Philippe Cuvillon

The continuous femoral nerve block catheter for postoperative analgesia: bacterial colonization, infectious rate and adverse effects.

We investigated the incidence of bacterial and vascular or neurological complications resulting from femoral nerve catheters used for postoperative analgesia. Patients requiring continuous femoral blockade were consecutively included. Using surgical aseptic procedure, 211 femoral nerve catheters were placed (short-beveled insulated needle, peripheral nerve stimulator). After 48 h, each catheter was removed and semiquantitative bacteriological cultures were performed on each distal catheter tip. Postoperative analgesia and antibiotics were standardized. All complications during the insertion of the catheters and postoperatively (after 48 h and 6 wk) were noted. Few initial complications with no immediate or delayed complications were noted (20 difficult insertions, 3 impossible injections, 3 ineffective catheters, and 12 vascular punctures). After 48 h, 208 catheters were analyzed; 57% had positive bacterial colonization (with a single organism in 53%). The most frequent organisms were Staphylococcus epidermidis (71%), Enteroccus (10%), and Klebsiella (4%). Neither cellulitis nor abscess occurred. Three transitory bacteriemias likely related to the catheter occurred. After 6 wk, no septic complications were noted. One femoral paresthesia, partially recovered 1 yr later, was noted. We conclude that the risk of bacterial complications is small with femoral nerve catheters, although the rate of colonization is frequent.

A comparison of the pharmacodynamics and pharmacokinetics of bupivacaine, ropivacaine (with epinephrine) and their equal volume mixtures with lidocaine used for femoral and sciatic nerve blocks: a double-blind randomized study.

BACKGROUND: Mixtures of lidocaine with a long-acting local anesthetic are commonly used for peripheral nerve block. Few data are available regarding the safety, efficacy, or pharmacokinetics of mixtures of local anesthetics. In the current study, we compared the effects of bupivacaine 0.5% or ropivacaine 0.75% alone or in a mixed solution of equal volumes of bupivacaine 0.5% and lidocaine 2% or ropivacaine 0.75% and lidocaine 2% for surgery after femoral-sciatic peripheral nerve block. The primary end point was onset time. METHODS: In a double-blind, randomized study, 82 adults scheduled for lower limb surgery received a sciatic (20 mL) and femoral (20 mL) peripheral nerve block with 0.5% bupivacaine (200 mg), a mixture of 0.5% bupivacaine 20 mL (100 mg) with 2% lidocaine (400 mg), 0.75% ropivacaine (300 mg) or a mixture of 0.75% ropivacaine 20 mL (150 mg) with 2% lidocaine (400 mg). Each solution contained epinephrine 1:200,000. Times to perform blocks, onset times (end of injection to complete sensory and motor block), duration of sensory and motor block, and morphine consumption via IV patient-controlled analgesia were compared. Venous blood samples of 5 mL were collected for determination of drug concentration at 0, 5, 15, 30, 45, 60, and 90 min after placement of the block. RESULTS: Patient demographics and surgical times were similar for all four groups. Sciatic onset times (sensory and motor block) were reduced by combining lidocaine with the long-acting local anesthetic. The onset of bupivacaine-lidocaine was 16 ± 9 min versus 28 ± 12 min for bupivacaine alone. The onset of ropivacaine-lidocaine was 16 ± 12 min versus 23 ± 12 for ropivacaine alone. Sensory blocks were complete for all patients within 40 min for those receiving bupivacaine–lidocaine versus 60 min for those receiving bupivacaine alone and 30 min for those receiving ropivacaine–lidocaine versus 40 min for those receiving ropivacaine alone (P < 0.05). Duration of sensory and motor block was significantly shorter in mixture groups. There was no difference among groups for visual analog scale pain scores and morphine consumption during the 48 h postoperative period, except for bupivacaine alone (median: 9 mg) versus bupivacaine–lidocaine mixture (15 mg), P < 0.01. There was no difference in the incidence of adverse events among groups. Plasma concentrations of bupivacaine and ropivacaine were higher, and remained elevated longer, in patients who received only the long-acting local anesthetic compared to patients who received the mixture of long-acting local anesthetic with lidocaine (P < 0.01). CONCLUSION: Mixtures of long-acting local anesthetics with lidocaine induced faster onset blocks of decreased duration. Whether there is a safety benefit is unclear, as the benefit of a decreased concentration of long-acting local anesthetic may be offset by the presence of a significant plasma concentration of lidocaine.

pulsed Doppler Ultrasonography Guidance for Catheterization of the Subclavian Vein : a Randomized Study

Background Catheterization of the subclavian vein may lead to severe complications. The current randomized study compared a technique of pulsed Doppler ultrasonography guidance and the standard method for subclavian vein catheterization. Methods Standard and Doppler ultrasonography guidance methods were performed by the same physician in 286 patients, 143 in each group. Primary end points were immediate complications (arterial puncture, pneumothorax, wrong position of catheter tip), failures, the number of subclavian vein catheterizations with immediate complication or failure, the number of skin punctures per catheterization, and the time to placement of the guide wire. The secondary end points were the determination of predicting factors of successful cannulation in each group. Results Both groups were similar according to morphologic parameters of the patients. A greater number of subclavian vein catheterizations were performed on the right side using Doppler guidance (105 vs. 73, P < 0.01). Doppler guidance decreased complications (5.6% vs. 16.8%, P < 0.01), largely because of a smaller number of catheters for which the tip was defined to be in incorrect position (0.7% vs. 7.7%, P < 0.01). The time to catheterization was longer with Doppler guidance (300 vs. 27 s, P < 0.001). Failures, catheterizations of the subclavian vein with immediate complications or failure, and the total number of skin punctures per catheterization were similar in both groups. Using Doppler guidance, the presence of a good Doppler signal (124 of 143) was predictive of successful catheterization (123 successful cannulations, P < 0.001). Conclusions Doppler guidance reduces the incidence of inappropriately positioned subclavian catheters.

Postoperative analgesia by femoral nerve block with ropivacaine 0.2% after major knee surgery: Continuous versus patient-controlled techniques

Background and Objectives This prospective study compared the efficacy and adverse effects after knee surgery of ropivacaine 0.2% administered as patient-controlled femoral analgesia (PCFA), as a continuous femoral infusion (Inf), or as both (PCFA+Inf). Methods Before general anesthesia, 140 adults scheduled to undergo major knee surgery received a sciatic/fascia iliaca nerve block with 0.75% ropivacaine (40 mL). After surgery, they were randomly assigned to receive, through the femoral catheter, an infusion of 0.2% ropivacaine administered as PCFA (boluses of 10 mL with a lockout time of 60 minutes), Inf (10 mL/h), or PCFA + Inf (5 mL/h plus boluses of 5 mL with a lockout time of 60 minutes). Pain was assessed at rest, on mobilization, and during physiotherapy using a visual analog scale (VAS). Additional use of intravenous (IV) analgesics was noted. Results Patients in all 3 groups experienced similar pain relief at rest, on mobilization, and after physiotherapy (P > .05). Additional use of analgesics and overall patient satisfaction (excellent or good in 80% of cases) were also similar in all groups. However, total postoperative ropivacaine consumption was lower in the PCFA group, 150 mL/48 h (90.5 to 210); than in the Inf group, 480 mL/48 h (478 to 480); and the PCFA + Inf group, 310 mL/48 h (280 to 340) (P < .05). Adverse events were similar in all 3 groups (hypotension, vomiting, insomnia). No paresthesia or motor block were observed. Conclusion All 3 strategies provided effective pain relief. PCFA resulted in a lower consumption of ropivacaine (toxic and financial impact). PCFA + Inf does not improve postoperative analgesia.

Comparison of the parasacral approach and the posterior approach, with single- and double-injection techniques, to block the sciatic nerve.

Background The purpose of this study was to compare parasacral and Winnies single- or double-injection approaches for sciatic nerve block. Methods One hundred fifty adults scheduled to undergo lower limb surgery were randomized to receive on the sciatic nerve 20 ml ropivacaine, 0.75%: single bolus for parasacral and Winnies single injection. For Winnies double injection, the peroneal and tibial nerves received separately 10 ml plus 10 ml. Blocks were performed with the use of nerve stimulator (intensity < 0.5 mA, 1 Hz). For the parasacral method, a line was drawn between the posterior superior iliac spine and the ischial tuberosity; needle entry was at 6 cm inferior to the posterior superior iliac spine. Results The groups were similar. Time to perform the block was 2 (1–5) min for the parasacral method, with no difference from Winnies single injection (3 [1–10] min), but was shorter with double injection (5.5 [2–15] min) (P = 0.0001). Onset of sensory block was similar in the parasacral (25 [7.5–50] min) and Winnie single-injection groups (25 [5–50] min) but significantly longer in the double-injection group (15 [5–50] min). Success rates for complete block were similar in the parasacral (66%) and Winnies double-injection groups (68%) after 30 min but higher in the Winnies single-injection group for tibial sensory and motor block (48%) (P < 0.017). Conclusion Time to perform a parasacral block was short, and the parasacral approach had a high success rate and a short onset time. Therefore, this block might be a useful alternative to Winnies modification for sciatic nerve block.

Prediction of difficult tracheal intubation: time for a paradigm change.

Background:It has been suggested that predicting difficult tracheal intubation is useless because of the poor predictive capacity of individual signs and scores. The authors tested the hypothesis that an accurate prediction of difficult tracheal intubation using simple clinical signs is possible using a computer-assist model. Methods:In a cohort of 1,655 patients, the authors analyzed the predictive properties of each of the main signs (Mallampati score, mouth opening, thyromental distance, and body mass index) to predict difficult tracheal intubation. They built the best score possible using a simple logistic model (SCOREClinic) and compared it with the more recently described score in the literature (SCORENaguib). Then they used a boosted tree analysis to build the best score possible using computer-assisted calculation (SCOREComputer). Results:Difficult tracheal intubation occurred in 101 patients (6.1%). The predictive properties of each sign remain low (maximum area under the receiver operating characteristic curve 0.70). Using receiver operating characteristic curve, the global prediction of the SCOREClinic (0.74, 95% CI: 0.72–0.76) was greater than that of the SCORENaguib (0.66, 95% CI: 0.60–0.72, P < 0.001) but significantly lower than that of the SCOREComputer (0.86, 95% CI: 0.84–0.91, P < 0.001). The proportion of patients in the inconclusive zone was 71% using SCORENaguib, 56% using SCOREClinic, and only 32 % using SCOREComputer (all P < 0.001). Conclusion:Computer-assisted models using complex interaction between variables enable an accurate prediction of difficult tracheal intubation with a low proportion of patients in the inconclusive zone. An external validation of the model is now required.

The Simplified Predictive Intubation Difficulty Score: a new weighted score for difficult airway assessment.

Background and objective Using the Intubation Difficulty Scale (IDS) more than 5 as a standardized definition of difficult intubation, we propose a new score to predict difficult intubation: the Simplified Predictive Intubation Difficulty Score (SPIDS). Methods We prospectively studied 1024 patients scheduled for elective surgery under general anaesthesia. Using bivariate and multivariable analysis, we established risk factors of difficult intubation. Then, we assigned point values to each of the adjusted risk factors, their sum composing the SPIDS. We assessed its predictive accuracy using sensitivity, specificity, positive (PPV) and negative predictive values (NPV), and the area under the receiver operating characteristic (ROC) curve (AUC), and compared it with the corresponding nonweighted score. The optimal predictive level of the SPIDS was determined using ROC curve analysis. Results We found five adjusted risk factors for IDS more than 5: pathological conditions associated with difficult intubation (malformation of the face, acromegaly, cervical rheumatism, tumours of the airway, and diabetes mellitus), mouth opening less than 3.5 cm, a ratio of patients height to thyromental distance 25 at least, head and neck movement less than 80°, and Mallampati 2 at least. Sensitivity, specificity, PPV and NPV of the SPIDS were 65, 76, 14 and 97%, respectively. AUC of the SPIDS and the nonweighted score (obtained previously using a stepwise logistic regression) were respectively 0.78 [95% confidence interval (CI) 0.72–0.84] and 0.69 (95% CI 0.64–0.73). The threshold for an optimal predictive level of the SPIDS was above 10 of 55. Conclusion The SPIDS seems easy to perform, and by weighting risk factors of difficult intubation, it could help anaesthesiologists to plan a difficult airway management strategy. A value of SPIDS strictly above 10 could encourage the anaesthesiologists to plan for the beginning of the anaesthetic induction with ‘alternative’ airway devices ready in the operating theatre.

Effect of Individualized vs Standard Blood Pressure Management Strategies on Postoperative Organ Dysfunction Among High-Risk Patients Undergoing Major Surgery: A Randomized Clinical Trial

Importance Perioperative hypotension is associated with an increase in postoperative morbidity and mortality, but the appropriate management strategy remains uncertain. Objective To evaluate whether an individualized blood pressure management strategy tailored to individual patient physiology could reduce postoperative organ dysfunction. Design, Setting, and Participants The Intraoperative Norepinephrine to Control Arterial Pressure (INPRESS) study was a multicenter, randomized, parallel-group clinical trial conducted in 9 French university and nonuniversity hospitals. Adult patients (n = 298) at increased risk of postoperative complications with a preoperative acute kidney injury risk index of class III or higher (indicating moderate to high risk of postoperative kidney injury) undergoing major surgery lasting 2 hours or longer under general anesthesia were enrolled from December 4, 2012, through August 28, 2016 (last follow-up, September 28, 2016). Interventions Individualized management strategy aimed at achieving a systolic blood pressure (SBP) within 10% of the reference value (ie, patient’s resting SBP) or standard management strategy of treating SBP less than 80 mm Hg or lower than 40% from the reference value during and for 4 hours following surgery. Main Outcomes and Measures The primary outcome was a composite of systemic inflammatory response syndrome and dysfunction of at least 1 organ system of the renal, respiratory, cardiovascular, coagulation, and neurologic systems by day 7 after surgery. Secondary outcomes included the individual components of the primary outcome, durations of ICU and hospital stay, adverse events, and all-cause mortality at 30 days after surgery. Results Among 298 patients who were randomized, 292 patients completed the trial (mean [SD] age, 70 [7] years; 44 [15.1%] women) and were included in the modified intention-to-treat analysis. The primary outcome event occurred in 56 of 147 patients (38.1%) assigned to the individualized treatment strategy vs 75 of 145 patients (51.7%) assigned to the standard treatment strategy (relative risk, 0.73; 95% CI, 0.56 to 0.94; P = .02; absolute risk difference, −14%, 95% CI, −25% to −2%). Sixty-eight patients (46.3%) in the individualized treatment group and 92 (63.4%) in the standard treatment group had postoperative organ dysfunction by day 30 (adjusted hazard ratio, 0.66; 95% CI, 0.52 to 0.84; P = .001). There were no significant between-group differences in severe adverse events or 30-day mortality. Conclusions and Relevance Among patients predominantly undergoing abdominal surgery who were at increased postoperative risk, management targeting an individualized systolic blood pressure, compared with standard management, reduced the risk of postoperative organ dysfunction. Trial Registration clinicaltrials.gov Identifier: NCT01536470

American Society of Anesthesiologists' physical status system: a multicentre Francophone study to analyse reasons for classification disagreement.

Context Variability of American Society of Anesthesiologists’ (ASA) physical status scores attributed to the same patient by multiple physicians has been reported in several studies. In these studies, the population was limited and diseases that induced disagreement were not analysed. Objectives To evaluate the reproducibility of ASA physical status assessment on a large population, as used in current practice before scheduled surgery. Design Multicentre, randomised, blinded cross-over observational study. Methods During a 2-week period in nine institutions, ASA physical status and details of assessment performed routinely by anaesthesiologists for patients who underwent elective surgery were recorded. Records were blinded (including ASA physical status) by an independent statistical division and returned randomly to one of the nine centres for reassessment by accredited specialist anaesthesiologists. Main outcome measures The level of agreement between the two measurements of the ASA physical status was calculated by using the weighted Kappa coefficient. Results During the study period, 1554 anaesthesia records were collected and 197 were excluded from analysis because of missing data. After the initial evaluation, the distribution of ASA physical status grades was as follows: ASA 1, 571; ASA 2, 591; ASA 3, 177; and ASA 4, 18. After the final evaluation, the distribution of ASA grades was as follows: ASA 1, 583; ASA 2, 520; ASA 3, 223; and ASA 4, 31. Two per cent of the patients had an underestimation of their physical status. The degree of agreement between the two measures evaluated by the weighted Kappa coefficient was 0.53 (0.49–0.56). No difference was observed between public and private institutions. Patients with co-existing diseases, obesity, allergy, sleep apnoea, obstructive lung disease, renal insufficiency and hypertension were least likely to have been graded correctly. Conclusion The degree of agreement between two measures of the ASA physical status grade is moderate and influenced by staff characteristics and the complexity of diseases.

Regional Anesthesia and Eye Surgery

THE vast majority of ophthalmic surgeries are performed under regional anesthesia only. However, its use is also described in association with general anesthesia for pediatric cases and for postoperative analgesia. Eye blocks have long been limited to retrobulbar anesthesia (RBA) as performed by surgeons. Surgical technique changes and research on improving patient safety during eye blocks has resulted in the development of alternative techniques, such as peribulbar anesthesia (PBA), followed by low-volume sub-Tenon block (STA) or topical anesthesia (TA). In this review, we present the general requirements necessary for an eye block and then briefly describe each technique, discussing their respective advantages and inconveniences. Although cataract surgery is the most frequent ophthalmic surgical procedure and a large number of articles we cite refer to studies concerning this procedure, implications to regional anesthesia are not limited to cataract surgery; much of the data we review can be extrapolated and reinterpreted for other ophthalmic applications.