Hyperbaric prilocaine vs. hyperbaric bupivacaine for spinal anaesthesia in women undergoing elective caesarean section: a comparative randomised double-blind study.

Hyperbaric bupivacaine spinal anaesthesia remains the gold standard for elective caesarean section, but the resultant clinical effects can be unpredictable. Hyperbaric prilocaine induces shorter motor block but has not previously been studied in the obstetric spinal anaesthesia setting. We aimed to compare duration of motor block after spinal anaesthesia with prilocaine or bupivacaine during elective caesarean section. In this prospective randomised, double-blind study, women with uncomplicated pregnancy undergoing elective caesarean section were eligible for inclusion. Exclusion criteria included: patients aged < 18 years; height < 155 cm or > 175 cm; a desire to breastfeed; or a contra-indication to spinal anaesthesia. Patients were randomly allocated to two groups: the prilocaine group underwent spinal anaesthesia with 60 mg intrathecal prilocaine; and the bupivacaine group received 12.5 mg intrathecal heavy bupivacaine. Both 2.5 µg sufentanil and 100 µg morphine were added to the local anaesthetic agent in both groups. The primary outcome was duration of motor block, which was assessed every 15 min after arriving in the post-anaesthetic care unit. Maternal haemodynamics, APGAR scores, pain scores, patient satisfaction and side-effects were recorded. Fifty patients were included, with 25 randomly allocated to each group. Median (IQR [range]) motor block duration was significantly shorter in the prilocaine group, 158 (125-188 [95-249]) vs. 220 (189-250 [89-302]) min, p < 0.001. Median length of stay in the post-anaesthetic care unit was significantly shorter in the prilocaine group, 135 (120-180 [120-230]) vs. 180 (150-195 [120-240]) min, p = 0.009. There was no difference between groups for: maternal intra-operative hypotension; APGAR score; umbilical cord blood pH; maternal postoperative pain; and patients' or obstetricians' satisfaction. We conclude that hyperbaric prilocaine induces a shorter and more reliable motor block than hyperbaric bupivacaine for women with uncomplicated pregnancy undergoing elective caesarean section.

The effect of rate of injection on injection pressure profiles measured using in-line and needle-tip sensors: an in-vitro study.

Alongside ultrasonic visualisation, measurement of injection pressure is an effective tool for reducing the risk of intraneural injection during peripheral nerve block. The aim of this study was to compare injection pressure profiles when measured along the injection line with the pressure measured directly at the needle tip using different rates of injection. A syringe pump delivered a 5-ml injection of saline into silicone gel at three different speeds (5 ml.min-1 , 10 ml.min-1 and 15 ml.min-1 ). Fibreoptic pressure sensors recorded real-time pressure profiles of the injection pressure directly at the needle tip and along the injection line. A total of 15 injections were successfully performed, five for each injection rate, totalling 30 recorded pressure profiles. More rapid rates of injection caused peak pressure measured in-line to increase, whereas pressure measured at the needle tip remained constant (mean (SD) pressure in-line 30.76 (3.45) kPa vs. 72.25 (1.55) kPa and mean (SD) pressure at needle tip 19.92 (1.22) kPa vs. 20.93 (2.66) kPa at 5 ml.min-1 and 15 ml.min-1 , respectively). Injection pressure profiles showed that in-line pressure measurement failed to record precise real-time pressure changes occurring at the needle tip (mean (95%CI) pressure difference 10.8 (6.98-14.70) kPa vs. 51.2 (47.52-54.89) kPa for in-line and needle-tip measures, respectively). We conclude that, in order to accurately monitor the true injection pressure generated, independent from operator and injection parameters, measurement at the needle tip is necessary, as injection pressure measured along the injection line is an unreliable surrogate.

The hip fracture surgery in elderly patients (HIPELD) study to evaluate xenon anaesthesia for the prevention of postoperative delirium: a multicentre, randomized clinical trial.

BACKGROUND: Postoperative delirium occurs frequently in elderly hip fracture surgery patients and is associated with poorer overall outcomes. Because xenon anaesthesia has neuroprotective properties, we evaluated its effect on the incidence of delirium and other outcomes after hip fracture surgery. METHODS: This was a phase II, multicentre, randomized, double-blind, parallel-group, controlled clinical trial conducted in hospitals in six European countries (September 2010 to October 2014). Elderly (≥75yr-old) and mentally functional hip fracture patients were randomly assigned 1:1 to receive either xenon- or sevoflurane-based general anaesthesia during surgery. The primary outcome was postoperative delirium diagnosed through postoperative day 4. Secondary outcomes were delirium diagnosed anytime after surgery, postoperative sequential organ failure assessment (SOFA) scores, and adverse events (AEs). RESULTS: Of 256 enrolled patients, 124 were treated with xenon and 132 with sevoflurane. The incidence of delirium with xenon (9.7% [95% CI: 4.5 -14.9]) or with sevoflurane (13.6% [95% CI: 7.8 -19.5]) were not significantly different (P=0.33). Overall SOFA scores were significantly lower with xenon (least-squares mean difference: -0.33 [95% CI: -0.60 to -0.06]; P=0.017). For xenon and sevoflurane, the incidence of serious AEs and fatal AEs was 8.0% vs 15.9% (P=0.05) and 0% vs 3.8% (P=0.06), respectively. CONCLUSIONS: Xenon anaesthesia did not significantly reduce the incidence of postoperative delirium after hip fracture surgery. Nevertheless, exploratory observations concerning postoperative SOFA-scores, serious AEs, and deaths warrant further study of the potential benefits of xenon anaesthesia in elderly hip fracture surgery patients. CLINICAL TRIAL REGISTRATION: EudraCT 2009-017153-35; ClinicalTrials.gov NCT01199276.

Real-time continuous monitoring of injection pressure at the needle tip for peripheral nerve blocks: description of a new method.

The measurement of injection pressure during the performance of peripheral nerve blocks can be pivotal to detect intraneural placement of the needle tip and thus avoid intrafascicular injection. However, injection pressure can only be measured along the injection line (tubing), which is influenced by several factors. The primary aim of this feasibility study was to describe and validate the principle of a novel nerve-block needle conceived for real-time continuous monitoring of injection pressures at the needle tip. Our secondary aim was to provide measurements and compare injection pressure values at the needle tip and in the injection line. Four porcine lower limb anatomic models were prepared and extraneural injections were performed with fractioned boluses of 2 ml saline at a controlled infusion rate of 10 ml.min-1 (0.16 ml.s-1 ). Injection pressure at the needle tip was monitored and compared with the pressure in the injection line. The system proved to be reliable. Thirty injections were successfully performed without technical failures. The mean (95%CI) difference between pressures at the needle tip and the injection line varied substantially from 14.33 (12.58-16.08) kPa at 0.5 ml injected volume to 41.56 (39.66-43.45) kPa at the end of the injection. This study demonstrates that the described system allows for real-time continuous monitoring of injection pressure at the needle tip. Moreover, this study shows that injection pressure values measured in the injection line cannot be assumed to be a reliable indicator of the injection pressure at the needle tip.

The ability of a real-time injection pressure monitoring system to discriminate between perineural and intraneural injection of the sciatic nerve in fresh cadavers.

Injection pressure monitoring provides valuable information to prevent intraneural injections and possibly consequent nerve damage during peripheral nerve block. However, the measurement of injection pressure along the injection line is inaccurate as it is influenced by several variables. The aim of this study was to test a new system for precise injection pressure monitoring at the needle tip in a cadaveric model. The system consists of a miniaturised pressure sensor embedded within the needle shaft that is connected via an optical fibre to an external control unit. In order to test the capacity of the system to discriminate between perineural and intraneural injections, a total of 24 ultrasound-guided injections at various locations of the sciatic nerve (12 perineural and 12 intraneural) were performed in fresh cadavers. The injections were delivered at a constant rate by an electronic pump (5 ml saline at 10 ml.min-1 ). Two perineural and two intraneural injections were excluded from analysis, since the operator could not confirm the exact needle-tip location. Mean (SD) peak injection pressure was significantly lower for perineural compared with intraneural injections (14 (6) kPa vs. 131 (56) kPa; p < 0.001). This study shows that this system is a reliable method to accurately monitor injection pressure at the needle tip, allowing for discrimination between perineural and intraneural injections of the sciatic nerve in fresh cadavers.

Influence of surgical bleeding on the relationship between admission coagulopathy and risk of massive transfusion: lesson from 704 severe trauma patients.

BACKGROUND: This study hypothesized that the relationship between early coagulopathy and massive transfusion (MT) in trauma was highly dependent on the presence of surgical bleeding. METHODS: Consecutive severe trauma patients admitted to our institution over a 4-year period were included in this retrospective study. Surgical bleeding was defined as an injury requiring an invasive endovascular or surgical haemostatic procedure. The ability of prothrombin time ratio (PTr) and activated partial thromboplastin time ratio (aPTTr) to predict MT (≥10 units of packed red blood cells during the first 24 h) was determined by ROC curves. The strength of association and interaction between PTr, surgical bleeding and MT was assessed using a logistic regression analysis. RESULTS: Among the 704 patients included (ISS 21·0 ± 16·2), MT rate was higher in patients with surgical bleeding than in those with no surgical bleeding (47% vs. 5%; P < 0·001). The global performance of PTr and aPTTr to predict MT was only fair in our study population (AUCs 0·83 and 0·81). MT rate was widely higher in the surgical bleeding group whatever the severity of coagulopathy (P < 0·001). PTr was found to be significantly associated with TM [PTr ≥ 1·5, OR 23·6 (95% CI 13·4-41·7); PTr 1·2-1·5, OR 3·0 (95% CI 1·7-5·3)]. Corresponding ORs were reduced after adjusting for the surgical bleeding: 12·1 (95% CI 6·5-22·5) and 2·1 (95% CI 1·2-4·0), respectively. However, no significant interaction was found regression models. CONCLUSION: The strength of association between MT and coagulation status on admission was found strongly influenced by surgical bleeding. The admission coagulopathy monitoring in trauma patients without considering the surgical bleeding does not allow a reliable determination of MT probability.

Cerebrospinal fluid volume in neonates undergoing spinal anaesthesia: a descriptive magnetic resonance imaging study.

BACKGROUND: Spinal anaesthesia (SA) reduces the risk of postoperative apnoea after general anaesthesia in neonates. In 30% of patients, however, the duration of anaesthesia provided does not allow completion of surgery. When compared with term infants, formerly preterm neonates experience a shorter duration of anaesthesia after SA. A difference in the cerebrospinal fluid (CSF) volume between those two populations could explain this difference, but this has never been investigated. The study was designed to evaluate the relationship between the spinal CSF volume and patient characteristics in neonates. METHODS: Sixty-seven neonates, aged 30-60 weeks postconception, were included in this study. Their spinal CSF volumes were calculated using magnetic resonance imaging, and these volumes were plotted individually against sex, term at birth, birth weight, current gestational age, civil age, and weight. Correlations between CSF volume and these variables were investigated. RESULTS: Fifty-four neonates completed the study. The CSF volume was found to be closely and linearly correlated with weight and postconceptional age. The relationship between spinal CSF volume and weight can be described as follows: CSF volume (ml)=1.94 weight (kg)+0.13. The CSF volume was not correlated with sex, weight, or term at birth, nor with civil age. CONCLUSIONS: The amount of spinal CSF in neonates can be estimated as 2 ml kg(-1) in both term and formerly preterm neonates. A difference in the CSF volume between them does not provide an explanation for a shorter duration of SA in the latter. Our findings reinforce weight-adjusted dosage of SA in neonates.

Blood pressure monitoring during arrhythmia: agreement between automated brachial cuff and intra-arterial measurements.

BACKGROUND: Since arrhythmia induces irregular pulse waves, it is widely considered to cause flawed oscillometric brachial cuff measurements of blood pressure (BP). However, strong data are lacking. We assessed whether the agreement of oscillometric measurements with intra-arterial measurements is worse during arrhythmia than during regular rhythm. METHODS: Among patients of three intensive care units (ICUs), a prospective comparison of three pairs of intra-arterial and oscillometric BP readings was performed among patients with arrhythmia and an arterial line already present. After each inclusion in the arrhythmia group, one patient with regular rhythm was included as a control. International Organization for Standardization (ISO) standard validation required a mean bias <5 (sd 8) mm Hg. RESULTS: In 135 patients with arrhythmia, the agreement between oscillometric and intra-arterial measurements of systolic, diastolic and mean BP was similar to that observed in 136 patients with regular rhythm: for mean BP, similar mean bias [-0.1 (sd 5.2) and 1.9 (sd 5.9) mm Hg]. In both groups, the ISO standard was satisfied for mean and diastolic BP, but not for systolic BP (sd >10 mm Hg) in our ICU population. The ability of oscillometry to detect hypotension (systolic BP <90 mm Hg or mean BP <65 mm Hg), response to therapy (>10% increase in mean BP after cardiovascular intervention) and hypertension (systolic BP >140 mm Hg) was good and similar during arrhythmia and regular rhythm (respective areas under the receiver operating characteristic curves ranging from 0.89 to 0.96, arrhythmia vs regular rhythm between-group comparisons all associated with P>0.3). CONCLUSIONS: Contrary to widespread belief, arrhythmia did not cause flawed automated brachial cuff measurements.

Difficult intubation in obese patients: incidence, risk factors, and complications in the operating theatre and in intensive care units.

BACKGROUND: Intubation procedure in obese patients is a challenging issue both in the intensive care unit (ICU) and in the operating theatre (OT). The objectives of the study were (i) to compare the incidence of difficult intubation and (ii) its related complications in obese patients admitted to ICU and OT. METHODS: We conducted a multicentre prospective observational cohort study in ICU and OT in obese (BMI≥30 kg m(-2)) patients. The primary endpoint was the incidence of difficult intubation. Secondary endpoints were the risk factors for difficult intubation, the use of difficult airway management techniques, and severe life-threatening complications related to intubation (death, cardiac arrest, severe hypoxaemia, severe cardiovascular collapse). RESULTS: In cohorts of 1400 and 11 035 consecutive patients intubated in ICU and in the OT, 282 (20%) and 2103 (19%) were obese. In obese patients, the incidence of difficult intubation was twice more frequent in ICU than in the OT (16.3% vs 8.2%, P<0.01). In both cohorts, risk factors for difficult intubation were Mallampati score III/IV, obstructive sleep apnoea syndrome, and reduced mobility of cervical spine, while limited mouth opening, severe hypoxaemia, and coma appeared only in ICU. Specific difficult airway management techniques were used in 66 (36%) cases of difficult intubation in obese patients in the OT and in 10 (22%) cases in ICU (P=0.04). Severe life-threatening complications were significantly more frequent in ICU than in the OT (41.1% vs 1.9%, relative risk 21.6, 95% confidence interval 15.4-30.3, P<0.01). CONCLUSIONS: In obese patients, the incidence of difficult intubation was twice more frequent in ICU than in the OT and severe life-threatening complications related to intubation occurred 20-fold more often in ICU. CLINICAL TRIAL REGISTRATION: Current controlled trials. Identifier: NCT01532063.

Intraoperative use of transoesophageal Doppler to predict response to volume expansion in infants and neonates.

BACKGROUND: Volume expansion (VE) in neonates or infants during volatile anaesthesia may lead to fluid overload if inappropriate. Transoesophageal Doppler (TED), a non-invasive cardiac output monitoring technique, can provide a comprehensive estimation of the volaemic status. We evaluated whether intraoperative TED-derived parameters can predict volume responsiveness. METHODS: Neonates and infants under general anaesthesia without myocardial dysfunction were prospectively included when the attending anaesthetist, blinded to TED measurements, decided to provide VE based on clinical appreciation and standard monitoring data. Standard and TED-derived data were recorded before and after VE. After VE, patients were classified as responders and non-responders, if their indexed stroke volume (iSV) increased by more than 15% or not, respectively. The attending anaesthetist assessment of VE responsiveness was recorded at the end of VE. RESULTS: Fifty patients aged 42 (4) post-conceptional weeks were included, among which 26 (52%) were responders. Baseline iSV was the only parameter associated with VE responsiveness. Baseline iSV was fairly correlated with VE-induced changes in iSV (ρ=-0.64) and was associated with an area under the receiver operating characteristic curve of 0.90 (0.80, 0.99). Using a cut-off of 25 ml m(-2), baseline iSV predicted volume responsiveness with a sensitivity of 92% and a specificity of 83%. Attending anaesthetists' assessment of VE effectiveness agreed only moderately with TED measurements of iSV changes. CONCLUSIONS: TED-derived iSV measurement during volatile anaesthesia is useful to predict and follow VE responsiveness in neonates and infants without myocardial dysfunction.

A multicentre observational study of intra-operative ventilatory management during general anaesthesia: tidal volumes and relation to body weight.

We conducted an observational prospective multicenter study to describe the practices of mechanical ventilation, to determine the incidence of use of large intra-operative tidal volumes (≥10 ml.kg(-1) of ideal body weight) and to identify patient factors associated with this practice. Of the 2960 patients studied in 97 anaesthesia units from 49 hospitals, volume controlled mode was the most commonly used (85%). The mean (SD) tidal volume was 533 (82) ml; 7.7 (1.3) ml.kg(-1) (actual weight) and 8.8 (1.4) ml.kg(-1) (ideal body weight)). The lungs of 381 (18%) patients were ventilated with a tidal volume>10 ml.kg(-1) ideal body weight. Being female (OR 5.58 (95% CI 4.20-7.43)) and by logistic regression, underweight (OR 0.06 (95% CI 0.01-0.45)), overweight (OR 1.98 (95% CI 1.49-2.65)), obese (OR 5.02 (95% CI 3.51-7.16)), severely obese (OR 10.12 (95% CI 5.79-17.68)) and morbidly obese (OR 14.49 (95% CI 6.99-30.03)) were the significant (p ≤ 0.005) independent factors for the use of large tidal volumes during anaesthesia.

Population pharmacokinetics of nalbuphine after surgery in children.

BACKGROUND: Nalbuphine is an opioid analgesic agent widely used for control of mild-to-severe pain. However, limited data are available on the pharmacokinetics of this drug in children. The aim of this study was to characterize the population pharmacokinetics of nalbuphine in patients with ages ranging from 1 to 11 yr and to identify patient characteristics partially explaining inter-individual variability in nalbuphine pharmacokinetic parameters. METHODS: Twenty-two children were included in this study. They received nalbuphine after surgery by continuous infusion (loading dose, 0.2 mg kg(-1) over 10 min followed by continuous infusion of 0.8 mg kg(-1) over 24 h). If pain relief was not adequate, 0.1 mg kg(-1) bolus doses were allowed in 10 min. Eleven blood samples were collected per patient. The data were analysed by non-linear mixed-effect modelling with the use of a two-compartment structural model. RESULTS: Twenty patients completed the study. In the final model, the parameter values were standardized for a body weight of 70 kg using an allometric model. Population parameter estimates were: clearance 130 litre h(-1) 70 kg(-1), inter-compartment clearance 75.6 litre h(-1) 70 kg(-1), central volume of distribution 210 litre 70 kg(-1), and peripheral volume of distribution 151 litre 70 kg(-1). In the children of this study, total clearance expressed in litre h(-1) kg(-1) decreased significantly with increasing age and the elimination half-life significantly increased. CONCLUSIONS: The allometric power model developed in this study best reflected the data and may be useful for dose adjustment.

Protracted deep coma after bromazepam poisoning.

BACKGROUND: Bromazepam intoxication is very common but surprisingly rarely reported. CASE DESCRIPTION: We describe the case of a 73-year-old woman who suffered from a prolonged coma after acute self poisoning with bromazepam (serum concentration of 2,000 ng/ml at admission, 2 - 10 hours after ingestion of up to 180 mg) and zolpidem (900 ng/ml at admission). Only the former lasted at toxic concentrations. Recovery of consciousness allowed extubation on Day 16. Repeat-dose activated charcoal (25 g every 6 h from Day 14 to 16) resulted in minimal effects on bromazepam grossly estimated kinetics. CONCLUSION: Despite its relatively low theoretic half-life, bromazepam may induce a prolonged life-threatening coma, even in the absence of renal or hepatic failure.

Population pharmacokinetics of the two enantiomers of tramadol and O-demethyl tramadol after surgery in children.

BACKGROUND: Few data are available on the stereoselective pharmacokinetics of tramadol in children. The aim of this study was to develop a population pharmacokinetic model for the (+)- and (-)-enantiomers of tramadol and its O-demethyl tramadol metabolite (M1) in children. METHODS: Twenty-five children (1-8 yr) were included in this study. Tramadol was administered after surgery by continuous infusion (loading dose, 2 mg kg(-1) i.v. over 10 min followed by continuous infusion of 8 mg kg(-1) over 24 h). If pain relief was inadequate, additional 1 mg kg(-1) i.v. bolus doses of tramadol were given over 10 min. A two-compartment structural model was used with NONMEM. RESULTS: For both enantiomers of tramadol, weight was the only patient characteristic parameter showing significant covariate effects on clearance (CL). CL increased by 5.7-6.1 litre h(-1) between 8-12 and 13-16 kg, and by 2.4-3.3 litre h(-1) between 13-16 and 17-33 kg. The rate constants associated with the metabolite elimination [0.144 h(-1), (+)-M1 and 0.18 h(-1), (-)-M1] were smaller than the elimination rate constants of the parent drugs [0.243 h(-1), (+)-tramadol and 0.241 h(-1), (-)-tramadol], suggesting that the metabolite disposition was rate-limited by its elimination. The presence of two subpopulations of patients was suspected on the basis of the observed bimodal distributions of the AUC(M1)/AUC(tramadol) ratios. CONCLUSIONS: The results of this study combine relationships between tramadol CL and patient covariates that may be useful for dose adjustment. Polymorphism is likely to contribute to the interpatient variability observed in the AUC M1/AUC tramadol ratios.

Avoiding propofol injection pain in children: a prospective, randomized, double-blinded, placebo-controlled study.

BACKGROUND: Pain on injection limits the use of propofol in children. The combination of lidocaine and propofol is widely used to reduce pain. A new solvent [medium-chain triglyceride (mct)/long-chain triglyceride (lct)] has been advocated to be less painful than standard (lct) propofol in adults, but no information is available of its usefulness in pre-school children. We designed a prospective, randomized, double-blinded, placebo-controlled study to assess injection pain with two different propofol emulsions, each given with or without lidocaine in children <7 yr. METHODS: A total of 160 ASA I-III children were randomly assigned to receive lct-propofol or mct/lct-propofol, 5 mg kg(-1), with lidocaine 10 mg ml(-1) or saline. The site and size of venous cannulation and restlessness before injection were recorded in each patient. A pain score graded 0-6 was established based on spontaneous verbal and motor reaction during injection, each graded 0-3. Kruskall-Wallis and Mann-Whitney tests were used for statistical analysis. RESULTS: Median pain scores decreased in all groups compared with lct-propofol-saline (P<0.001) and were least in the lct/mct-propofol-lidocaine group (P<0.001). Painless injection (score, 0-2) occurred in 92.5% of patients in the mct/lct-propofol-lidocaine group compared with 41-77% in the others (P<0.001). CONCLUSIONS: Mct/lct-propofol caused significantly less pain than lct-propofol in preschool children. Mixing of lidocaine with mct/lct-propofol resulted in a further significant decrease, virtually eliminating the pain on injection.

A prospective study on the user-friendliness of four anaesthesia workstations.

BACKGROUND AND OBJECTIVES: Unlike for intensive care unit and home mechanical ventilators, no study has evaluated the user-friendliness of the recently introduced new anaesthesia workstations. METHODS: We performed a prospective study to evaluate the user-friendliness of four anaesthesia workstations, which were categorized into two groups: first-generation (Kion) and second-generation (Avance, Felix and Primus). Twenty users (12 nurse-anaesthetists and 8 anaesthesiologists) from three different anaesthesia departments at the same univeristy hospital participated in the study. The user-friendliness scale evaluated 10 criteria, including two design and monitoring criteria, four maintenance criteria and four ventilation use criteria. Each criterion was evaluated from 0 (poor) to 10 (excellent). RESULTS: The mean score obtained for the first-generation workstation was lower than those obtained for the three second-generation workstations (P < 0.05). No significant differences in the overall user-friendliness score was observed for the three second-generation workstations. The first-generation workstation obtained a significantly lower score than the three second-generation workstations for the design criteria (P < 0.01). For the screen criteria, the highest score was obtained by Felix, which has the largest screen and associated characters. For the main maintenance criteria, Kion and Felix obtained the lowest scores. No significant differences between the four anaesthesia workstations were found for only three of the user-friendliness criteria (self-test, alarms and settings). CONCLUSIONS: Anaesthesia machines have benefited from considerable advances in design and technology. This novel user-friendliness scale revealed that the most recent workstations were more appreciated by users than the first-generation of anaesthesia workstations. This user-friendliness scale may help the anaesthetic staff to 'consensually' choose the future workstation for their anaesthesia department.

How and why to use ultrasound for regional blockade.

The practice of regional anaesthesia will be probably forever changed by the introduction of ultrasonography into everyday clinical practice. The ability to now visualise directly the spread of local anaesthetic solution and its relationship with the nerve allows for immediate adjustments to needle position and/or local anaesthetic volume and spread resulting theoratically in improved block performance through faster onset, reduced local anaesthetic volumes and higher success rates. However, whether US guided blocks will ever replace neurostimulation techniques is debatable especially when regional anaesthesia is performed by specialists in the field.