05 was considered statistically significant. Baseline pain thresholds to mechanical stimuli were similar in both groups, with mean values of 69 [95% confidence interval (CI): 50.2, 95.1] g in the group without N(2)O and 71 (95% CI: 45.7, 112.1) g in the group with N(2)O. Postoperative pain scores and cumulative morphine consumption were similar between the groups. The analysis revealed a decrease in the threshold value in both groups. However, post hoc comparisons showed that at 12-18 h after surgery, the decrease in mechanical threshold was greater in the group without N(2)O than the group with N(2)O (post hoc analysis with Bonferroni's correction, P<0.05). Intraoperative 70% N(2)O administration significantly reduced postoperative OIH in patients receiving propofol-remifentanil anaesthesia.

When Duzitol Does Not Do It All

When Duzitol Does Not Do It All

Efecto de dosis bajas de ketamina en la analgesia postoperatoria y consumo de morfina tras cirugía de revascularización miocárdica

Objectives To assess the efficacy of ketamine in low doses by continuous infusion (8 μg/kg/min) given during surgery and the reduction in morphine use in the first 24 h after coronary bypass surgery with remifentanil based anaesthesia. Material and method Randomised, prospective, double blind study on 60 patients, ASA III–IV, scheduled to have off-pump myocardial revascularisation surgery. A standard anaesthetic technique with propofol and remifentanil between 0.5−1 μg/kg/min, after induction of anaesthesia, the ketamine (K) group (n=30) received a continuous infusion of 8 μg/kg/min and the propofol and remifentanil (P) group (n=30) received 0.9% physiological saline intravenously at the same infusion rate. Before the end of the surgery 0.15 mg/kg of morphine was given intravenously. Post-operative analgesia consisted of 3 mg of morphine every 5 min when the simple verbal scale was <1 (SVS<1). The intra-operative use of remifentanil–propofol was determined, as well as, the time to giving the first analgesic, pain intensity using the SVS and visual analogue scale (VAS), haemodynamic and respiratory parameters, level of sedation and adverse effects. Results No statistically significant differences were found between the demographic parameters, or in the mean use and infusions of remifentanil and propofol by both groups. The patients from the K group significantly delayed the time of requesting the first analgesic dose compared to the P group ( P<0.03). There were no significant differences between both study groups in the use of morphine in recovery and the total use in the first 24 h. The haemodynamic and respiratory parameters, and the sedation level remained stable during the whole period of the study, with no statistically significant differences between both groups. Post-operative pain control was adequate in both groups VAS<30, SVS<2), with no significant differences during the 24 h of the study. There no significant differences between groups, in the incidence of adverse effects. The incidence of nausea and post-operative vomiting was 20% in group K and 30% in group P. None of the patients had hallucinations or dysphoria. Conclusions Low doses of ketamine in continuous infusion during the intra-operative period of coronary surgery prolongs the time of demanding the first morphine dose, without reducing the use of intra-operative remifentanil, or the total use of morphine in the first 24 h after surgery.

Volatile induction/maintenance of anaesthesia with sevoflurane increases jugular venous oxygen saturation and lumbar cerebrospinal fluid pressure in patients undergoing craniotomy

Sevoflurane is a widely used volatile agent in neuroanaesthesia, and its nonirritant properties on the respiratory tract make sevoflurane suitable for volatile induction/maintenance of anaesthesia (VIMA). In the current trial, we investigate the effects of sevoflurane VIMA on lumbar cerebral fluid pressure (LCSFP) and jugular venous oxygen partial pressure in patients undergoing craniotomy for supratentorial intracranial surgery under bispectral index monitoring, determine jugular bulb venous oxygen saturation (SjvO2) and calculate cerebral perfusion pressure (CPP), arteriojugular venous oxygen content difference and cerebral oxygen extraction rate (COER) at different time points during the operation. Moreover, we compare these with total intravenous anaesthesia (TIVA) in patients receiving remifentanil and propofol continuous infusion. Twenty-six adult patients undergoing elective craniotomy were randomly allocated to either remifentanil-propofol (group TIVA) or sevoflurane (group VIMA). Mean arterial blood pressure, heart rate, LCSFP, CPP, SjvO2, arteriojugular venous oxygen content difference and COER were compared in the two groups at different time points under bispectral monitoring. Heart rate, mean arterial blood pressure, saturation of peripheral oxygen, BIS value and LCSFP were recorded at the time points including intubation (Tintub), 5 min (T5'int) and 15 min (T15'int) after intubation, the beginning of surgery (Tsurg), 5 min (T5m), 0.5 h (T0.5h), 1 h (T1h), 1.5 h (T1.5h), 2 h (T2h) and 2.5 h (T2.5h) after incision, the end of surgery (Tend), extubation (Textub) and 30 min (T30'end) after surgery. Arterial blood gas and jugular venous bulb blood gas analysis were performed at the time points of T0, T5'int, T5m, T1h, T2h, Tend, 15 min after operation (T15'end) and T30'end. LCSFP was increased above baseline levels in group VIMA and decreased in group TIVA from Tintub to T5m, and decreased to similar levels from T0.5h to T30'end in both groups. Mean arterial blood pressure was decreased to similar levels from T0.5h to Tend and returned to baseline levels at T30'end in both groups, and was significantly higher in group VIMA than in group TIVA at T5'int, T15'int, Tsurg and T5m. CPP was decreased to similar levels between the groups from T0.5h to Tend and returned to baseline levels at T30'end in both groups, and was significantly higher at Tintub, T5'int and T15'int in group VIMA than in group TIVA. Jugular venous oxygen partial pressure and SjvO2 were increased above baseline level from T5'int to T30'end in group VIMA, and decreased from T5'int to Tend, and returned to baseline level at T30'end in group TIVA. Arteriojugular venous oxygen content difference and COER were decreased from T5'int to T30'end in group VIMA, and increased above the baseline level from T5'int to Tend, and returned to the baseline level at T30'end in group TIVA. Sevoflurane VIMA increases SjvO2, lumbar CSF pressure and CPP, and decreases COER, which suggested that VIMA could be a better choice for patients with the risk of cerebral hypoperfusion or insufficient oxygen delivery. Propofol-based TIVA is associated with decreased SjvO2, LCSFP and CPP, and increased COER, and it might be suitable for patients with increased intracranial pressure.

Excellent intubating conditions with remifentanil–propofol and either low-dose rocuronium or succinylcholine

The shortest time to tracheal intubation, the best intubating conditions, and the shortest duration of muscle paralysis are achieved with succinylcholine. During a lidocaine-remifentanil-propofol induction of anesthesia, we compared intubating conditions 90 s after administering low-dose rocuronium (0.3 mg . kg(-1)) with intubating conditions 60 s after administering succinylcholine 1.5 mg . kg(-1). The randomized double-blind study included 184 healthy adult patients scheduled for elective surgery. Anesthesia was induced in all patients with lidocaine 1.5 mg . kg(-1), remifentanil 2 microg . kg(-1), and propofol 2 mg . kg(-1) administered over 30 s. In one group, rocuronium 0.3 mg . kg(-1) was administered before the induction sequence, and in the other group, succinylcholine 1.5 mg . kg(-1) was administered after the induction sequence. Laryngoscopy was attempted 90 s after rocuronium administration and 60 s after succinylcholine administration. Intubating conditions were assessed as excellent, good, or poor on the basis of ease of laryngoscopy, position of the vocal cords, and reaction to insertion of the tracheal tube and cuff inflation. There were 92 patients per group. In the rocuronium group, intubating conditions were excellent in 83 patients (90%), good in 8 (9%), and poor in 1 (1%), not significantly different from the intubating conditions in the succinylcholine group, which were excellent in 88 patients (96%), good in 3 (3%), and poor in 1 (1%) (P = 0.3). During a lidocaine-remifentanil-propofol induction of anesthesia, rocuronium 0.3 mg . kg(-1) administered before the induction sequence provides intubating conditions comparable to those achieved with succinylcholine 1.5 mg . kg(-1) administered after the induction sequence.

Effects of remifentanil-based general anaesthesia with propofol or sevoflurane on muscle microcirculation as assessed by near-infrared spectroscopy

BackgroundAlthough anaesthetics are known to alter microcirculation no study has, to our knowledge, documented changes in human skeletal microcirculatory function during general anaesthesia. MethodsForty-four patients undergoing maxillofacial surgery at a university hospital were prospectively randomized to receive general anaesthesia with remifentanil combined with propofol or sevoflurane. Muscle microcirculation was investigated with near-infrared spectroscopy (NIRS) before general anaesthesia was induced and 30 min later. An NIRS device (NIMO, Nirox) was used to quantify calf deoxyhaemoglobin [HHb], oxyhaemoglobin [HbO2], and total haemoglobin [HbT] concentrations, coupled to a series of venous and arterial occlusions to measure calf blood flow, muscle oxygen consumption, calf vascular resistance, microvascular compliance, and haemoglobin resaturation rate (RR). ResultsIn both the groups, general anaesthesia induced marked changes in muscle microcirculation: the tissue blood volume increased (+33% in remifentanil–sevoflurane and +45% with remifentanil–propofol groups), microvascular resistance decreased (−31% and −38%, respectively), and the post-ischaemic haemoglobin RR decreased (−48% and −36%, respectively). In the remifentanil–propofol group, the muscle blood flow increased (P<0.001), whereas in the remifentanil–sevoflurane group microvascular compliance and muscle oxygen consumption decreased (P<0.01). ConclusionsRemifentanil-based general anaesthesia with propofol or sevoflurane altered the muscle microcirculation in different ways. Quantitative NIRS, a technique that takes into account the optical tissue properties of the individual subject, can effectively measure these changes non-invasively.

Remifentanil-TCI and propofol-TCI for conscious sedation during fibreoptic intubation in the acromegalic patient

To evaluate the use of remifentanil-propofol administered as target-controlled infusion during awake fibreoptic intubation for anticipated difficult tracheal intubation in acromegalic patients. In all, 20 consecutive acromegalic patients underwent elective endonasal endoscopic transsphenoidal pituitary surgery. After premedication with midazolam 0.03 mg kg(-1), initially a target-controlled infusion of remifentanil 1.0 ng mL(-1) and propofol 1.5 microg mL(-1) was started. The fibreoptic intubation was performed by the same physician experienced with the fibreoptic technique. During the fibreoptic procedure the target concentrations of remifentanil and propofol ranged between 1.0 and 5.0 ng mL(-1), and between 1.5 and 3.5 microg mL(-1), respectively. Changes in heart rate and mean arterial pressure were recorded during airway manipulation, during tracheal intubation, and at 1 and 3 min after. On the first postoperative day, patient recall and level of discomfort during fibreoptic intubation were evaluated. Endotracheal intubation was efficaciously and quickly secured in all patients. A significant increase in mean arterial pressure and heart rate was recorded only during tracheal intubation (P < 0.05). Oxygenation was sufficient and no bradypnea or apnoea was recorded. All patients later described their anaesthetic experience as satisfactory. During fibreoptic intubation, remifentanil (ng mL(-1)) and propofol (microg mL(-1)) mean effect-site concentrations were 3.2 +/- 0.3 and 2.0 +/- 1.0, respectively. Remifentanil and propofol target-controlled infusion provided satisfactory conscious sedation allowing for successful oral fibreoptic intubation in acromegalic patients with no recall.