BMC Anesthesiology - Latest Articles

Sciatic lateral popliteal block with clonidine alone or clonidine plus 0.2% ropivacaine : effect on the intra- and postoperative analgesia for lower extremity surgery in children: a randomized prospective controlled study

Kalliopi Petroheilou — 2012-02-01T00:00:00Z

Background: The effect of adding clonidine to local anesthetics for nerve or plexus blocks remains unclear. Most of the studies in adults have demonstrated the positive effects of clonidine on intra- and postoperative analgesia when used as an adjunctive agent or in some cases as a single to regional techniques. In the pediatric population, there are only few trials involving clonidine as an adjunct to regional anesthesia, and the analgesic benefits are not definite in this group of patients. The evidence concerning perineural administration of clonidine is so far inconclusive in children, as different types and volume of local anesthetic agents have been used in these studies. Moreover, the efficacy of regional anesthesia is largely affected by the operator's technique, accuracy and severity of operation. Methods: The use of clonidine alone or combined with 0.2% ropivacaine for effective analgesia after mild to moderate painful foot surgery was assessed in 66 children, after combined sciatic lateral popliteal block (SLPB) plus femoral block. The patients were randomly assigned into three groups to receive placebo, clonidine, and clonidine plus ropivacaine. Time to first analgesic request in the groups was analyzed by using Kaplan-Meier and the log-rank test (mean time, median time, 95% CI). Results: In our study, clonidine administered alone in the SLPB seems promising, maintaining intraoperatively the hemodynamic parameters SAP, DAP, HR to the lower normal values so that no patient needed nalbuphine under 0.6 MAC sevoflurane anesthesia, and postoperatively without analgesic request for a median time of 6 hours. In addition, clonidine administered as adjuvant enhances ropivacaine's analgesic effect for the first postoperative day (p=0.001). They didn't also demonstrate PONV, motor blockade. Moreover, children's parents in clonidine and clonidine plus ropivacaine groups expressed their satisfaction with the excellent perioperative management of their children, with satisfaction score 9.74+/-0.45 and 9.73+/-0.70 respectively. On the contrary all the patients in the control group required rescue nalbuphine in the recovery room, and postoperatively, along with high incidence of PONV, and children's parents reported a low satisfaction score (7.50 +/- 0.70). Conclusions: Clonidine appears promising more as an adjuvant in 0.2% ropivacaine and less than alone in the SLPB plus femoral block in children undergoing mild to moderate painful foot surgery, with no side effects.Trial registration: ClinicalTrials.gov, ISRCTN90832436, (ref: CCT-NAPN-20886).

Preoperative muscle weakness as defined by handgrip strength and postoperative outcomes: a systematic review.

Pervez Sultan — 2012-01-17T00:00:00Z

Background: Reduced muscle strength- commonly characterized by decreased handgrip strength compared to population norms- is associated with numerous untoward outcomes. Preoperative handgrip strength is a potentially attractive real-time, non-invasive, cheap and easy-to-perform "bedside" assessment tool. Using systematic review procedure, we investigated whether preoperative handgrip strength was associated with postoperative outcomes in adults undergoing surgery. Methods: PRISMA and MOOSE consensus guidelines for reporting systematic reviews were followed. MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Clinical Trials (1980-2010) were systematically searched by two independent reviewers. The selection criteria were limited to include studies of preoperative handgrip strength in human adults undergoing non-emergency, cardiac and non-cardiac surgery. Study procedural quality was analysed using the Newcastle-Ottawa Quality Assessment score. The outcomes assessed were postoperative morbidity, mortality and hospital stay. Results: Nineteen clinical studies (17 prospective; 4 in urgent surgery) comprising 2194 patients were identified between1980-2010. Impaired handgrip strength and postoperative morbidity were defined inconsistently between studies. Only 2 studies explicitly ensured investigators collecting postoperative outcomes data were blinded to preoperative handgrip strength test results. The heterogeneity of study design used and the diversity of surgical procedures precluded formal meta-analysis. Despite the moderate quality of these observational studies, lower handgrip strength was associated with increased morbidity (n=10 studies), mortality (n=2/5 studies) and length of hospital stay (n=3/7 studies). Conclusions: Impaired preoperative handgrip strength may be associated with poorer postoperative outcomes, but further work exploring its predictive power is warranted using prospectively acquired, objectively defined measures of postoperative morbidity.

High tidal volume mechanical ventilation-induced lung injury in rats is greater after acid instillation than after sepsis-induced acute lung injury, but does not increase systemic inflammation: an experimental study.

Jan Willem Kuiper — 2011-12-28T00:00:00Z

IntroductionTo examine whether acute lung injury from direct and indirect origins differ in susceptibility to ventilator-induced lung injury (VILI) and resultant systemic inflammatory responses. Methods: Rats were challenged by acid instillation or 24 h of sepsis induced by cecal ligation and puncture, followed by mechanical ventilation (MV) with either a low tidal volume (Vt) of 6 mL/kg and 5 cm H2O positive end-expiratory pressure (PEEP; LVt acid, LVt sepsis) or with a high Vt of 15 mL/kg and no PEEP (HVt acid, HVt sepsis). Rats sacrificed immediately after acid instillation and non-ventilated septic animals served as controls. Hemodynamic and respiratory variables were monitored. After 4 h, lung wet to dry (W/D) weight ratios, histological lung injury and plasma mediator concentrations were measured. Results: Oxygenation and lung compliance decreased after acid instillation as compared to sepsis. Additionally, W/D weight ratios and histological lung injury scores increased after acid instillation as compared to sepsis. MV increased W/D weight ratio and lung injury score, however this effect was mainly attributable to HVt ventilation after acid instillation. Similarly, effects of HVt on oxygenation were only observed after acid instillation. HVt during sepsis did not further affect oxygenation, compliance, W/D weight ratio or lung injury score. Plasma interleukin-6 and tumour necrosis factor-alpha concentrations were increased after acid instillation as compared to sepsis, but plasma intercellular adhesion molecule-1 concentration increased during sepsis only. In contrast to lung injury parameters, no additional effects of HVt MV after acid instillation on plasma mediator concentrations were observed. Conclusions: During MV more severe lung injury develops after acid instillation as compared to sepsis. HVt causes VILI after acid instillation, but not during sepsis. However, this differential effect was not observed in the systemic release of mediators.

Tolerability of NGX-4010, a capsaicin 8% dermal patch, following pretreatment with lidocaine 2.5%/prilocaine 2.5% cream in patients with post-herpetic neuralgia

Lynn Webster — 2011-12-19T00:00:00Z

Background: Post-herpetic neuralgia (PHN) is a common type of neuropathic pain that can severely affect quality of life. NGX-4010, a capsaicin 8% dermal patch, is a localized treatment that can provide patients with significant pain relief for up to 3 months following a single 60-minute application. The NGX-4010 application can be associated with application-site pain and in previous clinical trials pretreatment with a topical 4% lidocaine anesthetic was used to enhance tolerability. The aim of the current investigation was to evaluate tolerability of NGX-4010 after pretreatment with lidocaine 2.5%/prilocaine 2.5% anesthetic cream. Methods: Twenty-four patients with PHN were pretreated with lidocaine 2.5%/prilocaine 2.5% cream for 60 minutes before receiving a single 60-minute application of NGX-4010. Tolerability was assessed by measuring patch application duration, the proportion of patients completing over 90% of the intended treatment duration, application site-related pain using the Numeric Pain Rating Scale (NPRS), and analgesic medication use to relieve such pain. Safety was assessed by monitoring adverse events (AEs) and dermal irritation using dermal assessment scores. Results: The mean treatment duration of NGX-4010 was 60.2 minutes and all patients completed over 90% of the intended patch application duration. Pain during application was transient. A maximum mean change in NPRS score of +3.0 was observed at 55 minutes post-patch application; pain scores gradually declined to near pre-anesthetic levels (+0.71) within 85 minutes of patch removal. Half of the patients received analgesic medication on the day of treatment; by Day 7, no patients required medication. The most common AEs were application site-related pain, erythema, edema, and pruritus. All patients experienced mild dermal irritation 5 minutes after patch removal, which subsequently decreased; at Day 7, no irritation was evident. The maximum recorded dermal assessment score was 2. Conclusion: NGX-4010 was well tolerated following pretreatment with lidocaine 2.5%/prilocaine 2.5% cream in patients with PHN. The tolerability of the patch application appeared comparable with that seen in other studies that used 4% lidocaine cream as the pretreatment anesthetic. This study is registered at www.clinicaltrials.gov as number NCT00916942.

A bibliometric search of citation classics in anesthesiology

Ravi Tripathi — 2011-12-12T00:00:00Z

Background: Articles cited counts are catalogued and help identify landmark papers. This study provides a citation classics of anesthesiology literature using the framework of subspecialties to provide a review of well-developed areas of research in anesthesiology. Methods: A comprehensive list of the most-cited articles in anesthesia was compiled using a bibliometric database and general search terms such as "anesthesia" as well as subspecialty-specific search terms. Queries were reviewed for relevance to anesthesiology practice, categorized by subspecialty, and ranked according to their citation counts. Results: The database resulted in 2519 articles published between 1945 and 2008. The specialty areas most represented were chronic pain medicine (11%), pharmacology (9%), and pain sciences (9%). Conclusions: This citations classic allows for advances in anesthesiology and its subspecialties to be highlighted as well to provide useful manuscripts to guide patient care, direct future research, and serve as sources for future academic pursuit.

A double blind randomized trial of wound infiltration with ropivacaine after breast cancer surgery with axillary nodes dissection

Axelle Vigneau — 2011-11-24T00:00:00Z

Background: The effect of local infiltration after breast surgery is controversial. This prospective double blind randomized study sought to document the analgesic effect of local anaesthetic infiltration after breast cancer surgery. Methods: Patients scheduled for mastectomy or tumorectomy and axillary nodes dissection had immediate postoperative infiltration of the surgical wound with 20 ml of ropivacaine 7.5 mg.ml-1 or isotonic saline. Pain was assessed on a visual analogue scale at H2, H4, H6, H12, H24, H72, and at 2 month, at rest and on mobilization of the arm. Patient'comfort was evaluated with numerical 0-3 scales for fatigue, quality of sleep, state of mood, social function and activity. Results: Twenty-two and 24 patients were included in the ropivacaine and saline groups respectively. Postoperative pain was lower at rest and on mobilization at 2, 4 and 6 hour after surgery in the ropivacaine group. No other difference in pain intensity and patient 'comfort scoring was documented during the first 3 postoperative days. Patients did not differ at 2 month for pain and comfort scores. Conclusion: Single shot infiltration with ropivacaine transiently improves postoperative pain control after breast cancer surgery.Trial registration numberNCT01404377

Intraoperative ventilation: incidence and risk factors for receiving large tidal volumes during general anesthesia

Ana Fernandez-Bustamante — 2011-11-21T00:00:00Z

Background: There is a growing concern of the potential injurious role of ventilatory over-distention in patients without lung injury. No formal guidelines exist for intraoperative ventilation settings, but the use of tidal volumes (VT) under 10 mL/kg predicted body weight (PBW) has been recommended in healthy patients. We explored the incidence and risk factors for receiving large tidal volumes (VT > 10 mL/kg PBW). Methods: We performed a cross-sectional analysis of our prospectively collected perioperative electronic database for current intraoperative ventilation practices and risk factors for receiving large tidal volumes (VT > 10 mL/kg PBW). We included all adults undergoing prolonged (≥ 4 h) elective abdominal surgery and collected demographic, preoperative (comorbidities), intraoperative (i.e. ventilatory settings, fluid administration) and postoperative (outcomes) information. We compared patients receiving exhaled tidal volumes > 10 mL/kg PBW with those that received 8-10 or < 8 mL/kg PBW with univariate and logistic regression analyses. Results: Ventilatory settings were non-uniform in the 429 adults included in the analysis. 17.5% of all patients received VT > 10 mL/kg PBW. 34.0% of all obese patients (body mass index, BMI, ≥ 30), 51% of all patients with a height < 165 cm, and 34.6% of all female patients received VT > 10 mL/kg PBW. Conclusions: Ventilation with VT > 10 mL/kg PBW is still common, although poor correlation with PBW suggests it may be unintentional. BMI ≥ 30, female gender and height < 165 cm may predispose to receive large tidal volumes during general anesthesia. Further awareness of patients' height and PBW is needed to improve intraoperative ventilation practices. The impact on clinical outcome needs confirmation.

Early Rehabilitation in Sepsis : A Prospective Randomised Controlled Trial investigating Functional and Physiological Outcomes The i-PERFORM Trial (Protocol Article)

Geetha Kayambu — 2011-10-31T00:00:00Z

Background Patients with sepsis syndromes can have worse outcomes for physical function, quality of life and survival. Early intensive care rehabilitation can improve the outcome in general Intensive Care Unit (ICU) patients, however no investigations have specifically looked at patients with sepsis syndromes. The 'i-PERFORM Trial' will investigate if early targeted rehabilitation is both safe and effective in patients with sepsis syndromes admitted to ICU.Methods/Design A single-centred blinded randomized controlled trial will be conducted in Brisbane, Australia. Participants (n=252) will include those [greater than or equal to] 18 years, mechanically ventilated for [greater than or equal to] 48 hours and diagnosed with a sepsis syndrome. Participants will be randomised to an intervention arm which will undergo an early targeted rehabilitation program according to the level of arousal, strength and cardiovascular stability and a control group which will receive normal care.The primary outcome measures will be physical function tests on discharge from ICU (The Acute Care Index of Function and The Physical Function ICU Test). Health-related quality of life will be measured using the Short Form-36 and the psychological component will be tested using The Hospital Anxiety and Depression Scale. Secondary measures will include inflammatory biomarkers; Interleukin-6, Interleukin-10 and Tumour Necrosis Factor-alpha, peripheral blood mitochondrial DNA content and lactate, fat free muscle mass, tissue oxygenation and microcirculatory flow.Discussion The 'i-PERFORM Trial' will determine whether early rehabilitation for patients with sepsis is effective at improving patient outcomes with functional and physiological parameters reflecting long and short-term effects of early exercise and the safety in its application in critical illness.Trial Registration ACTRN12610000808044

Detachment of the carinal hook following endobronchial intubation with a double lumen tube

Ana Rocha — 2011-10-28T00:00:00Z

Background: Carinal hooks increases difficulty at endotracheal intubation. Amputation of the carinal hook during passage and malpositioning of the tube to the hook are some of the potential problems related with left-sided Carlens double lumen tube (DLT). This article reports an amputation of the hook during a difficult selective intubation and aimed at calling the attention to complications associated with DLTs and the importance of fiberoptic bronchoscopy.Case presentationA 68 year-old woman was scheduled for right-sided thoracotomy in whom blind DLT insertion was performed. Narrowed trachea causes difficulty in rotating the DLT 90° counter-clockwise. After carinal hook was noticed upon visual inspection of the DLT, fiberoptic bronchoscopy was used to remove the missing part (with the use of forceps) from the right mainstem bronchus. Conclusion: Insertion of DLTs with carinal hook is associated with technical problems and potentially life-threatening hazards have discouraged their use. Fiberoptic evaluation and repositioning solves most of the problems. Although amputation of the carinal hook has not been previously reported, clinicians should be alert. This case report emphasizes the utility of the fiberoptic bronchoscopy in the operating theatre for placement, positioning and inspection of the carinal hook DLT.

Subcutaneous dissociative conscious sedation (sDCS) an alternative method for airway regional blocks: a new approach

Mihan Javid — 2011-10-26T00:00:00Z

Background: Predicted difficult airway is a definite indication for awake intubation and spontaneous ventilation. Airway regional blocks which are commonly used to facilitate awake intubation are sometimes impossible or forbidden. On the other hand deep sedation could be life threatening in the case of compromised airway.The aim of this study is evaluating "Subcutaneous Dissociative Conscious Sedation" (sDCS) as an alternative method to airway regional blocks for awake intubation. Methods: In this prospective, non-randomized study, 30 patients with predicted difficult airway (laryngeal tumors), who were scheduled for direct laryngoscopic biopsy (DLB), underwent "Subcutaneous Dissociative Conscious Sedation" (sDCS) exerted by intravenous fentanyl 3-4ug/kg and subcutaneous ketamine 0.6-0.7 mg/kg. The tongue and pharynx were anesthetized with lidocaine spray (4%). 10 minutes after a subcutaneous injection of ketamine direct laryngoscopy was performed. Extra doses of fentanyl 50-100 ug were administered if the patient wasn't cooperative enough for laryngoscopy.Patients were evaluated for hemodynamic stability (heart rate and blood pressure), oxygen saturation (Spo2), patient cooperation (obedient to open the mouth for laryngoscopy and the number of tries for laryngoscopy), patient comfort (remaining moveless), hallucination, nystagmus and salivation (need for aspiration before laryngoscopy). Results: Direct laryngoscopy was performed successfully in all patients. One patient needed extra fentanyl and then laryngoscopy was performed successfully on the second try. All patients were cooperative enough during laryngoscopy. Hemodynamic changes more than 20% occurred in just one patient. Oxygen desaturation (spo2< 90%) didn't occur in any patient. Conclusions: Subcutaneous Dissociative Conscious Sedation (sDCS) as a new approach to airway is an acceptable and safe method for awake intubation and it can be suggested as a noninvasive substitute of low complication rate for regional airway blocks.Registration ID in IRCTIRCT201012075333N1