Enhanced visual acuity with echogenic needles in ultrasound-guided axillary brachial plexus block: a randomized, comparative, observer-blinded study.

BACKGROUND: We prospectively evaluated the effect of insertion angle on the visibility of echogenic and nonechogenic needles in phantoms and in axillary nerve blocks in patients. METHODS: Conventional and echogenic needles were studied in phantoms at insertion angles of 0-30°, 30-45°, and ≥ 45°. Operators rated comfort and image quality during the procedure and experts blinded to the needle groups randomly analyzed videos for tip and shaft visibility, surrounding tissue visibility, sharpness of the needle surface, and percentage of time with the needle completely visible. Patients scheduled for axillary nerve block were prospectively enrolled in the clinical study. Needle insertion angles were 0-30° for the median nerve approach, 30-45° for the radial nerve, and ≥ 45° for the musculocutaneous nerve. The same needle parameters were analyzed during the procedure and on videos. RESULTS: Physician comfort and image quality were significantly better for echogenic needles for phantoms and patients at 30-45° and ≥ 45° insertion angles. Needle tip and shaft visibility at 30-45° and ≥ 45° insertion angles in phantoms and for the musculocutaneous nerve in patients were significantly improved, as well as the percentage with complete needle visualization during the procedure. Tissue visibility and needle sharpness were significantly superior for conventional needles. There were no differences concerning block parameters and adverse events. CONCLUSION: Needles with enhanced echogenicity improved physician comfort, image quality, needle visibility, and visualization time of the needle during ultrasound-guided procedures in phantoms and axillary nerve blocks using insertion angles of 30-45° and ≥ 45°.

[Appropriate medication prescribing in older people]. / Bon usage des médicaments chez le sujet âgé.

Drug-induced adverse effects are one of the main avoidable causes of hospitalization in older people. Numerous lists of potentially inappropriate medications for older people have been published, as national and international guidelines for appropriate prescribing in numerous diseases and for different age categories. The present review describes the general rules for an appropriate prescribing in older people and summarizes, for the main conditions encountered in older people, medications that are too often under-prescribed, the precautions of use of the main drugs that induce adverse effects, and drugs for which the benefit to risk ratio is unfavourable in older people. All these data are assembled in educational tables designed to be printed in a practical pocket format and used in daily practice by prescribers, whether physicians, surgeons or pharmacists.

Bilateral continuous 3-in-1 nerve blockade for postoperative pain relief after bilateral femoral shaft surgery.

We tested the effectiveness of bilateral continuous paravascular femoral nerve blocks in a patient following bilateral femoral shaft surgery in whom other analgesic regimens were considered contraindicated or of limited effectiveness. Bilateral continuous femoral paravascular nerve blocks were performed using a previously described technique. General anesthesia was subsequently used to facilitate surgery, which was a bilateral osteosynthesis using dynamic hip screws for osteolytic metastases of the proximal extremities of both femurs. A continuous infusion of lidocaine, morphine, and clonidine was established in both femoral catheters preoperatively and used postoperatively as the principle source of analgesia. Radiographic contrast was used to document the position of both catheters and to document the spread of injectate. Visual analog scale (VAS) pain scores were recorded in the recovery room and at 4, 16, 24, 48, and 72 hours postoperatively. Plasma lidocaine levels were determined by gas chromatography at 4, 16, and 48 hours postoperatively. Sensory assessment in the distribution of the femoral, lateral cutaneous, and obturator nerves was performed to confirm the presence of sensory blockade. We successfully provided analgesia with bilateral continuous femoral paravascular nerve blocks. Pain scores at rest were consistently rated good to excellent (VAS < 20 mm). Evidence of sensory conduction block was present throughout the infusion. Plasma concentrations of lidocaine were consistently below toxic levels (1.35 to 1.65 micrograms/ml). Radiographic contrast studies failed to demonstrate movement of contrast to the level of the lumbar plexus. Bilateral continuous femoral paravascular nerve blocks can be used to provide effective and safe analgesia in patients requiring aggressive analgesia in whom other techniques may be contraindicated.

[Postoperative analgesia. Specificity in the elderly]. / Analgésie postopératoire. Spécificités du sujet âgé.

The necessity of an adapted, optimal postoperative analgesia in the elderly is widely recognised. Reduced physiological capacities must be taken into consideration during the perioperative period. Class I analgesics, such as paracetamol, are both safe and efficient, and can be used for basic analgesia. Non steroid anti-inflammatory drugs carry an increased iatrogenic risk in the elderly. Their benefits should always be considered with regard to their risk. Their dosage should be decreased by 40-60% in comparison to the standard adult doses. Opioids, though highly efficient, carry a higher risk of respiratory depression due to the increased sensitivity to this class of molecules in the elderly. Doses must be reduced by 50% of the standard adult dose in order to limit adverse events while maintaining an equivalent level of analgesia. Patient-controlled and spinal opioid analgesia can be used in elderly patients. However surveillance of both the state of consciousness and respiratory rate must be carried out hourly over a period ranging from 12 to 24 hours. Pulse oximetry can be of value. After orthopaedic surgery, perineural or peripheral analgesia should be favoured considering the excellent benefit-risk ratio. Close clinical monitoring is essential for providing safe and efficient analgesia in the elderly using the techniques currently at our disposal.

[Incidence and etiology of cardiac arrest occurring during the peroperative period and in the recovery room. Apropos of 102,468 anesthesia cases]. / Fréquence et cause des arrêts cardiaques peropératoires et en salle de réveil. A propos de 102,468 anesthésies.

This study reviewed retrospectively 186 cardiac arrests (CA) observed in a series of 102,468 anaesthetics, carried out in a University Hospital between 1983 and 1987. Among them 29 were partly or totally related to anaesthesia and 11 had a fatal outcome. On the other hand, 157 CA (144 deaths) were not related to anaesthesia. Mortality rate due to anaesthesia was therefore 1.1 per 10,000. The main causes of anaesthesia related CA were overdosage, with or without hypovolaemia (9 CA, 6 of which occurred under regional anaesthesia); hypoxaemia (6 CA, 5 of which occurred under regional anaesthesia) and multifactorial sudden cardiac arrest (n = 8). The other aetiologies were: myocardial ischaemia (n = 3); anaphylactic shock due to propanidid (n = 1); protamine accident (n = 1); ventricular arrhythmia due to hypokalemia (n = 1). Fourteen CA occurred during induction (2 deaths), 14 during maintenance (8 deaths), and one during recovery. Risk factors for CA included a high ASA class, and the type of anaesthesia: there were 8 CA for 12,981 regional anaesthetics, and 21 for 89,487 general anaesthetics (p = 0.017). Emergency and paediatric anaesthesia were not risk factors. Outcome was independent of ASA class, but was related to aetiology: hypoxaemia (5 out of 6 recovered) and overdose with or without hypovolaemia (7 out of 8 recovered) had favourable outcomes. Furthermore, outcome of CA due to regional anaesthesia was satisfactory (7/8 recovered) (p = 0.08, NS). Such an analysis of the causes of anaesthetic disasters and their rate of occurrence can lead to more effective prevention.

[Continuous analgesia with a femoral catheter: plexus or femoral block?]. / Analgésie continue par cathéter fémoral: bloc plexique ou bloc tronculaire fémoral?

OBJECTIVE: To evaluate the spread and quality of sensitive blockade produced by continuous and prolonged use of a femoral catheter inserted for postoperative analgesia. STUDY DESIGN: Prospective non comparative evaluation. PATIENTS: The study included 20 consecutive patients undergoing major knee surgery with postoperative analgesia obtained with a femoral catheter, a technique commonly used in our department. METHODS: Regional analgesia was induced after surgery with a bolus injection of 30 mL of 2% lidocaine with 1:200,000 epinephrine 1 in 200,000, maintained by continuous infusion of 1% lidocaine + morphine 0.03 mg.mL-1 + clonidine 2 micrograms.mL-1 for 48 h. The infusion rate was 0.1 mL.kg-1.h-1. The evaluation was based on: 1) the quality of analgesia at rest, at 30 min, h1, h3, h6, h12, h24 and h48; 2) the sensitive and motor blockade at the same time intervals. RESULTS: A "3 in 1" block was only observed in 50% of patients after the initial bolus via the femoral catheter. During the maintenance of analgesia with a continuous infusion a blockade of the three main nerves of the lumbar plexus occurred in less than 20% of patients after 6 h and was limited to the territory of the femoral nerve in 45 to 50% of patients after 12 to 48 h. In all cases the median values of VAS were below 42 mm. CONCLUSION: In most patients, a local anaesthetic administered continuously via a femoral catheter produces a blockade limited to the femoral nerve. These data do not substantiate the conclusions by those who consider they are producing a continuous "3 in 1" block with this technique. However, it is obviously not essential to produce a sensitive blockade of the three main nerves of the lumbar plexus to obtain an effective analgesia after knee surgery.

[Strategy of postoperative rehabilitation after femoral neck fracture in elderly patients]. / Stratégie de réhabilitation postopératoire de la fracture du col fémoral.

The femoral neck fracture in elderly patient is an entity that is within the scope of "disease causing a femoral neck fracture". The specific factors for successful management of these elderly patients are centered around patient's comorbidities, specific management in a clinical pathway, and more or less early rehabilitation after surgery. The type of fracture, surgery, specific treatment, early active recovery for the patients lying in bed after surgery optimize the functional outcome at mean term. The improvement of nutritional status, equilibrium for comorbidities and early rehabilitation with walking activities and physiotherapy significantly improve functional outcome at short and medium terms and postoperative mortality. The use of multimodal analgesia and regional analgesia primarily by perioperative continuous femoral nerve blocks also improve the medical prognosis and functional outcome of the patient.

Aprotinin decreases blood loss and homologous transfusions in patients undergoing major orthopedic surgery.

BACKGROUND: Major orthopedic surgery can be associated with dramatic blood loss, thereby requiring high-volume homologous transfusions in patients unable to benefit from blood salvage techniques. The effect of aprotinin on blood loss and transfusion requirements during orthopedic surgery for either the resection of malignancies of the removal of infected hardware was prospectively studied. METHODS: Twenty-three patients scheduled for orthopedic surgery of the hip, femur, or pelvis for sepsis or malignant tumors, all under general anesthesia, were randomly allocated to receive during operation, in a blinded manner, either aprotinin administered as a bolus of 1.106 kallikrein inactivation units (KIU) followed by an infusion of 5 x 10(5) KIU/h, or the equivalent volume of saline. The anesthesia and perioperative management, as well as the designated transfusion criteria, were standardized. The total blood loss of each patient was evaluated using intraoperative suction losses, sponge weights, and postoperative volumetric drainage. Homologous transfusion requirements were noted. Hemoglobin and hematocrit measures, as well as coagulation and fibrinolytic pathway explorations, were performed before and after surgery. Deep venous thrombosis prophylaxis was applied, and the incidence of this complication was assessed. RESULTS: Twelve patients received aprotinin. Aprotinin reduced the total blood loss from a median of 5,305 ml (range, 3,000-9,770 ml) to a median of 1,783 ml (range, 1,140-4,955 ml; P < 0.05). A blood loss reduction of 56% during surgery and 68% on discharge from the postanesthesia care unit was observed. Seven units (range, 4-16) of packed erythrocytes were transfused per patient in the placebo group, and 3 (range, 2-5) were transfused in the aprotinin group (P < 0.05). In the aprotinin group, platelet counts were higher, and postoperative prothrombin times and D. Dimer values were lower. The activated partial thromboplastin time values showed no significant difference between the two groups. No side effects were observed in the aprotinin group. A deep venous thrombosis developed in one patient in the placebo group. CONCLUSION: Aprotinin treatment during major orthopedic surgery significantly reduces both blood loss and consequent homologous blood transfusion requirements.

Haemodynamic effects of moderate normovolaemic haemodilution in conscious and anaesthetized patients.

We have assessed the haemodynamic effects of moderate normovolaemic haemodilution in ASA I patients, either conscious or during enflurane-fentanyl anaesthesia (10 patients in each group). Cardiac index (CI), stroke index (SI) and ejection fraction (EF) were measured by transthoracic electrical bioimpedance and, in the anaesthesia group, arterial and central venous blood samples were obtained to assess oxygen delivery (DO2), oxygen consumption (VO2) and oxygen extraction ratio (O2ER). In conscious patients, heart rate (HR) remained unchanged as SI, EF and CI increased. When haemodilution was performed during anaesthesia, CI remained stable in spite of a slight increase in SI, as HR decreased. This produced a reduction in DO2 which was compensated for by an increase in O2ER, allowing maintenance of VO2 without alteration in blood lactate concentration.

Causes and prediction of maldistribution during continuous spinal anesthesia with isobaric or hyperbaric bupivacaine.

BACKGROUND: Many cases of cauda equina syndrome after maldistribution of local anesthetics during continuous spinal anesthesia have been reported. In experiments, a caudad route of catheter travel and the use of hyperbaric agents have been shown to induce these limited blocks. The aim of this clinical study was to verify this hypothesis and seek a predictive factor for the maldistribution of bupivacaine. METHOD: Continuous spinal anesthesia via a 19-gauge end port spinal catheter was performed in 80 elderly patients randomly assigned to receive either isobaric or hyperbaric solutions. Successive injections of 2.5 mg bupivacaine were performed at 5-min intervals until a sensory level at or cranial to T8 was obtained. Maldistribution was defined by a sensory level caudal to T12 despite a total dose of 17.5 mg of either isobaric or hyperbaric bupivacaine. After surgery, all catheters were injected with contrast media and examined radiographically. RESULTS: The frequency of maldistribution was not significantly different in the isobaric and hyperbaric groups. A caudally oriented catheter tip was found to be a major cause of maldistribution (P < 10(-5)). A thoracic sensory level could be reached in all patients presenting a limited block by simply changing the baricity of the bupivacaine, the position of the patient, or both. The sensory level obtained 10 min after the first injection of 2.5 mg isobaric or hyperbaric bupivacaine was found to be a predictive factor of maldistribution. CONCLUSIONS: Hyperbaric solutions do not appear to be a clinical factor in the development of limited block. The principle factor causing the maldistribution of bupivacaine is the caudal orientation of the tip of the end-hole catheter rather than its level or the route of catheter travel.

Effects of perioperative analgesic technique on the surgical outcome and duration of rehabilitation after major knee surgery.

BACKGROUND: Continuous passive motion after major knee surgery optimizes the functional prognosis but causes severe pain. The authors tested the hypothesis that postoperative analgesic techniques influence surgical outcome and the duration of convalescence. METHODS: Before standardized general anesthesia, 56 adult scheduled for major knee surgery were randomly assigned to one of three groups, each to receive a different postoperative analgesic technique for 72 h: continuous epidural infusion, continuous femoral block, or intravenous patient-controlled morphine (dose, 1 mg; lockout interval, 7 min; maximum dose, 30 mg/4 h). The first two techniques were performed using a solution of 1% lidocaine, 0.03 mg/ml morphine, and 2 microg/ml clonidine administered at 0.1 ml x kg(-1) x h(-1). Pain was assessed at rest and during continuous passive motion using a visual analog scale. The early postoperative maximal amplitude of knee flexion was measured during continuous passive motion at 24 h and 48 h and compared with the target levels prescribed by the surgeon. To evaluate functional outcome, the maximal amplitudes were measured again on postoperative day 5, at hospital discharge (day 7), and at 1- and 3-month follow-up examinations. When the patients left the surgical ward, they were admitted to a rehabilitation center, where their length of stay depended on prospectively determined discharge criteria RESULTS: The continuous epidural infusion and continuous femoral block groups showed significantly lower visual analog scale scores at rest and during continuous passive motion compared with the patient-controlled morphine group. The early postoperative knee mobilization levels in both continuous epidural infusion and continuous femoral block groups were significantly closer to the target levels prescribed by the surgeon than in the patient-controlled morphine group. On postoperative day 7, these values were 90 degrees (60-100 degrees)(median and 25th-75th percentiles) in the continuous epidural infusion group, 90 degrees (60-100 degrees) in the continuous femoral block group, and 80 degrees (60-100 degrees) in the patient-controlled morphine group (P < 0.05). The durations of stay in the rehabilitation center were significantly shorter: 37 days (range, 30-45 days) in the continuous epidural infusion group, 40 days (range, 31-60 days) in the continuous femoral block group, and 50 days (range, 30-80 days) in the patient-controlled morphine group (P < 0.05). Side effects were encountered more frequently in the continuous epidural infusion group. CONCLUSION: Regional analgesic techniques improve early rehabilitation after major knee surgery by effectively controlling pain during continuous passive motion, thereby hastening convalescence.

Fatal and non fatal cardiac arrests related to anesthesia.

PURPOSE: The aim of this study was to assess the incidence and causes of cardiac arrests related to anesthesia. METHODS: All patients undergoing anesthesia over a six year period were included in a prospective study. The cardiac arrests encountered during anesthesia and the first twelve postoperative hours in the PACU or ICU were analysed. For each arrest, partially or totally related to anesthesia, the sequence of events leading to the accident was evaluated. RESULTS: Eleven cardiac arrests related to anesthesia were identified among the 101,769 anesthetic procedures (frequency: 1.1/10,000 [0.44-1.72]). Mortality related to anesthesia was 0.6/10,000 [0.12-1.06]. Age over 84 yr and an ASA physical status > 2 were found to be risk factors of cardiac arrest related to anesthesia. The main causes of anesthesia related cardiac arrest were anesthetic overdose (four cases), hypovolemia (two cases) and hypoxemia due to difficult tracheal intubation (two cases). No cardiac arrests due to alveolar hypoventilation were noted during the postoperative periods in either PACU or ICU. At least one human error was noted in ten of the eleven cardiac arrests cases, due to poor preoperative evaluation in seven. All cardiac arrests totally related to anesthesia were classified as avoidable. CONCLUSION: Efforts must be directed towards improving preoperative patient evaluation. Anesthetic induction doses should be titrated in all ASA 3 and 4 patients. The prediction of difficult tracheal intubation, and if required, the use of awake tracheal intubation techniques, should remain a priority when performing general anesthesia.

Continuous spinal anesthesia: does low-dose plain or hyperbaric bupivacaine allow the performance of hip surgery in the elderly?

OBJECTIVES: This study was designed to assess the predictability of 5 mg bupivacaine to give a T10 sensory level when injected subarachnoid in elderly patients. METHODS: Sixty-five patients aged 75 years or more, scheduled to undergo elective hip surgery, participated in the study. Patients were randomized to receive either 5 mg plain bupivacaine without epinephrine (isobaric group), or 5 mg hyperbaric bupivacaine (hyperbaric group). A 19-gauge catheter was inserted at the L3-4 interspace and threaded 4 cm cephalad in the subarachnoid space. Patients were placed in supine horizontal position and sensory level was assessed every 5 minutes over 20 minutes. Increments of 2.5 mg bupivacaine were given when sensory level did not reach T10 at the 20th minute. RESULTS: After 20 minutes, the mean sensory level was T8.8 +/- 3.2 in the isobaric group and T7.2 +/- 4.3 in the hyperbaric group without significant difference. Hypotension, defined as greater than a 25% drop in mean arterial pressure, was not significantly different in the two groups: 37.5% and 42.4%, respectively. However, patients who developed hypotension were older (84.3 +/- 7.8 years) than the others (80.3 +/- 5.9 years), and cephalad spread of sensory anesthesia was higher in patients who developed a hypotension (T5.3 +/- 1.4 versus T9.5 +/- 4). In each group, sensory levels did not reach T10 in five patients after initial dose. Five had a sensory block that was too low in spite of incremental doses with the patient in the horizontal position. For the last three, an unintentional sacral placement of the catheter was proved radiologically. CONCLUSIONS: The authors conclude that 5 mg bupivacaine is too high a dose in the elderly to limit the sensory blockade at T10 and avoid hypotension. In elderly patients, this dose allowed surgery to be performed, provided that the sensory level reached T10. When the initial dose only affects lumbar dermatomes, a caudal direction of the catheter must be evoked, and changing position must be preferred to incremental injections to reach thoracic levels.