Analgesic effect of intravenous dexamethasone after volar plate surgery for distal radius fracture with brachial plexus block anaesthesia: a prospective, double-blind randomised clinical trial.

Rebound pain after brachial plexus block resolution and development of long-lasting pain are problems associated with volar plate fixation for distal radius fractures. The aim of this double-blind study was to evaluate the effect of a single prophylactic intravenous dose of dexamethasone in this setting. The primary endpoint was highest pain score during the first 24 hours after surgery. We included 51 adults of ASA physical status 1-2 due to undergo planned acute fixation of the radius. All received premedication with oral paracetamol and etoricoxib, and a pre-operative brachial plexus block with ropivacaine. Patients were randomly allocated into two groups: a dexamethasone group receiving 16 mg dexamethasone intravenously at start of surgery and a control group receiving 4 ml saline. After surgery, all patients received fixed doses of paracetamol, etoricoxib and oxycodone, with further oxycodone added as needed in the first 48 hours. Pain, analgesic consumption and daily function were registered at predefined times up to 1 year after surgery. Median (IQR [range]) worst pain score in the first 24 hours, as assessed by verbal numeric rating scale (0-10), was 4 (2-6 [0-7]) in the dexamethasone group compared with 8 (5-8 [2-10]) in the placebo group (p < 0.001). Average pain score, 2 (1-4 [0-5]) vs. 5 (3-6 [0-8]), p = 0.001 and rescue oxycodone consumption, 5 (0-10 [0-35]) mg vs. 10 (5-15 [0-50]) mg, p = 0.037), respectively, were both significantly lower in the dexamethasone group compared with control from 8 to 24 hours. Brachial plexus block duration was 69% longer in the dexamethasone group, 21.5 (19.1-23.4 [12.9-24.1]) hours vs. 12.7 (11.9-15.3 [7.4-26.6]) hours, p < 0.001. Two patients (9%) in the dexamethasone group compared with 12 (50%) in the placebo group experienced worst pain scores of 8-10 during the first 36 hours (p = 0.002). At 3 and 7 days postoperatively, there were no significant differences between groups for pain scores or opioid consumption. At 6 months, 27 patients (57%) reported pain at the site of surgery, with significantly higher average pain score (p = 0.024) in the placebo group. At 1 year, two patients in the dexamethasone group reported pain compared with 10 in the placebo group (p = 0.015), and worst pain score was significantly higher in the placebo group (p = 0.018). We conclude that intravenous dexamethasone improves early postoperative analgesia and may also improve clinical outcomes after 6 and 12 months.

Microcirculation and haemodynamics after infraclavicular brachial plexus block using adrenaline as an adjuvant to lidocaine: a randomised, double-blind, crossover study in healthy volunteers.

We evaluated the effect of adrenaline on human skin microcirculation (nutritive and sub-papillary) and systemic cardiovascular variables after it was added to lidocaine in infraclavicular brachial plexus blocks. Twelve healthy, non-smoking male volunteers were included, each attending two study sessions 2 weeks apart, and they were studied using a crossover design. In both sessions, they received an ultrasound-guided infraclavicular brachial plexus block in the non-dominant arm with 0.4 ml.kg-1 lidocaine, 15 mg.ml-1 with or without adrenaline 5 µg.ml-1 . Microcirculation was assessed by laser Doppler fluxmetry (sub-papillary blood flow), capillary video microscopy (nutritive blood flow) and continuous temperature measurements. Heart rate and arterial pressure were recorded continuously and non-invasively. Median (IQR [range]) sub-papillary blood flow increased substantially 30 min after the brachial plexus block, from 8.5 (4.4-13.5 [2.9-28.2]) to 162.7 (111.0-197.8 [9.5-206.7]) arbitrary units with adrenaline (p = 0.017), and from 6.9 (5.3-28.5 [1.8-42.1] to 133.7 (16.5-216.7 [1.0-445.0] arbitrary units without adrenaline (p = 0.036). Nutritive blood flow (functional capillary density, capillaries.mm-2 , measured at the dorsal side of the hand) decreased in the blocked extremity when adrenaline was used as adjuvant, from median (IQR [range]) 45 (36-52 [26-59]) to 38 (29-41 [26-42]), p = 0.028, whereas no significant change occurred without adrenaline. Median finger skin temperature (°C) increased by 44% (data pooled) with no significant differences between the groups. No significant changes were found in the systemic cardiovascular variables with or without adrenaline. We conclude that lidocaine infraclavicular brachial plexus blocks caused an increase in skin sub-papillary blood flow. The addition of adrenaline produced stronger and longer lasting blocks, but decreased the nutritive blood flow.

Pre-operative brachial plexus block compared with an identical block performed at the end of surgery: a prospective, double-blind, randomised clinical trial.

We evaluated whether pre-emptive analgesia with a pre-operative ultrasound-guided infraclavicular brachial plexus block resulted in better postoperative analgesia than an identical block performed postoperatively. Fifty-two patients undergoing fixation of a fractured radius were included. All patients received general anaesthesia with remifentanil and propofol. Patients were randomly allocated into two groups: a pre-operative block or a postoperative block with 0.5 ml.kg-1 ropivacaine 0.75%. After surgery, all patients received regular paracetamol plus opioids for breakthrough pain. Mean (SD) time to first rescue analgesic after emergence from general anaesthesia was 544 (217) min in the pre-operative block group compared with 343 (316) min in the postoperative block group (p = 0.015). Postoperative pain scores were higher and more patients required rescue analgesia during the first 4 h after surgery in the postoperative block group. There were no significant differences in plasma stress mediators between the groups. Analgesic consumption was lower at day seven in the pre-operative block group. Pain was described as very strong at block resolution in 27 (63%) patients and 26 (76%) had episodes of mild pain after 6 months. We conclude that a pre-operative ultrasound-guided infraclavicular brachial plexus block provides longer and better analgesia in the acute postoperative period compared with an identical postoperative block in patients undergoing surgery for fractured radius.

Impact of acute kidney injury on patient outcome in out-of-hospital cardiac arrest: a prospective observational study.

BACKGROUND: Kidney disease after out-of-hospital cardiac arrest (OHCA) is incompletely described. We examined the occurrence of acute kidney injury (AKI) in OHCA patients and impact of AKI, with or without renal replacement therapy (RRT), on 6-month mortality and neurological outcome. METHODS: Prospective study at Oslo University Hospital, Oslo, Norway. Adult resuscitated comatose OHCA patients treated with targeted temperature management at 33°C for 24 h were included. AKI and chronic kidney disease (CKD) were classified according to the Kidney Disease Improving Global Outcomes (KDIGO) guidelines. Main outcomes were 6-month mortality and good neurological outcome defined as Cerebral Performance Category 1-2. RESULTS: Among 245 included patients (84% males, mean age 61 years), 11 (4%) had previously known CKD and 112 (46%) developed AKI. Overall 6-month outcome revealed that 112 (46%) died and 123 (50%) had good neurological outcome. Compared with no kidney disease, the presence of AKI was significantly associated with 6-month mortality (odds ratio (OR) 3.17, 95% confidence interval (CI) 1.95-5.43, P < 0.001) and good neurological outcome (OR 0.28, 95% CI 0.16-0.48, P < 0.001). Six-month mortality (50 vs. 61%, P = 0.401) and frequency of good neurological outcome (44 vs. 35%, P = 0.417) were not statistically different in AKI patients with or without RRT, also after excluding patients where RRT was withheld due to futility. CONCLUSIONS: Kidney disease occurred in about half of patients successfully resuscitated from OHCA. Presence of AKI, but not RRT, was associated with unfavourable 6-month outcome.

Gradual withdrawal of remifentanil infusion may prevent opioid-induced hyperalgesia.

BACKGROUND: The aim of this study was to examine if gradual withdrawal of remifentanil infusion prevented opioid-induced hyperalgesia (OIH) as opposed to abrupt withdrawal. OIH duration was also evaluated. METHODS: Nineteen volunteers were enrolled in this randomized, double-blinded, placebo-controlled, crossover study. All went through three sessions: abrupt or gradual withdrawal of remifentanil infusion and placebo. Remifentanil was administered at 2.5 ng ml(-1) for 30 min before abrupt withdrawal or gradual withdrawal by 0.6 ng ml(-1) every five min. Pain was assessed at baseline, during infusion, 45-50 min and 105-110 min after end of infusions using the heat pain test (HPT) and the cold pressor test (CPT). RESULTS: The HPT 45 min after infusion indicated OIH development in the abrupt withdrawal session with higher pain scores compared with the gradual withdrawal and placebo sessions (both P<0.01. Marginal mean scores: placebo 2.90; abrupt 3.39; gradual 2.88), but no OIH after gradual withdrawal compared with placebo (P=0.93). In the CPT 50 min after end of infusion there was OIH in both remifentanil sessions compared with placebo (gradual P=0.01, abrupt P<0.01. Marginal mean scores: placebo 4.56; abrupt 5.25; gradual 5.04). There were no differences between the three sessions 105-110 min after infusion. CONCLUSIONS: We found no development of OIH after gradual withdrawal of remifentanil infusion in the HPT. After abrupt withdrawal OIH was present in the HPT. In the CPT there was OIH after both gradual and abrupt withdrawal of infusion. The duration of OIH was less than 105 min for both pain modalities. CLINICAL TRIAL REGISTRATION: NCT 01702389. EudraCT number 2011-002734-39.

The discriminatory value of cardiorespiratory interactions in distinguishing awake from anaesthetised states: a randomised observational study.

Depth of anaesthesia monitors usually analyse cerebral function with or without other physiological signals; non-invasive monitoring of the measured cardiorespiratory signals alone would offer a simple, practical alternative. We aimed to investigate whether such signals, analysed with novel, non-linear dynamic methods, would distinguish between the awake and anaesthetised states. We recorded ECG, respiration, skin temperature, pulse and skin conductivity before and during general anaesthesia in 27 subjects in good cardiovascular health, randomly allocated to receive propofol or sevoflurane. Mean values, variability and dynamic interactions were determined. Respiratory rate (p = 0.0002), skin conductivity (p = 0.03) and skin temperature (p = 0.00006) changed with sevoflurane, and skin temperature (p = 0.0005) with propofol. Pulse transit time increased by 17% with sevoflurane (p = 0.02) and 11% with propofol (p = 0.007). Sevoflurane reduced the wavelet energy of heart (p = 0.0004) and respiratory (p = 0.02) rate variability at all frequencies, whereas propofol decreased only the heart rate variability below 0.021 Hz (p < 0.05). The phase coherence was reduced by both agents at frequencies below 0.145 Hz (p < 0.05), whereas the cardiorespiratory synchronisation time was increased (p < 0.05). A classification analysis based on an optimal set of discriminatory parameters distinguished with 95% success between the awake and anaesthetised states. We suggest that these results can contribute to the design of new monitors of anaesthetic depth based on cardiovascular signals alone.

Factors predicting the use of therapeutic hypothermia and survival in unconscious out-of-hospital cardiac arrest patients admitted to the ICU.

INTRODUCTION: Therapeutic hypothermia (TH) after out-of-hospital cardiac arrest (OHCA) was adopted early in Norway. Since 2004 the general recommendation has been to cool all unconscious OHCA patients treated in the intensive care unit (ICU), but the decision to cool individual patients was left to the responsible physician. We assessed factors that were associated with use of TH and predicted survival. METHOD: We conducted a retrospective observational study of prospectively collected cardiac arrest and ICU registry data from 2004 to 2008 at three university hospitals. RESULTS: A total of 715 unconscious patients older than 18 years of age, who suffered OHCA of both cardiac and non-cardiac causes, were included. With an overall TH use of 70%, the survival to discharge was 42%, with 90% of the survivors having a favourable cerebral outcome. Known positive prognostic factors such as witnessed arrest, bystander cardio pulmonary resuscitation (CPR), shockable rhythm and cardiac origin were all positive predictors of TH use and survival. On the other side, increasing age predicted a lower utilisation of TH: Odds Ratio (OR), 0.96 (95% CI, 0.94 to 0.97); as well as a lower survival: OR 0.96 (95% CI, 0.94 to 0.97). Female gender was also associated with a lower use of TH: OR 0.65 (95% CI, 0.43 to 0.97); and a poorer survival: OR 0.57 (95% CI, 0.36 to 0.92). After correcting for other prognostic factors, use of TH remained an independent predictor of improved survival with OR 1.91 (95% CI 1.18-3.06; P <0.001). Analysing subgroups divided after initial rhythm, these effects remained unchanged for patients with shockable rhythm, but not for patients with non-shockable rhythm where use of TH and female gender lost their predictive value. CONCLUSIONS: Although TH was used in the majority of unconscious OHCA patients admitted to the ICU, actual use varied significantly between subgroups. Increasing age predicted both a decreased utilisation of TH as well as lower survival. Further, in patients with a shockable rhythm female gender predicted both a lower use of TH and poorer survival. Our results indicate an underutilisation of TH in some subgroups. Hence, more research on factors affecting TH use and the associated outcomes in subgroups of post-resuscitation patients is needed.

A comparison of oxycodone prolonged-release vs. oxycodone + naloxone prolonged-release after laparoscopic hysterectomy.

BACKGROUND: Targiniq®, an oxycodone prolonged-release (PR) formulation combined with the opioid antagonist naloxone PR, aims to prevent opioid-induced constipation without impairing the analgesic efficacy. This has been confirmed during prolonged use in chronic pain or cancer patients. The purpose of our study was to compare clinical effects of oxycodone PR with oxycodone PR + naloxone PR for short-term post-operative pain management. METHODS: This randomised, double-blind, prospective study included 85 women undergoing laparoscopic hysterectomy. The two groups received either oxycodone PR 10 mg or oxycodone PR 10 mg + naloxone PR 5 mg as pre-medication and twice daily for 3 days. As rescue analgesic, the patients received oxycodone intravenous during the first 24 h post-operatively and oxycodone tablets in the 24-72-h period. Constipation, other side effects, pain and satisfaction were registered during the first 7 post-operative days. RESULTS: Demographic, pre- and perioperative variables and the use of rescue analgesics were similar in the groups. There were no significant differences in variables related to constipation. In the oxycodone PR + naloxone PR group, 25% had no defecation during the first 72 h post-operatively, compared with 20% in the oxycodone PR group (mean 1.2 ± 1.1 vs. 2.1 ± 2.4 defecations). Other opioid-induced effects and side effects showed no significant differences. Only 7% were dissatisfied with their oral pain treatment. CONCLUSION: Addition of naloxone to oxycodone PR tablets in a pain regimen administered twice daily the first three post-operative days had no significant clinical effects on constipation or other variables during the first week after hysterectomy.