Showing papers in "Acta Anaesthesiologica Scandinavica in 2011"

Continuous adductor-canal-blockade for adjuvant post-operative analgesia after major knee surgery: preliminary results

Abstract: Because both the saphenous nerve and in part the obturator nerve are traversing the adductor canal of the thigh, we hypothesised that repeated administration of a local anaesthetic (LA) into this aponeurotic space could be a useful option for post-operative analgesia after knee replacement surgery A systematic search of the literature pertinent to the blockade of the saphenous and/or obturator nerves for pain relief after knee surgery was conducted Further, pain and opioid requirements were evaluated in eight patients receiving a continuous blockade of the saphenous and obturator nerve (adductor-canal-blockade) after total knee arthroplasty (TKA) Finally, we performed cross-sectional MR scans of the adductor canal after injection of ropivacaine 30ml in one patient The systematic literature search revealed only one controlled study, where selective blockade of the saphenous nerve was investigated for the purpose of clinical pain relief after knee arthroscopy We located no studies reporting on saphenous and/or obturator nerve block for pain relief after TKA Preliminary findings in eight patients demonstrated that a continuous adductor-canal-blockade for 48h after TKA was associated with low mean pain scores at rest and low mean requirements for supplemental morphine MR scans in one patient demonstrated that 30ml of LA filled the adductor canal, including the distal part, where the posterior branch of the obturator nerve joins the vessels and the saphenous nerve Continuous adductor-canal-blockade may be a valuable adjunct for post-operative analgesia after major knee surgery These preliminary results should be confirmed in randomised, controlled trials

Ultrasonography in the management of the airway

Abstract: In this study, it is described how to use ultrasonography (US) for real-time imaging of the airway from the mouth, over pharynx, larynx, and trachea to the peripheral alveoli, and how to use this in airway management. US has several advantages for imaging of the airway - it is safe, quick, repeatable, portable, widely available, and it must be used dynamically for maximum benefit in airway management, in direct conjunction with the airway management, i.e. immediately before, during, and after airway interventions. US can be used for direct observation of whether the tube enters the trachea or the esophagus by placing the ultrasound probe transversely on the neck at the level of the suprasternal notch during intubation, thus confirming intubation without the need for ventilation or circulation. US can be applied before anesthesia induction and diagnose several conditions that affect airway management, but it remains to be determined in which kind of patients the predictive value of such an examination is high enough to recommend this as a routine approach to airway management planning. US can identify the croicothyroid membrane prior to management of a difficult airway, can confirm ventilation by observing lung sliding bilaterally and should be the first diagnostic approach when a pneumothorax is suspected intraoperatively or during initial trauma-evaluation. US can improve percutaneous dilatational tracheostomy by identifying the correct tracheal-ring interspace, avoiding blood vessels and determining the depth from the skin to the tracheal wall.

Local infiltration analgesia in joint replacement: the evidence and recommendations for clinical practice

Abstract: Relief of acute pain after hip and knee replacement represents a major therapeutic challenge as post-operative pain hinders early mobilisation and rehabilitation with subsequent consequences on mobility, duration of hospitalisation and overall recovery. In recent years, there has been increased interest in high-volume local wound infiltration/infusion techniques in these operations with a combined administration of local anaesthetics, NSAIDs and epinephrine. This review provides an update of the current knowledge of the efficacy of the high-volume wound infiltration technique based on randomised trials. It is concluded that a predominant part of the data have had an insufficient design by not being placebo-controlled or with comparable systemic analgesia provided in the investigated groups. It is concluded that there is little evidence to support the use of the technique in hip replacement either intraoperatively or with a post-operative wound infusion catheter technique, provided that multimodal, oral non-opioid analgesia is given. In knee replacement, the data support the intraoperative use of the local infiltration technique but not the post-operative use of wound catheter administration. In knee replacement, a compression bandage prolongs the analgesic effect. There are limited data to support the use of NSAIDs or epinephrine in the solution and the data on post-operative hospitalisation and recovery are conflicting. Thus, shorter lengths of stay have been achieved by oral multimodal, non-opioid analgesia together with organisational optimisation of care according to the fast-track methodology.

Ultrasonography of the optic nerve in neurocritically ill patients

Abstract: The rapid diagnosis of intracranial hypertension is urgently needed for therapeutic reasons in various clinical settings. This can rarely be achieved without invasive procedures such as intracranial pressure (ICP) monitoring or neuroimaging. The optic nerve is surrounded by cerebrospinal fluid (CSF) and dura mater, which forms the optic nerve sheath (ONS). Because of the connection with the intracranial subarachnoid space, ONS diameter (ONSD) is influenced by CSF pressure variations. Bedside ultrasonographic measurement of ONSD has been proposed as a non-invasive and reliable means to detect raised ICP in neurocritically ill patients. In several studies, it proves to have a good correlation with the direct measurement of ICP and a low interobserver variability. However, no general consensus exists over the upper normal ONSD limit. We performed a review of the literature on the use of the ultrasonography of the optic nerve in the evaluation of patients with suspected intracranial hypertension. The aim of this review is to describe the technique and to assess the validity of this diagnostic method.

Heart rate variability: a diagnostic and prognostic tool in anesthesia and intensive care

Abstract: The autonomic nervous system (ANS) plays an important role in the human response to various internal and external stimuli, which can modify homeostasis, and exerts a tight control on essential functions such as circulation, respiration, thermoregulation and hormonal secretion. ANS dysfunction may complicate the perioperative course in the surgical patient undergoing anesthesia, increasing morbidity and mortality, and, therefore, it should be considered as an additional risk factor during pre-operative evaluation. Furthermore, ANS dysfunction may complicate the clinical course of critically ill patients admitted to intensive care units, in the case of trauma, sepsis, neurologic disorders and cardiovascular diseases, and its occurrence adversely affects the outcome. In the care of these patients, the assessment of autonomic function may provide useful information concerning pathophysiology, risk stratification, early prognosis prediction and treatment strategies. Given the role of ANS in the maintenance of systemic homeostasis, anesthesiologists and intensivists should recognize as critical the evaluation of ANS function. Measurement of heart rate variability (HRV) is an easily accessible window into autonomic activity. It is a low-cost, non-invasive and simple to perform method reflecting the balance of the ANS regulation of the heart rate and offers the opportunity to detect the presence of autonomic neuropathy complicating several illnesses. The present review provides anesthesiologists and intensivists with a comprehensive summary of the possible clinical implications of HRV measurements, suggesting that autonomic dysfunction testing could potentially represent a diagnostic and prognostic tool in the care of patients both in the perioperative setting as well as in the critical care arena.

Dexmedetomidine attenuates remote lung injury induced by renal ischemia-reperfusion in mice.

Abstract: Background Renal ischemia–reperfusion (I/R) may cause acute lung injury (ALI). The mortality of combined acute kidney injury and ALI is extremely high. Dexmedetomidine, an α2 adrenergic agonist, exerts potent anti-inflammatory and organoprotective effects in addition to its sedative and analgesic properties. We sought to elucidate whether dexmedetomidine can attenuate lung injury following renal I/R in a murine model of renal I/R. Methods Adult C57BL/6J male mice were randomized to five groups: sham-operated control (Sham); renal I/R (I/R); intraperitoneal injection of dexmedetomidine 25 μg/kg before ischemia (pre-dex) and after perfusion (post-dex); combination of α2 adrenergic antagonist atipamezole 250 μg/kg prior to dexmedetomidine pre-treatment (atip-dex). Kidney I/R was induced by bilateral renal pedicle clamping for 45 min and followed by 6 h reperfusion. The pulmonary tissues were harvested for histopathological evaluation, wet/dry ratio measurement, biochemical analysis of myeloperoxidase (MPO), Polymerase chain reaction (PCR) determination of Inter-cellular adhesion molecule (ICAM-1) and Tumor necrosis factor – alpha (TNF-α) mRNA. Results Renal IR induced significant pulmonary injuries, increased wet/dry ratio together with the enhanced of MPO activities and increased ICAM-1 and TNF-α mRNA level. Both pre- and post-treatment with dexmedetomidine markedly reduced lung edema and inflammatory response and lowered MPO activity and ICAM-1 and TNF-α mRNA expression. The protective effects of dexmedetomidine in the lung were partially reversed by atipamezole, but there were no effect on ICAM-1 and TNF-α mRNA expression level. Conclusions Dexmedetomidine is capable of attenuating remote lung injury induced by renal IRvia both α2 adrenoceptors dependent and independent mechanisms.

Consequences of persistent pain after lung cancer surgery: a nationwide questionnaire study.

Abstract: Background: Post-thoracotomy pain syndrome (PTPS) and its social consequences have been inconsistently investigated as most studies were either small sized, focused on a limited number of risk factors or included heterogeneous surgical procedures. The current objectives were to obtain detailed information on the consequences of PTPS after thoracotomy and video-assisted thoracic surgery (VATS) from homogenous unselected nationwide data, and to suggest mechanisms for the development of PTPS. Methods: Data from 1327 patients were collected using a prospective national database and combined with a detailed questionnaire. Results: The response rate was 81.5%, resulting in 546 patients without prior thoracic surgery for the final analysis. Follow-up was 22 months (range 12–36). PTPS occurred in 33% thoracotomy patients and 25% VATS patients. Clinically relevant pain was present in 11–18% of the patients and severe pain in 4–12% depending on the level of physical activity. In PTPS patients, 64% also had pain from other locations on the body. Perceived sensory changes in the thoracic area were present in 63% of PTPS patients vs. 25% in pain-free patients (P<0.001). When comparing VATS with thoracotomy, no consistent differences in the prevalence, distribution of pain, sensory changes or effect of pain on daily activities were observed although clinically relevant and severe pain was reduced after VATS. Conclusions: This nationwide study corroborates that PTPS is a clinically relevant problem influencing daily activities a long time after thoracotomy and VATS. Nerve injury and increased pain responsiveness may explain the majority of symptoms, the prevalence and distribution of pain including perceived sensory sensations.

Scandinavian glutamine trial: a pragmatic multi-centre randomised clinical trial of intensive care unit patients.

Abstract: Background: Low plasma glutamine concentration is an independent prognostic factor for an unfavourable outcome in the intensive care unit (ICU). Intravenous (i.v.) supplementation with glutamine is ...

A pilot study of the implementation of WHO Surgical Checklist in Finland: improvements in activities and communication

Abstract: Background World Health Organisation (WHO) has introduced a surgical safety checklist that has reduced post-operative morbidity and mortality Prior to national checklist implementation, we assessed its possible impact on the operating room (OR) process, safety-related issues and communication among surgical staff in a high-income country Methods In four university and teaching hospitals, a structured questionnaire was delivered to OR personnel involved in consecutive operations over 4–6 weeks before and after the checklist implementation The questionnaire resembled the WHO checklist and comprised multiple-choice questions relating to performance of safety checks and communication Anaesthesiologists (A), surgeons (S) and circulating nurses (CN) answered the questions independently The WHO checklist was modified for national needs Results Questionnaires were returned from 1748 operations, 901 before and 847 after the checklist Patient's identity was more often confirmed (A: 627% vs 840%, S: 716% vs 855%, CN: 816% vs 942%, P < 0001) and knowledge of names and roles among team members (A: 657% vs 818%, S: 711% vs 836%, CN: 877% vs 932%, P < 001) improved with the checklist Anaesthesiologists and surgeons discussed critical events pre-operatively (A: 220% vs 426%, S: 347% vs 462%, P < 0001) more frequently after the checklist In addition, fewer communication failures (43 vs 17, P < 005) were reported with checklist Conclusions The checklist increased OR teams’ awareness of patient-related issues, the procedure and expected risks It also enhanced team communication and prevented communication failures Our findings support use of the WHO checklist in various surgical fields

A meta‐analysis of the efficacy of wound catheters for post‐operative pain management

Abstract: Local anesthetics (LA) are injected via catheters placed in surgical wounds for post-operative analgesia. The primary aim of this systematic review was to assess whether LA reduce pain intensity when injected via wound catheters. A literature search was performed from Medline via PubMed, EMBASE and the Cochrane database from 1966 until November 2009. The search strategy included the following key words: pain, postoperative, catheters and local anesthetics. Two co-authors independently read every article that was initially included and extracted data into a pre-defined study record form. A total of 753 studies primarily fit the search criteria and 163 were initially extracted. Of these, 32 studies were included in the meta-analysis. Wound catheters provided no significant analgesia at rest or on activity, except in patients undergoing gynecological and obstetric surgery at 48 h (P=0.03). The overall morphine consumption was lower (≈13 mg) during 0-24 h (P<0.001) in these patients. No significant differences in side effects were found, except for a lower risk of wound breakdown (P=0.048) and a shorter length of hospital stay (P=0.04) in patients receiving LA. A statistically significant heterogeneity was seen between the studies in most end-points. LA injected via wound catheters did not reduce pain intensity, except at 48 h in a subgroup of patients undergoing obstetric and gynecological surgery. Rescue analgesic consumption was also lower in this group at 0-24 h. The magnitude of these effects was small and compounded by pronounced heterogeneity.

Accuracy of the pleth variability index to predict fluid responsiveness depends on the perfusion index

Abstract: Background: Respiratory variations in plethysmographic waveform amplitudes derived from pulse oximetry are believed to predict fluid responsiveness. The non-invasive pleth variability index (PVI) is a variable based on the calculation of changes in the perfusion index (PI). The aim of the following study was to examine whether the predictive power of PVI depends on different values of PI. Methods: Eighty-one patients undergoing elective coronary artery surgery were studied before operation: at baseline after induction of anaesthesia and during passive leg raising (PLR). Each patient was monitored with central venous pressure (CVP), the PiCCO monitor and the non-invasive Masimo monitoring system. Stroke volume index by transpulmonary thermodilution (SVI(TPTD)), pulse pressure variation (PPV), stroke volume variation (SVV) and systemic vascular resistance index (SVRI) were measured using the PiCCO monitoring system. PI and PVI were obtained by pulse oximetry. Results: Responders were defined to increase their SVI(TPTD) > 15 after PLR. The highest area under the curve (AUC) was found for PPV (AUC: 0.83, P<0.0001) and SVV (AUC: 0.72, P=0.002), in contrast to PVI (AUC: 0.60, P=0.11) and CVP (AUC: 0.60, P=0.13). The accuracy of PVI to predict fluid responsiveness was improved on analysing patients with higher PI values. PI of about 4 (n=45) achieved statistical significance (AUC: 0.72, P=0.01). Conclusion: The PVI was not able to predict fluid responsiveness with sufficient accuracy. In patients with higher perfusion states, the PVI improved its ability to predict haemodynamic changes, strongly suggesting a relevant influence of the PI on the PVI.

Oxygen concentration and characteristics of progressive atelectasis formation during anaesthesia.

Abstract: Background: Atelectasis is a common consequence of pre-oxygenation with 100% oxygen during induction of anaesthesia. Lowering the oxygen level during pre-oxygenation reduces atelectasis. Whether this effect is maintained during anaesthesia is unknown. Methods: During and after pre-oxygenation and induction of anaesthesia with 60%, 80% or 100% oxygen concentration, followed by anaesthesia with mechanical ventilation with 40% oxygen in nitrogen and positive end-expiratory pressure of 3 cmH2O, we used repeated computed tomography (CT) to investigate the early (0–14 min) vs. the later time course (14–45 min) of atelectasis formation. Results: In the early time course, atelectasis was studied awake, 4, 7 and 14 min after start of pre-oxygenation with 60%, 80% or 100% oxygen concentration. The differences in the area of atelectasis formation between awake and 7 min and between 7 and 14 min were significant, irrespective of oxygen concentration (P<0.05). During the late time course, studied after pre-oxygenation with 80% oxygen, the differences in the area of atelectasis formation between awake and 14 min, between 14 and 21 min, between 21 and 28 min and finally between 21 and 45 min were all significant (P<0.05). Conclusion: Formation of atelectasis after pre-oxygenation and induction of anaesthesia is oxygen and time dependent. The benefit of using 80% oxygen during induction of anaesthesia in order to reduce atelectasis diminished gradually with time.

Mortality Reduction in Cardiac Anesthesia and Intensive Care: results of the first International Consensus Conference

Abstract: There is no consensus on which drugs/techniques/strategies can affect mortality in the perioperative period of cardiac surgery. With the aim of identifying these measures, and suggesting measures for prioritized future investigation we performed the first International Consensus Conference on this topic. The consensus was a continuous international internet-based process with a final meeting on 28 June 2010 in Milan at the Vita-Salute University. Participants included 340 cardiac anesthesiologists, cardiac surgeons, and cardiologists from 65 countries all over the world. A comprehensive literature review was performed to identify topics that subsequently generated position statements for discussion, voting, and ranking. Of the 17 major topics with a documented mortality effect, seven were subsequently excluded after further evaluation due to concerns about clinical applicability and/or study methodology. The following topics are documented as reducing mortality: administration of insulin, levosimendan, volatile anesthetics, statins, chronic β-blockade, early aspirin therapy, the use of pre-operative intra-aortic balloon counterpulsation, and referral to high-volume centers. The following are documented as increasing mortality: administration of aprotinin and aged red blood cell transfusion. These interventions were classified according to the level of evidence and effect on mortality and a position statement was generated. This International Consensus Conference has identified the non-surgical interventions that merit urgent study to achieve further reductions in mortality after cardiac surgery: insulin, intra-aortic balloon counterpulsation, levosimendan, volatile anesthetics, statins, chronic β-blockade, early aspirin therapy, and referral to high-volume centers. The use of aprotinin and aged red blood cells may result in increased mortality.

GlideScope videolaryngoscope vs. Macintosh direct laryngoscope for intubation of morbidly obese patients: a randomized trial

Abstract: Background Morbidly obese patients are at increased risk of hypoxemia during tracheal intubation because of increased frequency of difficult and impossible intubation and a decreased apnea tolerance. In this study, intubation with the GlideScope videolaryngoscope (GS) was compared with the Macintosh direct laryngoscope (DL) in a group of morbidly obese patients. Methods One hundred consecutive patients (body mass index ≥ 35 kg/m2) scheduled for bariatric surgery were randomized 1 : 1 to intubation with GS (group GS) or DL (group DL). The primary outcome was intubation time. Secondary outcomes were number of attempts, Cormack-Lehane grade, intubation difficulty scale score (IDS), subjective difficulty of intubation, desaturation, airway bleeding, postoperative sore throat, and hoarseness. Group assignment was not blinded. Results Intubation in group GS and group DL lasted 48 (22–148) and 32 s (17–209), respectively (median (range); P = 0.0001); median difference 11 s (95% confidence interval 6–17). Laryngoscopic views were better in group GS with Cormack–Lehane grades 1/2/3/4 distributed as 35/13/2/0 vs. 23/13/10/4 in group DL (P = 0.003). IDS scores were significantly lower with GS than with DL. No other statistically significant differences were found. Two cases of failed intubation occurred in group DL vs. none in group GS (non-significant). Both patients were intubated with the GlideScope without problems. Conclusion Intubation of morbidly obese patients with GS was slightly slower than with DL. The increased intubation time was of no clinical consequence as no patients became hypoxemic. Both devices generally performed well in the studied population, but the GS provided better laryngoscopic views and decreased IDS scores.

H-index is a sensitive indicator of academic activity in highly productive anaesthesiologists: results of a bibliometric analysis

Abstract: Background H-index distinguishes differences in scholarly output across faculty ranks in anaesthesiologists, but whether h-index also identifies differences in other aspects of productivity is unknown. We tested the hypothesis that h-index is an indicator of not only publication record, but also grant funding and mentoring in highly productive US academic anaesthesiologists. Methods We conducted an internet analysis of the Foundation for Anesthesia Education and Research Academy of Research Mentors in Anesthesiology (n = 43). Publications, citations, citations per publication, and h-index for each investigator were obtained using the Scopus®. Total grants, active grants, years of funding, and duration of longest funded grant were recorded using the USNational Institutes of Health Research Portfolio Online Reporting Tools®. Members were surveyed to identify the number of their career trainees and those who obtained independent funding. Results The median [IRQ (Interquartile range)] h-index of members was 23 [17–32 (8–50)]. Members published 136 [100–225 (39–461)] papers with 3573 [1832–5090 (150–11,601)] citations and 21 [15–32 (4–59)] citations per publication. Members received four [3–7 (0–10)] grants and were funded for 29 [17–45 (0–115)] grant-years. Survey respondents (79%) mentored 40 [26–69 (15–191)] trainees, three [2–6 (0–20)] of which subsequently received funding. Members with h-indices greater than the median had more publications, citations, citations per publication, grants, and years of funding compared with their counterparts. H-index was associated with total citations, active grants, and the number of trainees. Conclusions In addition to publication record, h-index sensitively indicates grant funding and mentoring in highly productive US academic anaesthesiologists.

Ultrasound-guided bilateral dual transversus abdominis plane block: a new four-point approach.

Abstract: Background: We describe a new ultrasound-guided bilateral dual transversus abdominis plane block. Our hypothesis was that we could anaesthetize both the upper (Th6–Th9) and the lower (Th10–Th12) abdominal wall bilaterally using a four-point singleshot technique to provide effective post-operative analgesia. Methods: A prospective cohort of 25 recovery room patients was included. They had undergone major open or laparoscopic abdominal surgery under general anaesthesia and had severe post-operative pain. The blocks were conducted using a high-frequency linear transducer and a 22 G, 80-mm-long needle. The needle was inserted inplane from medial to lateral for each injection. Fifteen millilitres of bupivacaine 2.5 mg/ml was injected at each of the four sites. Results: Block performance took on average 16 min (range 10–20 min). The 25 patients reported a reduction of their maximum pain (visual analogue scale 0–10) from a mean of 8.2 to a mean of 2.2 10 min after block performance (Po0.001). They were discharged from the post-anaesthesia care unit after an average of 34 min. Twenty-one patients (84%) did not require any i.v. opioids in the following 6 h. Sixteen patients (64%) were mobilized within 6 h after the block. Data were similar irrespective of open or laparoscopic surgery (P 5 0.68). Conclusion: This new four-point single-shot technique was effective in decreasing severe pain after a major abdominal surgery. The block, although short-lived, facilitated discharge from the post-anaesthesia care unit, few patients required opioids on the day of surgery and mobilization was improved.

Efficacy and safety of perioperative pregabalin for post-operative pain: a meta-analysis of randomized-controlled trials.

Abstract: We calculated in a meta-analysis the effect size for the reduction of post-operative pain and post-operative analgesic drugs, which can be obtained by the perioperative administration of pregabalin. Three end-points of efficacy were analysed: early (6 h-7 days) post-operative pain at rest (17 studies) and during movement (seven studies), and the amount of analgesic drugs in the studies that obtained identical results for pain at rest (12 studies). Reported adverse effects were also analysed. The daily dose of pregabalin ranged from 50 to 750 mg/day. The duration of treatment in patients assessed for pain ranged from a single administration to 2 weeks. Pregabalin administration reduced the amount of post-operative analgesic drugs (30.8% of non-overlapping values - odds ratio=0.43). There was no effect with 150, and 300 or 600 mg/day provided identical results. Pregabalin increased the risk of dizziness or light-headedness and of visual disturbances, and decreased the occurrence of post-operative nausea and vomiting (PONV) in patients who did not receive anti-PONV prophylaxis. The administration of pregabalin during a short perioperative period provides additional analgesia in the short term, but at the cost of additional adverse effects. The lowest effective dose was 225-300 mg/day.

Monitoring patients at risk of massive transfusion with Thrombelastography or Thromboelastometry: a systematic review

Abstract: Background Thrombelastography (TEG) and Thrombelastometry (ROTEM) are viscoelastic whole-blood assays evaluating the haemostatic capacity of blood. These devices are used in algorithms to guide transfusion of haemostatic blood components. Methods The methods used for this study were systematic reviews with meta-analyses and trial sequential analyses of randomised clinical trials (RCTs) of TEG/ROTEM-based algorithm compared with standard treatment in patients with bleeding. Primary outcome was all-cause mortality. We searched the literature in seven databases (up to 31 October 2010), reference lists, registers of ongoing trials, and contacted authors and experts. We extracted data from included studies related to study methods, interventions, outcomes, bias risk and adverse events using Cochrane methodology. All trials irrespective of blinding or language status were included. Results Nine trials involving 776 participants were included. Eight trials involved cardiac surgery with an average blood loss of 390–960 ml, and one trial investigated liver transplantations. One trial was classified as low-risk-of-bias trial. We found two ongoing trials. No impact was identified on mortality, amount of blood transfused, incidence of surgical reinterventions, time to extubation, or length of stay in hospital and intensive care unit. We identified a significant reduction in blood loss favouring the use of TEG/ROTEM {85 ml [95% confidence interval (CI) 29.4−140.7]} and in the proportion of patients receiving freshly frozen plasma and platelets [relative risk 0.39 (95%CI 0.27–0.57)]. Conclusion There is currently weak evidence to support the use of TEG/ROTEM as a tool to guide transfusion in patients with severe bleeding. Further studies need to address other clinical settings and with larger blood losses.

Ketamine as an analgesic in the pre-hospital setting: a systematic review.

Abstract: Background: Pain is a common presenting complaint and there is considerable debate regarding the best practice for analgesia in the pre-hospital environment for trauma patients with severe pain. Methods: A review of the literature was conducted using a number of electronic medical literature databases from their earliest record to the latest available at the time the search was conducted (May 2010). Medical Subject Headings, keywords and a pre-hospital search filter were used to yield relevant literature. Results: The search strategy yielded a total of 837 references. Seven hundred and fifty of these references were excluded as they did not meet the inclusion criteria. Of the 87 articles short listed for abstract or full-text review, six reported on ketamine use as an analgesic agent in the prehospital setting. Two papers were prospective randomized-controlled trials, and the number of patients included in the studies ranged from 4 to 164. Three studies aimed to report on the effectiveness of ketamine for pain intensity reduction; two concluded that ketamine provided safe and effective pain relief and one reported that ketamine reduced the amount of morphine required but was not associated with ar eduction in pain intensity. One study identified a significantly higher prevalence of adverse effects following ketamine administration. The other studies reported no significant side effects and concluded that ketamine was safe. Conclusion: Ketamine is a safe and effective analgesic agent. The addition of ketamine as an analgesic agent may improve the management of patients presenting with acute traumatic pain in the pre-hospital setting.

Phosphate-containing dialysis solution prevents hypophosphatemia during continuous renal replacement therapy.

Abstract: Background: Hypophosphatemia occurs in up to 80% of the patients during continuous renal replacement therapy (CRRT). Phosphate supplementation is time-consuming and the phosphate level might be dangerously low before normophosphatemia is re-established. This study evaluated the possibility to prevent hypophosphatemia during CRRT treatment by using a new commercially available phosphate-containing dialysis fluid. Methods: Forty-two heterogeneous intensive care unit patients, admitted between January 2007 and July 2008, undergoing hemodiafiltration, were treated with a new Gambro dialysis solution with 1.2 mM phosphate (Phoxilium) or with standard medical treatment (Hemosol B0). The patients were divided into three groups: group 1 (n=14) receiving standard medical treatment and intravenous phosphate supplementation as required, group 2 (n=14) receiving the phosphate solution as dialysate solution and Hemosol B0 as replacement solution and group 3 (n=14) receiving the phosphate-containing solution as both dialysate and replacement solutions. Results: Standard medical treatment resulted in hypophosphatemia in 11 of 14 of the patients (group 1) compared with five of 14 in the patients receiving phosphate solution as the dialysate solution and Hemosol B0 as the replacement solution (group 2). Patients treated with the phosphate-containing dialysis solution (group 3) experienced stable serum phosphate levels throughout the study. Potassium, ionized calcium, magnesium, pH, pCO(2) and bicarbonate remained unchanged throughout the study. Conclusion: The new phosphate-containing replacement and dialysis solution reduces the variability of serum phosphate levels during CRRT and eliminates the incidence of hypophosphatemia. (Less)

Effect of PEEP on regional ventilation during laparoscopic surgery monitored by electrical impedance tomography.

Abstract: Background: Anesthesia per se and pneumoperitoneum during laparoscopic surgery lead to atelectasis and impairment of oxygenation. We hypothesized that a ventilation with positive end-expiratory pressure (PEEP) during general anesthesia and laparoscopic surgery leads to a more homogeneous ventilation distribution as determined by electrical impedance tomography (EIT). Furthermore, we supposed that PEEP ventilation in lung-healthy patients would improve the parameters of oxygenation and respiratory compliance. Methods: Thirty-two patients scheduled to undergo laparoscopic cholecystectomy were randomly assigned to be ventilated with ZEEP (0 cmH2O) or with PEEP (10 cmH2O) and a subsequent recruitment maneuver. Differences in regional ventilation were analyzed by the EIT-based center-of-ventilation index (COV), which quantifies the distribution of ventilation and indicates ventilation shifts. Results: Higher amount of ventilation was examined in the dorsal parts of the lungs in the PEEP group. Throughout the application of PEEP, a lower shift of ventilation was found, whereas after the induction of anesthesia, a remarkable ventral shift of ventilation in ZEEP-ventilated patients (COV: ZEEP, 40.6 ± 2.4%; PEEP, 46.5 ± 3.5%; P<0.001) was observed. Compared with the PEEP group, ZEEP caused a ventral misalignment of ventilation during pneumoperitoneum (COV: ZEEP, 41.6 ± 2.4%; PEEP, 44 ± 2.7%; P=0.013). Throughout the study, there were significant differences in the parameters of oxygenation and respiratory compliance with improved values in PEEP-ventilated patients. Conclusion: The effect of anesthesia, pneumoperitoneum, and different PEEP levels can be evaluated by EIT-based COV monitoring. An initial recruitment maneuver and a PEEP of 10 cmH2O preserved homogeneous regional ventilation during laparoscopic surgery in most, but not all, patients and improved oxygenation and respiratory compliance.

Positive end-expiratory pressure-induced changes in end-expiratory lung volume measured by spirometry and electric impedance tomography.

Abstract: BACKGROUND A bedside tool for monitoring changes in end-expiratory lung volume (ΔEELV) would be helpful to set optimal positive end-expiratory pressure (PEEP) in acute lung injury/acute respiratory distress syndrome patients. The hypothesis of this study was that the cumulative difference of the inspiratory and expiratory tidal volumes of the first 10 breaths after a PEEP change accurately reflects the change in lung volume following a PEEP alteration. METHODS Changing PEEP induces lung volume changes, which are reflected in differences between inspiratory and expiratory tidal volumes measured by spirometry. By adding these differences with correction for offset, for the first 10 breaths after PEEP change, cumulative tidal volume difference was calculated to estimate ΔEELV(VT) ((i-e)) . This method was evaluated in a lung model and in patients with acute respiratory failure during a PEEP trial. In patients, ΔEELV(VT) ((i-e)) were compared with simultaneously measured changes in lung impedance, by electric impedance tomography (EIT), using calibration vs. tidal volume to estimate changes in ΔEELV(EIT) . RESULTS In the lung model, there was close correlation (R(2) = 0.99) between ΔEELV(VT) ((i-e)) and known lung model volume difference, with a bias of -4 ml and limits of agreement of 42 and -50 ml. In 12 patients, ΔEELV(EIT) was closely correlated to ΔEELV(VT) ((i-e)) (R(2) = 0.92), with mean bias of 50 ml and limits of agreement of 131 and -31 ml. Changes in EELV estimated by EIT (ΔEELV(EIT) ) exceeded measurements by spirometry (ΔEELV(VT) ((i-e)) ), with 15 (±15)%. CONCLUSIONS We conclude that spirometric measurements of inspiratory-expiratory tidal volumes agree well with impedance changes monitored by EIT and can be used bedside to estimate PEEP-induced changes in EELV.

Risk factors for intra-abdominal hypertension in mechanically ventilated patients

Abstract: Background: Intra-abdominal hypertension (IAH) in intensive care patients is associated with an adverse outcome, but the risk factors for development of IAH have not been extensively studied. We aimed to identify independent risk factors for IAH in mechanically ventilated (MV) patients. Methods: In this prospective observational study, 563 MV patients staying in the general intensive care unit (ICU) of a university hospital for more than 24 h were observed during their ICU stay. Repeated intermittent measurements of intra-abdominal pressure (IAP) via the urinary bladder were performed. Results: IAH (sustained or repeated IAP≥12 mmHg) developed in 182 patients (32.3%). From all the study patients, 44.4% had a primary pathology in the abdomino-pelvic region. Two thirds of all IAH cases developed in this group. Obesity [body mass index (BMI)>30], high positive end-expiratory pressure (PEEP>10), respiratory failure (PaO2/FiO2 <300), use of vasopressors/inotropes, pancreatitis, hepatic failure/cirrhosis with ascites, gastrointestinal bleeding and laparotomy on admission day were identified as independent risk factors for IAH. None of the patients without any of these risk factors (26 patients) developed IAH. Conclusion: The precise prediction of development IAH in mixed ICU population remains difficult. In the absence of BMI>30, PEEP>10 cmH2O, PaO2/FiO2 <300, use of vasopressors/inotropes, pancreatitis, hepatic failure/cirrhosis with ascites, gastrointestinal bleeding and laparotomy on admission day, the risk for development of IAH in MV ICU patients is minimal.

Pregabalin reduces post-operative pain after mastectomy: a double-blind, randomized, placebo-controlled study.

Abstract: Background: Pregabalin is used for the treatment of neuropathic pain and has shown analgesic efficacy in post-operative pain. The aim of this randomized, double-blinded, placebo-controlled trial (Clinical Trials.gov ID NCT00938548) was to investigate the efficacy and safety of pregabalin for reducing post-operative pain in patients after mastectomy. Methods: Eighty-four women scheduled for elective mastectomy were randomly assigned to groups that received either pregabalin (75 mg) or placebo, 1 h before surgery and 12 h after the initial dose. Assessments of pain [verbal numerical rating scale (VNRS), at rest and with arm abduction] and side effects were performed at 1, 6, 24 and 48 h post-operatively. After discharge from the hospital, pain was assessed by telephone interview at post-operative 1 week and 1 month. Results: VNRS scores for pain at rest were lower in the pregabalin group (n=42) than the placebo group (n=42) at 1, 24 and 48 h post-operatively (P<0.05). VNRS scores for pain with arm abduction were lower in the pregabalin group (n=42) than the placebo group (n=42) at 1 and 24 h, and 1 week post-operatively (P<0.05). Incidences of side effects such as nausea and vomiting, headache, dizziness and blurred vision were similar in both groups. Conclusion: Perioperative administration of pregabalin for a single day (75 mg twice daily) was easy, safe and effective in reducing post-operative pain in patients undergoing mastectomy.

Desaturation following rapid sequence induction using succinylcholine vs. rocuronium in overweight patients

Abstract: Background: Rapid sequence induction may be associated with hypoxemia. The purpose of this study was to investigate the possible difference in desaturation during rapid sequence induction in overweight patients using either succinylcholine or rocuronium. Methods: Sixty patients with a body mass index (BMI) between 25 and 30 kg/m 2 , American Society of Anesthesiologists class I or II, undergoing general anesthesia were randomly divided into a succinylcholine group and a rocuronium group. After a 3-min preoxygenation, patients received rapid sequence induction of general anesthesia with midazolum–fentanyl– propofol and succinylcholine (1.5 mg/kg) or rocuronium (0.9 mg/kg). Ventilation was not initiated until oxygen saturation declined to 92%. We measured the times when oxygen saturation reached 98%, 96%, 94% and 92%. Safe Apnea Time was defined as the time from administration of neuromuscular blocking drugs to oxygen saturation fell to 92%. The recovery period was defined as the time from initiation of ventilation until oxygen saturation was 97%. Arterial blood gases were taken at baseline, after preoxygenation and at 92% oxygen saturation. Results: The mean Safe Apnea Time (95% CI) was 283 (257–309) s in succinylcholine vs. 329 (303–356) s in rocuronium (P 5 0.01). The mean recovery period (95% CI) was 43 (39–48) s in succinylcholine vs. 36 (33–38) s in rocuronium (P 5 0.002). Blood gas analysis showed no difference between the two groups. Conclusions: Succinylcholine was associated with a significantly more rapid desaturation and longer recovery of oxygen saturation than rocuronium during rapid sequence induction in overweight patients.

Cardiac outcome after sevoflurane versus propofol sedation following coronary bypass surgery: a pilot study.

Abstract: Background: Studies of volatile anesthetic administration during coronary artery bypass grafting (CABG) report reduced serum levels of post-operative cardiac troponin-T (cTnT). Our primary objective was to evaluate whether short-term sedation with sevoflurane in the intensive care unit (ICU) – after CABG – could affect the release of cTnT, compared with propofol sedation. Methods: Following isolated CABG with cardiopulmonary bypass, 100 patients were randomized to either sevoflurane via the Anesthetic Conserving Device (AnaConDa®) or propofol for ICU sedation. Study drugs were administered for 2 h during mechanical ventilation and thereafter until extubation criteria were met. The primary endpoint was cTnT 12 h post-operatively. Crude cTnT data were not normally distributed and therefore compared with the Mann–Whitney U-test. Because of the skewed pre-operative and post-operative cTnT data, we performed a post hoc analysis of the change in cTnT between pre-operative values and 12 h post-operatively. Results: There was no statistically significant difference between groups in the primary endpoint cTnT values at 12 h post-operatively, cardiac events or the need for hemodynamic support. In the post hoc analysis, the cTnT increase from pre-operative values to 12 h post-operatively was less pronounced in the sevoflurane group (P=0.008). Conclusion: Post-operative short-term sevoflurane sedation following CABG, in comparison with propofol, did not affect the cTnT values at 12 h post-operatively and clinical outcome was equal between groups. The result from the post hoc analysis, with less cTnT change over time, is nevertheless hypothesis-generating and warrants a larger study.

Pregabalin and dexamethasone improves post-operative pain treatment after tonsillectomy.

Abstract: Background: Post-tonsillectomy pain can be severe. We investigated the analgesic effect from combinations of paracetamol, pregabalin and dexamethasone in adults undergoing tonsillectomy. Methods: In this randomized double-blind study, 131 patients were assigned to either group A (paracetamol+placebo), group B (paracetamol+pregabalin+placebo) or group C (paracetamol+pregabalin+dexamethasone). Pre-operatively, patients received either paracetamol 1000 mg, pregabalin 300 mg, dexamethasone 8 mg or placebo according to their allocation. Post-operative pain treatment included paracetamol 1000 mg 4 × and ketobemidone 2.5 mg p.n. Ketobemidone consumption, pain scores [visual analogue scale (VAS)], nausea, sedation, dizziness, number of vomits and consumption of ondansetron were recorded 2, 4 and 24 h after the operation. P<0.05 was considered statistically significant. Results: The mean 24-h VAS-pain score at rest was reduced in group C (P<0.003) vs. group A. The mean 24-h VAS-pain scores during swallowing were reduced in group B (P=0.009) and group C (P<0.003) vs. group A. Consumption of ketobemidone (1–4 h post-operatively) was lower in group B (P=0.003) and group C (P=0.003) vs. group A. The mean 24-h dizziness score was higher in group B (P<0.003) and C (P=0.003) vs. group A. Other parameters including re-operation for post-tonsillectomy bleeding were not different between groups. Conclusion: Pregabalin and pregabalin+dexamethasone reduced post-operative pain scores and consumption of ketobemidone following tonsillectomy. Dizziness was increased with pregabalin.

Plasma tau protein in comatose patients after cardiac arrest treated with therapeutic hypothermia

Abstract: Background Neurological outcome after cardiac arrest (CA) is difficult to predict in the acute phase. In this pilot study, we assessed blood levels of tau protein as a prognostic marker for the neurological outcome after 6 months in patients treated with hypothermia after resuscitation from CA. Methods 22 unconscious patients resuscitated after CA were treated with mild hypothermia (32–34°C) for 26 h. Blood samples were collected at 2, 6, 12, 24, 48, and 96 h after CA, and the concentration of tau protein was analyzed. Neurological outcome was assessed with the Glasgow-Pittsburgh cerebral performance category (CPC) scale at intensive care unit (ICU) discharge and after 6 months. The higher of the two CPC scores was used. Results At ICU discharge, 21/22 patients were alive, of whom 10 had a good (CPC 1–2) outcome. After 6 months, 15/22 patients were alive, of whom 14 had a good outcome. Tau protein levels were higher among those with a poor outcome at 48 h and 96 h. At 96 h sampling, tau concentration predicted a poor outcome (CPC 3–5) with a sensitivity of 71% and a specificity of 93%. Conclusions Although in a pilot study, a late increase in plasma tau protein seems to be associated with a worse outcome after hypothermia treatment after CA, although more studies are needed.

Chloroprocaine for spinal anesthesia: a retrospective analysis.

Abstract: Background Recent volunteer and clinical studies of chloroprocaine (CP) have evaluated its use for outpatient spinal anesthesia. This retrospective review describes the discharge characteristics and reported side effects of spinal CP in a large number of patients undergoing outpatient procedures. Methods All patients who received spinal anesthesia for ambulatory procedures over a 20-month period were accessed using computer-generated reports. Charts from 601 anesthetics were analyzed for spinal drug used, block characteristics, side effects and discharge data. Results CP was the most frequently used spinal anesthetic (84% of cases, n=503) for outpatient procedures. CP (median dose 40 mg, range 20-60 mg) times from injection to ambulation and discharge were 107±24 and 171±45 min, respectively. Lidocaine (median dose 60 mg, range 30-100 mg, n=84) times from injection to ambulation and discharge were 155±40 and 224±57 min, respectively (P Conclusions For ambulatory patients at our institution, the time to achievement of discharge criteria was significantly reduced with CP 40 vs. lidocaine 60 mg. There have been no reports of perioperative neurologic injury with the introduction of CP as a spinal anesthetic at our institution.

A preliminary validation of the Swedish version of the Critical-Care Pain Observation Tool in adults.

Abstract: Background: Assessing pain in critically ill patients can be complicated, especially for those unable to communicate. A recently developed pain assessment tool, the Critical-Care Pain Observation T ...