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The American Society of Regional Anesthesia and Pain Medicine's guidelines recommend a 1-hour interval after neuraxial anesthesia (NA) before systemic heparinization to mitigate the risk of spinal hematoma (SH). The study authors aimed to characterize the time interval between NA and systemic heparinization in vascular surgery patients (primary outcome). The secondary outcomes included the historic incidence of SH, and risk estimation of the SH formation based on available data. Heparin dose, length of surgery, difficulty and/or the number of NA attempts, and patient demographics were recorded.A retrospective analysis between April 2012 and April 2022.A single (academic) center.Vascular surgery patients.Intravenous heparin administration.All (N = 311) vascular patients were reviewed, of whom 127 (5 femoral-femoral bypass, 67 femoral-popliteal bypass, and 55 endovascular aneurysm repairs [EVAR]) received NA and were included in the final analysis. Patients receiving general anesthesia alone (N = 184) were excluded. Neuraxial anesthesia included spinal (N = 119), epidural (N = 4), or combined spinal-epidural (N = 4) blocks. The average time between NA and heparin administration was 42.8 ± 22.1 minutes, with 83.7% of patients receiving heparin within 1 hour of NA. The time between NA and heparin administration was 40.4 ± 22.3, 50.1 ± 23.4, and 31.3 ± 12.5 minutes for femoral-femoral bypass, femoral-popliteal bypass, and EVAR, respectively. Heparin was administered after 1 hour of NA in 20% of femoral-femoral bypass, 27% of femoral-popliteal bypass, and 3.9% of EVAR patients. No SHs were reported during the study period.The vast majority of vascular surgery patients at the authors' center received heparin within 1 hour of NA. Further studies are required to assess if their findings are consistent in other vascular surgery settings and/or centers.

IntroductionLiver resection patients may be at an increased risk of local anesthetic (LA) toxicity because the liver is essential for metabolizing LA and producing proteins (mainly α1-acid glycoprotein (AAG)) that bind to it and reduce the free (and pharmacologically active/toxic) levels in circulation. The liver resection itself, manipulation during surgery, and pre-existing liver disease may all interfere with normal hepatic protein synthesis and result in an attenuation of the increased AAG (a positive acute-phase protein) that normally occurs postoperatively. The purpose of this study was to determine whether the AAG response is attenuated postoperatively following liver resection and whether patients approach toxicity thresholds with continuous postoperative epidural infusion of bupivacaine.MethodsProspective, observational study with blood drawn preoperatively, in the postanesthetic care unit, on postoperative day (POD) 2, and prior to discontinuation of epidural analgesia on POD3/POD4. Plasma was analyzed for total and unbound bupivacaine via liquid chromatography–mass spectrometry and AAG via ELISA. Signs/symptoms of local anesthetic systemic toxicity (LAST), pain, and sedation scores were also recorded.ResultsFor the 19 patients completed, total plasma bupivacaine was correlated with total administered, but unbound levels were not associated with the total administered. Unlike non-hepatectomy surgery where unbound LA plasma levels remain stable (or decrease) with continuous postoperative epidural administration, we observed an overall increase. Several patients approached toxicity thresholds and 47% reported at least one symptom of LAST, but no epidurals were discontinued because of LAST. In contrast to the AAG response reported following major non-liver surgery where AAG levels increase twofold, we observed a reduction until POD2 and the magnitude was proportional to resection weight.DiscussionOur results are supported by the literature in suggesting that major liver resection patients may be at an increased vulnerability for LAST. Factors such as the extent of liver disease, resection and intraoperative blood loss should be considered when using continuous postoperative epidural infusion of bupivacaine and vigilance should be used in monitoring, for signs/symptoms of LAST, even for those subtle and non-specific. Future research will be required to verify these findings.Trial registration numberNCT03145805.

Postoperative analgesia following total knee arthroplasty (TKA) often includes intrathecal opioids, periarticular injection (PAI) of local anesthetic, systemic multimodal analgesia, and/or peripheral nerve blockade. The adductor canal block (ACB) provides analgesia without muscle weakness and magnesium sulphate (MgSO4) may extend its duration. The purpose of this trial was to compare the duration and quality of early post-TKA analgesia in patients receiving postoperative ACB (± MgSO4) in addition to standard care. Elective TKA patients were randomized to: 1) sham ACB, 2) ropivacaine ACB, or 3) ropivacaine ACB with added MgSO4. All received spinal anesthesia with intrathecal morphine, intraoperative PAI, and multimodal systemic analgesia. Patients and assessors remained blinded to allocation. Anesthesiologists knew whether patients had received sham or ACB but were blinded to MgSO4. The primary outcome was time to first analgesic (via patient-controlled analgesia [PCA] with iv morphine) following ACB. Secondary outcomes were morphine consumption, side effects, visual analogue scale pain scores, satisfaction until 24 hr postoperatively, and length of stay. Of 130 patients, 121 were included. Nine were excluded post randomization: four were protocol violations, three did not meet inclusion criteria, and two had severe pain requiring open label blockade. There were no differences in the median [interquartile range] time to first PCA request: sham, 310 min [165–550]; ropivacaine ACB, 298 min [120–776]; and ropivacaine ACB with MgSO4, 270 min [113–780] (P = 0.96). Similarly, we detected no differences in resting pain, opioid consumption, length of stay, or associated side effects until 24 hr postoperatively. We found no analgesic benefit of a postoperative ACB, with or without added MgSO4, in TKA patients undergoing spinal anesthesia and receiving intrathecal morphine, an intraoperative PAI, and multimodal systemic analgesia. www.clinicaltrials.gov (NCT02581683); registered 21 October 2015.

To describe an alternative method of measuring the Epidural Waveform Analysis (EWA), a technique through which anesthesiologists can confirm the position of a needle and/or catheter tip in the epidural space. EWA consists of epidural catheter transduction with a pressure system typically used for invasive arterial blood pressure monitoring which generates a characteristic oscillatory waveform (provided the catheter tip is within the epidural space) in synchrony with the pulsatile epidural circulation. The technique requires a double-male connector, a 3-way stopcock and an arterial pressure extension tubing along with the patient's existing arterial line setup while ensuring a meticulously sterile technique to mitigate the risks of neuraxial infection. The technique described herein has been successfully and routinely applied within our institution to measure EWA with the advantage of being potentially less wasteful. EWA allows anesthesiologists to confirm the correct position of an epidural needle/catheter. We describe a method of successfully measuring EWA while reducing wastefulness.

Resumo Justificativa e objetivos A ultrassonografia cardiaca no local de atendimento (USCLA) provou ser importante para orientar o processo de tomada de decisao clinica dos anestesiologistas. Treinar os residentes para fazer e interpretar uma USCLA e viavel e eficaz. No entanto, o grau de retencao do conhecimento apos o treinamento permanece um assunto de debate. Procuramos fornecer uma descricao do curriculo de quatro semanas do treinamento de USCLA e avaliar a retencao do conhecimento entre os residentes de anestesia seis meses apos a rotacao em USCLA. Metodos Uma analise prospectiva foi realizada com 11 residentes seniores de anestesia. Ao final da rotacao em USCLA, os participantes preencheram um questionario (avaliando o numero de exames ultrassonograficos concluidos, o conhecimento adquirido e o nivel de conforto dos residentes com a USCLA) e fizeram um exame de multipla escolha para USCLA, composto por perguntas escritas e baseadas em video. Seis meses depois, os participantes preencheram um questionario de acompanhamento e um exame similar. A autoavaliacao do conhecimento e os escores do exame foram comparados no final da rotacao e apos seis meses. Correlacoes de Spearman foram usadas para testar a relacao entre o numero de exames concluidos e os escores dos exames, o conhecimento percebido, os escores dos exames, o numero de exames e o conhecimento percebido. Resultados Os escores medios dos exames (50) foram: 44,1 no final da rotacao e 43 apos seis meses. Os residentes tiveram conhecimento percebido significativamente maior (10) no final da rotacao (8,0) que apos seis meses (5,5), p = 0,003. No final da rotacao, todos os residentes se sentiram confortaveis usando o aparelho de USCLA e, aos seis meses, 10/11 ainda se sentiam confortaveis. Todos os residentes haviam usado o USCLA em sua pratica clinica apos o final da rotacao e a razao mais citada para nao usar o USCLA com mais frequencia foi a falta de necessidade clinica percebida. Uma correlacao forte e estatisticamente significativa (rho = 0,804, p = 0,005) foi observada entre o numero de exames realizados durante a rotacao em USCLA e o conhecimento percebido em seis meses de seguimento. Conclusao Quatro semanas de treinamento intensivo de USCLA resultaram em aquisicao e retencao adequadas do conhecimento por seis meses.

Resumo Justificativa A intubacao seletiva neonatal do bronquio principal esquerdo para tratar a doenca pulmonar direita e tipicamente feita com elaboradas manobras, instrumentacao e dispositivos. Isso e frequentemente atribuido a geometria bronquica que favorece a entrada principal direita de um tubo endotraqueal (TET) deliberadamente avancado para alem da carina. Resumo do caso Recem‐nascido com enfisema bolhoso grave que afetava o pulmao direito e precisou com urgencia da nao ventilacao desse pulmao. Para conseguir a intubacao bronquica esquerda fizemos uma rotacao de 180° do TET, de forma que o olho de Murphy ficasse voltado para a esquerda, e nao para a direita, e para simular uma intubacao a esquerda orientamos ligeiramente o TET, de modo que sua concavidade virasse para a esquerda em vez de para a direita, como em uma intubacao convencional a direita. Conclusao A intubacao urgente do bronquio principal esquerdo com um TET pode ser facilmente obtida se reconhecermos que e a posicao da ponta do TET e a direcao de sua concavidade que determinam para qual bronquio o TET ira quando avancado. Isso e importante em neonatos criticamente doentes diante da margem de seguranca e janela de tempo pequenas e na ausencia de tubos de duplo lumen. O uso de broncofibroscopio e bloqueadores deve ser considerado como planos de seguranca.

From the *Department of Anesthesiology and Perioperative Medicine, Queen’s University, Kingston, Ontario, Canada; †Department of Anesthesiology and Pain Medicine, Nationwide Children’s Hospital, Columbus, OH; and ‡Department of Anaesthesia, The Tweed Hospital, Tweed Heads, Australia. Address reprint requests to Anthony M.-H. Ho, MD, FRCPC, FCCP, Department of Anesthesiology and Perioperative Medicine, Victory 2, Kingston General Hospital, Queen’s University, 76 Stuart Street, Kingston, Ontario, Canada, K7L 2V7. E-mail: hoamh@hotmail.com © 2016 Elsevier Inc. All rights reserved. 1053-0770/2601-0001$36.00/0 http://dx.doi.org/10.1053/j.jvca.2015.04.005

To the Editor, When performing nerve blocks or vascular cannulation under ultrasound (US) guidance, the depth of the target nerve/vessel and/or the defining landmark ( d US cm; [figure 1][1]) is seen on the US screen and noted by the practitioner. This depth serves as a guide for determining the

Renal dysfunction after coronary artery bypass grafting is common and is associated with increased morbidity and mortality. A number of strategies with potential renoprotective effects have been investigated, but no single one has been found to warrant routine use in CABG except fenoldopam in which the data to date appear promising. Other measures such as avoidance of nephrotoxic agents, including recent radiocontrast for coronary angiography, may reduce the incidence of renal dysfunction after cardiac surgery and should be implemented in routine care, whenever possible. The best renal protection strategy remains the same as for other organ protection and consists of optimizing haemodynamics, oxygenation, metabolic states and hydration.

Background Cannulation of the internal jugular vein (IJV) is traditionally performed using the central-longitudinal approach. Pneumothorax, carotid artery puncture, and failure to cannulate are uncommon, but by no means rare, complications. Ultrasound (US) guidance for IJV cannulation has reduced but not eliminated such complications. Technique We herein introduce a new approach, coined the “medial-transverse approach” due to the perpendicular angle at which the introducer needle is advanced toward the IJV from the median to lateral direction. Discussion The direction of the introducer needle is not toward the lung, thus virtually eliminating the possibility of pneumothorax. The image of the entire needle is seen when the US probe is typically orientated for a short-axis view of the IJV and carotid artery, thus improving the chance of uncomplicated IJV puncture. We have used this technique with apparent success in thousands of cases over the past 20 years in two different institutions. Conclusion A modified IJV cannulation technique that seems to have unique advantages over traditional approaches has been described. This technique is compatible with the blind and US-guided approaches.

When a professional soccer player required ankle surgery, his electrocardiogram showed several abnormalities.

If tracheal intubation is not possible using direct laryngoscopy, one option is to use a laryngeal mask airway (LMA) through which an endotracheal tube (ETT) can be passed. In children, however, the size of an uncuffed ETT that can pass through the lumen of an LMA is sometimes too small for the trachea, resulting in gas leakage around the ETT. Using a cuffed ETT may reduce the gas leak but withdrawal of the LMA is then prevented by the pilot balloon. In this study, the largest sizes of cuffed and uncuffed Mallinckrodt™ ETTs that could pass with ease through various sizes of paediatric Classic™ and ProSeal™ LMAs were documented. For cuffed ETTs, withdrawal of the LMA was made possible by simply cutting off the pilot balloon. The ETT cuff-inflating mechanism was then repaired by passing a 20 or 22 gauge cannula into the cut end of the inflating tubing. The proximal end of the cannula was then connected to a one-way valve or a three-way stopcock. This technique of cutting off the pilot balloon of the cuffed ETT made it possible to use paediatric cuffed ETTs in exchange for the LMAs tested. The task was easy to perform. Subsequent repair of the cuff-inflation tubing was effective and could withstand high pressures. These findings indicate that it is possible to pass cuffed ETTs through paediatric LMA lumens, which can provide ventilation without gas leaks, unlike uncuffed ETTs.

Objectives: Pulmonary dysfunction following lung ischaemia—reperfusion is a well-known phenomenon, which may contribute to post-cardiac surgical morbidity. The process is associated with pulmonary inflammatory response and cellular apoptosis. Early molecular mechanisms leading to such lung injury remain largely unknown. We examined whether lung ischaemia and reperfusion cause significant expression changes in numerousgenesin thelungs involved inpulmonaryapoptosisand othercellularprocessesbyusingoligonucleotidemicroarraysinan experimental model of rodent lung ischaemia—reperfusion injury. Methods: Sprague-Dawley rodents (n = 5 in each group) were anaesthetised and underwent controlled ventilation, with varying durations of warm lung ischaemia (60 and 90 min) followed by a short reperfusion period. The right middle lobe of the lung was harvested. Gene expression changes in the lungs were analysed by rodent DNA microarray chips, and reverse transcription polymerase chain reaction (RT-PCR) performed to validate changes in gene expression. Results:Significant expression changes, with reference to false discovery rate (FDR) controls, were detected in over 80 genes following controlled lung ventilation, and more than 50 were up-regulated more than 2-fold. Lung ischaemia—reperfusion caused expression changes in over 50 additional genes, including many novel genes not previously associated with lung ischaemia—reperfusion. Up-regulated genes identified include those associated with apoptosis, inflammation and cell-cycle control. Conclusions: Large numbers of genes relating to cell metabolism, transcription control, inflammation and apoptosis were significantly up- and down-regulated following controlled ventilation and early lung ischaemia—reperfusion, consistent with previous studies. In addition, novel genes related to lung injury were identified. These genetic signatures provide new insights into early molecular mechanisms of ischaemia— reperfusion lung injury and help refine therapeutic strategies to lessen pulmonary dysfunction following cardiac surgery. # 2010 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.

We describe a novel technique, previously applied to small children, for adult one-lung anaesthesia in which a single-lumen endotracheal tube is used with an endobronchial balloon blocker. The main aims of the technique are to reduce the likelihood of cephalad displacement of the balloon into the trachea and to facilitate directional placement of the endobronchial balloon. We present five illustrative cases of one-lung anaesthesia in patients of adult size, in which the endotracheal tube-endobronchial balloon technique was considered preferable to the use of a double-lumen tube technique. The situations included difficult intubation, need for postoperative ventilation, a tortuous trachea and an unexpected need to perform one-lung anaesthesia. The technique involved deliberate placement of the endotracheal tube tip near the carina to block cephalad dislodgement of the blocker. The chance of the balloon blocking the endotracheal tube tip could be further reduced by having the intraluminal endobronchial balloon blocker emerge through the Murphy eye.

Background Current methods of locating the epidural space rely on surface anatomical landmarks and loss-of-resistance (LOR). We are not aware of any data describing real-time ultrasound (US)-guided epidural access in adults. Methods We evaluated the feasibility of performing real-time US-guided paramedian epidural access with the epidural needle inserted in the plane of the US beam in 15 adults who were undergoing groin or lower limb surgery under an epidural or combined spinal–epidural anaesthesia. Results The epidural space was successfully identified in 14 of 15 (93.3%) patients in 1 (1–3) attempt using the technique described. There was a failure to locate the epidural space in one elderly man. In 8 of 15 (53.3%) patients, studied neuraxial changes, that is, anterior displacement of the posterior dura and widening of the posterior epidural space, were seen immediately after entry of the Tuohy needle and expulsion of the pressurized saline from the LOR syringe into the epidural space at the level of needle insertion. Compression of the thecal sac was also seen in two of these patients. There were no inadvertent dural punctures or complications directly related to the technique described. Anaesthesia adequate for surgery developed in all patients after the initial spinal or epidural injection and recovery from the epidural or spinal anaesthesia was also uneventful. Conclusions We have demonstrated the successful use of real-time US guidance in combination with LOR to saline for paramedian epidural access with the epidural needle inserted in the plane of the US beam.

Background: Cardiopulmonary bypass (CPB) is associated with neutrophil activation, pulmonary sequestration, and release of inflammatory mediators leading to pulmonary dysfunction. We investigate the effect of continuous ventilation during cardiopulmonary bypass on neutrophil activation and pulmonary sequestration. Methods: Forty-six patients undergoing coronary artery bypass grafting with cardiopulmonary bypass were prospectively randomized to continuous ventilation and nonventilation groups. Blood samples were collected, and bronchoalveolar lavage (BAL) was performed following induction of anesthesia and at 4 hr after aortic declamping. Differential white cell count was measured, and flow cytometry to determine cell count numbers and quantify CD45 and CD11b leukocyte cell surface adhesion molecule expression was performed on the blood and BAL samples. Results: Twenty-three patients were randomized to standard nonventilated CPB and 23 patients to ventilation throughout CPB. Significant increases in blood and BAL neutrophil numbers were detected at 4 hr following aortic declamping in both groups (Blood: NV p < .0001, V p < .0001; BAL: NV p = .017, V p = .0007). No significant inter-group differences in BAL and blood neutrophil numbers were found. Significantly higher blood neutrophil CD11b meanfluorescent intensity levels werepresent4hrfollowingdeclampingcomparedwithbaselineinbothgroups(NVBlood, p =.021; V Blood p < .0001). No significant inter- or intragroup differences in BAL neutrophil CD11b mean fluorescent intensity levels were found. There was no death or major complication. Conclusions: Cardiopulmonary bypass during coronary artery bypass grafting is associated with increased neutrophil pulmonary sequestration, and blood neutrophil CD11b activation. Continuous ventilation during cardiopulmonary bypass does not significantly reduce neutrophil pulmonary sequestration or activation.

The effects of flow rheology of non-Newtonian fluids on the time-dependent film-thickness history between non-parallel sliding-squeezing surfaces are studied. On the basis of the power-law fluid model, the hydrodynamic film pressure is obtained from the non-Newtonian dynamic Reynolds-type equation by considering the transient squeezing-action effect. The hydrodynamic film force is then applied to derive the non-linear motion equation of the squeezing part. Using the non-linear transient method, the film-height trajectory of the squeezing part is presented. The results of the present study provide a reference for engineer applications in machine tools, the matched gears, the rolling elements, and the piston-cylinder systems when viscosity-pressure dependence, viscosity-temperature variation, and elastic deformations of the contacting surfaces are neglected.

A four-hour integrated teaching session on clinical decision analysis has been developed and introduced as part of the Life Long Learning Skills course for medical students at The Chinese University of Hong Kong. The feasibility and effectiveness of teaching the principles and practice of clinical decision analysis to final-year undergraduate medical students was evaluated. One hundred and thirty-two students were randomly assigned to medical (intervention) and surgical rotations (control) and were assessed two weeks before and three weeks following a teaching session. The students' performance was assessed in response to 10 A-type multiple choice question items that incorporated various clinical scenarios requiring decision making and interpreting cost-effectiveness ratios and sensitivity analysis graphs. More students in the intervention group improved their overall performance scores compared with those in the control group (23.4% vs. 7.4%; 16.1% difference; 95% confidence interval [CI], 3.8-28.5%; p = 0.01). Improvements were in interpretation of decision making (22.2% difference; 95% CI, 10.1-34.4%; p0.001). No improvements were seen for calculating cost-effectiveness ratios or interpreting sensitivity analysis graphs. The overall educational intervention was well received by students and effective in improving students' clinical decision analysis skills under simulated conditions.

Severe bleeding from injury to abdominal wall blood vessels during minor laparoscopic procedures can occur. Two cases of shock presenting several hours after surgery are presented.

The aim of present study is to investigate the effect of chord-wise flexure amplitude on unsteady aerodynamic characteristics for a flapping airfoil with various combinations of Reynolds number and reduced frequency. Unsteady, viscous flows over a single flexible airfoil in plunge motion are computed using conformal hybrid meshes. The dynamic mesh technique is applied to illustrate the deformation modes of the flexible flapping airfoil. In order to investigate the influence of the flexure amplitude on the aerodynamic performance of the flapping airfoil, the present study considers eight different flexure amplitudes ( a 0 ) ranging from 0 to 0.7 in intervals of 0.1 under conditions of Re=10 4 , reduced frequency k =2, and dimensionless plunge amplitude h 0 =0.4. The computed unsteady flow fields clearly reveal the formation and evolution of a pair of leading edge vortices along the body of the flexible airfoil as it undergoes plunge motion. Thrust-indicative wake structures are generated when the flexure amplitude of the airfoil is less than 0.5 of the chord length. An enhancement in the propulsive efficiency is observed for a flapping airfoil with flexure amplitude of 0.3 of the chord length. This study also calculates the propulsive efficiency and thrust under various Reynolds numbers and reduced frequency conditions. The results indicate that the propulsive efficiency has a strong correlation with the reduced frequency. It is found that the flow conditions which yield the highest propulsive efficiency correspond to Strouhal number St of 0.255.

Thoracic sympathectomy remains an effective method for treatment of palmar hyperhidrosis refractory to other conservative forms of management. The procedure has become more acceptable following the introduction of the minimally invasive technique using video-assisted thoracic surgery (VATS). More recently, single-port VATS has gained popularity as an alternative approach to performing sympathectomy. We report on our experience and early results of single-port bilateral VATS sympathectomy using the Vasoview(®) (Maquet Inc., Rastatt, Germany) device at our institute.All patients who underwent VATS sympathectomy for primary palmar hyperhidrosis between June 2011 and March 2012 were recruited into this prospective study. Patients' demographics and intraoperative and postoperative outcomes were collected. Effectiveness of the procedure, postoperative pain, duration of hospital stay, and complications were also measured.Sixteen patients underwent Vasoview bilateral VATS sympathectomy for severe palmar hyperhidrosis. Mean age was 23.8 years (range, 17-36 years), and mean operative time to complete the bilateral procedure was 56 minutes (range, 42-81 minutes). The procedure was successfully completed in all patients without the need to enlarge the incision or convert. Postoperatively, there was no mortality and no residual palmar hyperhidrosis. Mean postoperative stay was 0.9 days (range, 0.7-1.9 days). The mean visual analog pain score at discharge was 1.8 (range, 1.2-3.4).Single-port Vasoview sympathectomy for treatment of severe palmar hyperhidrosis is technically feasible and safe with satisfactory immediate and early results. Intermediate and long-term follow-up is required to monitor recurrence or late complications. Future studies are warranted to compare Vasoview single-port and other minimal invasive VATS approaches.

Summary Continuous central pressure monitoring and simultaneous continuous infusion via the same central venous catheter are sometimes necessary. Based on theoretical calculations and experimental measurements, we have determined that pressure monitoring is essentially unaffected if the continuous infusion rate is 50 ml.h−1 or less for an adult and a paediatric central catheter. At rates > 200 ml.h−1, the central venous pressure is exaggerated by up to 4 mmHg and 8 mmHg for the adult and paediatric catheters, respectively.

Background Animal and volunteer studies indicate that ropivacaine is associated with less neurologic and cardiac toxicity than bupivacaine. Ropivacaine may offer advantages when used for thoracic paravertebral block. This study was designed to describe the pharmacokinetics of ropivacaine after thoracic paravertebral block. Methods Twenty female patients undergoing elective unilateral breast surgery were randomly assigned to receive a single bolus thoracic paravertebral injection of 2 mg/kg ropivacaine, with or without 5 mug/ml epinephrine. Simultaneous arterial and venous blood samples were obtained for plasma ropivacaine assay. Data were analyzed with NONMEM, using two possible absorption models: conventional first-order absorption and absorption following the inverse gaussian density function. Results Epinephrine reduced the peak plasma concentrations and delayed the time of peak concentration of ropivacaine in both the arterial and venous blood. The time course of drug input into the systemic circulation was best described by two inverse gaussian density functions. The median bioavailability of the rapid component was approximately 20% higher when epinephrine was not used. The mean absorption times were 7.8 min for the rapid absorption phase and 697 min for the slow absorption phase, with wide dispersion of the absorption function for the acute phase. The half-time of arterial-venous equilibration was 1.5 min. Conclusion The absorption of ropivacaine after thoracic paravertebral block is described by rapid and slow absorption phases. The rapid phase approximates the speed of intravenous administration and accounts for nearly half of ropivacaine absorption. The addition of 5 mug/ml epinephrine to ropivacaine significantly delays its systemic absorption and reduces the peak plasma concentration.

Hemorrhage is a major cause of trauma deaths. Coagulopathy exacerbates hemorrhage and is commonly seen during major trauma resuscitation, suggesting that current practice of coagulation factor transfusion is inadequate. Reversal of coagulopathy involves normalization of body temperature, elimination of the causes of disseminated intravascular coagulation (DIC), and transfusion with fresh-frozen plasma (FFP), platelets, and cryoprecipitate. Transfusion should be guided by clinical factors and laboratory results. However, in major trauma, clinical signs may be obscured and various factors conspire to make it difficult to provide the best transfusion therapy. Existing empiric transfusion strategies for, and prevailing teachings on, FFP transfusion appear to be based on old studies involving elective patients transfused with whole blood and may not be applicable to trauma patients in the era of transfusion with packed red blood cells (PRBCs). Perpetuation of such concepts is in part responsible for the common finding of refractory coagulopathy in major trauma patients today. In this review, we argue that coagulopathy can best be avoided or reversed when severe trauma victims are transfused with at least the equivalent of whole blood in a timely fashion.

Objective To evaluate, by systematic review, the efficacy of heliox on respiratory mechanics and outcomes in patients with acute asthma. Methods The search strategy included searching electronic databases (MEDLINE, EMBASE, and The Cochrane Library) and the references of relevant articles. Study quality was assessed based on allocation concealment. Randomized controlled trials (RCTs) comparing heliox to an air-oxygen mixture (airO 2 ) as an adjunct treatment in patients with acute asthmatic attacks were analyzed. For the qualitative portion of the analysis, all reports of the use of heliox in patients with acute asthma were included. Results Four RCTs (n = 278) were found to have a common respiratory parameter (peak expiratory flow rate as a percentage of predicted) suitable for meta-analysis. Within the 92% confidence interval (CI), there was a small benefit with the use of heliox compared to airO 2 (weighted mean difference, + 3%; 95% CI, − 2 to + 8%). There was also a slight improvement in the dyspnea index (weighted mean difference, 0.60; 95% CI, 0.04 to 1.16) with the use of heliox over airO 2 . Overall, five RCTs, one nonrandomized unblinded parallel trial, one retrospective case-matched control trial, three case series, and one case report had results in favor of heliox; one RCT and one case series showed no improvement with heliox; one RCT showed a possible detrimental effect with heliox; and 1 small RCT was inconclusive. Most investigators did not prevent entrainment of room air during heliox use or compensate for the lower nebulizing efficiency of heliox. Conclusion Based on surrogate markers, heliox may offer mild-to-moderate benefits in patients with acute asthma within the first hour of use, but its advantages become less apparent beyond 1 h, as most conventionally treated patients improve to similar levels, with or without it. The effect of heliox may be more pronounced in more severe cases. There are insufficient data on whether heliox can avert tracheal intubation, or change intensive care and hospital admission rates and duration, or mortality.

To report the use of a combined paravertebral lumbar plexus and parasacral sciatic nerve block for reduction of hip fracture in an elderly patient with severe aortic stenosis.In an 87-yr-old lady with severe aortic stenosis and fracture of the right trochanter due to a fall, a combined right-sided paravertebral lumbar plexus and parasacral sciatic nerve block was used successfully for operative reduction of the fracture. A moderate amount of phenylephrine was required to maintain adequate systemic blood pressure despite the largely unilateral nature of the blocks.Combined paravertebral lumbar plexus and parasacral sciatic nerve block can be a viable alternative to general anesthesia and epidural or spinal block for hip surgery in patients with severe aortic stenosis.