Spinal GABA transporter 1 contributes to evoked-pain related behavior but not resting pain after incision injury.

The inhibitory function of GABA at the spinal level and its central modulation in the brain are essential for pain perception. However, in post-surgical pain, the exact mechanism and modes of action of GABAergic transmission have been poorly studied. This work aimed to investigate GABA synthesis and uptake in the incisional pain model in a time-dependent manner. Here, we combined assays for mechanical and heat stimuli-induced withdrawal reflexes with video-based assessments and assays for non-evoked (NEP, guarding of affected hind paw) and movement-evoked (MEP, gait pattern) pain-related behaviors in a plantar incision model in male rats to phenotype the effects of the inhibition of the GABA transporter (GAT-1), using a specific antagonist (NO711). Further, we determined the expression profile of spinal dorsal horn GAT-1 and glutamate decarboxylase 65/67 (GAD65/67) by protein expression analyses at four time points post-incision. Four hours after incision, we detected an evoked pain phenotype (mechanical, heat and movement), which transiently ameliorated dose-dependently following spinal inhibition of GAT-1. However, the NEP-phenotype was not affected. Four hours after incision, GAT-1 expression was significantly increased, whereas GAD67 expression was significantly reduced. Our data suggest that GAT-1 plays a role in balancing spinal GABAergic signaling in the spinal dorsal horn shortly after incision, resulting in the evoked pain phenotype. Increased GAT-1 expression leads to increased GABA uptake from the synaptic cleft and reduces tonic GABAergic inhibition at the post-synapse. Inhibition of GAT-1 transiently reversed this imbalance and ameliorated the evoked pain phenotype.

Systematic Review on Pain-Related Outcome Domains After Sternotomy: A First Step Toward the Development of a Core Outcome Set.

OBJECTIVES: Pain after surgery has a major impact on acute and long-term recovery and quality of life, but its management is often insufficient. To enhance the quality of research and to allow for better comparability between studies, it is important to harmonize outcomes for assessing the efficacy and effectiveness of pain management interventions after surgery. As a first step in developing a core outcome set, this study aimed to systematically search for outcome domains assessed in research regarding acute pain management after sternotomy as an example of a typically painful surgical procedure. METHODS: A systematic literature review was performed using MEDLINE, Embase, and CENTRAL. Eligibility criteria consisted of randomized controlled trials and observational trials targeting pain management after sternotomy in adults in the acute postoperative setting (≤2 weeks). After duplicate removal and title and abstract screening by 2 independent reviewers, study characteristics and outcome domains were identified, which were extracted from full texts and summarized qualitatively. RESULTS: Of 1350 studies retrieved by database searching, 156 studies were included for full-text extraction. A total of 80 different outcome domains were identified: pain intensity, analgesic consumption, physiological function, and adverse events were the most frequent ones. Outcome domains were often not explicitly reported, and the combination of domains and assessment tools was heterogeneous. The choice of outcomes is commonly made within clinicians; patients' perspectives are not considered. CONCLUSIONS: The wide variety of commonly applied outcome domains, the nonexplicit wording, and the heterogeneous combination of the domains indicating treatment benefit demonstrate the need for harmonization of outcomes assessing perioperative pain management after surgery.

[Outpatient treatment of acute injuries of upper extremities with axillary plexus anesthesia in the emergency department-Is that possible without continuous anesthesia attendance?] / Ambulante Versorgung akuter Verletzungen der oberen Extremität in der Notfallambulanz in axillärer Plexusanästhesie ­ Ist das ohne durchgehende Anästhesiebegleitung machbar?

BACKGROUND: The incorporation into the routine operating procedure of patients with small but acute hand and forearm injuries requiring surgery who present in the emergency admission department, represents a challenge due to limited resources. The prompt treatment in the emergency admission department represents an alternative. This article retrospectively reports the authors' experiences with a treatment algorithm in which emergency patients were treated by ultrasound-guided axillary brachial plexus blocks (ABPB) and surgery carried out in the emergency department without further anesthesia attendance. METHODS: Patients were preselected by the surgeon if they were suitable for a standardized treatment without anesthesia attendance during surgery. If there were no anesthesiological or surgical contraindications patients received an ABPB in the holding area of the operating room (OR) under standard monitoring. Blocks were performed as a multi-injection, ultrasound-guided technique which is anatomically described in detail. Patients >60 kg received a total volume of 30 ml of a mixture of 10 ml 1% ropivacaine (100 mg) and 20 ml 2% prilocaine (400 mg). Patients <60 kg received the same mixture with a reduced volume of 25 ml corresponding to 82.5 mg ropivacaine and 332.5 mg prilocaine. After controlling for block success patients were admitted to the emergency department and the surgical procedure was carried out under supervision by the surgeon without further anesthesia attendance. At discharge patients were explicitly instructed that in the case of any complications or a continuation of the block for more than 24 h they should contact the emergency department. RESULTS: Between January 2013 and November 2017 a total of 566 patients (46.4 years, range 11-88 years, 174.9 cm, range 140-211cm, 80.8 kg, range 42-178kg, ASA 1/2/3, 190/338/38, respectively) were treated according to a standardized protocol. The ABPBs were performed by 74 anesthetists. In 5% of the patients the initial block was incomplete and rescue blocks were performed with a maximum of 2­3ml 1% prilocaine per corresponding nerve. After completion the block was ensured and all patients underwent surgery without further analgesics or local anesthetic infiltration by the surgeon. Complications related to the ABPB and readmissions were not observed. CONCLUSION: It could be demonstrated that minor surgery could be carried out safely and effectively with a defined algorithm using ABPB in selected patients outside the OR without permanent anesthesia attendance: however, indispensable prerequisites for such procedures are careful patient selection, patient compliance, the safe and effective performance of the ABPB and reliable agreement with the surgeon.

Anesthesia of the conditioned limb does not abolish the remote ischemic conditioning stimulus on cutaneous microcirculation in humans.

BACKGROUND: Mechanism of remote ischemic conditioning (RIC) remain not fully understood yet. Thus, a clinical trial was performed to assess the neuronal influence on its signal induction. METHODS: RIC was conducted on 45 patients who were randomized into 3 groups. Group A and B underwent brachial plexus anesthesia while RIC was performed on the blocked (A) and non-blocked side (B), respectively. In group C, RIC was conducted before regional anesthesia, thus serving as control group. All measurements were taken contralateral to RIC. The relative increase of microcirculatory parameters compared to baseline was evaluated and compared between the groups. RESULTS: Superficial blood flow (sBF) significantly increased in group A and C but values were higher among group C. Compared to group A, group C showed a significant increase of sBF during the initial 5 minutes of reperfusion (1.75; CI 1.139 - 2.361 vs. 0.97, CI 0.864 - 1.076, p < 0.05). Deep blood flow, tissue oxygen saturation and relative hemoglobin content were marginally influenced by RIC irrespectively of the presence of regional anesthesia. CONCLUSION: Despite regional anesthesia a significant RIC stimulus can be induced although its microcirculatory response is attenuated compared to control. Hence, RIC induction does not merely depend on neuronal signaling.

Ultrasound-guided anterior approach to the axillary and intercostobrachial nerves in the axillary fossa: an anatomical investigation.

BACKGROUND: The posterolateral and medial aspect of the arm is supplied by the axillary (AXN) and intercostobrachial nerves (ICBN), which are not anaesthetised by an axillary brachial plexus block (ABPB). Blockade of the AXN and the ICBN has been reported in the quadrangular space (QS) posteriorly or by serratus plane block, respectively. An anterior ultrasound-guided approach to block the AXN and ICBN would be desirable to complete an ABPB at a single insertion site. METHODS: After a preliminary dissection study in six cadavers, ultrasound-guided AXN and ICBN injection was performed in 46 Thiel embalmed cadavers bilaterally. Key sonographic landmarks to identify the AXN in the QS are the humerus, teres major muscle, and subscapular muscle. With the same probe position, the ICBN was identified in the subfascial axillary space. Then, 2 ml latex was injected at each nerve and confirmed by dissection. RESULTS: Muscular and bony landmarks were identified in all cadavers. The AXN was seen in 99% in the QS or at the inferolateral margin of the subscapular muscle and surrounded by latex in 96% of cases. Latex spread to the axillary fossa, within the subscapular muscle, or to the radial nerve was noted in 8% of the injections. The ICBN was seen and surrounded by latex in 100% of cases. CONCLUSIONS: We describe a reliable ultrasonographic approach to visualise the AXN and ICBN anteriorly from the conventional ABPB approach as confirmed in this cadaver study.

[Anesthesia management in microsurgical reconstructions]. / Anästhesiologisches Management bei mikrochirurgischen Rekonstruktionen.

Microsurgical procedures for construction of anastomoses present new challenges for anesthetists in the perioperative setting. Despite their increasing importance, so far no perioperative management guidelines for these patients existed. Anesthetists can influence the success of surgery (e. g. successful perfusion of a flap) via an optimal preoperative, intraoperative and postoperative approach. Patients should be carefully evaluated preoperatively for increased risks to avoid poor postoperative outcomes. Perioperatively, the choice of anesthetic procedure as well as the management of fluid infusion, blood glucose, temperature and blood transfusion are of great importance. Adequate analgesia as well as strict control should be performed as soon as possible postoperatively, preferably in a surveillance unit to detect and treat any complications as early as possible.

Influence of transcutaneous spinal stimulation on human LTP-like pain amplification. A randomized, double-blind study in volunteers.

OBJECTIVE: Transcutaneous spinal direct current stimulation (tsDCS) has been proven to affect nociceptive signal processing. We designed a randomized, double-blind, cross-over study to investigate whether tsDCS applied before or after inducing long-term potentiation-(LTP)-like hyperalgesia may decrease nociceptive sensitivity. METHODS: In healthy volunteers, tsDCS (2.5mA, 15min) was applied to the thoracic spine prior (n=14) or immediately following (n=12) electrical high-frequency stimulation (HFS) to the thigh, inducing hyperalgesia. Mechanical and electrical perception were assessed before HFS stimulation and at three time points following HFS stimulation (all within 90min of HFS). Subjects took part in three separate sessions to test effects of anodal, cathodal, or sham tsDCS. RESULTS: Within 60minHFS led to unilateral changes on the conditioned side: mechanical pain thresholds tended to decrease and electrical detection thresholds significantly decreased (p<0.001); pain ratings measured using the numerical rating scale (NRS) increased for electrical stimuli (p<0.01) and two categories of mechanical stimuli ("Light(8-64mN)": p=ns; "Heavy(128-512mN)": p<0.01). Irrespective of stimulation order or polarity, tsDCS could not influence nociceptive sensitivity. CONCLUSION: Hyperalgesia was adequately induced, but tsDCS had no effect on HFS-induced sensitization. SIGNIFICANCE: While tsDCS has been shown to affect pain measures, our results suggest irrespective of time of stimulation or polarity that tsDCS may be less effective in modulating pain in a sensitized state in healthy subjects.

Remote ischaemic conditioning decreases blood flow and improves oxygen extraction in patients with early complex regional pain syndrome.

BACKGROUND: Remote ischaemic conditioning (RIC) is the cyclic application of non-damaging ischaemia leading to an increased tissue perfusion, among others triggered by NO (monoxide). Complex regional pain syndrome (CRPS) is known to have vascular alterations such as increased blood shunting and decreased NO blood-levels, which in turn lead to decreased tissue perfusion. We therefore hypothesized that RIC could improve tissue perfusion in CRPS. METHOD: In this proof-of-concept study, RIC was applied in the following groups: in 21 patients with early CRPS with a clinical history less than a year, in 20 age/sex-matched controls and in 12 patients with unilateral nerve lesions via a tourniquet on the unaffected/non-dominant upper limb. Blood flow and tissue oxygen saturation (StO2 ) were assessed before, during and after RIC via laser Doppler and tissue spectroscopy on the affected extremity. The oxygen extraction fraction was calculated. RESULTS: After RIC, blood flow declined in CRPS (p < 0.01). StO2 decreased in CRPS and healthy controls (p < 0.01). Only in CRPS, the oxygen extraction fraction correlated negatively with the decreasing blood flow (p < 0.05). CONCLUSION: Contrary to our expectations, RIC induced a decrease of blood flow in CRPS, which led to a revised hypothesis: the decrease of blood flow might be due to an anti-inflammatory effect that attenuates vascular disturbances and reduces blood shunting, thus improving oxygen extraction. Further studies could determine whether a repeated application of RIC leads to a reduced hypoxia in chronic CRPS. SIGNIFICANCE: Remote ischaemic conditioning leads to a decrease of blood flow. This decrease inversely correlates with the oxygen extraction in patients with CRPS.

[Effects of Vibrax (Mechanical Vibrations) on the Arterial Blood Gases of Patients in the Intensive Care Unit after Cardiac Surgery]. / Effekte der Vibraxanwendung (mechanische Vibration) auf die Blutgaswerte von Patienten auf der Intensivstation nach einem kardiochirurgischen Eingriff.

OBJECTIVE: Respiratory physiotherapy is an integral part of the care of patients in intensive care units (ICU) after cardiac surgery. One of the most commonly used techniques in ICU to prevent pulmonary complications are mechanical vibrations, which can be applied with a tool called Vibrax.The aim of this study was to investigate the effects of Vibrax (mechanical vibrations) on the arterial blood gases of patients in ICU during the 1. or 2. day after cardiac surgery. METHODS: A randomized controlled pilot study was conducted with 23 patients. The participants of the control group (CG) received a cardiovascular training with mobilization to the edge of the bed and active breathing exercises. On the patients of the intervention group (IG) additionally Vibrax was applied for 5 minutes. As primary outcome parameter the PaO2/FiO2 ratio was measured. RESULTS: In the CG no significant changes over time were observed (p ≥ 0.06). The IG showed a significant (p = 0.009) increase in the PaO2/FiO2 ratio from before the physiotherapy intervention (M = 296.52, SE = 34.94 mmHg) to 60 minutes after completion of the physiotherapy intervention (M = 331.39, SE = 48.14 mmHg). There was no significant difference between the CG and IG at any measuring time (p ≥ 0.09). CONCLUSION: The results of this pilot study indicate that the application of Vibrax has positive effects on the arterial blood gases of patients in ICU on the 1. or 2. day after cardiac surgery. But whether the effects are clinically relevant could not be clarified.

Ultrasound-guided catheterisation of the subclavian vein: freehand vs needle-guided technique.

The objective of this prospective, randomised study was to examine the impact of a multi-angle needle guide for ultrasound-guided, in-plane, central venous catheter placement in the subclavian vein. One hundred and sixty patients were randomly allocated to two groups, freehand or needle-guided, and then 159 catheterisations were analysed. Cannulation of the first examined access site was successful in 96.9% of cases with no significant difference between groups. There were three arterial punctures and no other severe injuries. Catheter misplacements did not differ between the groups. Higher success rates within the first and second attempts in the needle-guided group were observed (p = 0.041 and p = 0.019, respectively). Use of the needle guide reduced the access time from a median (IQR [range]) of 30 (18-76 [6-1409]) s to 16 (10-30 [4-295]) s; p = 0.0001, and increased needle visibility from 31.8% (9.7%-52.2% [0-96.67]) to 86.2% (62.5%-100% [0-100]); p < 0.0001. A multi-angle needle guide significantly improved aligning the needle and ultrasound plane compared with the freehand technique when cannulating the subclavian vein. Use of the guide resulted in faster access times and increased success at the first and second attempts.

Transcutaneous spinal DC stimulation reduces pain sensitivity in humans.

Non-invasive approaches to pain management are needed to manage patient pain escalation and to providing sufficient pain relief. Here, we evaluate the potential of transcutaneous spinal direct current stimulation (tsDCS) to modulate pain sensitivity to electrical stimuli and mechanical pinpricks in 24 healthy subjects in a sham-controlled, single-blind study. Pain ratings to mechanical pinpricks and electrical stimuli were recorded prior to and at three time points (0, 30, and 60min) following 15min of anodal tsDCS (2.5mA, "active" electrode centered over the T11 spinous process, return electrode on the left posterior shoulder). Pain ratings to the pinpricks of the highest forces tested (128, 256, 512mN) were reduced at 30min and 60min following anodal tsDCS. These findings demonstrate that pain sensitivity in healthy subjects can be suppressed by anodal tsDCS and suggest that tsDCS may provide a non-invasive tool to manage mechanically-induced pain.

Selective prevention of mechanical hyperalgesia after incision by spinal ERK1/2 inhibition.

BACKGROUND: Activation of extracellular signal-regulated kinases (ERK1/2) has been shown to play an important role in several pain states. Here we investigated the ERK1/2 contribution to non-evoked and evoked pain-like behaviour in rats after surgical incision. METHODS: Spinal phosphorylation of ERK1 and ERK2 was assessed 15 min, 4 h, 24 h and 5 days after plantar incision and sham incision. The effect of PD98059, a specific inhibitor of ERK1/2 activation, administered intrathecally (IT) 1 h before or 2 h after incision on spinal ERK1 and ERK2 phosphorylation was assessed. In behavioural experiments, the effect of PD98059 administered 1 h before or after incision on non-evoked pain behaviour and mechanical and heat hyperalgesia was assessed. RESULTS: Phosphorylated ERK1 and ERK2 were rapidly increased in the ipsilateral dorsal horn from rats after incision post-operatively. This increased ERK1 and ERK2 phosphorylation were blocked by PD98059 administered before incision. In congruence, IT administration of PD98059 before incision delayed mechanical hyperalgesia after incision; however, administration after incision had only a modest effect on mechanical hyperalgesia. In addition, PD98059 did not affect non-evoked pain behaviour or heat hyperalgesia after incision. CONCLUSION: The results suggest that spinal ERK1 and ERK2 are involved in regulation of pain after incision differentially with regard to the pain modality. Furthermore, blockade of ERK1/2 activation was most effective in a preventive manner, a condition which is rare after incision. Spinal ERK1/2 inhibition could therefore be a very useful tool to manage selectively movement-evoked pain after surgery in the future.

[Differences of analgesic efficacy and complication rates between ultrasound and nervestimulator guided peripheral nerve catheters : Database analysis on patient-relevant target parameters]. / Vergleich der Analgesiequalität und Komplikationen von ultraschall- und nervenstimulatorgesteuerten peripheren Nervenkathetern : Datenbankanalyse zu patientenrelevanten Zielparametern.

BACKGROUND: Peripheral nerve catheters (PNC) play an important role in postoperative pain treatment following major extremity surgery. There are several trials reported in the literature which investigated the efficacy and safety of ultrasound (US) and nerve stimulator (NS) guided PNC placement; however, most of these trials were only small and focused mainly on anesthesiologist-related indicators of block success (e.g. block onset time and procedure time) but not primarily on patient-related outcome data including postoperative pain during movement. AIM: This retrospective analysis compared the analgesic efficacy and safety of US versus NS guided peripheral nerve catheters (PNC) for postoperative pain therapy in a large cohort of patients. MATERIAL AND METHODS: Data of patients (June 2006-December 2010) treated with US (nus = 368 June 2008-December 2010) and NS (nns = 574, June 2006-May 2008) guided PNC were systematically analyzed. Apart from demographic data, postoperative pain scores [numeric rating scale (NRS): 0-10] on each treatment day, the number of patients with need for additional opioids, cumulative local anesthetic consumption and catheter-related complications were compared. RESULTS: On the day of surgery patients treated with US-guided PNC reported lower NRS at rest (p = 0.034) and during movement (p < 0.001). Additionally, the number of patients requiring additional opioids on the day of surgery was lower in the US group (absolute difference 12.4 %, p = 0.001). Furthermore, the number of multiple puncture attempts (absolute difference 5.6 %, p < 0.001) and failed catheter placements (absolute difference 3.4 %, p = 0.06) were lower in the US group. There were no patients in both groups with long-lasting neurological impairment. CONCLUSION: This database analysis demonstrated that patients treated with US-guided PNC reported significantly lower postoperative pain scores and the number of patients requiring additional opioids was significantly lower on the day of surgery. The numbers of multiple punctures and failed catheter placements were reduced in the US group, which might be seen as an advantage of US-guided regional anaesthesia.

Ultrasound compared with nerve stimulation guidance for peripheral nerve catheter placement: a meta-analysis of randomized controlled trials.

BACKGROUND: The aim of this meta-analysis was to compare the efficacy and safety of ultrasound (US) vs nerve stimulation (NS) guidance for peripheral nerve catheter placement. METHODS: This meta-analysis was performed according to the PRISMA statement and the recommendations of the Cochrane Collaboration. For dichotomous outcomes relative risks [RRs; 95% confidence intervals (CIs)] were calculated, while for continuous outcomes, mean differences (MDs; 95% CI) were calculated. All statistical analyses were performed using the Revman® statistical software (Version 5.1). RESULTS: Fifteen randomized controlled trials including 977 patients satisfied the inclusion criteria. Peripheral nerve catheters placed under US guidance showed a higher RR of 1.14 (95% CI: 1.02-1.27; P=0.02) for an overall successful block in comparison with NS. However, postoperative pain scales at movement (numeric rating scale: 0-10) were comparable between US- vs NS-guided peripheral nerve catheters 24 (MD: 0.08; 95% CI: -0.77 to 0.94; P=0.85) and 48 (MD: 1.0; 95% CI: -0.3 to 2.3; P=0.13) h after surgery. Patients receiving a US-guided peripheral nerve catheter had a lower RR of 0.13 (95% CI: 0.04-0.38; P=0.0002) for an accidental vascular puncture. CONCLUSIONS: There is evidence that US-guided peripheral nerve catheters show a higher success rate and a lower risk for an accidental vascular puncture compared with NS guidance. However, this difference resulted only in marginally lower postoperative pain scores at rest. Nevertheless, these results were influenced by heterogeneity and should be interpreted with caution.

Is intraoperative dexmedetomidine a new option for postoperative pain treatment? A meta-analysis of randomized controlled trials.

In the present meta-analysis, we assessed the efficacy and safety of intravenous administration of dexmedetomidine (DEX) compared with placebo or opioids for acute postoperative pain treatment in adults undergoing surgery. The meta-analysis was performed according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement and the recommendations of the Cochrane Collaboration. Randomized controlled trials investigating perioperative administration of DEX were included. For dichotomous outcomes relative risks (RR; 95% confidence intervals [CI]) and for continuous outcomes mean differences (MD; 95% CI) were calculated. Twenty-eight randomized controlled trials including 1420 patients were finally included. Patients treated with DEX reported lower postoperative pain intensity (MD1h postoperatively: -1.59U (numeric rating scale: 0 to 10) 95% CI: -2.37 to -0.82; P=.000001) and showed a lower postoperative opioid consumption (MD24h postoperatively: -17.24mg; 95% CI: -24.38 to -10.10; P=.00001) compared with placebo. Additionally, the DEX group showed a lower RR for opioid-related adverse events (e.g. RRNausea (postanesthesia care unit): 0.66; 95% CI: 0.43 to 1.02; P=.06). The most common adverse event in patients treated with DEX was intraoperative bradycardia with a RR of 2.66 (RR: 2.66; 95% CI: 1.54 to 4.58; P=.0004) compared with placebo. There is evidence that DEX administration leads to lower postoperative pain, reduced opioid consumption, and a lower risk for opioid-related adverse events. The comparison of DEX vs opioids for postoperative pain treatment is less clear due to limited data. The most common adverse event was intraoperative bradycardia after DEX administration. Therefore cautions in patients at risk are warranted, and large trials focusing on long-term outcomes after intraoperative DEX use are needed.

[Oral therapy algorithm for the treatment of postoperative pain. A prospective observational study]. / Oraler Therapiealgorithmus bei akuten postoperativen Schmerzen. Eine prospektive Beobachtungsstudie.

BACKGROUND: Postoperative pain continues to be undermanaged, at least in part, due to inadequate organization and lack of use of opioids. Especially patients who do not receive consultation from an acute pain service and are therefore not eligible to receive regional anesthesia techniques or patient-controlled devices suffer from severe pain after surgery. The aim of the present prospective observational study was to assess the efficacy and feasibility of an analgesia algorithm for this subgroup of patients. METHODS: An oral opioid concept including controlled-release (cr) oxycodone, immediate-release (ir) hydromorphone and a non-opioid analgesic was implemented at three different departments at the University Clinic of Muenster, Germany. Briefly, cr-oxycodon was administered preoperatively to patients undergoing ear nose and throat (ENT), general or elective trauma surgery on the day of surgery and every 12 h for a maximum of 4 days postoperatively. Inadequately managed pain above 3 on a visual analog scale (VAS 0-10) at rest and above 5 during movement was treated with ir-hydromorphone on patient request. After written informed consent, patients were assessed prospectively for up to 5 days perioperatively using a standardized questionnaire preoperatively, for 4 days postoperatively as well as 6 and 12 months after surgery. RESULTS: A total of 275 patients were included in the present prospective observational study: (ENT surgery: 163, trauma surgery 82 and general surgery 30). Median resting and evoked numeric rating scale (NRS) pain scores were equal or less than 3 and 5, respectively. Less patients received cr-oxycodone after ENT and general surgery compared to trauma surgery (p < 0.001). Constipation was more frequent after general and trauma surgery compared to ENT surgery. Vomiting decreased from 20 %-30 % on the day of surgery to 10 % or less regardless of the type of operation. No severe adverse events were observed. Additionally, patients with an increased depression score before surgery reported greater immediate postoperative pain than non-depressed patients. Of the patients 11 (15.7 %) and 7 (14.9 %) complained about persistent postoperative pain 6 and 12 months after surgery, respectively and these patients had increased acute pain ratings during the first postoperative days. CONCLUSIONS: The present study has demonstrated that the implementation of an oral opioid algorithm for patients without patient-controlled intravenous or regional analgesia is effective and feasible on surgical wards. Patients who underwent trauma surgery needed more cr-oxycodone. Side effects were similar regardless of the operation with the exception of obstipation which was more frequent after trauma and general surgery compared to ENT surgery.

Efficacy and adverse effects of ketamine as an additive for paediatric caudal anaesthesia: a quantitative systematic review of randomized controlled trials.

BACKGROUND: The aim of this quantitative systematic review was to assess the efficacy and adverse effects of ketamine added to caudal local anaesthetics in comparison with local anaesthetics alone in children undergoing urological, lower abdominal, or lower limb surgery. METHODS: The systematic search, data extraction, critical appraisal, and pooled data analysis were performed according to the PRISMA statement. All randomized controlled trials (RCTs) were included in this meta-analysis and relative risk (RR), mean difference (MD), and the corresponding 95% confidence intervals (CIs) were calculated using the Revman(®) statistical software for dichotomous and continuous outcomes. RESULTS: Thirteen RCTs (published between 1991 and 2008) including 584 patients met the inclusion criteria. There was a significant longer time to first analgesic requirements in patients receiving ketamine in addition to a local anaesthetic compared with a local anaesthetic alone (MD: 5.60 h; 95% CI: 5.45-5.76; P<0.00001). There was a lower RR for the need of rescue analgesia in children receiving a caudal regional anaesthesia with ketamine in addition to local anaesthetics (RR: 0.71; 95% CI: 0.44-1.15; P=0.16). CONCLUSIONS: Caudally administered ketamine, in addition to a local anaesthetic, provides prolonged postoperative analgesia with few adverse effects compared with local anaesthetics alone. There is a clear benefit of caudal ketamine, but the uncertainties about neurotoxicity relating to the dose of ketamine, single vs repeated doses and the child's age, still need to be clarified for use in clinical practice.

Efficacy and safety of paravertebral blocks in breast surgery: a meta-analysis of randomized controlled trials.

BACKGROUND: Thoracic paravertebral blocks (PVBs) are successfully performed for pain management after breast surgery. The aim of the present quantitative systematic review was to assess the efficacy and adverse events of PVB in women undergoing breast surgery. METHODS: The systematic search, data extraction, critical appraisal, and pooled analysis were performed according to the PRISMA statement. The relative risk (RR), mean difference (MD), and their corresponding 95% confidence intervals (CIs) were calculated using the RevMan statistical software for dichotomous and continuous outcomes, respectively. Pain scores were converted to a scale ranging from 0 (no pain) to 10 (worst pain). RESULTS: Fifteen randomized controlled trials (published between 1999 and 2009) including 877 patients met the inclusion criteria. There was a significant difference in worst postoperative pain scores between PVB and general anaesthesia (GA) at <2 h (MD: -2.68; 95% CI: -3.33 to -2.02; P<0.00001), 2-24 h (MD: -2.34; 95% CI: -2.42 to -1.12; P<0.00001), and 24-48 h (MD: -1.75; 95% CI: -3.19 to 0.31; P=0.02). Accordingly, lower pain scores were observed for combined PVB with GA compared with GA alone for <2 h (MD: -1.87; 95% CI: -2.53 to -1.21; P<0.00001), 2-24 h (MD: -2.21; 95% CI: -3.07 to -1.35; P<0.00001), and 24-48 h (MD: -1.80; 95% CI: -2.92 to 0.68; P=0.002). The RR for the reported adverse events (e.g. pneumothorax) was low. CONCLUSIONS: There is considerable evidence that PVB in addition to GA or alone provide a better postoperative pain control with little adverse effects compared with other analgesic treatment strategies.

[Paracetamol for perioperative analgesia. Old substance - new insights]. / Paracetamol für die perioperative Analgesie. Alte Substanz - neue Erkenntnisse.

Since paracetamol was first synthesized in 1878 it has become one of the most popular and widely used drugs for the first-line treatment of fever and pain. The reasons for this popularity are a wide variety of formulations, an assumed positive safety record and the wide availability as an over-the-counter drug. However, recently several studies questioned the positive risk-benefit ratio of paracetamol for postoperative pain by observing several possible adverse effects and limitations. The aim of the present review is to give an update of the recent literature on the efficacy of paracetamol for postoperative pain and on the value of the clinical relevance of different adverse effects of paracetamol. Finally, based on the current findings the authors try to assess the role of paracetamol for the treatment of postoperative pain.