European Society of Anaesthesiology and Intensive Care Guidelines on peri-operative use of ultrasound for regional anaesthesia (PERSEUS regional anesthesia): Peripheral nerves blocks and neuraxial anaesthesia.

Nowadays, ultrasound-guidance is commonly used in regional anaesthesia (USGRA) and to locate the spinal anatomy in neuraxial analgesia. The aim of this second guideline on the PERi-operative uSE of UltraSound (PERSEUS-RA) is to provide evidence as to which areas of regional anaesthesia the use of ultrasound guidance should be considered a gold standard or beneficial to the patient. The PERSEUS Taskforce members were asked to define relevant outcomes and rank the relative importance of outcomes following the GRADE process. Whenever the literature was not able to provide enough evidence, we decided to use the RAND method with a modified Delphi process. Whenever compared with alternative techniques, the use of USGRA is considered well tolerated and effective for some nerve blocks but there are certain areas, such as truncal blocks, where a lack of robust data precludes useful comparison. The new frontiers for further research are represented by the application of USG during epidural analgesia or spinal anaesthesia as, in these cases, the evidence for the value of the use of ultrasound is limited to the preprocedure identification of the anatomy, providing the operator with a better idea of the depth and angle of the epidural or spinal space. USGRA can be considered an essential part of the curriculum of the anaesthesiologist with a defined training and certification path. Our recommendations will require considerable changes to some training programmes, and it will be necessary for these to be phased in before compliance becomes mandatory.

Compliance with sedation analgesia protocols: Do clinical pharmacists have an impact?

WHAT IS KNOWN AND OBJECTIVES: The agreement between prescribed sedation objectives and sedation pump syringe rate adaptation is not optimal. Delays in adjustment of sedation doses are associated with an increased patient length of stay in the intensive care unit. Our objectives were to assess compliance with the approved sedation protocol and to evaluate the impact of a clinical pharmacist daily controlling sedation and analgesia scores and pump syringe rates on patients' outcomes in a critical care unit. METHODS: Prospective before/after study involving 60 adult patients divided into two groups (non-intervention and intervention groups) who received mechanical ventilation and continuous infusions of sedative and analgesic drugs in an intensive care unit. In both groups, data were collected daily in 30 mechanically ventilated patients receiving a sedation/analgesia regimen during a 3-month period according to a standardized protocol. A pharmacist was in charge of intervening with physicians when the local sedation analgesia protocol was not followed. RESULTS AND DISCUSSION: There were no significant differences between the groups in terms of demographic characteristics except a higher proportion of men in the intervention group (70% vs 40%, P = .019). In the control group, sedation and analgesia objectives were not prescribed in more than half the cases. Pharmacist intervention reduced sedation duration (5 [2-11] vs 2 [1-5.5] days, P = .019). The cumulative delay in adaptation of the sedation analgesia electric syringe pump was significantly decreased in the intervention group (8 [0-29.5] vs 28.5 hours [11.1-68.4], P = .034). Total doses of sedatives (midazolam, propofol) and analgesics (sufentanil, remifentanil) per patient were decreased in the intervention group compared to the control group (respectively, P = .24, P = .0009, P = .0013 and P = .0007). CONCLUSIONS: Pharmacist intervention can decrease the sedation duration and the total dose of sedation medications and reinforce adherence to sedation/analgesia guidelines.

European Society of Anaesthesiology guidelines on peri-operative use of ultrasound-guided for vascular access (PERSEUS vascular access).

: Ultrasound for diagnostic and procedural purposes is becoming a standard in daily clinical practice including anaesthesiology and peri-operative medicine. The project of European Society of Anaesthesiology (ESA) Task Force for the development of clinical guidelines on the PERioperative uSE of Ultra-Sound (PERSEUS) project has focused on the use of ultrasound in two areas that account for the majority of procedures performed routinely in the operating room: vascular access and regional anaesthesia. Given the extensive literature available in these two areas, this paper will focus on the use of ultrasound-guidance for vascular access. A second part will be dedicated to peripheral nerve/neuraxial blocks. The Taskforce identified three main domains of application in ultrasound-guided vascular cannulation: adults, children and training. The literature search were performed by a professional librarian from the Cochrane Anaesthesia and Critical and Emergency Care Group in collaboration with the ESA Taskforce. The Grading of Recommendation Assessment (GRADE) system for assessing levels of evidence and grade of recommendations were used. For the use of ultrasound-guided cannulation of the internal jugular vein, femoral vein and arterial access, the level evidence was classified 1B. For other accesses, the evidence remains limited. For training in ultrasound guidance, there were no studies. The importance of proper training for achieving competency and full proficiency before performing any ultrasound-guided vascular procedure must be emphasised.

[Assessment of the therapeutic communication in order to improve the welcoming of patients in the operating room: impact study]. / Évaluation de la communication thérapeutique pour améliorer l'accueil du patient au bloc opératoire: étude d'impact.

PURPOSE: We wanted to assess the awareness of the nursing staff to therapeutic communications on improving the welcoming experience of patients in the operating room for outpatient surgery. METHODS: This was a single centre prospective impact study performed in an outpatient surgery clinic. In a first phase, a questionnaire was administered by the anesthetist nurse upon arrival of the patient to assess the patient's comfort (NRSc) and satisfaction on a simple numeric scale, and calculate a negative communication score ('NC'). In the second phase, the awareness of the nursing staff on therapeutic communication was emphasized on listening, empathy and the use of positive wording, using educational videos. In the third phase, after the staff awareness-raising period, the questionnaire was repeated. Quantitative variables (primary outcome criterion made of the number of patients with a NC score ≥ 5, NRSc, satisfaction), and qualitative variables before and after the awareness raising phase to therapeutic communications were compared. RESULTS: A total of 234 patients were included (109 before and 125 after). Following the staff awareness session to therapeutic communication, the NC score ≥ 5 decreased significantly from 20% to 6% as well as the median NRSc [P25-P75] before (8 [8-9] vs 8 [7-8]) and after (8 [8-9] vs 8 [7-8]) anesthesia. The proportion of less anxious patients before the initiation of anesthesia was significantly higher after the therapeutic communication (32% vs 17%). Satisfaction significantly increased after the awareness phase (8 [7-10] vs (9 [8-10]). CONCLUSION: This preliminary study shows a mild improvement of the patients' comfort and satisfaction after therapeutic communication. A controlled randomized trial is needed to confirm those results.

Real-time detection of gastric insufflation related to facemask pressure-controlled ventilation using ultrasonography of the antrum and epigastric auscultation in nonparalyzed patients: a prospective, randomized, double-blind study.

BACKGROUND: The authors sought to determine the level of inspiratory pressure minimizing the risk of gastric insufflation while providing adequate pulmonary ventilation. The primary endpoint was the increase in incidence of gastric insufflation detected by ultrasonography of the antrum while inspiratory pressure for facemask pressure-controlled ventilation increased from 10 to 25 cm H2O. METHODS: In this prospective, randomized, double-blind study, patients were allocated to one of the four groups (P10, P15, P20, and P25) defined by the inspiratory pressure applied during controlled-pressure ventilation: 10, 15, 20, and 25 cm H2O. Anesthesia was induced using propofol and remifentanil; no neuromuscular-blocking agent was administered. Once loss of eyelash reflex occurred, facemask ventilation was started for a 2-min period while gastric insufflation was detected by auscultation and by real-time ultrasonography of the antrum. The cross-sectional antral area was measured using ultrasonography before and after facemask ventilation. Respiratory parameters were recorded. RESULTS: Sixty-seven patients were analyzed. The authors registered statistically significant increases in incidences of gastric insufflation with inspiratory pressure, from 0% (group P10) to 41% (group P25) according to auscultation, and from 19 to 59% according to ultrasonography. In groups P20 and P25, detection of gastric insufflation by ultrasonography was associated with a statistically significant increase in the antral area. Lung ventilation was insufficient for group P10. CONCLUSION: Inspiratory pressure of 15 cm H2O allowed for reduced occurrence of gastric insufflation with proper lung ventilation during induction of anesthesia with remifentanil and propofol in nonparalyzed and nonobese patients. (Anesthesiology 2014; 120:326-34).

Training in regional anaesthesia: there is much to do.

This editorial discusses a survey of anaesthesia trainees and trainers from the UK concerning training in regional anaesthesia. The study found a large disparity in the number and diversity of regional anaesthesia procedures carried out by trainees during their initial training and that the presence of a departmental regional anaesthesia training lead improves the quality of teaching of these techniques. This study emphasises the fact that there is still a huge effort required to provide adequate training in regional anaesthetic techniques in the UK if patients are to benefit from the optimal postoperative analgesia they provide: the same probably applies also in many other European countries.

Hypobaric spinal anesthesia with ropivacaine plus sufentanil for traumatic femoral neck surgery in the elderly: a dose-response study.

BACKGROUND: In this randomized, prospective trial, we sought to determine the effective dose of hypobaric ropivacaine with sufentanil providing 95% success (ED95) in spinal anesthesia for traumatic femoral neck surgery in the elderly. METHODS: Sixty-eight elderly patients with unilateral hip fracture randomly received 6, 8, 10, or 12 mg spinal hypobaric ropivacaine combined with 5 µg sufentanil. Patients remained in a lateral position for 15 minutes after spinal injection. The dose was considered successful if a unilateral sensory block >T12 was achieved, and there was no need for additional analgesia or conversion to general anesthesia. The ED95 was determined using logit analysis. The incidence of severe and very severe hypotension (systolic blood pressure decrease by >30% and >40% baseline, respectively) and the use of remifentanil were compared among groups using χ(2) test for trend. RESULTS: Three patients were excluded because of failure to reach the subarachnoid space. No differences in baseline demographic data were observed among groups. The ED95 for hypobaric ropivacaine was determined to be 9 mg (95% confidence interval, 8-14). Increasing doses of ropivacaine (6, 8, 10, and 12 mg) demonstrated a positive trend with respect to incidence of hypotension (53%, 47%, 87%, and 81%, P = 0.0004) and a negative trend with respect to the use of remifentanil (41%, 12%, 0%, and 0%, P = 0.0004). A significant difference in the level of sensory block (P < 0.0001) was observed among operative and nonoperative sides but not among ropivacaine dosing groups (P = 0.16). No difference in motor blockade, incidence of very severe hypotension, total dose of ephedrine, duration of surgery, patient satisfaction, operating conditions, or surgeon satisfaction scores was observed among groups. No cases of bradycardia were observed. No patient had a preoperative sensory level

Alveolar diffusion and pharmacokinetics of linezolid administered in continuous infusion to critically ill patients with ventilator-associated pneumonia.

OBJECTIVES: This study aimed to determine the steady-state serum and alveolar concentrations of linezolid administered by continuous infusion to critically ill patients with ventilator-associated pneumonia (VAP). PATIENTS AND METHODS: This was a prospective, open-label study performed in an intensive care unit and research ward in a university hospital. Twelve critically ill adult patients with VAP received 600 mg of linezolid as a loading dose followed by 1200 mg/day by continuous infusion. After 2 days of therapy, the steady-state serum and alveolar (collected by a mini-bronchoalveolar procedure) concentrations of linezolid were determined by HPLC. RESULTS: The median (IQR) serum and epithelial lining fluid (ELF) linezolid concentrations at steady state (C(ss)) were 7.1 (6.1-9.8) and 6.9 (5.8-8.6) mg/L, respectively, and the median (IQR) AUC (AUC(0-24)) values were 169 (146-235) and 164 (139-202) mg · h/L, respectively, corresponding to a median (IQR) linezolid alveolar diffusion of 97% (80%-108%). CONCLUSIONS: Our study shows that the continuous infusion of 1200 mg of linezolid daily in critically ill patients with VAP provides satisfactory pharmacokinetic results, with a linezolid alveolar diffusion of 100% and concentrations exceeding almost twice the susceptibility breakpoint for Staphylococcus aureus (4 mg/L) in both serum and ELF for 100% of the time. However, the clinical benefit of continuous infusion in comparison with standard intermittent infusion is still to be determined.

Effect of GOAL-Directed ANalgesia using ANI (Analgesia/Nociception Index) during general anesthesia on immediate postoperative pain and intraoperative hemodynamics in adult patients (GOALDAN study): a study protocol for randomized, controlled, multicenter trial.

BACKGROUND: Severe postoperative pain remains a major problem that is seen in 20 to 40% of patients. The Analgesia/Nociception Index (ANI) is a 0-100 index reflecting the relative parasympathetic activity allowing for intraoperative analgesia monitoring. We have previously shown that an ANI value < 50 immediately before extubation may predict the occurrence of immediate postoperative pain with good performance. We hypothesized that GOAL-Directed ANalgesia may provide reduced immediate postoperative pain and optimized intraoperative remifentanil administration (GOLDAN study). METHODS: The GOALDAN study is an international, multicenter, simple-blind, parallel, prospective, randomized, controlled, two-armed trial. Patients are randomly assigned in a 1:1 ratio in the control group or in the experimental group. Patients will be randomly allocated to either the intervention group (ANI) or the control group (standard care only). In the ANI group, the administration of remifentanil will be goal-directed targeting a 50-80 ANI range, with a prophylactic injection of morphine immediately after extubation if the case of ANI < 50. Our primary objective was to determine whether the prophylactic administration of morphine at the end of the procedure in patients at risk of immediate postoperative pain (ANI < 50 immediately before extubation) could reduce the incidence of the latter by 50% in the post-anesthetic care unit. Our secondary objective was to determine whether the intraoperative use of goal-directed analgesia with an ANI target of 50 to 80 could improve intraoperative hemodynamics and postoperative outcome. DISCUSSION: Because of the paucity of well-conducted trials, the authors believe that a randomized-controlled trial will improve the evidence for using analgesia monitoring during general anesthesia and strengthen current recommendations for intraoperative analgesia management. TRIAL REGISTRATION: ClinicalTrials.gov NCT03618082. Registered on 7 August 2018.

Prospective multicenter study of heart rate variability with ANI monitor as predictor of mortality in critically ill patients with COVID-19.

The purpose of this study is to demonstrate that the most critically ill patients with COVID-19 have greater autonomic nervous system dysregulation and assessing the heart rate variability, allows us to predict severity and 30-day mortality. This was a multicentre, prospective, cohort study. Patients were divided into two groups depending on the 30-day mortality. The heart rate variability and more specifically the relative parasympathetic activity (ANIm), and the SDNN (Energy), were measured. To predict severity and mortality multivariate analyses of ANIm, Energy, SOFA score, and RASS scales were conducted. 112 patients were collected, the survival group (n = 55) and the deceased group (n = 57). The ANIm value was higher (p = 0.013) and the Energy was lower in the deceased group (p = 0.001); Higher Energy was correlated with higher survival days (p = 0.009), and a limit value of 0.31 s predicted mortalities with a sensitivity of 71.9% and a specificity of 74.5%. Autonomic nervous system and heart rate variability monitoring in critically ill patients with COVID-19 allows for predicting survival days and 30-day mortality through the Energy value. Those patients with greater severity and mortality showed higher sympathetic depletion with a predominance of relative parasympathetic activity.

Clinical assessment of the ultrasonographic measurement of antral area for estimating preoperative gastric content and volume.

BACKGROUND: This prospective observational study aimed to assess the feasibility and performance of the ultrasonographic measurement of antral cross-sectional area (CSA) for the preoperative assessment of gastric contents and volume in adult patients and for the diagnosis of risk stomach (defined by the presence of solid particles and/or gastric fluid volume >0.8 ml/kg). METHODS: A preoperative ultrasonographic measurement of the antral CSA was performed for each patient by a physician (L.B.) blinded to the history of the patient. Immediately after tracheal intubation, an 18-French multiorifice Salem tube was inserted and gastric contents were aspirated in five different patient positions; during this time, the patient's epigastrium was massaged and the tube was moved backward and forward in the stomach. The relationship between the antral area and the volume of aspirated gastric contents was analyzed, as was the performance of ultrasonographic measurement of antral area for the diagnosis of risk stomach. RESULTS: The measurement of antral CSA was performed on 180 of 183 patients. A significant positive relationship between antral CSA and aspirated fluid volume was found. The cutoff value of antral CSA of 340 mm(2) for the diagnosis of risk stomach was associated with a sensitivity of 91% and a specificity of 71%. The area under the receiver operating characteristic curve for the diagnosis of risk stomach was 90%. CONCLUSIONS: The ultrasonographic measurement of antral CSA could be an important help for the anesthesiologist in minimizing the risk of pulmonary aspiration of gastric contents due to general anesthesia.

Effects of a training program in medical hypnosis on burnout in anesthesiologists and other healthcare providers: A survey study.

OBJECTIVE: To determine whether the participation to a medical hypnosis training program reduces the levels of burnout in healthcare providers. DESIGN: Survey study. SETTINGS: Study conducted from 2014 to 2018 using the MBI-HSS questionnaire assessing three dimensions of burnout: emotional exhaustion (EE), depersonalization (DP) and personal accomplishment (PA). PARTICIPANTS: Healthcare providers in particular anesthesiologists participating to a one-year medical hypnosis training program. INTERVENTION: All participants were asked to fill the MBI-HSS on the first day before the training program had begun, then on the last day of the program once the entire training was completed. PRIMARY AND SECONDARY OUTCOME MEASURES: The EE, DP and PA scores and their grade (high, average and low) were compared before and after training and between physicians and caregivers. RESULTS: In total, 1850 persons participated to the training sessions, with 1366 participants enrolled before the first session (74%) and 1407 (76%) after the fourth. On the 1366 persons enrolled before training, 1139 (83%) completed the survey and on the 1407 enrolled after training, 1194 (85%) completed the survey. The scores were significantly smaller after training for EE and DP and significantly greater for PA. Before training, EE was significantly greater in physicians than in caregivers as well as DP, with no difference for PA. After training, DP was significantly greater in physicians than in caregivers and PA was smaller, with no difference for EE. Before training, there was high rates of burnout in both healthcare providers but there was a significant trend to smaller rates of burnout after training. CONCLUSIONS: This study shows that healthcare providers who participated to a medical hypnosis training program presented improvements in the three dimensions of burnout. Further study is required to investigate and recommend this type of continuous medical education to improve professional satisfaction and wellbeing in healthcare providers.

Evaluation of the sublingual microcirculation with sidestream dark field video microscopy in horses anesthetized for an elective procedure or intestinal surgery.

OBJECTIVE: To compare the sublingual microcirculation between healthy horses anesthetized for elective procedures and horses with colic anesthetized for abdominal surgery and to determine the effect of mean arterial blood pressure (MAP) on the microcirculation. ANIMALS: 9 horses in the elective group and 8 horses in the colic group. PROCEDURES: Sublingual microcirculation was assessed with sidestream dark field video microscopy. Videos were captured at 3 time points during anesthesia. Recorded microvasculature parameters were De Backer score (DBS), total density of perfused vessels (PVD) and small vessels (PVD-S), total proportion of perfused vessels (PPV) and small vessels (PPV-S), vascular flow index (MFI), and heterogeneity index (HI). Blood pressure during hypotensive (MAP < 60 mm Hg) and normotensive (MAP ≥ 60 mm Hg) episodes was also recorded. RESULTS: During normotensive episodes, the elective group had significantly better PPV and PPV-S versus the colic group (median PPV, 76% vs 50%; median PPV-S, 73% vs 51%). In both groups, PPV decreased during anesthesia (elective group, -29%; colic group, -16%) but significantly improved in the elective group 15 minutes before the end of anesthesia (59%). During hypotensive episodes, PVD-S was better preserved in the colic group (11.1 vs 3.8 mm/mm2). No differences were identified for the microcirculatory parameters between normo- and hypotensive episodes in the colic group. CONCLUSIONS AND CLINICAL RELEVANCE: Sublingual microcirculation was better preserved in healthy horses anesthetized for elective procedures than in horses with colic anesthetized for abdominal surgery despite resuscitation maneuvers. Results indicated that the macrocirculation and microcirculation in critically ill horses may be independent.

Performance of the Parasympathetic Tone Activity (PTA) index to predict changes in mean arterial pressure in anaesthetized horses with different health conditions.

The parasympathetic tone activity (PTA) index is based on heart rate variability and has been developed recently in animals to assess their relative parasympathetic tone. This study aimed to evaluate PTA index in anaesthetized horses with different health conditions and the performance of PTA variations (∆PTA) to predict changes in mean arterial pressure (MAP). Thirty-nine client-horses were anaesthetized for elective or colic surgery and divided into "Elective" and "Colic" groups. During anaesthesia, dobutamine was administered as treatment of hypotension (MAP <60 mmHg). In both groups, no significant variation of PTA and MAP were detected immediately before and after cutaneous incision. The PTA index increased 5 min before each hypotension, whereas it decreased 1 min after dobutamine administration. Horses of the Colic group had lower PTA values than those of the Elective group, whereas MAP did not differ between groups. To predict a 10% decrease in MAP, ΔPTA performance was associated with: AUC ROC [95% CI] =0.80 [0.73 to 0.85] (p < 0.0001), with a sensitivity of 62.5% and a specificity of 94.6% for a threshold value of 25%. The PTA index in anaesthetized horses appears to be influenced by the health condition. The shift toward lower PTA values in colic horses may reflect a sympathetic predominance. An increase in PTA of >25% in 1 min showed an acceptable performance to predict MAP decrease of >10% within 5 min. Even though these results require further evaluation, this index may thus help to predict potential autonomic dysfunctions in sick animals.

Pitfalls in chronobiology: a suggested analysis using intrathecal bupivacaine analgesia as an example.

BACKGROUND: The duration of analgesia from epidural administration of local anesthetics to parturients has been shown to follow a rhythmic pattern according to the time of drug administration. We studied whether there was a similar pattern after intrathecal administration of bupivacaine in parturients. In the course of the analysis, we came to believe that some data points coincident with provider shift changes were influenced by nonbiological, health care system factors, thus incorrectly suggesting a periodic signal in duration of labor analgesia. We developed graphical and analytical tools to help assess the influence of individual points on the chronobiological analysis. METHODS: Women with singleton term pregnancies in vertex presentation, cervical dilation 3 to 5 cm, pain score >50 mm (of 100 mm), and requesting labor analgesia were enrolled in this study. Patients received 2.5 mg of intrathecal bupivacaine in 2 mL using a combined spinal-epidural technique. Analgesia duration was the time from intrathecal injection until the first request for additional analgesia. The duration of analgesia was analyzed by visual inspection of the data, application of smoothing functions (Supersmoother; LOWESS and LOESS [locally weighted scatterplot smoothing functions]), analysis of variance, Cosinor (Chronos-Fit), Excel, and NONMEM (nonlinear mixed effect modeling). Confidence intervals (CIs) were determined by bootstrap analysis (1000 replications with replacement) using PLT Tools. RESULTS: Eighty-two women were included in the study. Examination of the raw data using 3 smoothing functions revealed a bimodal pattern, with a peak at approximately 0630 and a subsequent peak in the afternoon or evening, depending on the smoother. Analysis of variance did not identify any statistically significant difference between the duration of analgesia when intrathecal injection was given from midnight to 0600 compared with the duration of analgesia after intrathecal injection at other times. Chronos-Fit, Excel, and NONMEM produced identical results, with a mean duration of analgesia of 38.4 minutes (95% CI: 35.4-41.6 minutes), an 8-hour periodic waveform with an amplitude of 5.8 minutes (95% CI: 2.1-10.7 minutes), and a phase offset of 6.5 hours (95% CI: 5.4-8.0 hours) relative to midnight. The 8-hour periodic model did not reach statistical significance in 40% of bootstrap analyses, implying that statistical significance of the 8-hour periodic model was dependent on a subset of the data. Two data points before the change of shift at 0700 contributed most strongly to the statistical significance of the periodic waveform. Without these data points, there was no evidence of an 8-hour periodic waveform for intrathecal bupivacaine analgesia. CONCLUSION: Chronobiology includes the influence of external daily rhythms in the environment (e.g., nursing shifts) as well as human biological rhythms. We were able to distinguish the influence of an external rhythm by combining several novel analyses: (1) graphical presentation superimposing the raw data, external rhythms (e.g., nursing and anesthesia provider shifts), and smoothing functions; (2) graphical display of the contribution of each data point to the statistical significance; and (3) bootstrap analysis to identify whether the statistical significance was highly dependent on a data subset. These approaches suggested that 2 data points were likely artifacts of the change in nursing and anesthesia shifts. When these points were removed, there was no suggestion of biological rhythm in the duration of intrathecal bupivacaine analgesia.

Optimal remifentanil dose for laryngeal mask airway insertion when co-administered with a single standard dose of propofol.

PURPOSE: This dose-response study aimed to determine the optimal dose of remifentanil combined with propofol 2.5 mg.kg(-1) iv in order to achieve excellent conditions for laryngeal mask airway (LMA) insertion in 95% of adult female patients. METHODS: Sixty-eight adult premedicated female patients, American Society of Anesthesiologists (ASA) physical status I and II requiring anesthesia for ambulatory surgery, were randomly allocated to one of four remifentanil dose groups (0.25, 0.5, 1, or 2 microg.kg(-1)). Induction of anesthesia was achieved with one of the four blinded doses of remifentanil infused over 60 sec and simultaneously co-administered with propofol 2.5 mg.kg(-1) iv infused over 45 sec. Insertion of the LMA was attempted 150 sec after the beginning of the induction sequence. Insertion conditions were assessed using a six-category score according to resistance to mouth opening and insertion, swallowing, coughing and gagging, movement, and laryngospasm. A probit analysis was performed to calculate the effective dose for insertion of the LMA in 95% of patients (efficient dose [ED](95)). The changes in heart rate (HR) and mean arterial blood pressure (MAP) in response to LMA insertion were recorded and compared as secondary outcome variables. RESULTS: The ED(95) of remifentanil was 1.32 (95% confidence interval [CI] 0.99-2.46) microg.kg(-1). Changes in heart rate and mean arterial pressure were modest and similar over time across groups, with maximum decreases in heart rate and mean arterial pressure < 30% each during induction of anesthesia. CONCLUSIONS: The required dose of remifentanil is 1.32 (95% CI 0.99-2.46) microg.kg(-1) to achieve excellent LMA insertion conditions in 95% of patients when co-administered with propofol 2.5 mg.kg(-1) in healthy premedicated female patients undergoing elective ambulatory surgery.

What is the optimal remifentanil dosage for providing excellent intubating conditions when coadministered with thiopental? A prospective randomized dose-response study.

BACKGROUND AND OBJECTIVE: The aim of the present study was to determine the dosage of remifentanil that must be added to thiopental 5 mg kg(-1) to provide excellent intubating conditions in 95% of patients. METHODS: Sixty-eight premedicated female American Society of Anesthesiologists class 1 and 2 patients were randomly allocated to four remifentanil dose groups (3, 4, 5 or 6 microg kg(-1)). Induction of anaesthesia was performed with a blinded dose of remifentanil infused over 60 s, simultaneously coadministered with thiopental 5 mg kg(-1) infused over 20 s; and tracheal intubation was attempted 150 s after the beginning of induction. The intubating conditions were assessed with the Copenhagen score, according to jaw relaxation, resistance to laryngoscope, vocal cord position and movements and reaction to cuff inflation. A probit analysis was performed to calculate the intubating efficient doses (IEDs) of remifentanil in 50 and 95% of patients (IED50 and IED95). Haemodynamic tolerance was also analysed. RESULTS: The IED95 of remifentanil was 7.8 microg kg(-1) (95% confidence interval 5.9-10.9). Although the maximum decrease in heart rate and mean arterial pressure was less than 30% during induction of anaesthesia, the haemodynamic tolerance of such a relaxant-free protocol for anaesthesia providing excellent intubating conditions in 95% of patients when using remifentanil and thiopental could not be assessed, as the IED95 of remifentanil was more than 6 microg kg(-1). CONCLUSION: The dosage of remifentanil providing excellent intubating conditions in 95% of patients when coadministered with thiopental 5 mg kg(-1) in healthy premedicated female patients undergoing elective surgery was more than 7 microg kg(-1). Our results question the feasibility of using thiopental for a relaxant-free protocol for anaesthesia.

Performance of the Parasympathetic Tone Activity (PTA) index to assess the intraoperative nociception using different premedication drugs in anaesthetised dogs.

The dynamic variations of the Parasympathetic Tone Activity (PTA) index were evaluated to assess nociception in dogs undergoing anaesthetic protocols with different premedication drugs. Sixty-six dogs, divided into three groups of 22 dogs each, were given different premedication drugs "morphine" (0.2 mg/kg), "morphine + medetomidine (5 µg/kg)", "morphine + acepromazine (0.03 mg/kg)", then similarly induced and maintained under general anaesthesia. The PTA, HR (heart rate) and MAP (mean arterial pressure) were assessed at S (steady-state), Cut (cutaneous incision), PTAE (PTA Event, assessed 1 min before a significant PTA decrease), HDR (Haemodynamic reaction, assessed 5 min before an increase of ≥ 20% in HR and/or MAP). For each group, the dynamic variation of PTA (ΔPTA) was calculated and a Receiver Operating Characteristics (ROC) curve was performed to detect if any of the premedication drugs may alter the performance of PTA index to predict intraoperative haemodynamic reactions. In all groups, a haemodynamic reaction was detected after Cut, PTAE and HDR and was preceded with a significant decrease of PTA, except for "morphine + medetomidine" group which showed a significant drop of PTA only at PTAE and HDR. The ΔPTA showed a fair performance in all groups (a mean [95% CI] AUC of 0.73 [0.62-0.82], 0.70 [0.59-0.79] and 0.71 [0.59-0.80] respectively in morphine, morphine + ACP and morphine + medetomidine). Although ΔPTA was rather altered by the premedication drug, it was able to predict, to a certain extent, haemodynamic reactions in all groups.

Hematological and Hemostatic Alterations Associated With a Single Extracorporeal Renal Replacement Therapy in Dogs With Acute Kidney Injury Associated Leptospirosis: A Pilot Study.

Extracorporeal renal replacement therapy (ERRT) used in dogs with acute kidney injury (AKI) may be associated with hematological and hemostatic disorders. However, its characteristics are not fully described in dogs. The purpose of this pilot study was to characterize the impact of ERRT on hematological, hemostatic, and thromboelastometric parameters in dogs with AKI. We conducted a prospective observational single cohort study in 10 client-owned dogs with AKI associated leptospirosis undergoing ERRT. Results from the CBC, coagulation tests (prothrombin and activated partial thromboplastin times [aPTT]) and rotational thromboelastometry (TEM; intrinsic TEM [inTEM] and heparinase-based TEM [hepTEM]) were recorded before and after the first ERRT session. Blood abnormalities observed before the ERRT session included thrombocytopenia (10/10), anemia (8/10), leukocytosis (4/10), prolonged aPTT (4/10) and leukopenia (1/10). After ERRT, the platelet count decreased (-25%; P = .012) whereas leukocytes (+15%; P = .046) and aPTT (+24%; P = .006) increased. The clotting time (CT) on inTEM assay and the relative variation of CT based on inTEM and hepTEM profiles increased after the ERRT session (P = .037 and P = .048, respectively). Seven dogs, 2 dogs, and 1 dog were defined as having a normal, hypocoagulable, and hypercoagulable inTEM profile after ERRT, respectively. After ERRT, no hepTEM parameter was significantly different from before treatment. Platelet count, leukocytes, aPTT and CT were altered after the first ERRT session. Beyond the hemostatic abnormalities expected by the use of UFH, thrombocytopenia appears as the only hemostatic change after a single ERRT session in dogs with AKI.