bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Pre-Incision Skin Infiltration on Post-Hysterectomy Pain—A Double-Blind Randomized Controlled Trial
Authors: Leung C. C. , Chan Y. M. , Ngai S. W. , Ng K.-F. J. , Tsui S. L.
Published: January 2019

In this double-blind placebo-controlled randomized trial, we compared the analgesic effect of preoperative 0.25% bupivacaine (n=21) skin infiltration with normal saline (n=19) in patients undergoing abdominal hysterectomy through a lower midline incision. All patients received postoperative patient-controlled analgesia with morphine and were followed for 72 hours. The main outcome measures were morphine consumption and pain score at rest, and the contribution of different components of pain was also assessed prospectively. No statistically significant differences were found. All except one patient (n=39) could distinguish the different characteristics of somatic and visceral pain. Visceral pain predominated in the first 48 hours. We concluded that local anaesthetic infiltration is not effective in reducing pain after abdominal hysterectomy. Effective postoperative analgesia should aim to eliminate the visceral pain component.
Effects of the Laryngeal Mask Airway on the Lower Oesophageal Barrier Pressure in Children
Authors: Bunchungmongkol N. , Chumpathong S. , Catto-Smith A. G. , Brown T. C. K. , Simpson D. M.
Published: January 2019

The effects of laryngeal mask airway (LMA) insertion and cuff inflation on lower oesophageal sphincter, gastric and barrier pressure, and the relationship of the LMA cuff pressure and volume on the change in the barrier pressure were studied in 20 children. Subjects were aged one to five years, undergoing eye examination under general anaesthesia. There was no significant change in barrier pressure after insertion and inflation of the LMA compared with baseline measures. The cuff pressure and volume were not related to the change in barrier pressure. Two patients had marked decreases (10 to 15 mmHg) in barrier pressure after the LMA insertion. These decreases in barrier pressure would be expected to increase the risk of gastro-oesophageal reflux. We conclude that, although LMA use had little effect on barrier pressure in most children, occasional children will have potentially clinically significant decreases in barrier pressure with use of the LMA.
Routine Blood Test Ordering for Patients in Intensive Care
Authors: Flabouris A. , Bishop G. , Williams L. , Cunningham M.
Published: January 2019

Current practice is for a number of blood tests to be routinely performed on intensive care unit (ICU) patients. A survey of routine blood testing amongst ICUs in Australia and New Zealand was conducted. Ninety-six ICUs completed the survey form. Blood electrolytes, liver function, arterial blood gases and full blood count were the most frequently ordered tests. Routine blood testing was not practised in 12.6% of ICUs. The presence or absence of written guidelines did not influence the frequency of the most commonly performed routine blood tests. Clinical and operational factors specific to each ICU appear to impact on such blood tests and guidelines for their use.
Complementary Medicine in Intensive Care: Ethical and Legal Perspectives
Authors: Young R. J. , Worswick D. , Stoffell B.
Published: January 2019

Complementary medicine continues to increase in popularity in the general community. As a result it is likely that requests for the administration of complementary medicine to intensive care patients will be more frequent in the future. It is therefore prudent for intensive care clinicians to address this issue and develop an approach that is consistent.

Complementary medicine has not been subjected to well conducted trials to determine its efficacy and risks. Consequently decisions about its use cannot be based on risk/benefit analyses and genuine informed consent cannot be achieved. Therefore complementary medicine should not be incorporated into intensive care practice.

Strict adherence to a policy of negating requests for administration of complementary medicine in intensive care patients may result in significant conflicts between intensive care clinicians, patients and families. On occasions the patient or family may insist on the use of complementary medicine and it may be seen as important to their psychological wellbeing to accede to the request. The intensive care clinician is still legally responsible for any treatment administered to the patient, even if it is against medical advice. Nevertheless if there is no demonstrable risk to the patient, complementary medicine can be administered following appropriate counselling and documentation.

This review addresses the legal and ethical difficulties that may arise and an approach that may be followed when requests are made for complementary medicine in intensive care patients.
Do Anaesthetized Patients Recover Better after Bispectral Index Monitoring?
Authors: Burrow B. , McKenzie B. , Case C.
Published: January 2019

Could Bispectral Index (BIS) monitoring during anaesthesia improve the recovery characteristics of patients? Previous studies have shown conflicting results. To eliminate bias, a control group of 75 cases anaesthetized by the authors was compared to a reference group of 141 cases anaesthetized by other anaesthetists. A study group of 71 cases was then anaesthetized by the authors titrating to BIS 40–50 and this was compared with the control group.

Recovery characteristics were assessed using a Modified Aldrete score. BIS monitored cases had improvements in blood pressure stability (P=0.023) and respiratory score (P=0.016) throughout the study period. Activity and consciousness levels were higher on arrival in PACU in the BIS monitored group (P=0.015 and P=0.017) but were not maintained. There was no significant difference in mean oxygen saturation scores.

The improved recovery characteristics in BIS monitored patients may have positive implications for safety, nursing workload, staffing, and cost savings in the PACU.
PCA Ketamine and Morphine after Abdominal Hysterectomy
Authors: Burstal R. , Danjoux G. , Hayes C. , Lantry G.
Published: January 2019

Following a standardized general anaesthetic for total abdominal hysterectomy, patients received either patient controlled analgesia (PCA) with morphine 1 mg/ml (group M, n=33) or morphine 1 mg/ml plus ketamine 2 mg/ml (group K, n=37) for 48 hours in a randomized, double-blind fashion. In 43 women the area of allodynia around the scar was mapped as a measure of the degree of central sensitization.

A significant reduction in the area of allodynia was found in those receiving ketamine with morphine (42 cm 2 [interquartile range (IQR) 57] compared with 57 cm 2 [IQR 82] z=–2.0, P=0.04) in those receiving morphine alone. There were no significant differences between the two groups with respect to age, or weight, or between the subgroups within which the area of allodynia was measured with respect to length of incision.

No significant differences were found between the groups with respect to pain scores, total or hourly drug consumption, patient satisfaction, nausea scores or antiemetic use. Patients in group K were more likely to require PCA for a shorter period than those in group M (median 40 hours, IQR 26 versus 48 hours IQR 7). Ten patients in group K were withdrawn because of side-effects (dysphoria n=4, nausea n=2, pruritus n=4) compared with one in group M (nausea n=1)(P=0.006).

The potential usefulness of ketamine after hysterectomy was offset by a high incidence of adverse effects and a lack of opioid-sparing effects, such that combined intravenous ketamine and morphine PCA as used in this study cannot be recommended for routine care.
Intubation through Intubating Laryngeal Mask with and without a Lightwand: A Randomized Comparison
Authors: Chan P. L. , Lee T. W. , Lam K. K. , Chan W. S.
Published: January 2019

The combined use of a lightwand and the intubating laryngeal mask airway (ILMA) was compared with the use of the ILMA alone to determine whether the combination was a more efficient method of endotracheal intubation. One hundred healthy patients were randomly assigned to two groups. After induction of anaesthesia, Group A patients were intubated blindly through the ILMA while in Group B, intubation was guided by a lightwand. A sequence of standard manoeuvres was followed if attempts at intubation failed. The number of manoeuvres used, the time taken for successful intubation and complications associated with intubation were recorded. Intubations were successful in all patients, but the mean endotracheal intubation time was longer in Group A than in Group B (38.3±10.4 s versus 26.4±9.1 s, P<0.001). The number of patients who needed one or more manoeuvres was significantly higher in Group A than in Group B (76% versus 42%, P=0.001). We conclude that the lightwand is a useful adjunct in endotracheal intubation through an ILMA.
Ventilator-Patient Dyssynchrony Induced by Change in Ventilation Mode
Authors: Lydon A. M. , Doyle M. , Donnelly M. B.
Published: January 2019

Patient-ventilator interactions may be coordinated (synchronous) or uncoordinated (dyssynchronous). Ventilator-patient dyssynchrony increases the work of breathing by imposing a respiratory muscle workload. Respiratory centre output responds to feedback from respiratory muscle loading. Mismatching of respiratory centre output and mechanical assistance results in dyssynchrony. We describe a case of severe patient-ventilator dyssynchrony and hypothesize that dyssynchrony was induced by a change in mode of ventilation from pressure-cycled to volume-cycled ventilation, due to both ventilator settings and by the patient's own respiratory centre adaptation to mechanical ventilation. The causes, management and clinical implications of dyssynchrony are discussed.
Airway Protection with the ProSeal Laryngeal Mask Airway
Authors: Brimacombe J. , Keller C.
Published: January 2019

The ProSeal laryngeal mask airway is a new laryngeal mask device that has a modified cuff and a drainage tube. We describe a case where the ProSeal laryngeal mask successfully channelled regurgitated fluid away from the respiratory tract.
Propofol Anaesthesia via Target Controlled Infusion or Manually Controlled Infusion: Effects on the Bispectral Index as a Measure of Anaesthetic Depth
Authors: Gale T. , Leslie K. , Kluger M.
Published: January 2019

Target controlled infusions (TCI) of propofol allow anaesthetists to target constant blood concentrations and respond promptly to signs of inappropriate anaesthetic depth. Studies comparing propofol TCI with manually controlled infusion (MCI) reported similar control of anaesthesia, but did not use an objective measure of anaesthetic depth. We therefore tested whether the Bispectral Index (BIS), an electroencephalographic (EEG) variable, is more stable during propofol TCI or MCI. Forty patients received midazolam and fentanyl before induction and were randomized to TCI or MCI. Target propofol concentrations in the TCI group were 3 to 8 μg/ml. The MCI group received propofol bolus (≍2 mg/kg) and infusion (3 to 10 mg/kg/h). Neuromuscular blockade was achieved with rocuronium. Following endotracheal intubation, nitrous oxide (66%) in oxygen was delivered and propofol infusion and fentanyl boluses were titrated against clinical signs. Blood pressure, heart rate and EEG were recorded, although the anaesthetist was blind to BIS values. The ideal BIS for general anaesthesia was defined as 50. Performance error, absolute performance error, wobble and divergence of BIS, and maximum changes in blood pressure and heart rate were compared using two-sample t-tests or rank-sum tests where appropriate. There was no difference in absolute performance errors during maintenance of anaesthesia with propofol TCI or MCI (23±11% vs 23±9%; P=0.97). The two groups did not differ significantly in performance error, wobble, divergence on haemodynamic changes. We conclude that TCI and MCI result in similar depth of anaesthesia and haemodynamic stability when titrated against traditional clinical signs.
Human Serum Albumin Induced Hypotension in the Postoperative Phase of Cardiac Surgery
Authors: Howard G. , Downward G. , Bowie D.
Published: January 2019

Hypotension associated with the rapid infusion of human serum albumin products was first recognised in Australasia in the early 1970s. An association with the angiotensin converting enzyme inhibitor class of drugs (ACE-I) followed, leading to a proposed mechanism involving bradykinin generation through pre-kallikrein activator (PKA) presence in the infused fluid. The newer generation albumin products (Albumex®) contain very low concentrations of PKA and are generally thought safe to use in most patient populations. Anecdotal reports of paradoxical hypotension with rapid infusion of 4% albumin in our department led to an audit of practice over three months. Four out of 36 patients (11%) who received 4% albumin intravenously experienced paradoxical hypotension. Three of these patients were taking ACE-I preoperatively (P=0.04). There was no observed hypotension associated with intravenous infusion of crystalloid fluid. We believe 4% albumin should be used with caution, particularly in those patients receiving ACE-I preoperatively.
Post Dural Puncture Headache following Combined Spinal Epidural or Epidural Anaesthesia in Obstetric Patients
Authors: Van De Velde M. , Teunkens A. , Hanssens M. , Van Assche F. A. , Vandermeersch E.
Published: January 2019

A retrospective review of obstetric anaesthesia charts was performed for all parturients receiving regional anaesthesia over a 22-month period. The incidence of headache, post dural puncture headache (PDPH) and various other complications of regional anaesthesia that had been prospectively assessed were noted, as was the anaesthetic technique used (epidural or combined spinal epidural (CSE)). PDPH was rare (0.44%) and occurred with similar frequency in those managed with either epidural or CSE anaesthesia or analgesia. The pencil-point spinal needle gauge (27 or 29) did not influence the incidence of PDPH. Following a CSE technique, the epidural catheter more reliably produced effective analgesia/anaesthesia as compared with a standard epidural technique (1.49% versus 3.18% incidence of replaced catheters respectively). We conclude, based on the results of this retrospective review, that CSE is acceptable with respect to the occurrence of PDPH and that it is possible it is advantageous in relation to the correct placement of the epidural catheter.
A New Technique for Difficult Intubations
Authors: Taraporewalla K. J. , Washbourne D. E.
Published: January 2019

A Macintosh laryngoscope was modified to allow a rigid fibreoptic scope to be attached. Our purpose was to determine if Cormack and Lehane scores could be improved using the described fibreoptic technique, thus allowing easier intubating conditions. In order to assess its value for intubation, a study was performed on 53 patients. Thirty-three of these patients were classified to be difficult intubations (suspected or unanticipated). The Cormack and Lehane scores were improved by the use of the modified laryngoscope by one to three grades compared to the standard laryngoscopy. Significantly improved intubating condition were observed. The assessment demonstrates that many patients with Mallampati scores of III and IV can be successfully managed by this technique.
A Randomized Trial Comparing Two Laryngeal Mask Airway Insertion Techniques
Authors: Koay C. K. , Yoong C. S. , Kok P.
Published: January 2019

This study was undertaken to compare laryngoscopic-guided LMA insertion with a standard insertion technique. A total of 149 patients undergoing elective general surgical and orthopaedic procedures were randomly divided into two groups. Study endpoints included ease of insertion, haemodynamic changes, local trauma bleeding, and postoperative sore throat. There were no statistically significant differences found. The laryngoscope may aid laryngeal mask airway insertion in some circumstances.
Pneumomediastinum after Dental Surgery
Authors: Davies D. E.
Published: January 2019

A previously healthy woman presented with chest pain and cervical swelling several hours after undergoing surgical removal of third molar teeth. Mediastinal and subcutaneous emphysema was demonstrated by chest X-ray. Air had been introduced under the soft tissue flap by the high-speed turbine drill used to remove the alveolar bone, rather than the air/water syringe. Surgical handpieces that vent the air away from the surgical field should be used during such procedures. The mediastinal and subcutaneous air resolved after oxygen administration.
Unexpected Difficult Intubation in a Patient with Normal Airway on Assessment
Authors: Lim B. S. L. , Andrews R.
Published: January 2019

Routine preoperative assessment of the patient's airway includes an assessment of mouth opening and a grading of the view according to the Mallampati scale. This is carried out with the patient sitting and actively opening the mouth without phonation. This case report illustrates that the temporomandibular joint is a complex joint and that certain pathologies may prevent passive depression of the mandible after induction of anaesthesia.
The Efficacy and Cost-effectiveness of Prophylactic 5-hydroxytryptamine3 Receptor Antagonists: Tropisetron, Ondansetron and Dolasetron
Authors: Paech M. J. , Rucklidge M. W. M. , Banks S. L. , Gurrin L. C. , Orlikowski C. E. P. , Pavy T. J. G.
Published: January 2019

There are currently three 5-hydroxytryptamine 3 (5-HT 3 ) receptor antagonists available in Australia. In this randomized, double-blind, parallel group study the prophylactic antiemetic effect of a single dose of tropisetron 2 mg, ondansetron 4 mg or dolasetron 12.5 mg was compared after major gynaecological surgery.

One hundred and eighteen patients (group T n=42; group O n=36; group D n=40) were evaluated for nausea, vomiting, recovery characteristics and satisfaction for 24 hours postoperatively. A cost-effectiveness analysis was performed.

Rescue antiemetic, prochlorperazine 12.5 mg IM, was given if vomiting occurred more than 10 minutes after arrival in the recovery room. If prochlorperazine was ineffective one hour after administration, droperidol 1 mg IV was given.

There were no significant differences between groups for the incidence of vomiting during consecutive epochs until 24 hours postoperatively or overall (57%, 75% and 72.5% for groups T, O and D respectively, P=0.18). The incidence and number of rescue antiemetic treatments for nausea or vomiting were similar. The incidence of nausea and the overall and interval nausea scores were similar except for lower “worst nausea” score in group T between 12 and 18 hours (P=0.02). Recovery times, satisfaction and cost per patient did not differ between groups.

We conclude that the risk of postoperative nausea and vomiting remained high in this setting despite 5-HT 3 receptor antagonist prophylaxis and that the choice between these agents should be based on the lowest available acquisition cost.
Dimensions of Double-Lumen Tracheobronchial Tubes
Authors: Russell W. J. , Strong T. S.
Published: January 2019

The diameter of the left main bronchus is the determining dimension when selecting the size of a left tracheobronchial (double-lumen) tube for lung separation. However, this information is not given by any manufacturer, either on the tube or in the package insert.

This paper describes the lengths and diameters of the deflated bronchial cuff segment of left tracheobronchial tubes in common use. One hundred and seventy-one left tracheobronchial tubes ranging in size from 28 to 41 nominal French gauge from four manufacturers were measured. There was wide variation between tubes of the same nominal size from the same manufacturer. For tubes of the same size from the same manufacturer, the diameter of the segment with the deflated bronchial cuff varied by more than 1 mm in diameter in some instances.The diameter of the bronchial cuff segment did not consistently decrease as the nominal size decreased even for the same manufacturer. There was major overlap in diameters of the bronchial segments between Fr 41, Fr 39, and Fr 37 tubes from most manufacturers, so that some of the Fr 39 tubes have a bronchial cuff segment diameter as much as 0.5 mm larger than the Fr 41 tube.

It is concluded that the current French gauge markings on left tracheobronchial tubes are of very limited value in determining the appropriate size to be selected for a patient.

More accurate and consistent dimensions of tracheobronchial tubes are required to improve clinical selection.
Detection and Correction of Accidental Oesophageal Intubation during Flexible Lightwand-Guided Intubation via the Intubating Laryngeal Mask
Authors: Dimitriou V. , Voyagis G. S. , Brimacombe J.
Published: January 2019

In the following two-part study, we determined the efficacy of observation of the light glow to detect correct placement of the tracheal tube after lightwand-guided tracheal intubation via the intubating laryngeal mask (ILM). We also determined the efficacy of a protocol to correct oesophageal intubation in this situation. In study 1, 80 ASA 1–3, anaesthetized, paralysed patients were randomly assigned to have a tracheal tube, preloaded with a flexible lightwand, placed into either the trachea (n=40) or oesophagus (n=40) under laryngoscope guidance. A blinded observer experienced with the lightwand technique determined whether oesophageal or tracheal intubation had occurred by observation of the light glow. In study 2, 1000 patients, 400 of whom were included in a previous study, underwent flexible lightwand-guided intubation via the ILM. Placement of the tracheal tube in oesophagus or trachea was determined by observation of the glow and verified by capnography. Oesophageal intubation was corrected by adjusting the ILM position using a protocol comprising two adjusting manoeuvres. Observation, verification and correction were by experienced anaesthetists conducting the case. In study 1, oesophageal and tracheal intubation was correctly detected in 38/40 (95%) and 37/40 (92.5%) patients respectively. In study 2, oesophageal and tracheal intubation was correctly detected in 55/55 (100%) and 945/945 (100%) patients respectively. In 40/55 (73%) patients, tracheal intubation was successful at the second attempt and in 13/55 (24%) at the third or fourth attempt. In 2/55 (4%) patients, persistent oesophageal intubation occurred. The sensitivity, specificity and positive predictive value were 95%, 92.5% and 92.7% respectively in study 1, and were all 100% in study 2.
Papaverine Angioplasty to Treat Cerebral Vasospasm following Traumatic Subarachnoid Haemorrhage
Authors: Cairns C. J. S. , Finfer S. R. , Harrington T. J. , Cook R.
Published: January 2019

The management of vasospasm associated with traumatic subarachnoid haemorrhage presents many challenges. We present a 20-year-old male admitted after sustaining a closed head injury complicated by a Fisher grade III traumatic subarachnoid haemorrhage. Despite treatment with intravenous nimodipine he developed a delayed ischaemic neurological deficit due to cerebral arterial vasospasm. The vasospasm was successfully managed with serial papaverine angioplasty.
Anaesthesia for Caesarean Section in a Patient with Spinal Muscular Atrophy
Authors: Buettner A. U.
Published: January 2019

This report describes a 33-year-old primigravid woman with spinal muscular atrophy Type III (Kugelberg-Welander syndrome). Elective caesarean section was performed at 38 weeks gestation under spinal anaesthesia. The implications of spinal muscular atrophy for anaesthesia for caesarean section are described.
Legal Aspects of Withdrawal of Therapy
Authors: Young R. J. , King A.
Published: January 2019

The ability of intensive care to replace or support vital organ function has resulted in some patients surviving for long periods of time without improvement or a terminal event. In patients with no realistic chance of survival, decisions to withdraw or withhold life-sustaining therapies are commonly made.

Withdrawal of life support at the patient's request is lawful at common law and, in some states of Australia, by legal statute. In the intensive care setting though, it is more common for therapy to be withdrawn because the therapy is of no perceived benefit or not in the patient's best interests. However, in Australia there is little case law and very little legislation to direct the decision of whether to withdraw life-sustaining therapy on the grounds of futility or the patient's best interests.

The legislation that does exist in Australia, as well as law from other jurisdictions, largely places responsibility for the decision to withdraw therapy on the doctor in charge of the patient's care. However much weight is frequently placed on the wishes of the family.

Disagreements between family and clinicians over decisions to withdraw therapy are unusual and generally resolve over time. However if disagreement persists, it may be advisable to apply to the courts for a declaratory judgement, given the tenuous legal basis of withdrawal of life-sustaining therapy in Australia and the uncertainty over the courts’ view of the role of the patient's family in the decision-making process.
Epidural Catheter Migration: A Comparison of Tunnelling against a New Technique of Catheter Fixation
Authors: Chadwick V. L. , Jones M. , Poulton B. , Fleming B. G.
Published: January 2019

We investigated the efficacy of a new technique of epidural catheter fixation that relies on a strip of adhesive foam transfixed by a securing suture. We compared this technique to a tunnelled technique in a prospective, randomized trial (n=25 in each group). Epidural catheter depth was recorded at the time of insertion and at the time of removal. Clinically significant catheter movement was considered as >2 cm outward movement or >1 cm inward movement. The mean duration of epidural analgesia was five days for both groups. Clinically significant movement was noted in eight patients (32%) in the tunnelled group and seven patients (28%) in the sutured group (P=0.75). Movement of the epidural catheter did not correlate with analgesic failure. The sutured technique provided similar protection against migration to tunnelling but any potential advantages were offset by concerns about a significantly higher incidence of erythema around the catheter exit site in the sutured group (1 vs 6 patients, P=0.04).
Subglottic Tracheal Stenosis in Pregnancy: Anaesthetic Implications
Authors: Kuczkowski K. M. , Benumof J. L.
Published: January 2019

We present the first reported case of a pregnant patient with severe subglottic tracheal stenosis who required elective surgical tracheostomy prior to administration of labour analgesia.
Failed Extubation of a Double-lumen Tube Requiring a Cricoid Split
Authors: Probert D. J. , Hardman J. G.
Published: January 2019

Following a five-hour procedure, it was not possible to remove a double-lumen endobronchial tube that had been placed to facilitate the removal of a massive spleen from a 45-year-old female. The tube had been passed easily at the start of surgery, but was firmly stuck at the level of the cricoid at the end of surgery. Surgical removal of the tube by a cricoid split was required 48 hours later. Consideration of previous airway manipulations, careful choice of airway devices and regular checks of airway patency around tracheal tubes during lengthy procedures may prevent similar events in the future.
Modelling Thirty-day Mortality in the Acute Respiratory Distress Syndrome (ARDS) in an Adult ICU
Authors: Moran J. L. , Solomon P. J. , Fox V , Salagaras M. , Williams P. J. , Quinlan K. , Bersten A. D.
Published: January 2019

Variables predicting thirty-day outcome from Acute Respiratory Distress Syndrome (ARDS) were analysed using Cox regression structured for time-varying covariates. Over a three-year period, 1996–1998, consecutive patients with ARDS (bilateral chest X-ray opacities, PaO2/FiO2 ratio of <200 and an acute precipitating event) were identified using a prospective computerized data base in a university teaching hospital ICU.

The cohort, 106 mechanically ventilated patients, was of mean (SD) age 63.5 (15.5) years and 37% were female. Primary lung injury occurred in 45% and 24% were postoperative. ICU-admission day APACHE II score was 25 (8); ARDS onset time from ICU admission was 1 day (median: range 0-16) and 30 day mortality was 41% (95% CI: 33%-51%). At ARDS onset, PaO2/FiO2 ratio was 92 (31), 81% had four-quadrant chest X-ray opacification and lung injury score was 2.75 (0.45). Average mechanical ventilator tidal volume was 10.3 ml/ predicted kg weight. Cox model mortality predictors (hazard ratio, 95% CI) were: APACHE II score, 1.15 (1.09-1.21); ARDS lag time (days), 0.72 (0.58-0.89); direct versus indirect injury, 2.89 (1.45-5.76); PaO2/FiO2 ratio, 0.98 (0.97-0.99); operative versus non-operative category, 0.24 (0.09-0.63). Time-varying effects were evident for PaO2/FiO2 ratio, operative versus non-operative category and ventilator tidal volume assessed as a categorical predictor with a cut-point of 8 ml/kg predicted weight (mean tidal volumes, 7.1 (1.9) vs 10.7 (1.6) ml/kg predicted weight). Thirty-day survival was improved for patients ventilated with lower tidal volumes.

Survival predictors in ARDS were multifactorial and related to patient-injury-time interaction and level of mechanical ventilator tidal volume.
Intraoperative Patient Warming using Radiant Warming or Forced-air Warming during Long Operations
Authors: Lee L. , Leslie K. , Kayak E. , Myles P. S.
Published: January 2019

Forced-air warming is the most commonly used and effective method of active warming. A new radiant warming device (Suntouch™, Fisher and Paykel) may provide an alternative when the skin surface available for warming is limited. We conducted a randomized controlled trial to compare the efficacy of the Suntouch™ radiant warmer and forced-air warming. With ethics committee approval, 60 surgical patients having procedures anticipated to be more than two hours in duration were recruited. Patients were randomized to either radiant warming or forced-air warming. All intravenous fluids were warmed but prewarming was not used. The final intraoperative core temperatures (°C) for the radiant warming and forced-air warming groups were 36.0±0.5 and 36.4±0.6 (P=0.002) respectively. No other patient variables were significantly different. The Suntouch™ is not as effective as the forced air warming for intraoperative warming during long surgical procedures. The device may be useful when forced-air warming is not possible.
Pethidine and Skin Warming to Prevent Shivering during Endovascular Cooling
Authors: Leslie K. , Williams D. , Irwin K. , Bjorksten A. R. , Sessler D. I.
Published: January 2019

We tested the efficacy of pethidine and cutaneous warming to prevent shivering during percutaneous cooling in unanaesthetized patients. Ten patients scheduled for cranial neurosurgery received pethidine infusion and skin warming. The Setpoint™ internal heat-exchanging catheter was inserted and cooling to 33.5°C was started. Clonidine and chlorpromazine were given as “rescue medication” to treat shivering. General anaesthesia was planned to be induced after cooling was complete. Rewarming was initiated at dural closure. Three patients successfully completed the protocol, cooling to 33.8°C at a median rate of 3.6 (range: 3.4-3.8) °C/h. Two patients cooled to 33.8°C but required treatment for shivering (cooling rate: 2.9 [2.8-3.1] °C/h). Four patients failed to cool adequately because of refractory shivering (cooling rate: 2.0 [1.5-2.9] °C/h). One patient did not shiver and yet failed to cool adequately (cooling rate: 0.76 °C/h). Rewarming was at a rate of 2.6 (1.2-4.3) °C/h. There were no significant complications arising from catheter placement. The combination of skin warming and pethidine was not reliable enough to be recommended for use during endovascular cooling in unanaesthetized patients.
The Differential Flow of Epidural Local Anaesthetic via Needle or Catheter: A Prospective Randomized Double-blind Study
Authors: Yun M. J. , Kim Y. C. , Lim Y. J. , Choi G. H. , Ha M. , Lee J. Y. , Ham B. M.
Published: January 2019

The extent of epidural anaesthesia and pattern of spread of contrast medium, using different injection techniques, has not been well documented. Therefore, in this prospective, randomized, double-blind study, the extent of anaesthesia and pattern of spread of contrast medium following an epidural bolus injection, via either a Tuohy needle or an epidural catheter, were compared.

The study had two parts. In the first, 59 of 79 patients scheduled for a lower extremity operation under epidural anaesthesia were randomly allocated to one of the two groups. Anaesthesia was achieved with an epidural injection of 10 to 15 ml (including a 3 ml test dose) of 0.75% ropivacaine and fentanyl 25 μg via either a Tuohy needle (Group N, n=31) or a catheter (Group C, n=28). The level of sensory anaesthesia was recorded. In the second part, the remaining 20 patients were randomized to initially receive 5 ml of contrast medium via either a Tuohy needle (Group NE, n=10) or a catheter (Group CE, n=10). The extent of spread was recorded radiologically.

Unilateral or missed blocks and additional dose requirement were absent in Groups N and C. No differences were found in the extent of sensory anaesthesia or the spread of contrast medium. Twenty per cent of catheter tips lay outside the lateral margins of the vertebral bodies.

We found that an epidural bolus injection, via either a Tuohy needle or a catheter, made no difference in regard to spread of local anaesthetic or contrast medium in the epidural space.
Residual Protein Contamination of ProSeal™ Laryngeal Mask Airways after Two Washing Protocols
Authors: Stone T. , Brimacombe J. , Keller C. , Kelley D. , Clery G.
Published: January 2019

The risk of prion protein cross-infection has focussed attention on the potential hazards of protein contamination of re-usable medical devices. This study determined the frequency of protein contamination of ProSeal™ laryngeal mask airways (PLMA) after two cleaning procedures and tested the hypothesis that the combination of hand- and machine-washing removes protein contamination more effectively than hand-washing alone. After clinical use fifty-four PLMAs were randomly allocated to be washed by hand or by hand then machine. All PLMAs were then autoclaved at 134°C for 4 minutes. After processing, each PLMA was immersed in a 1.2% solution of erythrosin B and examined for uptake of stain. The site (outer surface, bowl and edges of the cuff, airway and drain tube, finger strap) and severity (nil/mild/moderate/severe) of staining was scored by a blinded observer. There were no differences in the site or severity of staining between the two cleaning procedures. Staining was detected on 89% of PLMAs that were hand-washed and 78% of PLMAs that were hand-, then machine-washed (P=0.27). When staining occurred, it was mild in 98%, moderate in 2% and was never severe. Staining was more frequent on the edge than at any other location (all comparisons: P≤0.01). The strap never had any staining. We conclude that residual contamination of PLMAs with protein deposits is common even when machine-washing is used to augment hand-washing before autoclaving. The infection risk associated with these deposits remains to be determined.
Small Simulators for Teaching Procedural Skills in a Difficult Airway Algorithm
Authors: Parry K. , Owen H.
Published: January 2019

Difficulty with intubation, ventilation or both is a significant issue for anaesthetists. The American Society of Anesthesiologists’ Guidelines for the Management of the Difficult Airway is an algorithm widely used when airway difficulties are encountered. Ideally, anaesthetic trainees should have access to simulators suitable for learning and practising how to manage airway difficulties, but most models have been designed primarily for resuscitation training. The aim of this study was to determine which small airway simulators could be used to practise steps in the Difficult Airway Algorithm (DAA).

We identified the essential elements of the DAA relating to endotracheal intubation (laryngoscope, Trachlight and Fastrach), external laryngeal manipulation, dedicated airway devices (LMA, Combitube) and trans-tracheal ventilation using the Enk oxygen flow modulator (Cook). Each element was studied in adult airway models sold for airway management training.

The DAA elements were studied in 16 different airway models. No single model achieved our criteria of “good/very realistic” for all elements. All elements of the DAA could be used in the Difficult Airway Trainer Deluxe (MPL) and Bill (VBM/Mallinckrodt) but it would be necessary to acquire at least two trainers to achieve “good/very realistic” in all techniques studied.

Anaesthetic departments planning to acquire small simulators for airway management training should undertake a training-needs analysis and apply this to the performance characteristics of the simulators. Generally, at least two airway training models will be needed to teach all steps of the DAA effectively.
Difficult Extubation: Calming the Sympathetic Storm
Authors: Kulkarni A. , Price G. , Saxena M. , Skowronski G.
Published: January 2019

Tracheal extubation can evoke an equally strong haemodyamic stress response as tracheal intubation. We present a patient with myocardial infarction who repeatedly failed tracheal extubation. He developed acute pulmonary oedema following each attempt at tracheal extubation due to sympathetic overactivity. A change of approach with extubation under propofol sedation followed by continued sympatholysis with dexmedetomidine infusion allowed successful extubation.
Presumed Central Anticholinergic Syndrome from Inadvertent Intravenous Hyoscine Hydrobromide (Scopolamine) Injection
Authors: Wilden J. , Rapeport D.
Published: January 2019

We present a case of presumed central anticholinergic syndrome due to a drug administration error. A 35-year-old woman was slow to emerge from anaesthesia for laparoscopic biliary surgery. Postoperative neurological and metabolic abnormalities were later diagnosed as central anticholinergic syndrome. Only after resolution of the clinical problems did the drug error origin of the syndrome become apparent. It was realized that hyoscine hydrobromide (scopolamine) had been inadvertently administered intraoperatively for biliary relaxation, instead of hyoscine butylbromide. This case report describes central anticholinergic syndrome and highlights potential problems involved for anaesthetists administering drugs they do not commonly use.
Suspected Case of Venous Air Embolism in an Infant Undergoing Hip Arthrogram
Authors: Sarantopoulos S. , Lew J.
Published: January 2019

An otherwise well ten-week-old girl underwent an air contrast hip arthrogram and application of a hip spica for a developmentally dislocated hip. The child displayed signs consistent with venous air embolism after injection of 5 ml of air into the hip joint. These signs included a decrease in arterial haemoglobin oxygen saturation as measured by pulse oximetry, decreased end-tidal carbon dioxide level and tachycardia. The signs initially resolved, but the patient deteriorated with injection of a further 5 ml of air. The patient responded to cessation of injection and resuscitative measures. The infant remained well postoperatively. The need for the use of air to confirm intra-articular placement of the needle prior to injection of contrast during a hip arthrogram is questioned.
The Use of the Novel Calcium Sensitizer Levosimendan in Critically Ill Patients
Authors: Plöchl W. , Rajek A.
Published: January 2019

Levosimendan, a novel calcium sensitizer, enhances cardiac contractility by increasing myocyte sensitivity to calcium, and induces vasodilation. In this prospective observational study the haemodynamic effects of levosimendan in postoperative critically ill patients are reported. Twelve patients with the need for inotropic support were studied. One dose of levosimendan (12.5 mg) was administered at a rate of 0.1-0.2 μg.kg−1.min−1, either alone or in addition to pre-existing inotropic therapy. Haemodynamic measurements were obtained at baseline, and at 3 h, 6 h, 12 h, and 24 h after the start of the levosimendan infusion.

Levosimendan significantly increased cardiac output from (mean±SD) 4.3±0.9 l.min−1 to 5.2±1.5 l.min−1 after 24 h (P=0.013), by increases in stroke volume (baseline 47±15 ml, after 24 h 57±25 ml, P=0.05), as heart rate remained unchanged. Systemic vascular resistance decreased from 1239±430 dyn.sec.cm−5 at baseline to 963± 322 dyn.sec.cm−5 at 24 h (P<0.001). Pre-existing inotropic therapy present in ten patients remained unchanged or was reduced.

In postoperative critically ill patients, infusion of levosimendan exerted favourable haemodynamic responses. Levosimendan increased cardiac output by increasing stroke volume, which might be attributed primarily to its inotropic properties. Due to its cyclic adenosine monophosphate independent positive inotropic effects, levosimendan may be of value as adjunctive therapy to other inotropic drugs in critically ill patients.
Entropy and Bispectral Index during Anaesthesia in Children
Authors: Davidson A. J. , Kim M. J. , Sangolt G. K.
Published: January 2019

Entropy™ is a new EEG based technology developed as a measure of depth of anaesthesia. The Entropy algorithm quantifies the degree of disorder in the EEG. During anaesthesia the disorder of the EEG, or entropy, falls. Entropy is independent of absolute frequency or amplitude of the EEG. This may make it suitable for paediatric anaesthesia.

In this prospective observational blinded study we recorded the Entropy and Bispectral Index™ in 23 children undergoing general anaesthesia with isoflurane and nitrous oxide, supplemented with peripheral nerve blockade. We recorded Entropy at several times during anaesthesia, pre-awakening and 1-minute post-awakening. Entropy pre-awakening and 1 minute after awakening was compared to a value during anaesthesia in three age groups; less than one-year-old (infants), one to five years (toddlers) and five to twelve years (children). The correlation between BIS and Entropy was also calculated.

Entropy post-awakening was higher than during anaesthesia for all age groups. Entropy pre-awakening was higher than during anaesthesia for the children and toddlers. This was not as apparent in infants. There was a strong correlation between BIS and Entropy for children and toddlers. The correlation was less for infants.

This study demonstrates that, in children, Entropy is lower during anaesthesia when compared to awake values. Further evaluation in the paediatric population is worthwhile.
Challenges that Opioid-dependent Women Present to the Obstetric Anaesthetist
Authors: Cassidy B. , Cyna A. M.
Published: January 2019

A retrospective casenote review was performed to identify anaesthetic challenges relevant to the opioid-dependent obstetric population. Medical records showed that of the 7,449 deliveries during a 24 month period, 85 women (1.1%) were taking regular opioids such as methadone and/or heroin. Of these 67 (79%) received anaesthetic services, ten of whom (11.7%) were referred antenatally. Forty opioid-dependent women (47%) received epidural analgesia in labour compared with the overall hospital rate of 38%. Twenty-three women (27%) delivered by caesarean section: five received general anaesthesia, five combined spinal anaesthesia, five spinal anaesthesia and eight epidural anaesthesia. Twenty opioid-dependent women (23.5%) had documented problems related to labour analgesia and 17 (74%) had problems with analgesia after caesarean section. A variety of postoperative analgesia methods were administered in addition to maintenance methadone. Fourteen patients (16.5%) had difficult intravenous access and seven “arrest” calls were documented. One anaesthetist was exposed to hepatitis C. This review demonstrates the demands placed on obstetric anaesthetic services by opioid-dependent women. Early antenatal referral for anaesthetic review is recommended.
Safe Duration of Postoperative Monitoring for Malignant Hyperthermia Susceptible Patients
Authors: Pollock N. , Langton E. , Stowell K. , Simpson C. , McDonnell N.
Published: January 2019

Postoperative management of malignant hyperthermia (MH) susceptible patients has changed substantially over the last 20 years, with many patients now managed as day cases. Our previous policy was to monitor known MH susceptible patients (and relatives of known MH susceptible individuals not yet investigated by muscle biopsy) for four hours in the Post Anaesthetic Care Unit. However, anaesthetic literature reports suggest that MH reactions usually commence within one hour of anaesthesia. For this reason we conducted a retrospective review of Post Anaesthetic Care Unit data in 254 MH susceptible/related patients treated between 1991 and late 2000. On the basis of this review we instituted a policy change and reduced our monitoring time to one hour in the Post Anaesthetic Care Unit with a further 1.5h in a step-down unit if indicated. A prospective study in a further 68 MH susceptible/related patients showed that no MH reactions were missed due to the shorter monitoring period.
Anaesthetic Management of Planned or Emergency Endovascular Stent Graft Surgery for Thoracic Aneurysms and Dissections
Authors: See J. J. , Lee C. W. , Lew T. W. K.
Published: January 2019

We reviewed the intraoperative anaesthetic management and outcome of seven consecutive cases of endovascular stent graft surgery for thoracic aortic aneurysms or dissections over a period of 20 months in our institution. Seven males (median age 63) underwent endovascular stent graft surgery of the thoracic aorta under general anaesthesia. Four were emergency procedures for acute dissection or leaks of thoracic aneurysms. The duration of the procedures ranged from 120 to 300 minutes. Intraoperative stent migration occurred in one patient. Induced hypotension and immobilization were critical during stent deployment. Six out of the seven patients were discharged home between three to 20 days postoperatively. There was no 30-day mortality. One patient died sixty days postoperatively. Anaemia and respiratory complications were the most common postoperative problems encountered. None of the patients sustained spinal cord ischaemia, acute myocardial infarction or renal impairment. Endovascular stent graft surgery of the thoracic aorta is a relatively new alternative to conventional open surgery. Our experience suggests satisfactory short-term outcome even for patients with acute dissection. However, long-term survival and results require further evaluation.