Xavier Capdevila

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.

Continuous peripheral nerve blocks in hospital wards after orthopedic surgery: a multicenter prospective analysis of the quality of postoperative analgesia and complications in 1,416 patients.

Background:Continuous peripheral nerve block (CPNB) is the technique of choice for postoperative analgesia after painful orthopedic surgery. However, the incidence of neurologic and infectious adverse events in the postoperative period are not well established. This issue was the aim of the study. Methods:Patients scheduled to undergo orthopedic surgery performed with a CPNB were prospectively included during 1 yr in a multicenter study. Efficacy of postoperative analgesia, bacteriologic cultures of the catheter, and acute neurologic and infectious adverse events were evaluated after surgery in 1,416 patients at arrival in the postanesthesia care unit, at hour 1, and every 24 h up to day 5. Risk factors for adverse events were determined using logistic regression. Results:The median duration of CPNB was 56 h. Both general anesthesia and CPNB were performed in 73.6% of the patients. Postoperative analgesia was effective in 96.3%, but an increase in pain scores was noted at hour 24 (P = 0.01). Hypoesthesia or numbness occurred in 3% and 2.2%, respectively, and paresthesia occurred in 1.5%. Three neural lesions (0.21%) were noted after continuous femoral nerve block. Two of these patients were anesthetized during block procedure. Nerve damage completely resolved 36 h to 10 weeks later. Cultures from 28.7% of the catheters were positive. Three percent of patients had local inflammatory signs. The bacterial species most frequently found were coagulase-negative staphylococcus (61%) and gram-negative bacillus (21.6%). A Staphylococcus aureus psoas abscess (0.07%) was reported in one diabetic woman. Independent risk factors for paresthesia/dysesthesia were postoperative monitoring in intensive care, age less than 40 yr, and use of bupivacaine. Risk factors for local inflammation/infection were postoperative monitoring in intensive care, catheter duration greater than 48 h, male sex, and absence of antibiotic prophylaxis. Conclusion:CPNB is an effective technique for postoperative analgesia. Minor incidents and bacterial colonization of catheters are frequent, with no adverse clinical consequences in the large majority of cases. Major neurologic and infectious adverse events are rare.

Clinical practice and risk factors for immediate complications of endotracheal intubation in the intensive care unit : A prospective, multiple-center study

Objectives:To describe the current practice of physicians, to report complications associated with endotracheal intubation (ETI) performed in THE intensive care unit (ICU), and to isolate predictive factors of immediate life-threatening complications. Design:Multiple-center observational study. Setting:Seven intensive care units of two university hospitals. Patients:We evaluated 253 occurrences of ETI in 220 patients. Interventions:From January 1 to June 30, 2003, data related to all ETI performed in ICU were collected. Information regarding patient descriptors, procedures, and immediate complications were analyzed. Measurements and Main Results:The main indications to intubate the trachea were acute respiratory failure, shock, and coma. Some 148 ETIs (59%) were performed by residents. At least one severe complication occurred in 71 ETIs (28%): severe hypoxemia (26%), hemodynamic collapse (25%), and cardiac arrest (2%). The other complications were difficult intubation (12%), cardiac arrhythmia (10%), esophageal intubation (5%), and aspiration (2%). Presence of acute respiratory failure and the presence of shock as an indication for ETI were identified as independent risk factors for occurrence of complications, and ETI performed by a junior physician supervised by a senior (i.e., two operators) was identified as a protective factor for the occurrence of complications. Conclusions:ETI in ICU patients is associated with a high rate of immediate and severe life-threatening complications. Independent risk factors of complication occurrence were presence of acute respiratory failure and presence of shock as an indication for ETI. Further studies should aim to better define protocols for intubation in critically ill patients to make this procedure safer.

Rapidly Progressive Diaphragmatic Weakness and Injury during Mechanical Ventilation in Humans

RATIONALE Diaphragmatic function is a major determinant of the ability to successfully wean patients from mechanical ventilation (MV). Paradoxically, MV itself results in a rapid loss of diaphragmatic strength in animals. However, very little is known about the time course or mechanistic basis for such a phenomenon in humans. OBJECTIVES To determine in a prospective fashion the time course for development of diaphragmatic weakness during MV; and the relationship between MV duration and diaphragmatic injury or atrophy, and the status of candidate cellular pathways implicated in these phenomena. METHODS Airway occlusion pressure (TwPtr) generated by the diaphragm during phrenic nerve stimulation was measured in short-term (0.5 h; n = 6) and long-term (>5 d; n = 6) MV groups. Diaphragmatic biopsies obtained during thoracic surgery (MV for 2-3 h; n = 10) and from brain-dead organ donors (MV for 24-249 h; n = 15) were analyzed for ultrastructural injury, atrophy, and expression of proteolysis-related proteins (ubiquitin, nuclear factor-κB, and calpains). MEASUREMENTS AND MAIN RESULTS TwPtr decreased progressively during MV, with a mean reduction of 32 ± 6% after 6 days. Longer periods of MV were associated with significantly greater ultrastructural fiber injury (26.2 ± 4.8 vs. 4.7 ± 0.6% area), decreased cross-sectional area of muscle fibers (1,904 ± 220 vs. 3,100 ± 329 μm²), an increase of ubiquitinated proteins (+19%), higher expression of p65 nuclear factor-κB (+77%), and greater levels of the calcium-activated proteases calpain-1, -2, and -3 (+104%, +432%, and +266%, respectively) in the diaphragm. CONCLUSIONS Diaphragmatic weakness, injury, and atrophy occur rapidly in critically ill patients during MV, and are significantly correlated with the duration of ventilator support.

Continuous psoas compartment block for postoperative analgesia after total hip arthroplasty: new landmarks, technical guidelines, and clinical evaluation.

A computed tomographic scan was obtained in 35 patients to measure the depth and the relationship of the branches of the lumbar plexus to the posterior superior iliac spine projection and the vertebral column. In addition, we prospectively studied 80 patients scheduled for total hip arthroplasty who received a continuous psoas compartment block (CPCB) in the postoperative period. CPCB was performed after surgical procedures by using modified Winnie’s landmarks and nerve stimulation. From 5 to 8 cm of catheter was inserted. Radiographs were obtained after injection of 10 mL of contrast medium. An initial loading dose (0.4 mL/kg) of 0.2% ropivacaine was injected, followed by continuous infusion of 0.2% ropivacaine for 48 h. The depth of the lumbar plexus and the distance between the lumbar plexus and the L4 transverse process were measured. Visual analog scale values of pain at 1, 12, 24, and 48 h were obtained at rest and during mobilization. Amounts of rescue analgesia were also recorded. Sensory blockade of the principal branches of the lumbosacral plexus was noted at 1 and 24 h, as were adverse events related to the technique. There was a significant difference between men and women in depth of the lumbar plexus (median values, 85 vs 70 mm for men and women, respectively). There was a positive correlation between the body mass index and skin-lumbar plexus distances. In contrast, there was no difference regarding the distance between the transverse process of L4 and the lumbar plexus. The catheter tip lay within the psoas major muscle in 74% of the patients and between the psoas and quadratus lumborum muscles in 22%. In three patients, the catheter was improperly positioned. At 1 h, sensory blockade of the femoral, obturator, and lateral femoral cutaneous nerves was successful in, respectively, 95%, 90%, and 85% of patients. At 24 h, these rates were 88%, 88%, and 83%, respectively. During the 48-h study period, median visual analog scale values of pain were approximately 10 mm at rest and from 18 to 25 mm during physiotherapy. Five patients received 5 mg of morphine at 1 h. Five cases of unilateral epidural anesthesia were noted after the bolus injection. We conclude that CPCB with 0.2% ropivacaine allows optimal analgesia after hip arthroplasty, with few side effects and a small failure rate. Before lumbar plexus branch stimulation and catheter insertion, anesthesiologists should be aware of the L4 transverse process location and lumbar plexus depth.

Voluven, a Lower Substituted Novel Hydroxyethyl Starch (hes 130/0.4), Causes Fewer Effects on Coagulation in Major Orthopedic Surgery than Hes 200/0.5

Hydroxyethyl starch (HES) solutions are effective plasma volume expanders. Impairment of coagulation occurs with large HES volumes infused perioperatively. Therefore, a lower substituted novel HES (Voluven®; Fresenius Kabi, Bad Homburg, Germany) was developed to minimize hemostatic interactions, and was compared with HAES-steril® (Fresenius Kabi) (pentastarch) regarding safety and efficacy. We performed a prospective, randomized, double-blinded study in 100 major orthopedic surgery patients. Because the 95% confidence interval (-330 mL; +284 mL) for the treatment contrast Voluven®-HAES-steril® was entirely included in the predefined equivalence range (± 500 mL), comparable efficacy was established. Voluven® interfered significantly less than HAES-steril® with coagulation factor VIII levels and partial thromboplastin time postoperatively. Total amounts of red blood cells transfused were comparable between the Voluven® and HAES-steril® groups, but a significantly reduced need for homologous red blood cells was observed in the Voluven® group. We conclude that in large-blood–loss surgery, Voluven® has a comparable efficacy with HAES-steril® and may reduce coagulation impairment, possibly leading to a smaller number of allogeneic blood transfusions.

Postoperative analgesia after total-hip arthroplasty: Comparison of intravenous patient-controlled analgesia with morphine and single injection of femoral nerve or psoas compartment block. a prospective, randomized, double-blind study.

Background The authors compared the analgesic effects and quality of rehabilitation of three analgesic techniques after total-hip arthroplasty in a double-blind, randomized trial. Methods Forty-five patients were assigned to 1 of 3 groups, patient-controlled analgesia with morphine (PCA), femoral nerve block (FNB), or psoas compartment block (PCB). At the end of the procedure performed under general anesthesia, nerve blocks using 2 mg/kg of 0.375% bupivacaine and 2 μg/kg of clonidine were performed in the FNB (n = 16) and PCB (n = 15) groups. In the recovery room, all 3 groups received initial intravenous morphine titration if their pain score was higher than 30 on a 100-mm visual analog scale (VAS), and then a PCA device was initiated. Morphine consumption was the primary end point to assess postoperative analgesia. Results After extubation (H0), morphine titration was higher in the PCA group (P < .05). During the first 4 postoperative hours (H0 to H4), morphine consumption per hour and VAS pain score were lower in the PCB group (P < .05). After H4, there was no difference in morphine consumption and VAS among groups, either at rest or during mobilization. After H4, morphine consumption remained lower than 0.5 mg/h, and VAS remained lower than 30 mm in the 3 groups. In 4 patients of the PCB group, an epidural diffusion was noted. Hip mobility and length of stay in the rehabilitation center were not different among the groups. Conclusions PCA is an efficient and safe analgesia technique. FNB and PCB should not be used routinely after total-hip arthroplasty.

Continuous Peripheral Nerve Blocks at Home for Treatment of Recurrent Complex Regional Pain Syndrome I in Children

Background:Recurrent complex regional pain syndrome I is not rare in the pediatric population. The authors conducted this study to evaluate the efficacy of continuous peripheral nerve blocks with elastomeric disposable pumps associated with initial Bier blocks for the treatment of recurrent complex regional pain syndrome I in children. Methods:After parental informed consent, 13 children who did not respond to conventional complex regional pain syndrome treatment were included (mean age, 13 yr; range, 9–16 yr). After general anesthesia, peripheral nerve block was performed using 0.5 ml/kg lidocaine, 1%, with epinephrine and 0.5% ropivacaine injected in the peripheral nerve block catheter. Then, a 20-min Bier block was performed using a tourniquet and 0.2 ml/kg lidocaine, 1%; 3 ml/kg hydroxyethyl starch 130/06; and 5 mg/kg buflomedil injected intravenously. A solution of 0.1 ml · kg−1 · h−1 continuous ropivacaine, 0.2%, was infused through the catheter using an elastomeric pump for 96 h. Need for rescue analgesia, occurrence of side effects, and status of motor and sensory block were recorded at hours 1, 6, 12, 24, 48, 72, and 96. Children and parents completed a satisfaction assessment. All of the children had follow-up visits after 2 months. Results:Postoperative analgesia was excellent. The median pain score was 0 for each period studied. Motor blockade was minimal before 12 h (median, 1) and absent thereafter. One child needed rescue analgesia. All children were able to walk easily after the initial 24-h period (walking score, > 4). Children and parents were all satisfied. Children returned home under parental surveillance beginning in the 24th hour. Neither peripheral nerve block nor Bier block caused side effects. After 2 months, none of the children exhibited any clinical symptom of recurrent complex regional pain syndrome. Conclusion:Ambulatory continuous peripheral nerve block associated with an initial Bier block seems to be a significant and novel contribution to treat recurrent pediatric complex regional pain syndrome I. It allows complete pain relief, early mobilization, and rapid return home, representing a psychological advantage for these children.

Continuous three-in-one block for postoperative pain after lower limb orthopedic surgery: where do the catheters go?

Continuous three-in-one block is widely used for postoperative analgesia after proximal lower limb surgery, but location of the catheter has not been well addressed in the literature. We prospectively studied, in 100 patients, the characteristics of catheter threading under the iliac fascia and the correlations between catheter tip location and effective sensory and motor blockade of the three principal nerves of the lumbar plexus. Postoperatively, in conscious patients, 16 to 20 cm of a catheter was placed in the fascial sheath after femoral nerve location with a nerve stimulator. Contrast media (3 mL Iopamidol 390®) was injected, and the catheter tip was located by means of an anteroposterior pelvic radiograph. An equal-volume mixture of 0.5% bupivacaine/2% lidocaine with epinephrine (30 mL) was injected through the catheter. Patient and catheter-insertion characteristics were noted. Thirty minutes after injection, sensory blockade was evaluated in the cutaneous territories of the lateral femoral cutaneous, femoral, and obturator nerves, along with motor blockade of the last two nerves. Pain scores at 30 min were also recorded. Seven block failures were noted. The tip of the catheter reached the lumbar plexus (Group 1) in 23% of the patients and lay deep to the medial (Group 2) or lateral (Group 3) part of the fascia iliaca in 33% and 37% of the patients, respectively. Demographic data and catheter threading characteristics were comparable among the groups. A three-in-one block was noted in 91% of Group 1 patients, but in only 52% and 27% of Group 2 and 3 patients, respectively (P < 0.05). Comparing Group 2 and 3 patients, sensory block was achieved in respectively 100% and 94% for the femoral nerve, 52% and 94% for the lateral femoral cutaneous nerve (P < 0.05), and 82% and 27% for the obturator nerve (P < 0.05). Visual analog scale pain scores on movement were significantly lower in Group 1 patients (P < 0.05). We conclude that during a continuous three-in-one block, the threaded catheter rarely reached the lumbar plexus. The quality of sensory and motor blockade and initial pain relief depend on the location of the catheter tip under the fascia iliaca.

Infectious risk of continuous peripheral nerve blocks.

CONTINUOUS peripheral nerve block (CPNB) techniques continue to be increasingly used. CPNB catheter infection is an issue that has received little attention to date. The frequency of infection associated with peripheral nerve catheters remains poorly defined. Although the risk of infection during CPNB is a major issue, the published literature has mainly focused on the conflicting evidence of the frequency of infectious complications associated with epidural anesthesia. Recent studies show that between 23 and 57% of peripheral nerve catheters may become colonized, with 0–3% resulting in localized infection. Severe infectious complications recently reported in the literature include psoas abscess complicating continuous femoral nerve blocks, axillary abscess and necrotizing fasciitis after continuous and single shot axillary nerve blocks, and thigh and interscalene abscesses after continuous popliteal sciatic and interscalene nerve blocks, respectively (table 1). An exogenous source of contamination is frequently suspected. The most frequently detected microorganism on the skin surface and in colonized catheter is Staphylococcus epidermidis, whereas Staphylococcus aureus is mainly reported in infections or abscess formation. Several risk factors, including appropriate patient selection (intensive care unit or trauma patients), catheter site insertion, prophylactic antibiotic use, local anesthetic solution contamination, and catheter duration, have been suspected to modify the risk of infection related to CPNB. The current recommendations to control infectious complications associated with CPNB are based on existing literature and guidelines for the prevention of epidural or intravascular catheter-related infection. The American Society for Regional Anesthesia and Pain Medicine guidelines on this topic have been published in Regional Anesthesia and Pain Medicine. These recommendations highlighted the importance of asepsis during regional anesthesia needle and catheter insertion, including handwashing, use of protective barriers (mask, gloves, gowns, and drapes), and skin disinfectants. The role of subcutaneous tunneling and of bacterial filters is still controversial. Guidelines for practice improvement must be built according to specific actual risk applied to each procedure and certainly cannot be extrapolated without some restrictions. CPNBs are increasing in popularity, and the incidence of infection associated with CPNB is thankfully rare. However, infectious complications will become undoubtedly more common. This review is to tell the reader what is actually known about risk factors specific to CPNBs.