Background
Goal-directed fluid therapy (GDFT) has been shown to reduce complications and hospital length of stay following major surgery. However, there has been no assessment regarding its use in clinical practice.
Methods
An electronic survey was administered to randomly selected anaesthetists from the United Kingdom (UK, n = 2000) and the United States of America (USA, n = 2000), and 500 anaesthetists from Australia/New Zealand (AUS/NZ). Preferences, clinical use and attitudes towards GDFT were investigated. Results were collated to examine regional differences.
Results
The response rates from the UK (n = 708) and AUS/NZ (n = 180) were 35%, and 36% respectively. The response rate from the USA was very low (n = 178; 9%). GDFT use was significantly more common in the UK than in AUS/NZ (p < 0.01). The Oesophageal Doppler Monitor was the most preferred instrument in the UK (n = 362; h76%) with no clear preferences in other regions. GDFT was most commonly utilised in major abdominal surgery and for patients with significant comorbidities. The commonest reasons stated for not using GDFT were either lack of availability of monitoring tools (AUS/NZ: 57 (70%); UK: 94 (64%)) or a lack of experience with instruments (AUS/NZ: 43 (53%); UK: 51 (35%)). A subset of respondents (AUS/NZ: 22(27%); UK: 45 (30%)) felt GDFT provided no perceived benefit. Enthusiasm towards the use of GDFT in the absence of existing barriers was high.
Conclusion
Several hypotheses were generated regarding important differences in the use of GDFT between anaesthetists from the UK and AUS/NZ. There is significant interest in utilising GDFT in clinical practice and existing barriers should be addressed.
doi:10.1186/1471-2253-13-5
PMCID: PMC3598228
PMID: 23433064
Intravenous fluid; Goal-directed fluid therapy; Perioperative care; Surgery
Background
Most studies that follow up hepatectomy cases are limited in scope to an investigation of mortality and morbidity rates or the costs and length of hospital stay. In this study the authors aimed to characterize the quality of life and to evaluate mortality and its determinants after hepatectomy.
Methods
This prospective study was carried in a Post-Anaesthesia Care Unit (PACU) over 15 months, and 70 patients submitted to hepatectomy were enrolled. Demographic and peri-operative characteristics were evaluated for associations with mortality. At admission and 6 months after discharge, patients completed a Short Form-36 questionnaire (SF-36) and have their independence in Activities of Daily Living (ADL) was evaluated. Binary and multiple logistic regression analyses were used to evaluate of associations with mortality, and the Wilcoxon signed rank test was used to compare SF-36 scores before and after 6 months after hepatectomy.
Results
The mortality rate was 19% at 6 months. Multivariate analysis identified postoperative delirium as an independent determinant for mortality. Six months after discharge, 46% patients stated that their health in general was better or much better than that 1 year previously. Six months after hepatectomy, patients had worse scores in the physical function domain of SF-36; however, scores for all the other domains did not differ. At this time point, patients were more dependent in instrumental ADL than before surgery (32% versus 7%, p = 0.027).
Conclusion
This study identified postoperative delirium as an independent risk factor for mortality 6 months after hepatectomy. After 6 months, survivors were more dependent in instrumental ADL tasks and had worse scores in the physical function domain of SF-36.
doi:10.1186/1471-2253-13-4
PMCID: PMC3566959
PMID: 23374538
Quality of life; Hepatectomy; Outcome; Mortality; Activities of daily living
Background
In 1993, the American Society of Anesthesiologists (ASA) published guidelines stating that automatic perioperative suspension of Do Not Resuscitate (DNR) orders conflicts with patients’ rights to self-determination. Almost 20 years later, we aimed to explore both patient and doctor views concerning perioperative DNR status.
Methods
Five-hundred consecutive patients visiting our preoperative evaluation clinic were surveyed and asked whether they had made decisions regarding resuscitation and to rate their agreement with several statements concerning perioperative resuscitation. Anesthesiologists, surgeons and internists at our tertiary referral institution were also surveyed. They were asked to assess their likelihood of following a hypothetical patient’s DNR status and to rate their level of agreement with a series of non-scenario related statements concerning ethical and practical aspects of perioperative resuscitation.
Results
Over half of patients (57%) agreed that pre-existing DNR requests should be suspended while undergoing a surgical procedure under anesthesia, but 92% believed a discussion between the doctor and patient regarding perioperative resuscitation plans should still occur. Thirty percent of doctors completing the survey believed that DNR orders should automatically be suspended intraoperatively. Anesthesiologists (18%) were significantly less likely to suspend DNR orders than surgeons (38%) or internists (34%) (p < 0.01).
Conclusions
Although many patients agree that their DNR orders should be suspended for their operation, they expect a discussion regarding the performance and nature of perioperative resuscitation. In contrast to previous studies, anesthesiologists were least likely to automatically suspend a DNR order.
doi:10.1186/1471-2253-13-2
PMCID: PMC3548687
PMID: 23320623
Do not resuscitate; Perioperative medicine; Patient decisions/choice
A study by Burkle et al. in BMC Anesthesiology examined attitudes around perioperative do-not-resuscitate orders. Questionnaires were given to patients, as well as to anesthesiologists, internists and surgeons. The study has limitations and is open to interpretation. However, the findings are important. There appear to be attitudinal differences between patients and doctors, and between specialties. A small majority of patients are content to have a do-not-resuscitate order postponed during the perioperative period. A large majority expects open communication from doctors before proceeding. However, this article could also encourage a broader debate. This is about how to respect patient autonomy, while ensuring that resuscitation truly serves the patient’s best interests. This commentary outlines how more communication is needed at the bedside and in wider society.
doi:10.1186/1471-2253-13-1
PMCID: PMC3546949
PMID: 23312034
Do not resuscitate; Perioperative; Cardiopulmonary resuscitation
Background
The widespread of hallux valgus surgery in a day care setting enhanced the role of regional anaesthesia in the last few years. Sciatic nerve block at popliteal fossa has been shown to provide safe and effective analgesia. Our purpose was to compare the success rate and performance time of popliteal block during resident’s training for regional anaesthesia by using nerve stimulation (NS) or combined nerve stimulation and ultrasound (NS + US).
Methods
70 adult patients undergoing hallux valgus surgery were randomly assigned to receive sciatic nerve block at popliteal fossa with US+NS or NS alone with a double injection technique for peroneal and tibial branches, respectively. Two residents experienced with nerve stimulator performed the procedures after a learning phase concerning ultrasonography. A local anaesthetic solution, containing 10 mL of 0.75% ropivacaine and 10 mL of 2% lidocaine was used: 12 mL were infiltrated close the tibial nerve, and 8mL were infiltrated close the common peroneal nerve. Block success rate, sensory block onset time, block performance time were evaluated. Recourse to general anaesthesia was considered as failure.
Results
No differences were detected in success rate and onset time of sensory block between the two groups (P > 0.05). The time to block tibial nerve and the overall block time were significantly faster in US+NS group (P < 0.05).
Conclusions
Ultrasound guidance for popliteal nerve block resulted in similar success rate with a faster procedure time when compared with nerve stimulator, thus providing a possible effect on resident education and operating room efficiency.
doi:10.1186/1471-2253-12-33
PMCID: PMC3534337
PMID: 23253617
Peripheral nervous block; Hallux valgus; Resident’s education
Background
The purpose of our study was to organize the literature regarding the efficacy of modern videolaryngoscopes in oral endotracheal intubation, then perform a quality assessment according to recommended external criteria and make recommendations for use.
Methods
Inclusion criteria included devices with recent studies of human subjects. A total of 980 articles were returned in the initial search and 65 additional items were identified using cited references. After exclusion of articles failing to meet study criteria, 77 articles remained. Data were extracted according to the rate of successful intubation and improvement of glottic view compared with direct laryngoscopy. Studies were classified according to whether they primarily examined subjects with normal airways, possessing risk factors for difficult direct laryngoscopy, or following difficult or failed direct laryngoscopy.
Results
The evidence of efficacy for videolaryngoscopy in the difficult airway is limited. What evidence exists is both randomized prospective and observational in nature, requiring a scheme that evaluates both forms and allows recommendations to be made.
Conclusions
In patients at higher risk of difficult laryngoscopy we recommend the use of the Airtraq, CTrach, GlideScope, Pentax AWS and V-MAC to achieve successful intubation. In difficult direct laryngoscopy (C&L >/= 3) we cautiously recommend the use of the Airtraq, Bonfils, Bullard, CTrach, GlideScope, and Pentax AWS, by an operator with reasonable prior experience, to achieve successful intubation when used in accordance with the ASA practice guidelines for management of the difficult airway. There is additional evidence to support the use of the Airtraq, Bonfils, CTrach, GlideScope, McGrath, and Pentax AWS following failed intubation via direct laryngoscopy to achieve successful intubation. Future investigation would benefit from precise qualification of the subjects under study, and an improvement in overall methodology to include randomization and blinding.
doi:10.1186/1471-2253-12-32
PMCID: PMC3562270
PMID: 23241277
Laryngoscopy; Airway management; Intubation; Technology
Background
Epidural Anesthesia (EA) is a well-established procedure. The aim of the present study was to evaluate the incidence of immediate complications following epidural puncture, such as sanguineous puncture, accidental dural perforation, unsuccessful catheter placement or insufficient analgesia and to identify patient and maneuver related risk factors.
Methods
A total of 7958 non-obstetrical EA were analyzed. The risk of each complication was calculated according to the preconditions and the level of puncture. For probabilistic evaluation we used a logistic regression model with forward selection.
Results
The risk of sanguineous puncture (n = 247, 3.1%) increases with both the patient’s age (P = 0.013) and the more caudal the approach (P < 0.01). Dural perforation (n = 123, 1.6%) was found to be influenced only by advanced age (P = 0.019). Unsuccessful catheter placement (n = 68, 0.94%) occurred more often in smaller individuals (P < 0.001) and at lower lumbar sites (P < 0.01). Amongst all cases with successful catheter placement a (partial) insufficient analgesia was found in 692 cases (8.8%). This risk of insufficient analgesia decreased with patient’s age (P <0 .01), being least likely for punctures of the lower thoracic spine (P < 0.001).
Conclusions
Compared to more cranial levels, EA of the lower spine is associated with an increased risk of sanguineous and unsuccessful puncture. Insufficient analgesia more often accompanies high thoracic and low lumbar approaches. The risk of a sanguineous puncture increases in elderly patients. Gender, weight and body mass index seem to have no influence on the investigated complications.
doi:10.1186/1471-2253-12-31
PMCID: PMC3566923
PMID: 23227938
Background
Increasing numbers of elective surgical procedures are performed as day-cases. The impact of ambulatory surgery on health-related quality of life in the recovery period has seldom been described.
Methods
We assessed health-related quality of life in 143 adult outpatients scheduled for arthroscopic procedures of the knee and shoulder joints, laparoscopic cholecystectomy and inguinal hernia repair using the RAND 36-Item Health Survey preoperatively and one week after patients had returned to work or comparable normal daily routines.
Results
Postoperatively all patient groups reported significant improvements in bodily pain and vitality. Physical functioning improved significantly in orthopedic and inguinal hernia patients. However, in the orthopedic groups, postoperative scores for physical health were still relatively lower compared to the general population reference values.
Conclusions
Ambulatory surgery has a positive impact on health-related quality of life. Assessment of the recovery process is necessary for recognition of potential areas of improvement in care and postoperative rehabilitation.
doi:10.1186/1471-2253-12-30
PMCID: PMC3556308
PMID: 23217178
Quality of life; Outcome; Ambulatory surgery procedures; RAND-36
Shekar, Kiran | Roberts, Jason A | Welch, Susan | Buscher, Hergen | Rudham, Sam | Burrows, Fay | Ghassabian, Sussan | Wallis, Steven C | Levkovich, Bianca | Pellegrino, Vin | McGuinness, Shay | Parke, Rachael | Gilder, Eileen | Barnett, Adrian G | Walsham, James | Mullany, Daniel V | Fung, Yoke L | Smith, Maree T | Fraser, John F
Background
Given the expanding scope of extracorporeal membrane oxygenation (ECMO) and its variable impact on drug pharmacokinetics as observed in neonatal studies, it is imperative that the effects of the device on the drugs commonly prescribed in the intensive care unit (ICU) are further investigated. Currently, there are no data to confirm the appropriateness of standard drug dosing in adult patients on ECMO. Ineffective drug regimens in these critically ill patients can seriously worsen patient outcomes. This study was designed to describe the pharmacokinetics of the commonly used antibiotic, analgesic and sedative drugs in adult patients receiving ECMO.
Methods/Design
This is a multi-centre, open-label, descriptive pharmacokinetic (PK) study. Eligible patients will be adults treated with ECMO for severe cardiac and/or respiratory failure at five Intensive Care Units in Australia and New Zealand. Patients will receive the study drugs as part of their routine management. Blood samples will be taken from indwelling catheters to investigate plasma concentrations of several antibiotics (ceftriaxone, meropenem, vancomycin, ciprofloxacin, gentamicin, piperacillin-tazobactum, ticarcillin-clavulunate, linezolid, fluconazole, voriconazole, caspofungin, oseltamivir), sedatives and analgesics (midazolam, morphine, fentanyl, propofol, dexmedetomidine, thiopentone). The PK of each drug will be characterised to determine the variability of PK in these patients and to develop dosing guidelines for prescription during ECMO.
Discussion
The evidence-based dosing algorithms generated from this analysis can be evaluated in later clinical studies. This knowledge is vitally important for optimising pharmacotherapy in these most severely ill patients to maximise the opportunity for therapeutic success and minimise the risk of therapeutic failure.
Trial registration
ACTRN12612000559819
doi:10.1186/1471-2253-12-29
PMCID: PMC3543712
PMID: 23190792
ECMO; Pharmacokinetics; Pharmacodynamics; Antibiotics; Sedatives; Analgesics; Therapeutic failure; Drug toxicity
Background
Signs of serious clinical events overlap with those of sepsis. We hypothesised that any education on severe sepsis/septic shock may affect the outcome of all hospital patients. We designed this study to assess the trend of the mortality rate of adults admitted to hospital for at least one night in relationship with a hospital staff educational program dedicated to severe sepsis/septic shock.
Methods
This study was performed in six Italian hospitals in the same region. Multidisciplinary Sepsis Teams members were selected by each hospital management among senior staff. The education included the following steps: i) the Teams were taught about adult learning, problem based learning, and Surviving Sepsis guidelines, and provided with educational material (literature, electronic presentations, scenarios of clinical cases for training and booklets); ii) they started delivering courses and seminars each to their own hospital staff in the last quarter of 2007.
To analyse mortality, we selected adult patients, admitted for at least one night to the wards or units present in all the study hospitals and responsible for 80% of hospital deaths. We fitted a Poisson model with monthly hospital mortality rates from December 2003 to August 2009 as dependent variable. The effect of the educational program on hospital mortality was measured as two dummy variables identifying a first (November 2007 to December 2008) and a second (January to August 2009) education period. The analysis was adjusted for a linear time trend, seasonality and monthly average values of age, Charlson score, length of stay in hospital and urgent/non-urgent admission.
Results
The hospital staff educated reached 30.6% at the end of June 2009. In comparison with the pre-education period, the Relative Risk of death of the patient population considered was 0.93 (95% confidence interval [CI] 0.87-0.99; p 0.025) for in-patients in the first, and 0.89 (95% CI 0.81-0.98; p 0.012) for those in the second period after education.
Conclusion
Our hypothesis that a program educating hospital staff to early detection and treatment of severe sepsis/septic shock may affect the outcome of all hospital patients is original, but it has to be corroborated by other experiences.
doi:10.1186/1471-2253-12-28
PMCID: PMC3524041
PMID: 23167611
Background
Enhanced bleeding remains a serious problem after cardiac surgery, and fibrinolysis is often involved. We speculate that lower plasma concentrations of plasminogen activator inhibitor – 1 (PAI-1) preoperatively and tissue plasminogen activator/PAI-1 (t-PA/PAI-1) complex postoperatively might predispose for enhanced fibrinolysis and increased postoperative bleeding.
Methods
Totally 88 adult patients (mean age 66 ± 10 years) scheduled for cardiac surgery, were enrolled into a prospective study. Blood samples were collected pre-operatively, on admission to the recovery and at 6 and 24 hours postoperatively. Patients with a surgical bleeding that was diagnosed during reoperation were discarded from the study. The patients were allocated to two groups depending on the 24-hour postoperative chest tube drainage (CTD): Group I > 500ml, Group II ≤ 500ml. Associations between CTD, PAI-1, t-PA/PAI-1 complex and D-dimer were analyzed with SPSS.
Results
Nine patients were excluded because of surgical bleeding. Of the 79 remaining patients, 38 were allocated to Group I and 41 to Group II. The CTD volumes correlated with the preoperative plasma levels of PAI-1 (r = − 0.3, P = 0.009). Plasma concentrations of preoperative PAI-1 and postoperative t-PA/PAI-1 complex differed significantly between the groups (P < 0.001 and P = 0.012, respectively). Group I displayed significantly lower plasma concentrations of fibrinogen and higher levels of D-dimer from immediately after the operation and throughout the first 24 hours postoperatively.
Conclusions
Lower plasma concentrations of PAI-1 preoperatively and t-PA/PAI-1 complex postoperatively leads to higher plasma levels of D-dimer in association with more postoperative bleeding after cardiac surgery.
doi:10.1186/1471-2253-12-27
PMCID: PMC3524048
PMID: 23110524
Cardiac surgery; Fibrinolysis; Plasminogen activator inhibitor; Tissue plasminogen activator
Background
The efficacy of epidural steroid injections in the management of chronic low back pain is disputed, yet the technique remains popular amongst physicians and patients alike. This study assesses the cost effectiveness of injections administered in a routine outpatient setting in England.
Methods
Patients attending the Nottingham University Hospitals’ Pain Clinic received two injections of methylprednisolone plus levobupivacaine at different dosages, separated by at least 12 weeks. Prior to each injection, and every week thereafter for 12 weeks, participants completed the EQ-5D health-related quality of life instrument. For each patient for each injection, total health state utility gain relative to baseline was calculated. The cost of the procedure was modelled from observed clinical practice. Cost effectiveness was calculated as procedure cost relative to utility gain.
Results
39 patients provided records. Over a 13-week period commencing with injection, mean quality adjusted life year (QALY) gains per patient for the two dosages were 0.028 (SD 0.063) and 0.021 (SD 0.057). The difference in QALYs gained by dosage was insignificant (paired t-test, CIs -0.019 – 0.033). Based on modelled resource use and data from other studies, the mean cost of an injection was estimated at £219 (SD 83). The cost utility ratio of the two injections amounted to £8,975 per QALY gained (CIs 5,480 – 22,915). However, at costs equivalent to the tariff price typically paid to providers by health care purchasers, the ratio increased to £27,459 (CIs 16,779 – 70,091).
Conclusions
When provided in an outpatient setting, epidural steroid injections are a short term, but nevertheless cost effective, means of managing chronic low back pain. However, designation of the procedure as a day case requires the National Health Service to reimburse providers at a price which pushes the procedure to the margin of cost effectiveness.
Trial registration
ISRCTN 43299460
doi:10.1186/1471-2253-12-26
PMCID: PMC3468401
PMID: 23016755
Background
Left ventricular (LV) dysfunction is well documented in the critically ill. We assessed 1-year mortality in relation to cardiac biomarkers and LV function parameters by echocardiography in patients with shock.
Methods
A prospective, observational, cohort study of 49 patients. B-natriuretic peptide (BNP), high-sensitive troponin T (hsTNT) and transthoracic echocardiography (TTE) were assessed within 12 h of study inclusion. LV systolic function was measured by ejection fraction (LVEF), mean atrioventricular plane displacement (AVPDm), peak systolic tissue Doppler velocity imaging (TDIs) and velocity time integral in the LV outflow tract (LVOT VTI). LV diastolic function was evaluated by transmitral pulsed Doppler (E, A, E/A, E-deceleration time), tissue Doppler indices (é, á, E/é) and left atrial volume (La volume). APACHE II (Acute Physiology and Chronic Health Evaluation) and SOFA (Sequential Organ Failure Assessment) scores were calculated.
Results
hsTNT was significantly higher in non-survivors than in survivors (60 [17.0-99.5] vs 168 [89.8-358] ng/l, p = 0.003). Other univariate predictors of mortality were APACHE II (p = 0.009), E/é (p = 0.023), SOFA (p = 0.024) and age (p = 0.031). Survivors and non-survivors did not differ regarding BNP (p = 0.26) or any LV systolic function parameter (LVEF p = 0.87, AVPDm p = 0.087, TDIs p = 0.93, LVOT VTI p = 0.18). Multivariable logistic regression analysis identified hsTNT (p = 0.010) as the only independent predictor of 1-year mortality; adjusted odds ratio 2.0 (95% CI 1.2- 3.5).
Conclusions
hsTNT was the only independent predictor of 1-year mortality in patients with shock. Neither BNP nor echocardiographic parameters had an independent prognostic value. Further studies are needed to establish the clinical significance of elevated hsTNT in patients in shock.
doi:10.1186/1471-2253-12-25
PMCID: PMC3524030
PMID: 23006477
Echocardiography; BNP; High-sensitive TNT; Myocardial function; Mortality; Shock
Zimmermann, Johannes B | Lehmann, Monika | Hofer, Stefan | Hüsing, Johannes | Alles, Catharina | Werner, Jens | Stiller, Jürgen | Künnecke, Wolfgang | Luntz, Steffen | Motsch, Johann | Weigand, Markus A
Background
Although a device is needed to continuously measure blood glucose levels within an intensive care setting, and several large-scale prospective studies have shown that patients might benefit from intensive insulin, potassium, or glucose therapy during intensive care, no devices are currently available to continuously assess blood glucose levels in critically ill patients. We conceived the study described here to evaluate the clinical use of the Continuous Glucose Monitor (CGM) performed via a central vein, and to determine the impact of phenomena, such as drift and shift, on the agreement between the CGM and a RAPIDLab® 1265 blood gas analyser (BGA).
Methods/design
In the CONTinuous ASSessment of blood GLUcose (CONTASSGLU) study, up to 130 patients under intensive care will be fitted with the CGM, an ex vivo device that continuously measures blood glucose and lactate levels. Readings from the device taken 8 h after initial placement and calibration will be compared with values measured by a BGA. For this study, we chose the BGA as it is an established standard point-of-care device, instead of the devices used in certified central laboratories. Nevertheless, we will also independently compare the results from the point-of-care BGA with those determined by a central laboratory-based device. Blood samples will be collected from each patient from the same site in which the CGM will measure blood glucose. Consequently, each participant will serve as their own control, and no randomisation is necessary. The 95% limits of agreement and the corresponding confidence intervals will be calculated and compared with a prespecified clinically acceptable relative difference of 20%.
Discussion
Several attempts have been made to develop a device to continuously measure blood glucose levels within an intensive care setting or to use the devices that were originally designed for diabetes management, as several of these devices are already available. However, none of these devices were successful in intensive care settings. CONTASSGLU may well bridge this gap by confirming the ability of the CGM to continuously measure blood glucose levels in intensive care settings.
Trial registration
ClinicalTrials.gov NCT01580176
doi:10.1186/1471-2253-12-24
PMCID: PMC3532142
PMID: 22998112
Agreement; Continuous; Monitor* (monitor~s~ing); Blood glucose [MeSH]; Lactate [MeSH]; Insulin [MeSH]; Potassium [MeSH]; Perioperative care [MeSH]; Critical care [MeSH]; Intensive care
Background
Beach chair positioning during general anesthesia is associated with a high incidence of cerebral desaturation; poor neurological outcome is a growing concern. There are no published data pertaining to changes in cerebral oxygenation seen with increases in the inspired oxygen fraction or end-tidal carbon dioxide in patients anesthetized in the beach chair position. Furthermore, the effect anesthetic agents have has not been thoroughly investigated in this context. We plan to test the hypothesis that changes in inspired oxygen fraction or end-tidal carbon dioxide correlate to a significant change in regional cerebral oxygenation in anesthetized patients in beach chair position. We will also compare the effects that inhaled and intravenous anesthetics have on this process.
Methods/design
This is a prospective within-group study of patients undergoing shoulder arthroscopy in the beach chair position which incorporates a randomized comparison between two anesthetics, approved by the Institutional Review Board of the University of Michigan, Ann Arbor. The primary outcome measure is the change in regional cerebral oxygenation due to sequential changes in oxygenation and ventilation. A sample size of 48 will have greater than 80% power to detect an absolute 4-5% difference in regional cerebral oxygenation caused by changes in ventilation strategy. The secondary outcome is the effect of anesthetic choice on cerebral desaturation in the beach chair position or response to changes in ventilation strategy. Fifty-four patients will be recruited, allowing for drop out, targeting 24 patients in each group randomized to an anesthetic. Regional cerebral oxygenation will be measured using the INVOS 5100C monitor (Covidien, Boulder, CO). Following induction of anesthesia, intubation and positioning, inspired oxygen fraction and minute ventilation will be sequentially adjusted. At each set point, regional cerebral oxygenation will be recorded and venous blood gas analysis performed. The overall statistical analysis will use a repeated measures analysis of variance with Tukey’s HSD procedure for post hoc contrasts.
Discussion
If simple maneuvers of ventilation or anesthetic technique can prevent cerebral hypoxia, patient outcome may be improved. This is the first study to investigate the effects of ventilation strategies on cerebral oxygenation in patients anesthetized in beach chair position.
Trial registration
NCT01535274
doi:10.1186/1471-2253-12-23
PMCID: PMC3499238
PMID: 22994896
Background
Hyperventilation may be used to hasten recovery from general anesthesia with potent inhaled anesthetics. However, its effect may be less pronounced with the newer, less soluble agents, and it may result in rehypnotization if subsequent hypoventilation occurs because more residual anesthetic will be available in the body for redistribution to the central nervous system. We used GasMan® simulations to examine these issues.
Methods
One MAC of isoflurane, sevoflurane, or desflurane was administered to a fictitious 70 kg patient for 8 h with normoventilation (alveolar minute ventilation [VA] 5 L.min-1), resulting in full saturation of the vessel rich group (VRG) and >95% saturation of the muscle group. After 8 h, agent administration was stopped, and fresh gas flow was increased to 10 L.min-1 to avoid rebreathing. At that same time, we continued with one simulation where normoventilation was maintained, while in a second simulation hyperventilation was instituted (10 L.min-1). We determined the time needed for the partial pressure in the VRG (FVRG; representing the central nervous system) to reach 0.3 MAC (MACawake). After reaching MACawake in the VRG, several degrees of hypoventilation were instituted (VA of 2.5, 1.5, 1, and 0.5 L.min-1) to determine whether FVRG would increase above 0.3 MAC(= rehypnotization).
Results
Time to reach 0.3 MAC in the VRG with normoventilation was 14 min 42 s with isoflurane, 9 min 12 s with sevoflurane, and 6 min 12 s with desflurane. Hyperventilation reduced these recovery times by 30, 18, and 13% for isoflurane, sevoflurane, and desflurane, respectively. Rehypnotization was observed with VA of 0.5 L.min-1 with desflurane, 0.5 and 1 L.min-1 with sevoflurane, and 0.5, 1, 1.5, and 2.5 L.min-1 with isoflurane. Only with isoflurane did initial hyperventilation slightly increase the risk of rehypnotization.
Conclusions
These GasMan® simulations confirm that the use of hyperventilation to hasten recovery is marginally beneficial with the newer, less soluble agents. In addition, subsequent hypoventilation results in rehypnotization only with more soluble agents, unless hypoventilation is severe. Also, initial hyperventilation does not increase the risk of rehypnotization with less soluble agents when subsequent hypoventilation occurs. Well-controlled clinical studies are required to validate these simulations.
doi:10.1186/1471-2253-12-22
PMCID: PMC3502091
PMID: 22989260
Inhaled anesthetics; Rehypnotization; Isocapnic hyperventilation; Pharmacokinetic modelling
Background
The Functional Comorbidity Index (FCI) was recently developed to predict physical function in acute lung injury patients using comorbidity data. Our objectives were to determine: (1) the inter-rater reliability of the FCI collected using in-patient discharge summaries (primary objective); and (2) the accuracy and predictive validity of the FCI collected using hospital discharge summaries and admission records versus complete chart review (secondary objectives).
Methods
For reliability, we evaluated the FCI’s intraclass correlation coefficient (ICC) among trained research staff performing data collection for 421 acute lung injury patients enrolled in a prospective cohort study. For validity and accuracy, we compared the detection of FCI comorbidities across three types of inpatient medical records, and the association of the respective FCI scores obtained with patients’ SF-36 physical function subscale (PFS) scores at 1-year follow-up.
Results
Inter-rater reliability was near-perfect (ICC 0.91; 95% CI 0.89-0.94). Hospital admission records and discharge summaries (vs. complete chart review) significantly underestimated the total FCI score. However, using multivariable linear regression, FCI scores collected using each of the three types of inpatient medical records had similar associations with PFS, suggesting similar predictive value.
Conclusions
Data collection using in-patient discharge summaries represents a reliable and valid method for collecting FCI comorbidity information.
doi:10.1186/1471-2253-12-21
PMCID: PMC3517372
PMID: 22974239
Comorbidity; Intensive care unit; Reproducibility of results; Respiratory distress syndrome, Adult
Background
ERCP practically requires moderate to deep sedation controlled by a combination of benzodiazepine and opiod. Propofol as a sole agent may cause oversedation. A combination (cocktail) of infused propofol, meperidine, and midazolam can reduce the dosage of propofol and we hypothesized that it might decrease the risk of oversedation. We prospectively compare the efficacy, recovery time, patient satisfactory, and side effects between cocktail and conventional sedations in patients undergoing ERCP.
Methods
ERCP patients were randomized into 2 groups; the cocktail group (n = 103) and the controls (n = 102). For induction, a combination of 25 mg of meperidine and 2.5 mg of midazolam were administered in both groups. In the cocktail group, a bolus dose of propofol 1 mg/kg was administered and continuously infused. In the controls, 25 mg of meperidine or 2.5 mg/kg of midazolam were titrated to maintain the level of sedation.
Results
In the cocktail group, the average administration rate of propofol was 6.2 mg/kg/hr. In the control group; average weight base dosage of meperidine and midazolam were 1.03 mg/kg and 0.12 mg/kg, respectively. Recovery times and patients’ satisfaction scores in the cocktail and control groups were 9.67 minutes and 12.89 minutes (P = 0.045), 93.1and 87.6 (P <0.001), respectively. Desaturation rates in the cocktail and conventional groups were 58.3% and 31.4% (P <0.001), respectively. All desaturations were corrected with temporary oxygen supplementation without the need for scope removal.
Conclusions
Cocktail sedation containing propofol provides faster recovery time and better patients’ satisfaction for patients undergoing ERCP. However, mild degree of desaturation may still develop.
Trial registration
ClinicalTrials.gov, NCT01540084
doi:10.1186/1471-2253-12-20
PMCID: PMC3434082
PMID: 22873637
Cocktail sedation containing propofol; Meperidine; Midazolam; ERCP
Background
Approximately 90 haemoglobinopathies have been identified that result in abnormally high oxygen affinity. One of these is haemoglobinopathy York (HbY), first described in 1976. HbY causes an extreme leftward shift of the oxygen dissociation curve with the P50 value changing to 12.5 - 15.5 mmHg (normal value 26.7 mmHg), indicating that approximately half of the haemoglobin is not available as oxygen carrier. Patients with haemoglobinopathies with increased oxygen affinity could suffer from the risk developing ischaemic complications due to a lack of functional oxygen carriers. This is, to best of our knowledge, the first case report on a patient with HbY published in connection with anesthesia.
Case Presentation
A 42-year-old female with a severe headache and Glasgow coma scale (GCS) of 15 was admitted to the neurosurgical intensive care unit with a ruptured, right sided ICA aneurysm with consecutive subarachnoid haemorrhage [Fisher III, World Federation of Neurosurgical Societies (WFNS) I)]. The medical history of the patient included an erythrocytosis (Hb 17.5 g/dl) on the base of a high-oxygen-affinity haemoglobinopathy, called Hb York (HbY). With no time available to take special preoperative precautions, rapid blood loss occurred during the first attempt to clip the aneurysm. General transfusion procedures, according to the guidelines based on haemoglobin and haematocrit values, could not be applied due to the uncertainty in the oxygen carrier reduction. To maintain tissue oxygen supply, clinical indicators of ischaemia were instead utilized to gauge the appropriate required blood products, crystalloids and colloids replacements. Despite this, the patient survived the neurosurgical intervention without any neurological deficit.
Conclusions
Family members of patients with HbY (and other haemoglobinopathies with increased oxygen affinity) should undergo clinical assessment, particularly if they are polycythaemic. If the diagnosis of HbY is confirmed, they should carry an "emergency anaesthesiology card" in order to avert perioperative risks arising from their "hidden" anemia.
doi:10.1186/1471-2253-12-19
PMCID: PMC3459697
PMID: 22870883
Haemoglobinopathy; Hb York; Oxygen affinity; Neuroanaesthesia; Subarachnoid haemorrhage; Anaemia; Hypoxia
Background
The i-gel™, LMA-Supreme (LMA-S) and Laryngeal Tube Suction-D (LTS-D) are single-use supraglottic airway devices with an inbuilt drainage channel. We compared them with regard to their position in situ as well as to clinical performance data during elective surgery.
Methods
Prospective, randomized, comparative study of three groups of 40 elective surgical patients each. Speed of insertion and success rates, leak pressures (LP) at different cuff pressures, dynamic airway compliance, and signs of postoperative airway morbidity were recorded. Fibreoptic evaluation was used to determine the devices’ position in situ.
Results
Leak pressures were similar (i-gel™ 25.9, LMA-S 27.1, LTS-D 24.0 cmH2O; the latter two at 60 cmH2O cuff pressure) as were insertion times (i-gel™ 10, LMA-S 11, LTS-D 14 sec). LP of the LMA-S was higher than that of the LTS-D at lower cuff pressures (p <0.05). Insertion success rates differed significantly: i-gel™ 95%, LMA-S 95%, LTS-D 70% (p <0.05). The fibreoptically assessed position was more frequently suboptimal with the LTS-D but this was not associated with impaired ventilation. Dynamic airway compliance was highest with the i-gel™ and lowest with the LTS-D (p <0.05). Airway morbidity was more pronounced with the LTS-D (p <0.01).
Conclusion
All devices were suitable for ventilating the patients’ lungs during elective surgery.
Trial registration
German Clinical Trial Register DRKS00000760
doi:10.1186/1471-2253-12-18
PMCID: PMC3434115
PMID: 22871204
Laryngeal mask airway; Leak pressure; Laryngeal Tube
Background
Electrolyte values are measured in most critically ill intensive care unit (ICU) patients using both an arterial blood gas analyzer (ABG) and a central laboratory auto-analyzer (AA). The aim of the present study was to investigate whether electrolyte levels assessed using an ABG and an AA were equivalent; data on sodium and potassium ion concentrations were examined.
Methods
We retrospectively studied patients hospitalized in the ICU between July and August 2011. Of 1,105 test samples, we identified 84 instances of simultaneous sampling of arterial and venous blood, where both Na+ and K+ levels were measured using a pHOx Stat Profile Plus L blood gas analyzer (Nova Biomedical, Waltham MA, USA) and a Roche Modular P autoanalyzer (Roche Diagnostics, Mannheim, Germany). Statistical measures employed to compare the data included Spearman's correlation coefficients, paired Student’s t-tests, Deming regression analysis, and Bland-Altman plots.
Results
The mean sodium concentration was 138.1 mmol/L (SD 10.2 mmol/L) using the ABG and 143.0 mmol/L (SD 10.5) using the AA (p < 0.001). The mean potassium level was 3.5 mmol/L (SD 0.9 mmol/L) using the ABG and 3.7 mmol/L (SD 1.0 mmol/L) using the AA (p < 0.001). The extent of inter-analyzer agreement was unacceptable for both K+ and Na+, with biases of 0.150-0.352 and −0.97-10.05 respectively; the associated correlation coefficients were 0.88 and 0.90.
Conclusions
We conclude that the ABG and AA do not yield equivalent Na+ and K+ data. Concordance between ABG and AA should be established prior to introduction of new ABG systems.
doi:10.1186/1471-2253-12-17
PMCID: PMC3431979
PMID: 22862792
Background
Practices for withholding or withdrawing therapy vary according to professional, cultural and religious differences. No Danish-validated questionnaire examining withholding and withdrawing practices exists, thus the aim of this study was to develop and validate a questionnaire for surveying the views of intensive care nurses, intensivists, and primary physicians regarding collaboration and other aspects of withholding and withdrawing therapy in the ICU.
Methods
A questionnaire was developed on the basis of literature, focus group interviews with intensive care nurses and intensivists, and individual interviews with primary physicians. The questionnaire was validated in the following 3 phases: a qualitative test with 17 participants; a quantitative pilot test with 60 participants; and a survey with 776 participants. The validation process included tests for face and content validity (by interviewing participants in the qualitative part of the pilot study), reliability (by assessing the distribution of responses within the individual response categories), agreement (by conducting a test-retest, evaluated by paired analyses), known groups’ validity (as a surrogate test for responsiveness, by comparing two ICUs with a known difference in end-of-life practices), floor and ceiling effect, and missing data.
Results
Face and content validity were assessed as good by the participants in the qualitative pilot test; all considered the questions relevant and none of the participants found areas lacking. Almost all response categories were used by the participants, thus demonstrating the questionnaires ability to distinguish between different respondents, agreement was fair (the average test-retest agreement for the Likert scale responses was 0.54 (weighted kappa; range, 0.25-0.73), and known groups’ validity was proved by finding significant differences in level of satisfaction with interdisciplinary collaboration and in experiences of withdrawal decisions being unnecessarily postponed. Floor and ceiling effect was in accordance with other questionnaires, and missing data was limited to a range of 0-7% for all questions.
Conclusions
The validation showed good and fair areas of validity of the questionnaire. The questionnaire is considered a useful tool to assess the perceptions of collaboration and other aspects of withholding and withdrawing therapy practices in Danish ICUs amongst nurses, intensivists, and primary physicians.
doi:10.1186/1471-2253-12-16
PMCID: PMC3519525
PMID: 22853051
Background
Intravenous fluid is recommended in international guidelines to improve patient post-operative symptoms, particularly nausea and vomiting. The optimum fluid regimen has not been established. This prospective, randomized, blinded study was designed to determine if administration of equivolumes of a colloid (hydroxyethyl starch 130/0.4) reduced post operative nausea and vomiting in healthy volunteers undergoing ambulatory gynecologic laparoscopy surgery compared to a crystalloid solution (Hartmann’s Solution).
Methods
120 patients were randomized to receive intravenous colloid (N = 60) or crystalloid (N = 60) intra-operatively. The volume of fluid administered was calculated at 1.5 ml.kg-1 per hour of fasting. Patients were interviewed to assess nausea, vomiting, anti-emetic use, dizziness, sore throat, headache and subjective general well being at 30 minutes and 2, 24 and 48 hours post operatively. Pulmonary function testing was performed on a subgroup.
Results
At 2 hours the proportion of patients experiencing nausea (38.2 % vs 17.9%, P = 0.03) and the mean nausea score were increased in the colloid compared to crystalloid group respectively (1.49 ± 0.3 vs 0.68 ± 0.2, P = 0.028). The incidence of vomiting and anti-emetic usage was low and did not differ between the groups. Sore throat, dizziness, headache and general well being were not different between the groups. A comparable reduction on post-operative FVC and FEV-1 and PEFR was observed in both groups.
Conclusions
Intra-operative administration of colloid increased the incidence of early postoperative nausea and has no advantage over crystalloid for symptom control after gynaecological laparoscopic surgery.
doi:10.1186/1471-2253-12-15
PMCID: PMC3441250
PMID: 22849587
Fluid therapy; Colloid; Crystalloid solutions; Nausea; Vomiting
Background
We made a survey among Finnish anesthesiologists concerning the current perioperative anesthetic practice of hip fracture patients for further development in patient care.
Methods
All members of the Finnish Society of Anesthesiologists with a known e-mail address (786) were invited to participate in an internet-based survey.
Results
The overall response rate was 55% (423 responses); 298 respondents participated in the care of hip fracture patients. Preoperative analgesia was mostly managed with oxycodone and paracetamol; every fifth respondent applied an epidural infusion. Most respondents (98%) employed a spinal block with or without an epidural catheter for intraoperative anesthesia. Midazolam, propofol and/or fentanyl were used for additional sedation. General anesthesia was used rarely. Postoperatively, paracetamol and non-steroidal anti-inflammatory drugs and occasionally peroral oxycodone, were prescribed in addition to epidural analgesia.
Conclusions
The survey suggests that the impact of more individualised analgesia regimens, both preoperatively and postoperatively, should be investigated in further studies.
doi:10.1186/1471-2253-12-14
PMCID: PMC3432003
PMID: 22839198
Hip fracture; Perioperative management; Anesthetic practice
Background
Randomized controlled trials (RCTs) are routinely used in systematic reviews and meta-analyses that help inform healthcare and policy decision making. The proper reporting of RCTs is important because it acts as a proxy for health care providers and researchers to appraise the quality of the methodology, conduct and analysis of an RCT. The aims of this study are to analyse the overall quality of reporting in 23 RCTs that were used in a meta-analysis by assessing 3 key methodological items, and to determine factors associated with high quality of reporting. It is hypothesized that studies with larger sample sizes, that have funding reported, that are published in journals with a higher impact factor and that are in journals that have adopted or endorsed the CONSORT statement will be associated with better overall quality of reporting and reporting of key methodological items.
Methods
We systematically reviewed RCTs used within an anesthesiology related post-operative pain management meta-analysis. We included all of the 23 RCTs used, all of which were parallel design that addressed the use of femoral nerve block in improving outcomes after total knee arthroplasty. Data abstraction was done independently by two reviewers. The two main outcomes were: 1) 15 point overall quality of reporting score (OQRS) based on the Consolidated Standards for Reporting Trials (CONSORT) and 2) 3 point key methodological item score (KMIS) based on allocation concealment, blinding and intention-to-treat analysis.
Results
Twenty-three RCTs were included. The median OQRS was 9.0 (Interquartile Range = 3). A multivariable regression analysis did not show any significant association between OQRS or KMIS and our four predictor variables hypothesized to improve reporting. The direction and magnitude of our results when compared to similar studies suggest that the sample size and impact factor are associated with improved key methodological item reporting.
Conclusions
The quality of reporting of RCTs used within an anesthesia related meta-analysis is poor to moderate. The information gained from this study should be used by journals to register the urgency for RCTs to be clear and transparent in reporting to help make literature accessible and comparable.
doi:10.1186/1471-2253-12-13
PMCID: PMC3407517
PMID: 22762351