bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of Outcomes by Modality for Critically Ill Patients Requiring Renal Replacement Therapy: A Single-Centre Cohort Study Adjusting for Time-Varying Illness Severity and Modality Exposure
Authors: Khanal N. , Marshall M. R. , Ma T. M. , Pridmore P. J. , Williams A. B. , Rankin A. P. N.
Published: January 2019

Prolonged intermittent renal replacement therapy (PIRRT) is a recently defined acute modality for critically ill patients, and in theory combines the superior detoxification and haemodynamic stability of continuous renal replacement therapy (CRRT) with the operational convenience and low cost of intermittent haemodialysis (iHD). We performed a retrospective cohort study for all critically ill adults treated with renal replacement therapy at our centre in Auckland, New Zealand from 1 January 2002 to 31 December 2008. The exposure of interest was modality (PIRRT, CRRT, iHD). Primary and secondary outcomes were patient mortality determined at hospital discharge and 90 days post renal replacement therapy inception, respectively. Co-variates included co-morbidity and baseline illness severity measured by Acute Physiology and Chronic Health Evaluation IV and Sepsis-Related Organ Failure Assessment (SOFA) and time-varying illness severity measured by daily SOFA scores. We used Marginal Structural Modelling to estimate mortality risk adjusting for both time-varying illness severity and modality exposure. A total of 146 patients with 633 treatment-days had sufficient data for modelling. With PIRRT as the reference, the adjusted hazard ratios for patient hospital mortality were 1.31 (0.60 to 2.90) for CRRT and 1.22 (0.21 to 2.29) for iHD. Corresponding estimates for mortality at 90 days were 0.96 (0.39 to 2.36) and 2.22 (0.49 to 10.11), respectively, reflecting the poorer longer-term prognosis of patients still on iHD at hospital discharge with delayed or non-recovery of acute kidney injury. Our study supports the recent increased use of PIRRT, which within limits can be regarded as safe and effective.
Pharmacokinetics of Oxycodone after Subcutaneous Administration in a Critically Ill Population Compared with a Healthy Cohort
Authors: Krishnamurthy R. B. , Upton R. N. , Fajumi A. O. , Lai S. , Charlton C. S. , Ousley R. M. , Martinez A. M. , Mcconnell H. , O'Connor S. N. , Ong J. , Macintyre P. E. , Chapman M. J. , Ludbrook G. L.
Published: January 2019

This study aimed to characterise and compare the absorption pharmacokinetics of a single subcutaneous dose of oxycodone in critically ill patients and healthy subjects. Blood samples taken at intervals from two minutes to eight hours after a subcutaneous dose of oxycodone in patients (5 mg) and healthy volunteers (10 mg) were assayed using high performance liquid chromatography. Data were analysed using a non-compartmental approach and presented as mean (SD). Parameters were corrected for dose differences between the groups assuming linear kinetics. Ten patients (eight male, two female) and seven healthy male subjects were included. Maximum venous concentration and area under the concentration curve were approximately two-fold lower in the patient group for an equivalent dose, suggesting either reduced bioavailability or increased clearance: maximum venous concentration 0.14±0.06 vs 0.05±0.02 μg/ml (P P P=0.81); mean residence time 353±191 vs 291±80 minutes (P=0.26). Kinetic parameters were less variable in patients than in volunteers. The patients therefore had reduced exposure to subcutaneous oxycodone. This warrants further model-based analysis and experimentation. Dose regimens for subcutaneous oxycodone developed in healthy volunteers cannot be directly translated to critically ill patients.
The Influence of Unrestricted Use of Sugammadex on Clinical Anaesthetic Practice in a Tertiary Teaching Hospital
Authors: Watts R. W. , London J. A. , van Wijk R. M. A. W. , Lui Y.-L.
Published: January 2019

This retrospective casenote audit involving 374 patients requiring intubation for an anaesthetic found that when the availability of sugammadex became unrestricted, its use increased from 7.1 to 65.3% (P P=0.006) but vecuronium use increased (2.1 to 8.3%, P=0.02). Cisatracurium and suxamethonium use were unchanged.

Total rocuronium dose (55.9±24.1 vs 60.4±22.3 mg) and the number of doses (1.9±1.48 to 1.96±1.27) were unchanged, but the time between the last dose and reversal decreased (91.7±68.1 to 62±52.4 minutes, P=0.0002).

There appeared to be no change in postoperative nausea and vomiting, or post-anaesthesia care unit time or oxygen saturation levels. Anaesthetic theatre time fell from 143.5±85.8 to 120±71.2 minutes (P=0.01) and remained significant when adjusted for confounding variables (ratio of means 1.17, 95% confidence interval 1.03 to 1.34, P=0.02), although inferences in relation to causality are limited by the retrospective and observational design of the study. Hospital stay also appeared to fall (4.2±3.5 to 3.4±3.0 days, P=0.035), but was not statistically significant when adjusted for confounding variables (ratio of means 1.04, 95% confidence interval 0.89 to 1.2, P=0.59).

These observations suggest that the unrestricted availability of sugammadex will change how steroid-based neuromuscular blocking drugs are used and reversed, but further research is needed to determine if patient outcomes will improve.
Postpartum Seizure and Ischaemic Stroke following Dural Puncture and Epidural Blood Patch
Authors: Ng M. D. , Manikappa S.
Published: January 2019

A 33-year-old parturient experienced seizures, then an ischaemic stroke after caesarean section, while undergoing an epidural blood patch for dural puncture. A diagnosis of normotensive late postpartum eclampsia, with either a posterior reversible encephalopathy syndrome or postpartum vasculopathy, leading to stroke, was made – based primarily on a temporal relationship to the postpartum period and consistent findings on magnetic resonance imaging and angiography scans and an electroencephalogram. The difficulties in definitively elucidating the cause of seizures and cerebral infarction in the postpartum period and the impact of anaesthetic interventions in this case are discussed.
The Effect of Body Mass Index on Spinal Anaesthesia for Total Knee Replacement Arthroplasty: A Dose-response Study
Authors: Kim W. H. , Lee J. H. , Ko J. S. , Ahn H. J. , Park S. K. , Gwak M. S. , Kim G. S.
Published: January 2019

The aim of this study was to compare the duration of spinal anaesthesia in obese and non-obese subjects. We also quantified the effect of body mass index (BMI) on spinal anaesthesia by comparing the median effective dose (ED50) of intrathecal hyperbaric bupivacaine required in the two cohorts. One hundred and eight patients undergoing elective total knee replacement arthroplasty under combined spinal-epidural anaesthesia were enrolled as a non-obese group (BMI <27.5 kg/m2) or obese (O) group (BMI ≤27.5 kg/m2). Each group was further subdivided by bupivacaine doses of 6, 7, 8, 9, 10 or 11 mg, respectively. Anaesthesia was deemed successful if a bilateral T12 sensory block occurred within 15 minutes of intrathecal drug administration and epidural supplementation was not required. The ED50 for successful anaesthesia and that for successful block of tourniquet pain were determined separately by probit regression analysis. Although the analgesic duration was prolonged with higher doses of bupivacaine in group O, the ED50 for successful anaesthesia did not differ between groups. However, the incidence of tourniquet pain was lower in group O and the ED50 for block of tourniquet pain was less in group O. This study suggests that bupivacaine dose reduction is not necessary, but analgesic duration may be prolonged in patients with higher BMI. These patients require careful consideration of spinal anaesthetic dose to minimise the risk of unnecessary prolongation of anaesthesia.
Lactate/Pyruvate Ratio as a Marker of Tissue Hypoxia in Circulatory and Septic Shock
Authors: Rimachi R. , De Carvahlo F. Bruzzi , Orellano-Jimenez C. , Cotton F. , Vincent J. L. , De Backer D.
Published: January 2019

In this prospective, observational study, we measured arterial lactate and pyruvate concentrations within the first four hours of shock and at four hour intervals during the first 24 hours in 26 patients with septic and 13 with cardiogenic shock. We also studied 10 intensive care unit patients with normal lactate levels as controls. Seven patients (18%) died during the first 24 hours of shock, 12 (31%) patients died later in the intensive care unit and 21 (54%) were discharged alive from the intensive care unit. Blood lactate values were higher at shock onset in the non-survivors than in the survivors ( P=0.02) and remained significantly elevated throughout the study. The lactate/pyruvate ratio at shock onset was significantly higher in the non-survivors (24 [17 to 34] vs 15 [10 to 19], P=0.01) than in the survivors. All patients with cardiogenic shock had hyperlactataemia at the onset of shock and 69% had a high lactate/pyruvate ratio. Only 65% of patients with septic shock had hyperlactataemia at the onset of shock and 76% of these also had a high lactate/pyruvate ratio. In conclusion, the lactate/pyruvate ratio confirms that hyperlactataemia is frequently, but not solely, due to hypoxia, especially at the onset of shock.
Assessing the Performance of a Continuous Infusion for Potassium Supplementation in the Critically Ill
Authors: Chalwin R. P. , Moran J. L. , Peake S. L. , Feynn S. , Pieterse J. , Williams P.
Published: January 2019

Hypokalaemia is a common problem in critically ill patients, which if untreated, can result in dysrhythmia or another adverse outcome. We assessed the safety and efficacy of a continuous infusion of potassium chloride versus an existing intermittent infusion regimen. In this open-label randomised parallel-arm active-controlled pilot study, critically ill adults with plasma potassium concentration between 2.5 and 3.8 mmol/l were randomised to receive either a continuous infusion or intermittent infusions of potassium chloride for establishment and maintenance of normokalaemia. The primary outcome was the mean difference in plasma potassium concentration over time between the two study arms as assessed by a linear mixed-effects model. Although a statistically significant difference was observed (0.22 mmol/l; 95% confidence interval 0.17, 0.27; P <0.0001), this did not reach the pre-determined level indicative of a treatment effect (0.5 mmol/l). The continuous group demonstrated less variance in (mean) plasma potassium as reflected in narrower confidence intervals in a prediction-by-time model. The incidence rate ratio of dysrhythmia, assessed by a mixed-effects Poisson model, was similar in each group (0.62; 95% confidence interval 0.32, 1.21; P=0.16). We recorded no adverse events directly attributable to infusion of potassium chloride in either study arm. Although titrated continuous infusion did not demonstrate a clinically important difference by comparison with intermittent infusions for the maintenance of normokalaemia, there was more consistent control of plasma potassium with no observed complications or adverse events. Therefore, this trial showed an acceptable efficacy and safety profile for the continuous infusion regimen, suggesting scope for further study.
Elimination of Teicoplanin by Adsorption to the Filter Membrane during Haemodiafiltration: Screening Experiments for Linezolid, Teicoplanin and Vancomycin followed by in vitro Haemodiafiltration Models for Teicoplanin
Authors: Shiraishi Y. , Okajima M. , Sai Y. , Miyamoto K. , Inaba H.
Published: January 2019

Pharmaceutical agents directed against methicillin-resistant Staphylococcus aureus can be eliminated during haemodiafiltration, not only by diffusion and ultrafiltration, but also by adsorption onto haemofilters. The latter may be affected by the binding of agents to serum albumin. The present study therefore investigated the affinity of anti-methicillin-resistant Staphylococcus aureus agents (teicoplanin, linezolid, vancomycin) for haemofilters and the pharmacokinetic properties of teicoplanin during haemodiafiltration. Linezolid, teicoplanin and vancomycin were first screened for their in vitro affinity for three different kinds of filter membranes: polysulfone, polyacrylonitrile and polymethylmethacrylate. Only teicoplanin showed significant filter-binding activity. An in vitro haemodiafiltration circulation model was then developed that incorporated a one-litre beaker containing Krebs-Ringer's bicarbonate solution with/without human albumin (0 or 3 g/dl) as an artificial plasma. Teicoplanin (initial concentration 50 μg/ml, representing the maximum plasma concentration (Cmax) resulting from a typical clinical dosage) was circulated throughout the beaker. Teicoplanin concentrations in the ‘plasma’ and ultrafiltrate were determined by high performance liquid chromatography. In the screening experiment, teicoplanin was predominantly adsorbed onto polysulfone and polymethylmethacrylate membranes. Furthermore, teicoplanin was primarily eliminated by adsorption onto these filters during in vitro haemodiafiltration. Albumin significantly reduced both haemodiafiltration clearance and the adsorption-dependent elimination, although there were complex but significant interactions between albumin and the filter membrane. Elimination of teicoplanin in an in vitro haemodiafiltration model was largely due to adsorption onto polysulfone and polymethylmethacrylate haemofilters. Future clinical studies should likely be designed to evaluate present recommendations of teicoplanin dosages in patients on haemodiafiltration.
Enhanced Recovery after Surgery Program for Elective Abdominal Surgery at Three Victorian Hospitals
Authors: Thompson E. G. E. , Gower S. T. , Beilby D. S. , Wallace S. , Tomlinson S. , Guest G. D. , Cade R. , Serpell J. S. , Myles P. S.
Published: January 2019

The aim of this study was to evaluate the anaesthesia care of an enhanced recovery after surgery (ERAS) program for patients having abdominal surgery in Victorian hospitals. The main outcome measure was the number of ERAS items implemented following introduction of the ERAS program. Secondary endpoints included process of care measures, outcomes and hospital stay. We used a before-and-after design; the control group was a prospective cohort (n=154) representing pre-existing practice for elective abdominal surgical patients from July 2009. The introduction of a comprehensive ERAS program took place over two months and included the education of surgeons, anaesthetists, nurses and allied health professionals. A postimplementation cohort (n=169) was enrolled in early 2010. From a total of 14 ERAS-recommended items, there were significantly more implemented in the post-ERAS period, median 8 (interquartile range 7 to 9) vs 9 (8 to 10), P <0.0001. There were, however, persistent low rates of intravenous fluid restriction (25%) and early removal of urinary catheter (31%) in the post-ERAS period. ERAS patients had less pain and faster recovery parameters, and this was associated with a reduced hospital stay, geometric mean (SD) 5.7 (2.5) vs 7.4 (2.1) days, P=0.006. We found that perioperative anaesthesia practices can be readily modified to incorporate an enhanced recovery program in Victorian hospitals.
Cyanoacrylate Tissue Adhesives – Effective Securement Technique for Intravascular Catheters: In Vitro Testing of Safety and Feasibility
Authors: Simonova G. , Rickard C. M. , Dunster K. R. , Smyth D. J. , McMillan D. , Fraser J. F.
Published: January 2019

Partial or complete dislodgement of intravascular catheters remains a significant problem in hospitals despite current securement methods. Cyanoacrylate tissue adhesives (TA) are currently used to close skin wounds as an alternative to sutures. These adhesives have high mechanical strength and can remain in situ for several days. This study investigated in vitro use of TAs in securing intravascular catheters (IVC). We compared two adhesives for interaction with IVC material, comparing skin glues with current securement methods in terms of their ability to prevent IVC dislodgement and to inhibit microbial growth. Two TAs (Dermabond®, Ethicon Inc. and Histoacryl®, B. Braun) and three removal agents (Remove™, paraffin and acetone) were tested for interaction with IVC material by use of tensile testing. TAs were also compared against two polyurethane (standard and bordered) dressings (Tegaderm™ 1624 and 1633, 3M Australia Pty Ltd) and an external stabilisation device (Statlock®, Bard Medical, Covington) against control (unsecured IVCs) for ability to prevent pull-out of 16 G peripheral IVCs from newborn fresh porcine skin. Agar media containing pH-sensitive dye was used to assess antimicrobial properties of TAs and polyurethane dressings to inhibit growth of Staphylococcus aureus and Staphylococcus epidermidis. Neither TA weakened the IVCs ( P >0.05). Of removal agents, only acetone was associated with a significant decrease in IVC strength ( P <0.05). Both TAs and Statlock significantly increased the pull-out force ( P <0.01). TA was quick and easy to apply to IVCs, with no irritation or skin damage noted on removal and no bacterial colony growth under either TA.
Preparation of Datex-Ohmeda Aestiva® and Aisys® anaesthetic machines for use in malignant hyperthermia susceptible patients
Authors: Jones C. , Bennett K. , Kim T. W. , Bulger T. F. , Pollock N.
Published: January 2019

Preparation of anaesthesia machines for use by malignant hyperthermia susceptible patients requires purging the machines of halogenated anaesthetic agents. The endpoint of this process is to reach a gas concentration of 5 ppm or less, which has been arbitrarily chosen as the safe limit of exposure to avoid triggering a malignant hyperthermia event. We examined the washout characteristics of sevoflurane and desflurane from the Datex-Ohmeda Aestiva® Anaesthesia System and Aisys® Anaesthesia Carestation®anaesthetic machines. The machines were contaminated for two hours using either sevoflurane 2 vol% or desflurane 6 vol%. At the end of the priming period, the patient breathing circuit and reservoir bag, carbon dioxide absorbent, sampling line and test lung were replaced with uncontaminated components. During the test period, machines were purged using oxygen flows of 10 l/minute. The average time to reach 5 ppm with the Aestiva machines was 51 minutes with sevoflurane and 71 minutes with desflurane. The average time to reach 5 ppm for the Aisys machines was 55 minutes with sevoflurane and 69 minutes with desflurane. All configurations of machines and anaesthetic gases demonstrated a rebound effect in agent concentration above 5 ppm when the fresh gas flow was subsequently reduced from 10 to 2 l/minute. Aestiva and Aisys anaesthetic machines require a prolonged period to adequately purge them of halogenated volatile anaesthetic agent. The rebound effect poses a serious concern, suggesting that after the purging period, fresh gas flows of 10 l/minute should be maintained for the duration of anaesthesia care of the malignant hyperthermia susceptible patient.
Circumcision of neonates and children without appropriate anaesthesia is unacceptable practice
Authors: Paix B. R. , Peterson S. E.
Published: January 2019

Circumcision is painful surgery and appropriate intraoperative anaesthesia and postoperative analgesia is required. This is recognised in the policies of the Royal Australasian College of Physicians and the majority of Australian State Health Departments. Nevertheless, anecdotal evidence exists that neonatal circumcision continues to be performed in Australia with either no anaesthesia or with inadequate anaesthesia. This paper presents the evidence that neonatal circumcision is painful and reviews the available anaesthetic techniques. The authors conclude that general anaesthesia is arguably the most reliable way of ensuring adequate anaesthesia, although this may mean deferment of the procedure until the child is older. Local or regional anaesthesia for neonatal circumcision ideally requires a separate skilled anaesthetist (other than the proceduralist) to monitor the patient and intervene if the anaesthesia is inadequate. Topical anaesthesia with lignocaine-prilocaine (EMLA) cream is insufficient.
Donation after Cardiac Death in Queensland: Review of the Pilot Project
Authors: Kumar R. , Shekar K. , Widdicombe N. , Fraser J. F.
Published: January 2019

Organ transplantation is a viable therapeutic option for patients with endstage organ failure when other therapies have been exhausted. Donation after cardiac death (DCD) is re-emerging as a potential option to expand the donor pool in order to meet an increasing demand for organ transplantation. In this review, we evaluate the evolution of the Queensland DCD pilot project since its inception in August 2008. A retrospective analysis of registry data from Australia and New Zealand Organ Donation (ANZOD) and DonateLife Queensland was performed to collect information relating to donor characteristics, DCD process and outcomes. Data was compared with the ANZOD registry annual reports from 2008 to 2010. Twenty-three (82%) out of 28 potential DCD organ donors were successful in donating their organs. The median time from presentation to reaching consensus to withdraw cardiorespiratory support was four days (interquartile range three to eight days). The median time from withdrawal to death was 20 minutes (interquartile range 18 to 25 minutes), and the median warm ischaemia time was 17 minutes (interquartile range 14 to 19 minutes). DCD donors represented 16% (23) of the 144 deceased donors over the study period and provided approximately 10% (48) of the 505 deceased organs in Queensland. The DCD pilot project resulted in an increase in solid organ transplantation in Queensland. It allowed the development of policies to facilitate DCD, in accordance with state's legislation and DonateLife practices. If implemented state-wide, the program has the potential to be an effective way to improve organ donation rates in Queensland.
A Survey of Antiemetic Dexamethasone Administration— Frequency of use and Perceptions of Benefits and Risks
Authors: Corcoran T. B. , Edwards T.
Published: January 2019

Postoperative nausea and vomiting (PONV) is a significant concern for anaesthetists. There are many agents from different classes that are effective in both preventing and treating PONV. Dexamethasone is a very effective antiemetic, but there are concerns regarding its safety. We performed an anonymous survey of a random selection of the fellows of the Australian and New Zealand College of Anaesthetists to ascertain patterns of practice in relation to PONV prophylaxis and treatment and also to determine awareness of the risks and benefits of perioperative dexamethasone administration. The response rate was 33%. From the responses, 71.2% of all patients undergoing general anaesthesia in the respondents’ institutions receive PONV prophylaxis in total and 46.6% receive dexamethasone. No respondent gives more than a single dose of dexamethasone and there was an almost equal split between those who administer 4 and 8 mg, with a smaller number dosing on a weight basis. 5HT-3 receptor antagonists and dexamethasone are the preferred first-line PONV prophylactic agents and 5HT-3 receptor antagonists and droperidol are the preferred first-line PONV therapeutic agents. Concerns relating to the safety of dexamethasone were expressed by 80% of respondents. From this survey, we concluded that the PONV practice of the respondents is largely compliant with recent consensus guidelines, although PONV prophylaxis appears to be given more routinely. It also appears that more education is required on issues regarding dexamethasone safety.
Efficacy of the APACHE II Score at ICU Discharge in Predicting Post-ICU Mortality and ICU Readmission in Critically Ill Surgical Patients
Authors: Lee H. , Lim C. W. , Hong H. P. , Ju J. W. , Jeon Y. T. , Hwang J. W. , Park H. P.
Published: January 2019

In this study, we evaluated the efficacy of the discharge Acute Physiology and Chronic Health Evaluation (APACHE) II score in predicting post-intensive care unit (ICU) mortality and ICU readmission during the same hospitalisation in a surgical ICU. Of 1190 patients who were admitted to the ICU and stayed >48 hours between October 2007 and March 2010, 23 (1.9%) died and 86 (7.2%) were readmitted after initial ICU discharge, with 26 (3.0%) admitted within 48 hours. The area under the receiver operating characteristics curve of the discharge and admission APACHE II scores in predicting in-hospital mortality was 0.631 (95% confidence interval [CI] 0.603 to 0.658) and 0.669 (95% CI 0.642 to 0.696), respectively ( P=0.510). The area under the receiver operating characteristics curve of discharge and admission APACHE II scores for predicting all forms of readmission was 0.606 (95% CI 0.578 to 0.634) and 0.574 (95% CI 0.545 to 0.602), respectively ( P=0.316). The area under the receiver operating characteristics curve of discharge APACHE II score in predicting early ICU readmissions was, however, higher than that of admission APACHE II score (0.688 [95% CI 0.660 to 0.714] versus 0.505 [95% CI 0.476 to 0.534], P=0.001). The discharge APACHE II score (odds ratio [OR] 1.1, 95% CI 1.01 to 1.22, P=0.024), unplanned ICU readmission (OR 20.0, 95% CI 7.6 to 53.1, P=0.001), eosinopenia at ICU discharge (OR 6.0, 95% CI 1.34 to 26.9, P=0.019), and hospital length-of-stay before ICU admission (OR 1.02, 95% CI 1.01 to 1.03, P=0.021) were significant independent factors in predicting post-ICU mortality. This study suggests that the discharge APACHE II score may be useful in predicting post-ICU mortality and is superior to the admission APACHE II score in predicting early ICU readmission in surgical ICU patients.
The role of an ambient pressure oxygen source during one-lung ventilation for thoracoscopic surgery
Authors: Pfitzner J.
Published: January 2019

Video-assisted thoracoscopic surgery is facilitated by prompt collapse of the non-ventilated (‘operated’) lung, and interrupted and impeded if there is a need for oxygen (O2) delivery by continuous positive airways pressure in order to manage hypoxaemia. It has been proposed that connecting an ambient pressure O2 source to the airway of the non-ventilated lung at the time one-lung ventilation is initiated and before the chest is opened will, by avoiding entrainment of ambient nitrogen, serve to facilitate lung collapse. It has also been proposed that leaving the O2 source connected will enable, not only ongoing apnoeic oxygenation before the chest is opened, but also the thoracoscopic procedure to commence with the operated lung fully pre-oxygenated (with an inspired oxygen fraction of 1), and apnoeic oxygenation to continue throughout the operative procedure in those patients who exhibit a degree of small airways patency at ambient pressure. In reality, several factors can influence the speed of collapse of the operated lung, and very many factors can influence the incidence of hypoxaemia during one-lung ventilation. It therefore appears unlikely that the necessary evidence to support these proposals will be forthcoming from randomised clinical studies on large numbers of patients. Rather, the necessary evidence may only be provided by specifically designed within-patient clinical measurement studies. Nevertheless, it is argued that, in the meantime, there is already sufficient rationale for an ambient pressure O2 source to be connected to the airway of the non-ventilated lung, and for it to remain connected for the duration of one-lung ventilation.
A Trial of Nebulised Heparin to Limit Lung Injury following Cardiac Surgery
Authors: Dixon B. , Smith R. , Santamaria J. D. , Orford N. R. , Wakefield B. J. , Ives K. , McKenzie R. , Zhang B. , Yap C. H.
Published: January 2019

Cardiac surgery with cardiopulmonary bypass triggers an acute inflammatory response in the lungs. This response gives rise to fibrin deposition in the microvasculature and alveoli of the lungs. Fibrin deposition in the microvasculature increases alveolar dead space, while fibrin deposition in alveoli causes shunting. We investigated whether prophylactic nebulised heparin could limit this form of lung injury. We undertook a single-centre double-blind randomised trial. Forty patients undergoing elective cardiac surgery with cardiopulmonary bypass were randomised to prophylactic nebulised heparin (50,000 U) or placebo. The primary endpoint was the change in arterial oxygen levels over the operative period. Secondary endpoints included end-tidal CO2, the alveolar dead space fraction and bleeding complications. We found nebulised heparin did not improve arterial oxygen levels. Nebulised heparin was, however, associated with a lower alveolar dead space fraction ( P <0.05) and lower tidal volumes at the end of surgery ( P <0.01). Nebulised heparin was not associated with bleeding complications. In conclusion, prophylactic nebulised heparin did not improve oxygenation, but was associated with evidence of better alveolar perfusion and CO2 elimination at the end of surgery.
Day 3 versus Day 1 Disseminated Intravascular Coagulation Score among Sepsis Patients: A Prospective Observational Study
Authors: Park J. Y. , Park S. , Park S. Y. , Sim Y. S. , Kim J. H. , Hwang Y. I. , Jang S. H. , Jung K. S.
Published: January 2019

The role of disseminated intravascular coagulation (DIC) has not been extensively studied in patients with sepsis. A prospective study was performed in a single university hospital. The incidences of DIC at day 1 (<24 hours post-sepsis diagnosis) and day 3 (48 to 72 hours) were investigated among patients with sepsis. The International Society of Thrombosis and Haemostasis criteria for DIC were used. Among 381 patients initially screened, 219 were enrolled in this study and the incidences of overt DIC were 27.9% and 30.1% on day 1 and day 3, respectively. Patients with pneumonia had a lower incidence of DIC on day 1, but a higher hospital mortality rate compared to those with non-pneumonia sepsis. In multivariate models, although day 1 and day 3 DIC scores were not associated with hospital mortality after adjusting for existing severity scores, the change in DIC scores (odds ratio 1.862; 95% confidence interval 1.061 to 3.266) exhibited a significant association. Day 3 DIC scores were more accurate in predicting hospital mortality than day 1 DIC scores ( P <0.001), especially in patients with non-pneumonia sepsis. However, DIC scores did not give additional discriminative power to the existing prognostic scores in predicting mortality of patients with sepsis. In conclusion, the change in DIC score was significantly associated with hospital mortality. Patients with pneumonia sepsis had a lower incidence of DIC on day 1, despite their higher disease severity and mortality rate, compared to those with other sources of sepsis.
Characteristics of Sepsis-Induced Cardiac Dysfunction using Speckle-Tracking Echocardiography: A Feasibility Study
Authors: Zaky A. , Gill E. A. , Paul C. P. , Bendjelid K. , Treggiari M. M.
Published: January 2019

Septic cardiomyopathy is commonly encountered in patients with severe sepsis and septic shock. This study explores whether novel global and segmental echocardiographic markers of myocardial deformation, using two-dimensional speckle tracking, are associated with adverse sepsis outcomes. We conducted a retrospective observational feasibility study, at a tertiary care centre, of patients admitted to the ICU with a diagnosis of sepsis who underwent an echocardiogram within the first week of sepsis diagnosis. Data were collected on chamber dimensions, systolic and diastolic function, demographics, haemodynamics, and laboratory parameters. Global and segmental left ventricular longitudinal strain (LVLS) and tissue mitral annular displacement (TMAD) were assessed on 12 left ventricular segments and six mitral annulus segments in apical views, respectively. We explored associations of abnormal LVLS and TMAD with duration of mechanical ventilation, hospital length of stay, and mortality. Fifty-four patients were included. Global LVLS was not associated with any of the primary study endpoints. However, reduced systolic LVLS of the basal anterior segment was associated with in-hospital mortality. There was a suggestion that patients with a reduced global TMAD were associated with an increased risk of mortality and a short length of hospital stay but these associations were not statistically significant. Reduced global LVLS was associated with lower ejection fraction. Reduced global TMAD was associated with reduced global and segmental LVLS, reduced left ventricular ejection fraction, and increased left ventricular end-systolic and end-diastolic volumes. Speckle-tracking echocardiography can be performed feasibly in patients in sepsis. Global and segmental left ventricular deformation indices are associated with ejection fraction. Further studies need to evaluate the ability of these new indices to predict sepsis outcomes.
End-tidal Sevoflurane Concentration for ProSeal™ versus Classic™ Laryngeal Mask Airway Insertion in Unpremedicated Anaesthetised Adult Females
Authors: Ghai B. , Jain K. , Bansal D. , Bhatia N.
Published: January 2019

Summary

The optimal end-tidal sevoflurane concentration for successful ProSeal™ (Teleflex, Morrisville, NC, USA) laryngeal mask airway (PLMA) versus Classic™ (Teleflex, Morrisville, NC, USA) laryngeal mask airway (CLMA) insertion in unpremedicated anaesthetised adults is unknown. We determined end-tidal sevoflurane concentrations for successful insertion in fifty percent of anaesthetised adults. This randomised, prospective, double-blind study was conducted in the operating theatre of a government tertiary care hospital. Forty-four unpremedicated American Society of Anesthesiologists physical status I and II women with cervical carcinoma (aged 30 to 60 years), scheduled for intracavity caesium implantation under general anaesthesia with a laryngeal mask airway (LMA) were included in the study. The participants were randomised to one of the two groups, to receive either a PLMA or CLMA. After anaesthetic induction with sevoflurane, a predetermined end-tidal sevoflurane concentration (starting at 2.5%) was sustained for 10 minutes before LMA insertion was attempted. End-tidal sevoflurane concentration was increased/decreased (step-size 0.25%) using Dixon and Massey's up-and-down method for the next patient based on the previous patient's response. Placement without clenching, movement, coughing or biting within one minute was considered successful insertion. The end-tidal sevoflurane concentration required for successful LMA insertion in fifty percent of anaesthetised adults was calculated as the mean of the crossover pairs' midpoints in each group and further confirmed by probit regression analysis. The end-tidal sevoflurane concentration (95% confidence interval) required for successful PLMA insertion in 50% of anaesthetised adults (3.15% [3.12% to 3.18%]) was significantly higher than that for CLMA insertion (2.71% [2.66% to 2.76%], P <0.001). These findings suggest that deeper anaesthesia is required for placement of a PLMA in comparison to a CLMA.
Risk Factors for Bleeding Complications after Percutaneous Dilatational Tracheostomy: A Ten-year Institutional Analysis
Authors: Pilarczyk K. , Haake N. , Dudasova M. , Huschens B. , Wendt D. , Demircioglu E. , Jakob H. , Dusse F.
Published: January 2019

Summary

Bleeding complications after percutaneous dilatational tracheostomy (PDT) are infrequent but may have a tremendous impact on a patient's further clinical course. Therefore, it seems necessary to perform risk stratification for patients scheduled for PDT. We retrospectively reviewed the records of 1001 patients (46% male, mean age 68.1 years) undergoing PDT (using the Ciaglia Blue Rhino® technique with direct bronchoscopic guidance) in our cardiothoracic ICU between January 2003 and February 2013. Patients were stratified into two groups: patients suffering acute moderate, severe, or major bleeding (Group A) and patients who had no or only mild bleeding (Group B). In the majority of patients, no or only mild bleeding during PDT occurred (none: 425 [42.5%], mild: 488 [48.8%]). In 84 patients (8.4%), bleeding was classified as moderate. Three patients suffered from severe bleeding; only one major bleed with need for emergency surgery occured. Patients in Group A had a significantly higher Simplified Acute Physiology Score on the day of PDT ( P=0.042), higher prevalence of renal replacement therapy on the day of PDT ( P=0.026), higher incidence of coagulopathy ( P=0.043), lower platelet counts ( P=0.037), lower fibrinogen levels ( P=0.012), higher proportion of PDTs performed by residents ( P=0.034) and higher difficulty grading of PDT ( P=0.001). Using logistic regression analyses, difficult PDT, less experienced operator, Simplified Acute Physiology Score >40 and low fibrinogen levels were independent predictors of clinically significant bleeding after PDT.
Acute Kidney Injury following Liver Transplantation: A Systematic Review of Published Predictive Models
Authors: Caragata R. , Wyssusek K. H. , Kruger P.
Published: January 2019

Summary

Acute kidney injury (AKI) is a frequent postoperative complication amongst liver transplant recipients and is associated with increased morbidity and mortality. This systematic review analysed the existing predictive models, in order to solidify current understanding. Articles were selected for inclusion if they described the primary development of a clinical prediction model (either an algorithm or risk score) to predict AKI post liver transplantation. The database search yielded a total of seven studies describing the primary development of a prediction model or risk score for the development of AKI following liver transplantation. The models span thirteen years of clinical research and highlight a gradual change in the definitions of AKI, emphasising the need to employ standardised definitions for subsequent studies. Collectively, the models identify a diverse range of predictive factors with several common trends. They emphasise the impact of preoperative renal dysfunction, liver disease severity and aetiology, metabolic risk factors as well as intraoperative variables including measures of haemodynamic instability and graft quality. Although several of the models address postoperative parameters, their utility in predictive modelling seems to be of questionable relevance. The common risk factors identified within this systematic review provide a minimum list of variables, which future studies should address. Research in this area would benefit from prospective, multisite studies with larger cohorts as well as the subsequent internal and external validation of predictive models. Ultimately, the ability to identify patients at high risk of post-transplant AKI may enable early intervention and perhaps prevention.
Characteristics and Dying Trajectories of Adult Hospital Patients from Acute Care Wards who Die following review by the Rapid Response Team
Authors: Coombs M. A. , Nelson K. , Psirides A. J. , Suter N. , Pedersen A.
Published: January 2019

A third of patients reviewed by rapid response teams (RRT) require end-of-life care. However, little is known about the characteristics and management of these patients following RRT review. This paper presents results of a retrospective, descriptive audit that explored the dying trajectory of adult ward inpatients who died outside of the intensive care unit following RRT review. The study setting was a 430-bed tertiary New Zealand hospital during 2013. RRT, inpatient databases and hospital notes were used to identify 100 consecutive adult inpatients who died subsequent to RRT review. Outcome measures included time from RRT review to death, place of death, pre-existing comorbidities and frequency of medical review. Results demonstrated that patients were old (median 77 years, IQR 63–85years), emergency admissions (n=100) and admitted under a medical specialty (n=71). All but one of the cohort had pre-existing comorbidities (mean 3.2, SD 1.7), almost a third (n=31) had cancer and 51% had 1–4 previous inpatient admissions within the previous 12 months. The mean length of stay prior to RRT review was 4.9 days (SD 5.5) during which patients were frequently reviewed by senior medical staff (mean 6.8 times, SD 6.9, range 0–44). Twenty percent of patients died after their first RRT review with a further 40% receiving treatment limitation/palliation. Fifty-two percent of patients had a pre-existing Do Not Attempt Resuscitation (DNAR) order. Eighty percent of patients died in hospital. Whilst the RRT fulfils an unmet need in decision-making at end of life, there is a need to understand what RRT, instead of ward-based or palliative care teams, offers dying patients.
Spontaneous Ventilation Using Target-Controlled Propofol Infusion for Microlaryngoscopy in Adults: A Retrospective Audit
Authors: Booth A. W. G. , Vidhani K.
Published: January 2019

Summary

We conducted a retrospective audit of 285 adult elective microlaryngoscopy cases in our institution over a three-and-a-half year period. Conventional anaesthesia with intubation and mechanical ventilation was the most common technique, used in 71% of cases. Tubeless spontaneous ventilation during total intravenous anaesthesia with a target-controlled infusion of propofol (SVTCI) was the most common alternative. Spontaneous ventilation with target-controlled infusion was used for 79 (27.7%) anaesthetic inductions and was continued through the maintenance phase for 60 patients (21.1%). Jet and intermittent ventilation were both used infrequently (1% each). The most common SVTCI technique since 2013 involved adjusting the target-controlled infusion rate during induction using a formula we developed based on intermittently increasing the target rate, such that the predicted plasma concentration minus the predicted effect site concentration was maintained at 1 μg/ml. We found that this method maintained ventilation during induction more reliably than other SVTCI strategies, and was associated with fewer complications than other spontaneous ventilation techniques or mechanical ventilation: it was associated with only one (3.1%) failed induction and one (3.9%) episode of apnoea. Jet ventilation was associated with the most severe complications, including two cases of barotrauma.
Percutaneous Dilatational Tracheostomy using a Tracheoscopic Ventilation Tube in an Experimental ex Vivo Animal Model
Authors: Fiorelli A. F. , Ferraro F. F. , Milione R. M. , Scarumuzzi R. S. , Imitazione P. I. , Marulli L. M. , Orsini A. O. , Santini M. S.
Published: January 2019

The ETView® tube is a standard endotracheal tube with an embedded miniature video camera that permits real-time video imaging of the tracheal lumen. We evaluated its use when performing percutaneous dilatational tracheostomy (PDT) in an ex vivo animal model. The model consisted of a pig larynyx and trachea. The ETView tube was used as an alternative to bronchoscopy, to see all manoeuvres of PDT in real time. At the end of the PDT, operative time and any complications such as trauma to the cricoid cartilage, tracheal wall or tube cuff were assessed. Nine PDT procedures were performed by two experienced operators. The mean operative time was 7.1 ± 0.9 minutes. No complications were observed. Our study supports the use of the ETView tube as a suitable alternative to bronchoscopy when performing PDT, although clinical studies are required to confirm our experimental results.
Potential Rapid Solutions to Maintain Ventilation in the Event of Anaesthesia Machine Failure with no Access to the Patient's Airway
Authors: Liu E. H. , Tan Y. , Loh N. H. W. , Siau C.
Published: January 2019

Anaesthesia machine failure requires rapid solutions to maintain ventilation and anaesthesia. During procedures with poor access to the patient's airway, it may not be possible to use a self-inflating mechanical ventilation device (SIMVD) for emergency ventilation, and alternative solutions are needed. We evaluated five methods for rescue ventilation using a patient simulator. In Method 1, we used the inspiratory and expiratory tubes and the alternative common gas outlet (ACGO) on the anaesthesia machine to produce a Mapleson E system. In Method 2, we used the tubes, ACGO and an open-ended reservoir bag to produce a Mapleson F system, controlling the bag to achieve ventilation. In Method 3, we attached a SIMVD to the inspiratory tube, and controlled occlusion of the expiratory tube. In Method 4, we used the tubes and ACGO in a Mapleson F configuration, replacing the open-ended bag with a SIMVD to facilitate manual ventilation. In Method 5, we attached a SIMVD to the expiratory tube and left the inspiratory tube attached to its mounting. We were able to achieve ventilation, maintain inhalational anaesthesia, and prevent expired gas rebreathing in Methods 1 and 2. In Method 3 ventilation was achieved with minimal rebreathing of expiratory gas, but with no inhalational agent. Methods 4 and 5 led to rebreathing. Our findings indicate that Methods 1 or 2 are the preferred rapid solutions to maintain ventilation and inhalational anaesthesia in the event of anaesthesia machine failure where there is poor airway access.
Organ Donation after Circulatory Death in a University Teaching Hospital
Authors: Sidiropoulos S. , Treasure E. , Silvester W. , Opdam H. , Warrillow S. J. , Jones D.
Published: January 2019

Although organ transplantation is well established for end-stage organ failure, many patients die on waiting lists due to insufficient donor numbers. Recently, there has been renewed interest in donation after circulatory death (DCD). In a retrospective observational study we reviewed the screening of patients considered for DCD between March 2007 and December 2012 in our hospital. Overall, 148 patients were screened, 17 of whom were transferred from other hospitals. Ninety-three patients were excluded (53 immediately and 40 after review by donation staff). The 55 DCD patients were younger than those excluded ( P=0.007) and they died from hypoxic brain injury (43.6%), intraparenchymal haemorrhage (21.8%) and subarachnoid haemorrhage (14.5%). Antemortem heparin administration and bronchoscopy occurred in 50/53 (94.3%) and 22/55 (40%) of cases, respectively. Forty-eight patients died within 90 minutes and proceeded to donation surgery. Associations with not dying in 90 minutes included spontaneous ventilation mode ( P=0.022), absence of noradrenaline infusion ( P=0.051) and higher PaO2:FiO2 ratio ( P=0.052). The number of brain dead donors did not decrease over the study period. The time interval between admission and death was longer for DCD than for the 45 brain dead donors (5 [3–11] versus 2 [2–3] days; P <0.001), and 95 additional patients received organ transplants due to DCD. Introducing a DCD program can increase potential organ donors without reducing brain dead donors. Antemortem investigations appear to be acceptable to relatives when included in the consent process.
A Site Check Prior to Regional Anaesthesia to Prevent Wrong-Sided Blocks
Authors: Slocombe P. , Pattullo S.
Published: January 2019

This paper describes the implementation of the ‘Stop Before You Block’ (SB4YB) initiative in an Australian teaching hospital. This process, which began in the UK in 2010, is a pre-procedure pause to confirm the correct side of a regional anaesthetic block. A change in practice was implemented with the formal roll out of a SB4YB educational program. Use of the initiative was then audited over a subsequent three-month period. It was hoped that after implementing the initiative, at least 80% of blocks would have a site check performed. However, despite apparent support for the initiative, uptake was less than expected with only about 57% of blocks having a site check performed. A site check was less frequent if the block was done as an emergency procedure, outside of an operating theatre or by a locum or visiting anaesthetist. Our conclusion from the audit was that education is insufficient to promote a change in this practice. We propose that Stop Before You Block or a block time-out should be performed prior to all unilateral nerve blocks. Success of this initiative requires education, and both cultural and systems changes to occur. We propose that a formal block time-out should become part of the surgical safety checklist and this activity should be endorsed and promoted by anaesthetic professional bodies.