bluuebunny/crossref_metadata_2025 huggingface dataset:
A Pilot Study to Test the Use of a Checklist in a Tertiary Intensive Care Unit as a Method of Ensuring Quality Processes of Care
Authors: Hewson K. M. , Burrell A. R.
Published: January 2019

This pilot study aimed to test the use of a checklist as a method of ensuring that certain processes of care are performed routinely and systematically in a tertiary intensive care unit. The pilot involved the development of a process indicator checklist, its implementation and review. The checklist contained 16 items sourced from the literature or deemed important by local clinicians. Checklists were completed on the morning round for all adult patients admitted to the unit for approximately one month. Baseline and evaluation surveys were conducted with medical staff to assess both the benefits and shortcomings of using the checklist. Results demonstrated good compliance in completing the checklist (81%) and that when checked, certain aspects of care were not always delivered when appropriate. At the conclusion of the study the majority of medical staff believed that care in the intensive care unit actually improved with the use of the checklist, and all thought that it assisted in ensuring that good quality care was delivered. The checklist is a useful tool that can be readily applied to facilitate best practice and quality in everyday clinical care, ultimately leading to better health outcomes for patients.
A Serious and Repeatable Electrical Hazard—Compressed Electrical Cord and an Operating Table
Authors: Courtney N. M. , Mccoy E. P. , Scolaro R. J. , Watt P. A.
Published: January 2019

We describe a previously unreported hazard resulting from compression of an electrical cable by an operating theatre table. This resulted in a live wire contact to the operating table. Intermittent connection of the table to earth during a procedure resulted in triggering of a residual current device mitigating the effects of the hazard. The actual cause was not readily identified as the devices connecting the table to earth were considered most likely to be the source of the current. There was potential for significant injury to the patient and theatre staff which would have been diminished if staff had had a better understanding of the electrical safety equipment in use. We examine the underlying causes of the accident, discuss electrical safety and correct use of safety devices in the operating theatre, and propose guidelines for appropriate management.
Mixed Opioid—Mixed Message?
Authors: Lake A. P. J. , Coates O. L.
Published: January 2019

By exposing the mu-receptor (MOP-R) to more than one exogenous ligand, the administration during general anaesthesia of more than one opioid with principal action on the receptor may confound and lead to complications or unexpected outcomes. The giving of such a ‘mixed message’ can result in respiratory depression, excess sedation and delayed recovery to an unusual degree. We present a case of apparent extreme opioid sensitivity and discuss a possible mechanism. Such occurrences may be more common than previously realised.
Upper Airway Obstruction Caused by Ingestion of Concentrated Acetic Acid
Authors: Tibballs J. , Cathie R. , Buist M. , Shimizu K. , Stokes K. , Millar J.
Published: January 2019

We report a case of rapidly progressive severe upper airway obstruction in a small child caused by accidental ingestion of 80% acetic acid. Emergency cricothyrotomy was necessary after both endotracheal intubation and bag-valve-mask ventilation were not possible. Although intubation was eventually achieved, a tracheostomy was necessary. Toxin spilled over the anterior chest and abdomen caused third degree skin burns which required grafting. Mild liver dysfunction was observed. Complete recovery occurred.
Relative Adrenal Insufficiency in Etomidate-Naïve Patients with Septic Shock
Authors: Jones D. , Hayes M. , Webb S. , French C. , Bellomo R.
Published: January 2019

A recent study reported that 77% of patients with septic shock had relative adrenal insufficiency. However, all patients were mechanically ventilated and received high-dose inotropes. In addition, at least 24% had prior exposure to etomidate, a drug known to suppress adrenal function. We studied the incidence of relative adrenal insufficiency in etomidate-naïve patients with septic shock by analysing the adrenal response to high-dose short synacthen test in 113 consecutive patients from three university-affiliated intensive care units in Australia. Patients were allocated to three groups according to severity of illness and inclusion criteria of the trial of low dose hydrocortisone supplementation using information from patient records.

Of the 113 patients, 98 had septic shock (Group A). The incidence of relative adrenal insufficiency in this sub-population was 24.5%. Eighty-one per cent of patients with septic shock were mechanically ventilated (Group B). In this group, the incidence of relative adrenal insufficiency was 27.8%. Only 38 of the 98 patients with septic shock (39%) fulfilled inclusion criteria for the steroid supplementation trial (Group C). In this group, the incidence of relative adrenal insufficiency was only 34.2%. In all groups its presence was associated with a higher mortality.

We conclude that the incidence of relative adrenal insufficiency in etomidate-naïve septic shock patients was lower than observed in the steroid supplementation trial. Further, in those who fulfilled inclusion criteria for the trial, the incidence of relative adrenal insufficiency was half that reported by the trial. Our observations raise concerns about the generalizability of the findings of the above trial to etomidate-naïve patients.
The Effect of Excess Protamine on Thrombelastography in Vitro
Authors: Gibbs N. M. , Yim D. , Weightman W. , Sheminant M. , Rowe R.
Published: January 2019

The aim of the current study was to assess the direct effect of protamine on conventional thrombelastography in vitro. Protamine was added to blood samples collected from 25 adult cardiac surgical patients prior to the induction of anaesthesia and after separation from cardiopulmonary bypass. The final protamine concentrations were 0 (control), 0.05 mg/ml, 0.1 mg/ml and 0.2 mg/ml (i.e. sufficient to reverse heparin 0, 5, 10 and 20 IU/ml respectively, assuming a 1:1 reversal ratio). In the pre-induction samples, protamine was associated with increases in r time and reductions in maximum amplitude (P<0.01). After bypass, the control samples demonstrated a heparin effect as expected, which was corrected by the addition of protamine 0.05 mg/ml. However, the higher concentrations of protamine were again associated with increases in r time and reductions in maximum amplitude (P<0.01). The results indicate that protamine has a direct anticoagulant effect on conventional thrombelastography in vitro. This effect occurs whether protamine is present alone, or whether protamine is present in excess after neutralization of heparin. Unless this effect is taken into account, excess protamine may confound the interpretation of conventional thrombelastography in cardiac surgical patients.
Thrombogenic Side-Effects of Recombinant Factor VIIa after use in Coronary Artery Bypass Surgery
Authors: White M. C. , Pryn S. J. , Monk C. R.
Published: January 2019

Recombinant activated factor VII (rFVIIa) has been used ‘off licence’ to successfully treat bleeding and reduce transfusion requirements in complex cardiac surgery. However, concerns over thrombogenic side-effects have limited but not excluded its use in patients undergoing coronary artery bypass surgery (CABG).

We present two cases of CABG (one ‘on pump’ and one ‘off pump’) which were complicated by intraoperative aortic dissection and severe bleeding. In both cases the bleeding was successfully treated with rFVIIa. However the first case suffered from severe postoperative arrhythmias, myocardial infarction, cardiac arrest and worsening left ventricular dysfunction, suggesting graft patency may have been impaired, whereas the second case remained symptom-free suggesting graft patency was unaffected by the use of rFVIIa. If rFVIIa is needed to treat bleeding during CABG surgery, it may be more appropriate to administer smaller, repeated doses to minimize the risk of thrombosis and early graft failure.
Use of Elastin Fibres Detected in Non-Directed Low Volume Bronchial Lavage in Ventilated ICU Patients
Authors: Boots R. J. , Phillips G. E. , George N. , Faoagali J. L.
Published: January 2019

Elastin fibres in sputum have been described as a more sensitive marker of pulmonary necrosis than plain chest X-rays. This study aimed to determine the prevalence of elastin fibres using non-directed non-protected mini-bronchoalveolarlavage (BM-BAL) in mechanically ventilated patients in the intensive care unit. Patients admitted to the general intensive care unit of a tertiary referral hospital requiring more than 48 hours of mechanical ventilation had surveillance BM-BAL performed on admission and were then examined weekly using potassium hydroxide wet preparations for the presence of elastin fibres. All positive and a random selection of 16 negative preparations from patients with acute respiratory distress syndrome or pneumonia were fixed and examined using Weigert's staining method for elastin. Of 412 patients enrolled, 130 (32%) had pneumonia on admission, 50 (12%) developed 58 episodes of ventilator-associated pneumonia and acute respiratory distress syndrome was diagnosed in 86 patients (21%). No chest X-ray showed cavitating infiltrates. Of 985 specimens examined, only seven had elastin fibres. Elastin fibres are uncommonly found using BM-BAL in general screening, acute respiratory distress syndrome or pneumonia in the intensive care unit, the incidence too low to be a useful indicator of pulmonary necrosis.
The Impact of Bispectral Index Monitoring on Sedation Administration in Mechanically Ventilated Patients
Authors: Weatherburn C. , Endacott R. , Tynan P. , Bailey M.
Published: January 2019

The aim of this prospective randomised controlled trial was to assess the effectiveness of the Bispectral Index (BIS) monitor in supporting clinical sedation management decisions in mechanically ventilated intensive care unit patients. Fifty adult mechanically ventilated surgical and general intensive care unit patients receiving sedative infusions of morphine and midazolam were randomly allocated to receive BIS monitoring (n=25) or standard sedation management (n=25). In the BIS group, sedation was titrated to maintain a BIS value of greater than 70. In the standard management group, sedative needs were titrated based on subjective assessment and clinical signs.

There was no statistically significant difference in the amount of sedation administered (morphine P =0.67 and midazolam P =0.85). However, there was a statistically significant difference in sedation administration over time. Patients in the BIS group received increasing amounts of sedation over time whilst those in the control group received decreasing amounts of sedation over time. The same inverse relationship existed for both sedative agents (morphine P=0.005, midazolam P=0.03). Duration of mechanical ventilation was comparable in the two groups. We conclude that the use of BIS monitoring did not reduce the amount of sedation used, the length of mechanical ventilation time or the length of ICU stay.
Changing from Epidural to Multimodal Analgesia for Colorectal Laparotomy: An Audit
Authors: Chilvers C. R. , Nguyen M. H. , Robertson I. K.
Published: January 2019

In April 2002 our practice ceased routine use of epidural analgesia for colorectal laparotomy in favour of a six-drug multimodal regimen comprising ketamine, clonidine, morphine, tramadol, paracetamol and a nonsteroidal antiinflammatory drug. The records of 54 patients who received this multimodal analgesia regimen (MM) after April 2002 were compared to the 59 patients who had previously received epidural analgesia (EPI). Patients had the same surgeon and anaesthetist. Daily pain score (verbal rated 0-10) at rest (mean) over the first three postoperative days was satisfactorily low with both MM (1.2 ± 1.2) and EPI (0.4 ± 0.4). Over this period there was little difference between the maximum pain score at rest (MM 2.3 ± 1.9 vs. EPI 2.2 ± 1.7, P=0.58). Major complications and side-effects occurred solely in EPI patients: epidural abscess (1), respiratory depression (2), pneumonia (3), venous thromboembolism (3), delirium (7), high block (7) and motor block (3). Hypotension requiring intervention was 4.8 times more frequent in the EPI group (95% CI 2.1-11). Antiemetic use was similar between groups; on average 13 patients in the MM groups (24%) and 15 patients in the EPI groups (26%) received antiemetics each day. MM patients had shorter anaesthetic preparation time (20±8 min vs. 32±8 min, P<0.001), shorter high-dependency unit stay (0.4 ± 1.2 days vs. 4.5 ± 0.9 days, P <0.001), and shorter hospital stay(10±4 days vs. 13±8 days, P=0.003). In our practice, changing from epidural to multimodal analgesia produced comparable pain relief with reduction in anaesthesia preparation time, high-dependency unit stay and hospital stay and the requirement for staff interventions. There was also a reduction in the incidence of major complications and side-effects.
Ultrasound Guided Dorsal Penile Nerve Block in Children
Authors: Sandeman D. J. , Dilley A. V.
Published: January 2019

We describe a technique for using a portable ultrasound scanner (38 mm broadband (10-5 MHz) linear array transducer (Sonosite Titan® SonoSite, Inc. 21919 30th Drive SE Bothell, W.A.)) to guide dorsal penile nerve block in children under general anaesthesia. Real-time scanning is used to guide bilateral injections into the subpubic space, deep to Scarpa's fascia either side of the midline fundiform ligament. Scanning can confirm that the local anaesthetic has spread to contact the deep fascia on each side. A subcutaneous wheal of local anaesthetic along the penoscrotal junction completes the block.
Pneumothorax in Association with Spontaneous Ventilation General Anaesthesia—An Unusual Cause of Hypoxaemia
Authors: Choy M. C. K. , Pescod D.
Published: January 2019

A 43-year-old ASA PS II male patient developed a pneumothorax while breathing pontaneously through a supraglottic airway device duringa general anaesthetic. Unexplained hypoxaemia occurred after an episode of coughing. Clinical examination appeared to be normal apart from the persistent oxygen desaturation. A pneumothorax was diagnosed in the post anaesthesia care unit by chest X-ray. The pneumothorax responded to conventional management and the patient made an uneventful recovery. We recommend a high index of suspicion in any patient who coughs and later has unexplained hypoxaemia during general anaesthesia, even if a supraglottic airway device has been inserted.
Late Onset Nephrogenic Diabetes Insipidus following Cessation of Lithium Therapy
Authors: Paw H. , Slingo M. E. , Tinker M.
Published: January 2019

Lithium-induced diabetes insipidus occurs in up to one third of patients on long-term therapy. It usually manifests during the treatment course, often with preceding signs or symptoms. We wish to highlight a case in which diabetes insipidus developed many days after cessation of long-term lithium therapy. We seek to explain this delayed onset by a discussion of the molecular and genetic changes underlying the pathogenesis of lithium-induced nephrogenic diabetes insipidus.
Detection of Intravascular Epidural Catheter Placement: A Review
Authors: Bell D. N. , Leslie K.
Published: January 2019

Intravascular placement of an epidural catheter is recognised as a potentially fatal complication of epidural anaesthesia and analgesia. Up to 10% of epidural catheters may be inserted into an epidural vessel, the majority of which will be recognised; however, a proportion (1% of all epidural catheters inserted) may not be identified as lying intravascularly. Opinions differ on the optimal method for identifying intravascular catheters and no perfect method exists. Some debate the need for a test of correct location, as a lack of specificity may mean that a proportion of correctly located catheters are withdrawn and resited. This review outlines the incidence and risk factors associated with intravascular placement and aims to evaluate the detection methods that have been described, in an attempt to answer the question: “What is the optimal way of detecting intravascular placement of an epidural catheter?”
Closed-Loop Anaesthesia Delivery System (CLADSTM) using Bispectral Index: A Performance Assessment Study
Authors: Puri G. D. , Kumar B. , Aveek J.
Published: January 2019

The development of electroencephalographic indices of anaesthetic depth has in turn generated interest in automated anaesthesia delivery systems using these as the input variable. In this paper, one patented closed loop anaesthesia delivery system (CLADS) (502/DEL/2003) is compared to manual control of propofol delivery titrated to the bispectral index (BIS™). Forty ASA I-II patients undergoing elective surgery under general anaesthesia were enrolled in the study. The study participants were randomised using computer generated random numbers to two equal groups. One group received propofol titrated by the CLADS while in the other group (control), anaesthetic delivery was manually titrated to BIS™. Closed loop anaesthetic delivery using our patented system led to lower induction doses of propofol (P<0.05) and less overshoot of the target BIS (P<0.05). The closed loop system maintained BIS to within ±10 of target for a significantly longer time during the maintenance phase of anaesthesia (P <0.01). Smaller amounts of anaesthetic agent were required (P <0.01) and there was faster postoperative recovery (P <0.05). Manual delivery of propofol required the infusion rate to be changed a median of 30 times (IQR 12-45), which required considerable time and attention by the anaesthetist. In conclusion, automated delivery of propofol adjusted to the bispectral index using our CLADS was both effective and efficient as compared to manual control.
In Vivo Validation of the M-COVX® Metabolic Monitor in Patients under Anaesthesia
Authors: Stuart-Andrews C. R. , Peyton P. , Robinson G. J. B. , Terry D. , O'Connor B. , Van Der Herten C. , Lithgow B.
Published: January 2019

A practical method of breath-by-breath monitoring of metabolic gas exchange has been developed by GE Healthcare/Datex Ohmeda and incorporated into existing anaesthetic and critical care monitoring systems (M-COVX®). This device relates flow measurements made at the mouth by pneumotachograph to measurements of inspired and expired gas composition by matching the two waveforms thereby allowing continuous, breath-by-breath monitoring of an intubated patient's oxygen uptake and carbon dioxide production. Given that there is a paucity of data comparing this new device against methods more widely used clinically, we tested the device on 11 patients undergoing cardiopulmonary bypass surgery. Using a standard anaesthetic machine (Datex Ohmeda Excel 210 SE) with a semi-closed circle absorber system, oxygen uptake was measured at the mouth continuously throughout the operation at approximately six-second intervals. The data were compared against the reverse Fick method and against standard indirect calorimetry using the Haldane transformation. When compared to the calculated reverse Fick oxygen uptake, a mean difference of +16.5% was found pre-bypass and +9.9% post-bypass, consistent with uptake of oxygen by lung tissue, which is not taken into account by the reverse Fick method. Measurements made comparing the M-COVX metabolic monitor against standard Haldane showed a mean difference of +5.1% pre-bypass and –2.1% post-bypass. Given the ease with which this device can be incorporated into existing anaesthetic monitoring systems and its accuracy in measuring oxygen uptake, the M-COVX module is an attractive addition to existing perioperative monitoring.
Myocardial Depression Associated with Pneumococcal Septic Shock Reversed by Levosimendan
Authors: Ramaswamykanive H. , Bihari D. , Solano T. R.
Published: January 2019

Levosimendan is a myocardial calcium sensitiser and potassium-ATP channel opener. Levosimendan has been used in critically ill patients in various conditions to support myocardial function as an inotrope, lusitrope and vasodilator. We report the use of levosimendan in a patient with invasive streptococcal septic shock.
In-Hospital Cardiac Arrest: Different Wards Show Different Survival Patterns
Authors: Smith S. , Shipton E. A. , Wells J. E.
Published: January 2019

The purpose of the study was to investigate the characteristics and outcomes of in-hospital cardiac arrests that occurred outside of the hospital critical care areas. A prospective register of adult in-hospital cardiac arrests occurring in non-critical care areas of Christchurch Hospital, Christchurch, New Zealand, from January 2001 to December 2004 was compiled. Two-hundred-and-forty-three cardiac arrests were recorded in this period. The overall return of spontaneous circulation was 38.7% (CI 32.6, 44.8) and survival to discharge was 21.0% (CI 15.9, 26.1). Comparison of clinical areas showed that the percentage with successful resuscitation and the percentage with survival to discharge were highest in the cardiology wards (52.2%, 41.3%) and lowest in the medical wards (24.9%, 8.8%). After taking account of rhythm, age, gender and time of day, differences between clinical areas were slightly reduced. Cardiology wards, however, still had a higher resuscitation percentage than medical wards (P=0.03) and a higher percentage with survival to discharge than all other areas (P =0.005 overall, P ≤0.05 for each individual comparison). Reporting of hospital-wide survival rates does not accurately reflect the survival rates in a variety of specific clinical areas. The analysis of outcomes across different clinical areas at Christchurch Hospital revealed differences in outcomes and therefore the clinical experience of staff in those areas. These differences have implications for the resuscitation training of health professionals. The further development of national resuscitation registries may allow more specific analysis of outcomes in different clinical areas.
Continuous Venovenous Haemofiltration Using a Citrate Buffered Substitution Fluid
Authors: Schmitz M. , Taskaya G. , Plum J. , Hennersdorf M. , Sucker C. , Grabensee B. , Hetzel G. R.
Published: January 2019

Different methods of regional anticoagulation using citrate in continuous renal replacement therapy have been described in the past. However, these procedures were usually very complex or did not reach modern requirements for effective continuous renal replacement therapy. Furthermore, little is known about long-term acid-base stability and citrate levels during the treatment. We describe a system in which citrate is used both as anticoagulant and as the sole buffer substance in continuous venovenous haemofiltration. Our citrate-containing, calcium-free substitution fluid was used in predilution mode with a constant ratio between blood flow (120 to 150 ml/min) and substitution flow (2400 to 3000 ml/hour). Anticoagulation was limited to the extracorporeal circuit. Twenty patients with acute renal failure on mechanical ventilation were treated, four for eight hours, four for 24 hours and 12 as long they needed continuous renal replacement therapy (9.6 ± 5.0 days, range 4.0 to 39.3 days).

We achieved stable acid-base and electrolyte balance in all patients. We observed no bleeding complications (patient activated clotting time 112.4±17.1 s, post-filter circuit activated clotting time 270.5 ± 80.3 s) and achieved appropriate filter life times (48.6 ± 13.2 h).

Predilution, citrate-based substitution fluid provides both anticoagulation within the extracorporeal circuit and control of acid-base balance in critically ill patients at risk of bleeding in acute renal failure. It is easy to apply and safe. Clearance can be varied as long as a constant ratio between blood and substitution flow is maintained.
Comparative Safety and Efficacy of Two High Dose Regimens of Oral Paracetamol in Healthy Adults Undergoing Third Molar Surgery under Local Anaesthesia
Authors: Zacharias M. , De Silva R. K. , Hickling J. , Medlicott N. J. , Reith D. M.
Published: January 2019

This study compared the efficacy and safety of single oral doses of 60 mg/kg and 90 mg/kg paracetamol in fit young adult patients undergoing third molar extractions. The study was a randomised, blinded, crossover design on 20 young, fit adults. Paracetamol was administered 30 minutes prior to the surgical extraction of the teeth, which was done under intravenous sedation and local anaesthesia. There were no clinically or statistically significant differences in the pain scores between 60 mg/kg or 90 mg/kg doses until the intake of rescue analgesics. There was a reduction in factor VII activity with 90 mg/kg dose compared to 60 mg/kg dose. It may be concluded that the 90 mg/kg dose, though safe, does not offer any advantages over 60 mg/kg dose of paracetamol in young fit adults undergoing third molar surgery.
Patterns of Sevoflurane use in a Children's Hospital: The Effects of a Simple Educational Intervention
Authors: Lethbridge M. , Bouckley A. , Chambers N. A.
Published: January 2019

We conducted a prospective observational study of sevoflurane use over a four-week period at our tertiary referral children's hospital. Sevoflurane vaporisers were weighed before and after all general anaesthesia sessions and anaesthesia time intervals recorded. Midway through the audit, the initial findings were presented to the department with a brief reminder of ways to reduce sevoflurane use. These included recommendations for fresh gas flows and use of alternative agents during maintenance. Sevoflurane use then continued to be audited over a further two-week period. Anaesthesia in induction rooms accounted for 60% of total sevoflurane use but involved only 15% of total general anaesthetic time. Thus sevoflurane was used eight times faster in the induction rooms when compared to operating theatres. There was a 53% reduction in the rate of use of sevoflurane after the educational intervention, with an 87% reduction in in-theatre use and a 31% reduction in induction room use. This represents a potential saving of $108, 120 per annum in our institution. Workloads before and after the educational intervention were comparable. A more complete cost benefit analysis of this initiative would include the costs of alternative agents and any clinical disadvantages incurred and would be seen in the context of the overall health budget. This was beyond the scope of this project. Clinicians can be relatively complacent about financial accountability. In this study, a simple educational reminder halved sevoflurane use in the short term. This study suggests that specific reminders or recommendations about anaesthetic technique in the induction rooms may be indicated.
Nocardia Sepsis in a Multigravida with Systemic Lupus Erythematosus and Autoimmune Hepatitis
Authors: Cassar C. L.
Published: January 2019

This report describes a pregnant woman with systemic lupus erythematosus and autoimmune hepatitis who presented with threatened labour and acute renal failure. She developed respiratory distress, haematemesis and became coagulopathic. Intrauterine death occurred and she was admitted to the intensive care unit after caesarean section. She suffered sudden cardiovascular collapse and succumbed. At autopsy, Nocardia was cultured from multiple renal abscesses. The co-existence of Nocardia sepsis, systemic lupus erythematosus, autoimmune hepatitis and pregnancy are discussed. This case illustrates diagnostic challenges associated with Nocardia infection in the presence of co-existing disease.
A Clinician's Guide to Predicting Fluid Responsiveness in Critical Illness: Applied Physiology and Research Methodology
Authors: Sturgess D. J. , Joyce C. , Marwick T. H. , Venkatesh B.
Published: January 2019

Intravenous fluid administration is often used in critical care with the goal of improving haemodynamics and consequently tissue perfusion and oxygen delivery. While inotropic and vasoactive drugs are often necessary to correct haemodynamic instability, resuscitation usually begins with fluid therapy. As fluid challenge can result in clinical deterioration, the ability to predict haemodynamic response is desirable. In this way it might be possible to avoid unnecessary volume replacement in critically ill patients.

Cardiac preload is a concept that accounts for the relationship between ventricular filling and stroke volume. It has been challenging to apply this concept to clinical practice. For this reason, the study of fluid responsiveness is of increasing research and clinical interest.

The clinical application of predicting fluid responsiveness requires an understanding of relevant physiological principles. Furthermore, an improved understanding of these principles should assist the clinician in appraising published data, which has been characterised by significant methodological differences. This review aims to assist the clinician by detailing the physiological principles that underlie the prediction of fluid responsiveness in the critically ill. In addition, the potential importance of methodological differences in the current literature will be considered.
Gastrointestinal Perfusion in Septic Shock
Authors: van Haren F. M. P. , Sleigh J. W. , Pickkers R , Van Der Hoeven J. G.
Published: January 2019

Septic shock is characterised by vasodilation, myocardial depression and impaired microcirculatory blood flow, resulting in redistribution of regional blood flow. Animal and human studies have shown that gastrointestinal mucosal blood flow is impaired in septic shock. This is consistent with abnormalities found in many other microcirculatory vascular beds. Gastrointestinal mucosal microcirculatory perfusion deficits have been associated with gut injury and a decrease in gut barrier function, possibly causing augmentation of systemic inflammation and distant organ dysfunction.

A range of techniques have been developed and used to quantify these gastrointestinal perfusion abnormalities. The following techniques have been used to study gastrointestinal perfusion in humans: tonometry, laser Doppler flowmetry reflectance spectrophotometry, near-infrared spectroscopy, orthogonal polarisation spectral imaging, indocyanine green clearance, hepatic vein catheterisation and measurements of plasma D-lactate. Although these methods share the ability to predict outcome in septic shock patients, it is important to emphasise that the measurement results are not interchangeable. Different techniques measure different elements of gastrointestinal perfusion. Gastric tonometry is currently the most widely used technique because of its non-invasiveness and ease of use.

Despite all the recent advances, the usefulness of gastrointestinal perfusion parameters in clinical decision-making is still limited. Treatment strategies specifically aimed at improving gastrointestinal perfusion have failed to actually correct mucosal perfusion abnormalities and hence not shown to improve important clinical endpoints.

Current and future treatment strategies for septic shock should be tested for their effects on gastrointestinal perfusion; to further clarify its exact role in patient management, and to prevent therapies detrimental to gastrointestinal perfusion being implemented.
Efficacy of Risperidone for Prevention of Postoperative Delirium in Cardiac Surgery
Authors: Prakanrattana U. , Prapaitrakool S.
Published: January 2019

This randomised, double-blinded, placebo-controlled study was primarily aimed to evaluate the potential of risperidone to prevent postoperative delirium following cardiac surgery with cardiopulmonary bypass and the secondary objective was to explore clinical factors associated with postoperative delirium.

One-hundred-and-twenty-six adult patients undergoing elective cardiac surgery with cardiopulmonary bypass were randomly assigned to receive either 1 mg of risperidone or placebo sublingually when they regained consciousness. Delirium and other outcomes were assessed. The confusion assessment method for intensive care unit was used to assess postoperative delirium.

The incidence of postoperative delirium in the risperidone group was lower than the placebo group (11.1% vs. 31.7% respectively, P=0.009, relative risk=0.35, 95% confidence interval [CI]=0.16-0.77). Other postoperative outcomes were not statistically different between the groups. In exploring the factors associated with delirium, univariate analysis showed many factors were associated with postoperative delirium. However multiple logistic regression analysis showed a lapse of 70 minutes from the time of opening eyes to following commands and postoperative respiratory failure were independent risk factors (P=0.003, odds ratio [OR]=4.57, 95% CI=1.66-12.59 and P=0.038, OR=13.78, 95% CI=1.15-165.18 respectively).

A single dose of risperidone administered soon after cardiac surgery with cardiopulmonary bypass reduces the incidence of postoperative delirium. Multiple factors tended to be associated with postoperative delirium, but only the time from opening eyes to following commands and postoperative respiratory failure were independent risk factors in this study.
Anticoagulation, bleeding and blood transfusion practices in Australasian cardiac surgical practice
Authors: Daly D. J. , Myles P. S. , Smith J. A. , Knight J. L. , Clavisi O. , Bain D. L. , Glew R. , Gibbs N. M. , Merry A. F.
Published: January 2019

We surveyed contemporary Australasian cardiac surgical and anaesthetic practice, focusing on antiplatelet and antifibrinolytic therapies and blood transfusion practices. The cohort included 499 sequential adult cardiac surgical patients in 12 Australasian teaching hospitals. A total of 282 (57%) patients received red cell or component transfusion. The median (IQR) red cell transfusion threshold haemogloblin levels were 66 (61-73) g/l intraoperative^ and 79 (74-85) g/l postoperatively. Many (40%) patients had aspirin within five days of surgery but this was not associated with blood loss or transfusion; 15% had Clopidogrel within seven days of surgery. In all, 30 patients (6%) required surgical re-exploration for bleeding. Factors associated with transfusion and excessive bleeding include pre-existing renal impairment, preoperative Clopidogrel therapy, and complex or emergency surgery. Despite frequent (67%) use of antifibrinolytic therapy, there was a marked variability in red cell transfusion rates between centres (range 17 to 79%, P <0.001). This suggests opportunities for improvement in implementation of guidelines and effective blood-sparing interventions. Many patients presenting for surgery receive antiplatelet and/or antifibrinolytic therapy, yet the subsequent benefits and risks remain unclear.
Bayesian Approach to Predict Hospital Mortality of Intensive Care Readmissions during the Same Hospitalisation
Authors: Ho K. M. , Knuiman M.
Published: January 2019

No specific prognostic model has been developed for patients readmitted to the intensive care unit (ICU) during the same hospitalisation. This study assesses the performance of the Acute Physiology and Chronic Health Evaluation (APACHE) II predicted mortality measured at the time of ICU readmission and whether incorporating information prior to the readmission will improve its performance to predict hospital mortality of patients readmitted to ICU during the same hospitalisation. A total of 602 readmissions during the same hospitalisation between 1987 and 2002 were identified. The first admission APACHE II predicted mortality was significantly associated with the hospital mortality only in the subgroup of patients readmitted within seven days of ICU discharge (odds ratio 1.16, 95% confidence interval 1.01 to 1.34; P=0.035). In the subgroups of patients readmitted within seven days of discharge, the readmission APACHE II predicted mortality was also significantly better than the first admission APACHE II predicted mortality in discriminating between survivors and non-survivors (area under the receiver operating characteristic curve: 0.785 vs. 0.676, z statistic=2.93; P=0.003). Incorporating the first admission APACHE II predicted mortality to the readmission APACHE II predicted mortality, either by multilevel likelihood ratios or logistic regression, did not significantly improve its discrimination (area under the receiver operating characteristic curve: 0.792 vs. 0.785, z statistic=0.52; P=0.603). Our results suggested that information on prior ICU admission during the same hospitalisation is not as important as the severity of illness measured at the time of readmission in determining the mortality of intensive care readmissions during the same hospitalisation.
A Comparison of the Effect of Total Intravenous Anaesthesia with Propofol and Remifentanil and Inhalational Anaesthesia with Isoflurane on the Release of Pro- and Anti-Inflammatory Cytokines in Patients Undergoing Open Cholecystectomy
Authors: Ke J. J. , Zhan J. , Feng X. B. , Wu Y. , Rao Y. , Wang Y. L.
Published: January 2019

The aim of the study was to investigate the effects of two anaesthetic techniques (total intravenous technique vs. inhalational technique) on changes in pro- and anti-inflammatory cytokine levels during open cholecystectomy. Forty ASA PS I-II patients undergoing open cholecystectomy were randomly assigned to two groups. Group R received total intravenous anaesthesia with propofol and remifentanil and group F received balanced inhalational anaesthesia with isoflurane. The plasma levels of tumour necrosis factor-α (TNF-α), interleukin IL-6 and interleukin IL-10 were measured during and after surgery.

The proinflammatory cytokine levels (TNF-α and IL-6) and the anti-inflammatory cytokine (IL-10) showed a significant increase in their concentrations compared with pre-induction levels in both groups (P <0.05). By the end of anaesthesia and surgery, TNF-α and IL-6 were significantly lower in group R than in group F (P <0.05). At the end of anaesthesia and 12 hours postoperatively, IL-10 levels in group R were higher than in group F (P <0.05). These findings suggest that total intravenous anaesthesia using propofol and remifentanil suppresses the inflammatory response caused by surgery to a greater extent than a balanced inhalation technique using isoflurane.
Assessment of an Unplanned Admission to the Intensive Care Unit as a Global Safety Indicator in Surgical Patients
Authors: Haller G. , Myles P. S. , Langley M. , Stoelwinder J. , Mcneil J.
Published: January 2019

An unplanned intensive care unit admission within 24 hours of a procedure with an anaesthetist in attendance (UIA) is a recommended clinical indicator. It is designed to identify preventable iatrogenic complications. Often understood as a specific anaesthetic outcome, its value has been repeatedly questioned. Iatrogenic complications however, often result from successive mishaps. In the specific context of an UIA these complications can be related both to anaesthesia and surgery. UIA is therefore probably more a global indicator of the safety of surgical care (anaesthetic and surgical) rather than a specific anaesthetic outcome. Its utility as such is however unknown. The purpose of this study was to assess the value of UIA as a global measure of avoidable iatrogenic complications in surgical patients.

Using computerised patient records and medical charts, all patients with an UIA over a study period of five years were identified. The proportion, cause and preventability of iatrogenic complications amongst these patients were assessed. A total of 188 UIA patients were identified by peer reviewers. Of these, 87% to 92% had a complication caused by anaesthesia and/or surgery. Anaesthesia was found to be responsible for 24% to 31% of iatrogenic complications. All other cases related to the combination of anaesthesia and surgery or surgery alone. Of these, 74% to 92% of complications were found to be preventable. Despite intrinsic limitations of the retrospective chart review method, UIA can be considered as a valuable tool to detect avoidable iatrogenic complications related to both surgical and anaesthetic care.
Review of Procedures for Investigation of Anaesthesia-Associated Anaphylaxis in Newcastle, Australia
Authors: Mcneill O. , kerridge R. K. , Boyle M. J.
Published: January 2019

The procedures, results and outcomes of investigation of 50 patients with clinical episodes of anaesthesia-associated anaphylaxis were retrospectively reviewed. Assessment was performed by measurement of serum tryptase and specific IgE and a combination of skin prick and intradermal skin testing. Testing was performed both for agents received during the anaesthetic and for agents the patient may encounter in future procedures. Twenty of 50 patients underwent a subsequent procedure after assessment. Sensitisation to neuromuscular blocking agents was identified in 18 patients (36%). Sensitisation to propofol (14 patients; 28%) and latex (four patients; 8%) was also frequently identified. No precise cause was identified in 11 cases (22%). Reactivity to more than one agent was identified in 14 patients (28%). Serum tryptase was measured within six hours of the episode in only 28 of the 50 cases. All the patients with elevated serum tryptase had clinically severe reactions. One patient initially found to be sensitised to propofol had another reaction during a second procedure, prompting further assessment where chlorhexidine reactivity was identified. Subsequent surgery in that patient and in 19 other patients where agents implicated in the testing were avoided, proceeded without incident. The results reaffirm that neuromuscular blocking agents are the most common cause of anaphylaxis during anaesthesia. The importance of serum tryptase measurement at the time of the acute episode needs to be emphasised. Investigation should include screening for chlorhexidine and latex in all patients, as exposure to both these agents is common and may be overlooked.
Job Satisfaction, Stress and Burnout in Anaesthetic Technicians in New Zealand
Authors: Kluger M. T. , Bryant J.
Published: January 2019

Anaesthetic technicians play a key role in the operating room, yet little is known about their levels of job satisfaction or workplace stress. A blinded, confidential single mail-out survey was posted to anaesthetic technicians in New Zealand. The survey consisted of demographic information, a job satisfaction survey, the Maslach Burnout Inventory and the Short Form 12. At total of 154 forms were returned (51% response rate). Respondents worked predominantly in public hospitals and many had duties outside the operating room. Job satisfaction was related to teamwork, practical nature of work and patient contact, while dissatisfaction was related to lack of respect from nurses and limited career pathway. High to moderate levels of emotional exhaustion (48%), depersonalisation (39%) and low levels of personal accomplishment (58%) were indicators of burnout. The Short Form 12 revealed high levels of physical impairment in 24% and emotional impairment in 35% of respondents. These data suggest that work is needed to evaluate anaesthetic assistants’ job structure and actively manage their important physical and emotional sequelae.
Anaesthetic Management of a Child with Freeman-Sheldon Syndrome Undergoing Spinal Surgery
Authors: Richa F. C. , Yazbeck P. H.
Published: January 2019

Freeman-Sheldon syndrome, or distal arthrogryposis type 2A, is a rare congenital myopathy and dysplasia characterised by multiple contractures, abnormalities of the head and face, defective development of the hands and feet and skeletal malformations. The facial muscle contracture produces the typical ‘whistling face’ appearance. Anaesthetic issues include difficult intravenous access, difficult airway and postoperative pulmonary complications. Although an association with malignant hyperthermia has been suggested, this has not been confirmed. We report the management of a seven-year-old girl with Freeman-Sheldon syndrome undergoing anterior and posterior spinal surgery and describe a successful anaesthetic regimen based on a total intravenous anaesthesia technique with remifentanil and propofol without neuromuscular blocking agents. The child had an uneventful anaesthetic and postoperative course. We believe the presence of the myopathy warranted the use of a ‘non-triggering’ anaesthetic, as suxamethonium and volatile agents may be associated with significant complications such as muscle rigidity and rhabdomyolysis in myopathic patients, even in the absence of malignant hyperthermia.
Evaluation of an Oxford Miniature Vaporizer Placed in-Circuit during the Maintenance Phase of Low-Flow Anaesthesia
Authors: Beck A. Ali , Boesel T. , Seppelt I. M.
Published: January 2019

The aim of the study was to assess Oxford Miniature Vaporizer output when mounted in-circuit during the maintenance phase of anaesthesia, using isoflurane, controlled ventilation and a fresh gas flow rate less than 1 l/min.

Twenty patients of ASA Physical Status I and II were recruited from routine general surgical lists. All patients were paralysed and ventilated. An out-of-circuit isoflurane vaporiser was used during the induction period (first 20 to 30 minutes). Anaesthesia was maintained using an Oxford Miniature Vaporizer placed in-circuit, using a fresh gas flow of 500 ml/min. The end-tidal isoflurane concentration was recorded for 90 minutes at five-minute intervals using a sidestream agent analyser. Two groups were compared, with the Oxford Miniature Vaporizer dial setting at either the 0.5 mark (low output setting) or at the 1.0 mark (higher output setting).

At a dial setting of 0.5, the Oxford Miniature Vaporizer produced a steady end-tidal isoflurane of 0.63% (95% confidence interval 0.60 to 0.66). However, when the dial was turned to 1.0 the output was almost always excessive and had to be reduced.

These findings indicate that a stable, predictable and clinically useful output can be achieved when the Oxford Miniature Vaporizer is positioned in-circuit using low-flow and controlled ventilation.
Analgesic Efficacy using Loss of Resistance to Air Vs. Saline in Combined Spinal Epidural Technique for Labour Analgesia
Authors: Leo S. , Lim Y. , Sia A. T. H.
Published: January 2019

Identification of the epidural space is often performed using the loss of resistance technique to either air or saline. We sought to investigate if the medium used affected the quality of analgesia obtained by parturients who received labour epidurals.

We conducted a retrospective audit of labour epidurals performed on nulliparous parturients in our institution from May 2003 to March 2005. All epidural catheters were inserted by senior obstetric anaesthetists using a combined spinal epidural technique. The following information was recorded: parturients’ demographic data, loss of resistance technique used, type and amount of local anaesthetic solution administered, complications encountered during procedure, pre-block and post-block pain scores, incidence of breakthrough pain requiring supplemental medication and post-block side-effects.

Data from 2848 patients were collected and analysed; 56% of patients made up the saline group and 44% the air group. Patients in both groups had similar demographic profiles and similar incidences of complications and post-block side-effects. However, patients in the air group had a higher incidence of recurrent breakthrough pain P=0.023). We also identified three other factors that were associated with an increased incidence of recurrent breakthrough pain; administration of pre-block oxytocin, sitting position of the parturient during the procedure and the use of intrathecal bupivacaine for induction of analgesia.

Our findings suggest that a loss of resistance to air is associated with a higher incidence of recurrent breakthrough pain among parturients who received combined spinal epidural analgesia for labour than a loss of resistance to saline.