F. Remérand

The early and delayed analgesic effects of ketamine after total hip arthroplasty: a prospective, randomized, controlled, double-blind study.

BACKGROUND: Ketamine has been shown to have a morphine-sparing effect soon after surgery. Nevertheless, whether this effect still exists after being combined with nonsteroidal antiinflammatory drugs and acetaminophen, and whether ketamine can decrease chronic pain after nononcologic surgery remain unclear. Thus, we designed a study to assess ketamine’s effect on acute and chronic postoperative pain when combined with multimodal analgesia after total hip arthroplasty (THA). METHODS: Patients scheduled for primary nononcologic THA using standardized general anesthesia were randomized. They received IV ketamine before incision (0.5 mg/kg), and a 24-h infusion (2 &mgr;g · kg−1 · min−1) or a similar blinded saline bolus and infusion. Postoperative analgesia included IV acetaminophen, ketoprofen, plus morphine/droperidol patient-controlled analgesia for 48 h. Data pertaining to pain scores, morphine consumption, and need for crutches were collected for 6 mo after THA. Our primary outcome was 24-h morphine consumption. RESULTS: One hundred fifty-four patients were included (placebo, 75; ketamine, 79). Patients and operative data were similar in both groups. Ketamine decreased morphine consumption at 24 h from 19 ± 12 mg to 14 ± 13 mg (P = 0.004). At Day 30, ketamine decreased the proportion of patients needing 2 crutches or a walking frame from 56% to 31% (P = 0.0035). From Day 30 to Day 180, ketamine decreased the proportion of patients with persistent pain at rest in the operated hip (P = 0.008). At Day 180, 21% of placebo group patients (15 of 70) experienced pain at rest in the operated hip versus 8% (6 of 72) in the ketamine group (P = 0.036, odds ratio 0.33, 95% confidence interval 0.12–0.91, risk reduction 67%). CONCLUSIONS: Ketamine had a morphine-sparing effect after THA, even when morphine was combined with multimodal systemic analgesia. It also facilitated rehabilitation at 1 mo and decreased postoperative chronic pain up to 6 mo after surgery.

Elastomeric pump reliability in postoperative regional anesthesia: a survey of 430 consecutive devices.

BACKGROUND:Postoperative analgesia via continuous perineural infusion of local anesthetics compares favorably with systemic analgesia. Elastomeric pumps increase patient satisfaction compared with electronic models. In in vitro investigations, infusions remained within 15% of their designated set rates. We assessed in vivo the infusion rate of elastomeric pumps in regional analgesia after orthopedic surgery. METHODS:All consecutive elastomeric pumps were retrospectively studied during a 10-mo period. Perineural catheters were inserted preoperatively and connected postoperatively to elastomeric pumps filled with ropivacaine 0.2%. Before infusion, elastomeric pumps and ropivacaine were stored at room temperature. Two models of pumps were randomly used: Infusor™ LV5 (Baxter, France) or Easypump™ (Braun, Germany), both set at 5 mL/h. Nurses weighed the devices at the bedside using a portable electronic scale several times a day until catheter removal. Weights over time allowed accurate deflation profile assessment and flow rate calculation. An unchanged weight over time indicated either an obstructed catheter or an ineffective device. RESULTS:After connection to the catheter, 88 devices did not deflate (80 Easypump of 300 and 8 Infusor of 130, P < 0.0001). One Easypump was impossible to deflate, even after disconnection from its catheter. In two cases, catheters were obstructed. In 21 cases, catheters were removed 11 to 72 h later without being tested for patency. In 24 cases, pumps correctly deflated after catheters were injected without difficulty with a local anesthetic bolus. The remaining 40 devices spontaneously started to deflate 6 to 43 h after their connection. These 88 elastomeric pumps were associated with higher maximal visual analog scale scores during the first postoperative night than devices showing immediate deflation after connection (34 ± 21 mm vs 26 ± 19 mm, P = 0.006). Flow rates were calculated over a mean period of 54 ± 18 h (Easypump) and 49 ± 19 h (Infusor). The flow rates differed from those set by manufacturers (5 mL/h ± 15%) in 47% of Easypump and in 34% of Infusor devices (P = 0.01). CONCLUSIONS:In vivo reliability of elastomeric pumps is different than in vitro. In the event of early insufficient postoperative perineural analgesia, an absence of deflation of the elastomeric pump must be considered. We recommend weighing these devices every 3 h during the first 24 h of infusion.

Is the musculocutaneous nerve really in the coracobrachialis muscle when performing an axillary block? An ultrasound study.

BACKGROUND: In reference textbooks describing axillary block, the ulnar, radial, and median nerves are located in a common sheath surrounding the axillary artery. In contrast, the musculocutaneous nerve is described as lying outside this sheath in the coracobrachialis muscle. In a recent case report of ultrasound-guided axillary block, the musculocutaneous nerve was joined to the median nerve outside this muscle. Our study evaluated the prevalence of atypical musculocutaneous nerve localizations during axillary block. METHODS: All patients undergoing ultrasound-guided axillary block were included from December 2006 to December 2008. Before needle insertion, musculocutaneous, median, ulnar, and radial nerves were localized using ultrasound. Nerve stimulation confirmed atypical nerve localization. After injection of local anesthetics, musculocutaneous and median nerve anatomical relationships were observed. RESULTS: The musculocutaneous nerve was outside the coracobrachialis muscle in 83 of the 387 analyzed blocks (22%). It was near the axillary artery in 22 cases (6%). The musculocutaneous and median nerves appeared as a common neural structure in 61 cases (16%). After local anesthetic injection, a common trunk persisted in 16 of 61 cases (26%), musculocutaneous and median nerves separated in 37 cases (61%), and 2 roots of the median nerve appeared (with or without a separated musculocutaneous nerve) in 6 cases (10%). Two cases (3%) remained undefined. Ulnar nerve location of the 83 patients with atypical musculocutaneous nerve position differed from the ones with a classical musculocutaneous nerve localization. CONCLUSIONS: During axillary block, the musculocutaneous nerve is outside the coracobrachialis muscle in 1 of 5 patients. This atypical location should be considered during performance of axillary blockade to avoid repeated IM puncture.

Prévenir les hallucinations aiguës associées à la perfusion intraveineuse continue de kétamine

OBJECTIVE Continuous low dose infusion of intravenous ketamine for postoperative analgesia was often associated with frightening acute psychodysleptic experiences in our patients. We hypothesized they were due to boluses of ketamine accumulated in the infusion line. We evaluated on two successive groups the impact of perfusion line modifications on psychodysleptic side effects occurrence. METHODS We compared a reference historic group (in which ketamine line was connected to perfusion line) to a second prospective group (in which ketamine line was connected to the venous catheter via an unidirectional valve). RESULTS Psychodysleptic experiences occurrence decreased from 4 patients of 26 (15%) to 2 of 116 (2%, p = 0.01). Moreover, these experiences were no longer associated with severe anxious symptoms like near death experiences. CONCLUSION An unidirectional valve must be considered to limit the occurrence of low dose intravenous ketamine infusion associated psychedelic side effects, during postoperative analgesia.

Mandibular nerve block can improve intraoperative inferior alveolar nerve visualization during sagittal split mandibular osteotomy

INTRODUCTION The main procedure specific complication of sagittal split osteotomy of the mandibular ramus (SSOMR) is inferior alveolar nerve (IAN) injury. This can be produced by poor intraoperative visibility of the IAN due to bone bleeding. In our centre, mandibular nerve blocks (MNBs) are usually performed for intra- and post-operative analgesia. We observed that MNB seems to decrease intraoperative bleeding and thus to improve IAN visibility. Our study was performed to evaluate the effect of MNB on intraoperative bleeding during SSOMR and, secondarily, on the duration of this procedure. MATERIAL AND METHODS Patients scheduled for bilateral SSOMR under general anaesthesia were prospectively randomized into two groups. The Block group received bilateral MNB (5 mL ropivacaine 0.5% for each block) and the Control group sham MNBs (bilateral cutaneous puncture, without block). The operations were carried out under a standardised general anaesthetic. Post-operatively, the surgeon, blinded to group allocation, assessed intraoperative bone bleeding using a Numerical Rating Scale (NRS) (0: no bleeding, perfect visibility to 100: major bleeding, no visibility). Osteotomy duration, intraoperative anaesthetic requirements, and pain score in the recovery room were also recorded. Results are expressed as median [25-75th percentiles]. RESULTS Nineteen patients were included in each group. Osteotomy under MNB had a decreased intraoperative bone bleeding score compared with controls (20 [0-40] versus 55 [20-80], p=0.0002). They had a dry surgical field more frequently (29% versus 5%, p=0.01), and a shorter mean time for the osteotomy (15 [12.25-17.75] versus 17.5 [15-21]min, p=0.009). Block patients had reduced intraoperative opioid consumption (770 [678-1430] versus 2310 [1908-3058]mcg of remifentanil, p=0.0001), and lower pain scores in the recovery room (0 [0-2] versus 3 [1-5], p=0.12). CONCLUSION MNB decreases intraoperative bone bleeding during SSOMR under general anaesthesia. Three hypotheses to explain this result are discussed.

Balance bénéfique risque de la prégabaline en périopératoire : revue systématique de la littérature

OBJECTIVE Perioperative gabapentine administration improves analgesia, reduces postoperative nausea and vomiting, but increases sedation. Pregabalin is also a gabapentinoid, with an improved bioavailability. This systematic review evaluates the analgesic effect and tolerance of perioperative pregabaline. STUDY DESIGN Systematic review. METHODS Systematic search in Pubmed database of clinical human randomized controlled studies dealing with perioperative administration of pregabalin. A quantitative review of pregabalin efficiency and an analysis of the main side effects reported in these studies was then performed. RESULTS Twenty-three study arms (884 patients) received at least one dose of pregabalin in 17 studies (totalizing 1577 patients). Pregabalin improved analgesia in 11 of 23 study arms. Pregabalin improved analgesia in three of 12 study arms after ambulatory surgery, and in eight of 11 after major surgery (P=0.04). Two of three studies about chronic postoperative pain revealed improved results in pregabalin groups. Nevertheless, pregabalin did not reduce postoperative nausea/vomiting, pruritus and headache, but increased trouble with vision, drowsiness, severe sedation and dizziness during the first postoperative hours, without severe clinical consequence. Severe sedation seemed clearly dose dependant, while drowsiness, dizziness or visual disturbance did not. CONCLUSION A favorable benefit risk-ratio is demonstrated only for major surgery (excluding ambulatory surgery). The lack of data concerning tolerance of pregabalin in the elderly and/or in case of renal dysfunction forbids any conclusion in these populations.

A survey of percutaneous chest drainage practice in French university surgical ICU's☆

OBJECTIVE Percutaneous chest drainage guidelines were published in 2010 by the British Thoracic Society. On several points (insertion technique, drain size), they seem to differ from French practices. Our objectives were to evaluate practice of pleural drainage in French University surgical intensive care units (ICUs), and to compare it with the British guidelines. STUDY DESIGN National phone survey. METHODS Physicians working in 58 ICUs were surveyed first in 2007, and subsequently in 2012. They were read a questionnaire to evaluate the demographic characteristics of their units, their indication for pleural drainage, how they quantified pleural effusion, and their technique for drain insertion. Data from the two surveys were compared to detect an evolution in practice following the publication of the British guidelines. Results are expressed as the mean response. RESULTS In 2007, pleural drainage indications relied on various respiratory criteria in 91% of cases (versus 95% in 2012) and/or on pleural effusion volume in 71% of cases (versus 59% in 2012). Trocars (Monod or Joly) were used in 68% of the procedures in 2007. In the rest, either blunt dissection, a Pleurocath® or the Seldinger technique was utilized. From 2007 to 2012, the Seldinger technique increased in frequency (10% versus 22%, P=0.005) while Monod trocar usage decreased (41% vs 29%, P=0.012). Ultrasound before pleural effusion drainage became nearly systematic in 2012 (60% vs 86%, P<0.001). CONCLUSION The frequent use of trocar (and therefore of large drains) for pleural drainage in French ICUs differs significantly from the British guidelines.

Tranexamic acid decreases risk of haematomas but not pain after hip arthroplasty.

BACKGROUND Tranexamic acid decreases total blood loss after total hip arthroplasty (THA). Total blood loss is the sum of external bleeding and bleeding into tissues, i.e., haematomas. Haematomas may cause acute or even chronic postoperative pain. HYPOTHESIS Tranexamic acid decreases haematomas, thereby diminishing postoperative pain after THA. METHODS In a retrospective matched case-control study, patients receiving tranexamic acid (15 mg/kg, before the incision and again at skin closure) were compared to controls not given tranexamic acid. Matching was on sex, surgeon, and peri-operative analgesics (ketamine, ketoprofen, pregabalin, and nefopam). Standardised protocols were used for anaesthesia, analgesia, and blood sparing. Haematoma volume was computed as the difference between total blood loss (estimated from the erythrocyte counts on days -1 and +5) and measured external blood loss. Patients were monitored from D0 to D7 then interviewed by telephone on D30, D90, and D180. To detect a 30%-decrease in the morphine dose at H24 (criterion 1) and D7 (criterion 2) and a 20% decrease in haematoma volume on D5 (criterion 3), the required numbers of patients were 90, 90, and 77, respectively; therefore, 95 patients were included. RESULTS Tranexamic acid decreased haematoma volume by 30% (351±254 mL versus 247±189 mL erythrocytes, P=0.002), had no effect on morphine consumption at H24 (12±11 mg versus 14±12 mg, P=0.346), increased morphine consumption on D7 (26±24 mg versus 35±36 mg, P=0.029), and had no effect on long-term pain. DISCUSSION After THA, tranexamic acid decreases haematoma volume without improving analgesia. LEVEL OF EVIDENCE 3 (case-control study).

Chronic pain after carpal tunnel surgery: epidemiology and associated factors.

BACKGROUND Chronic postoperative pain (CPOP) has been assessed after major orthopedic surgeries but not after carpal tunnel surgery (CTS). This study aimed at describing the evolution of nocturnal and diurnal pains during the year following CTS, and at looking for factors associated with CPOP. METHODS Cohort of adult outpatients operated by one single surgeon, under regional anaesthesia (RA). Patients were questioned in the recovery room, and phoned 3 days and 12 months later. A multivariate analysis tested the association between CPOP and preoperative demographics, regional anaesthesia protocol, pain during RA, surgery and the first 3 postoperative days, postoperative complications. RESULTS Between November 2006 and June 2010, 324 of 389 patients could be included. The nocturnal and diurnal pains disappeared on the evening of the procedure in 55% (180/324) and 50% (163/324) of patients respectively. At one year, 12% of patients (40/324) complained of pain which characteristic was similar to the preoperative one, and 22% (71/324) complained of a new pain (different from the preoperative one), which was therefore considered as CPOP. CPOP was associated with a decreased functional score (QuickDASH). After multivariate analysis, CPOP was associated with postoperative pain from D0 to D3 (p=0.02), minor postoperative complications (p<0.001) and absence of hypnotic approach during surgery (p=0.01). CONCLUSION One year after CTS, 22% of patients have CPOP. This incidence is similar to the one observed after major surgeries. This study suggests for the first time that a hypnotic approach during the surgical procedure might decrease the CPOP incidence.

Nefopam after total hip arthroplasty: role in multimodal analgesia.

BACKGROUND Multimodal analgesia combining several non-opioid analgesics is recommended for pain control after surgery. In one study of total hip arthroplasty (THA), pain relief achieved by adding ketamine to the paracetamol-ketoprofen combination was statistically significant but remained inadequate in most patients. In two other studies, the analgesic effect of nefopam was synergistic with that of ketoprofen and additive with that of paracetamol. Adding nefopam to the paracetamol-ketoprofen-ketamine combination has not been evaluated. HYPOTHESIS Adding nefopam to the paracetamol-ketoprofen-ketamine combination significantly improves analgesia after THA. MATERIAL AND METHODS A prospective single-centre comparative non-randomised study (control group then nefopam group) was conducted in patients undergoing THA under general anaesthesia. All patients received paracetamol-ketoprofen-ketamine and morphine/droperidol patient-controlled analgesia. The nefopam group also received a continuous infusion of nefopam (120 mg/d for 48 h). Pain was evaluated daily for 7 days. The main evaluation criteria were morphine consumption, and pain intensity evaluated using a numerical rating scale and a validated questionnaire. To detect a 40% morphine-sparing effect by H24 (α=0.05 and β=0.2), 85 patients were needed in each group. RESULTS The two groups (90 patients/group) had no significant differences for perioperative characteristics, pain scores, morphine consumption at H24 (nefopam, 13 ± 12 mg and control, 14 ± 13 mg, P=0.39), or functional recovery. Compared to the control group, the nefopam group had lower rates of nausea/vomiting (P<0.0001), pruritus (P=0.002), and visual disturbances (P=0.02). DISCUSSION Nefopam failed to improve pain relief when added to a multimodal analgesia regimen but alleviated several morphine-induced side effects. Redundancy between nefopam and ketamine may explain the absence of greater pain relief. This study emphasises the need for clinical evaluations of every analgesic regimen, as the available data were not sufficient to predict these results. LEVEL OF EVIDENCE Level III, case-control study.