bluuebunny/crossref_metadata_2025_split huggingface dataset:
Opioids, Ventilation and Acute Pain Management
Authors: Macintyre P. E. , Loadsman J. A. , Scott D. A. 
Published: January 2019

Despite the increasing use of a variety of different analgesic strategies, opioids continue as the mainstay for management of moderate to severe acute pain. However, concerns remain about their potential adverse effects on ventilation. The most commonly used term, respiratory depression, only describes part of that risk. Opioid-induced ventilatory impairment (OIVI) is a more complete term encompassing opioid-induced central respiratory depression (decreased respiratory drive), decreased level of consciousness (sedation) and upper airway obstruction, all of which, alone or in combination, may result in decreased alveolar ventilation and increased arterial carbon dioxide levels. Concerns about OIVI are warranted, as deaths related to opioid administration in the acute pain setting continue to be reported. Risks are often said to be higher in patients with obstructive sleep apnoea. However, the tendency to use the term ‘obstructive sleep apnoea’ to encompass the much broader spectrum of sleep- and obesity-related hypoventilation syndromes and the related misuse of terminology in papers relating to obstructive sleep apnoea and sleep-disordered breathing remain significant problems in discussions of opioid-related effects. Opioids given for management of acute pain must be titrated to effect for each patient. However, strategies aiming for better pain scores alone, without highlighting the need for appropriate monitoring of OIVI, can and will lead to an increase in adverse events. Therefore, all patients must be monitored appropriately for OIVI (at the very least using sedation scores as a ‘6th vital sign’) so that it can be detected at an early stage and appropriate interventions triggered.
The Influence of Objective Prognostic Information on the Likelihood of Informed Consent for Decompressive Craniectomy: A Study of Australian Anaesthetists
Authors: Honeybul S. , O'Hanlon S. , Ho K. M. , Gillett G. 
Published: January 2019

The aim of this study was to assess the influence of detailed prognostic information on the likelihood of informed consent for decompressive craniectomy for severe traumatic brain injury. The study was a simulation exercise, asking anaesthetists to give opinions as if they themselves were the injured party. Anaesthetists were chosen as they represent a distinct group likely to be familiar with the procedure and the decision-making process, but not necessarily aware of the longer-term outcomes. A two-part structured interview was used. Seventy-five anaesthetists were shown three cases of differing severity of traumatic brain injury. A visual analogue scale (1 to 10) was used to assess the strengths of their opinion. Initially they were asked their opinion with no predictive outcome data. They were then shown the prediction of an unfavourable outcome (Glasgow Outcome Scale severely disabled, vegetative state or dead) and the observed outcome at 18-month follow-up from a cohort of 147 patients (who had had a decompressive craniectomy for severe traumatic brain injury in Perth, Western Australia between the years 2004 and 2008). The opinions of the participants before and after seeing the prediction outcome data were compared. The participants’ preferences to consent to the procedure changed after being informed of the predicted risks of unfavourable outcomes (P values <0.01). The changes in attitude appeared to be independent of age group, amount of experience in caring for similar patients and religious background. These findings suggest that access to objective information on risks of unfavourable outcomes may influence opinions in relation to consent for decompressive craniectomy for traumatic brain injury.
Acute Pain Management in Opioid-Tolerant Patients: A Growing Challenge
Authors: Huxtable C. A. , Roberts L. J. , Somogyi A. A. , Macintyre P. E. 
Published: January 2019

In Australia and New Zealand, in parallel with other developed countries, the number of patients prescribed opioids on a long-term basis has grown rapidly over the last decade. The burden of chronic pain is more widely recognised and there has been an increase in the use of opioids for both cancer and non-cancer indications. While the prevalence of illicit opioid use has remained relatively stable, the diversion and abuse of prescription opioids has escalated, as has the number of individuals receiving methadone or buprenorphine pharmacotherapy for opioid addiction. As a result, the proportion of opioid-tolerant patients requiring acute pain management has increased, often presenting clinicians with greater challenges than those faced when treating the opioid-naïve. Treatment aims include effective relief of acute pain, prevention of drug withdrawal, assistance with any related social, psychiatric and behavioural issues, and ensuring continuity of long-term care. Pharmacological approaches incorporate the continuation of usual medications (or equivalent), short-term use of sometimes much higher than average doses of additional opioid, and prescription of non-opioid and adjuvant drugs, aiming to improve pain relief and attenuate opioid tolerance and/or opioid-induced hyperalgesia. Discharge planning should commence at an early stage and may involve the use of a ‘Reverse Pain Ladder’ aiming to limit duration of additional opioid use. Legislative requirements may restrict which drugs can be prescribed at the time of hospital discharge. At all stages, there should be appropriate and regular consultation and liaison with the patient, other treating teams and specialist services.
Prophylactic Use of Midazolam or Propofol at the End of Surgery May Reduce the Incidence of Emergence Agitation after Sevoflurane Anaesthesia
Authors: Kim Y. H. , Yoon S. Z. , Lim H. J. , Yoon S. M. 
Published: January 2019

Sevoflurane is associated with a high incidence of emergence agitation in children. Midazolam and propofol have been examined with the aim of reducing emergence agitation after sevoflurane anaesthesia. However, the effect of both drugs on emergence agitation is still controversial. Therefore we designed this study to measure the effect of midazolam or propofol at the end of surgery on emergence agitation during the recovery period. One hundred and one children, aged one to 13 years, undergoing strabismus surgery were enrolled in this randomised double-blind study. Anaesthesia was induced and maintained with sevoflurane in N2O/O2. Children were randomly assigned to receive midazolam 0.05 mg/kg (group M, n=35), propofol 1 mg/kg (group P, n=31) or saline (group S, n=35). A four-point scale was used to evaluate recovery characteristics upon awakening and during the first hour after emergence from anaesthesia. The incidence of emergence agitation in group M was 42.9% (15/35), in group P 48.4% (15/31) and in group S 74.3% (26/35). The incidence of emergence agitation in groups M and P was significantly less than in group S. The emergence time was prolonged for patients in groups M and P compared to group S. There was no significant difference in the incidence of emergence agitation or in emergence times between the groups P and M. We conclude that propofol or midazolam administration before the end of surgery may be effective in reducing the incidence of emergence agitation in children undergoing strabismus surgery under sevoflurane anaesthesia.
Single Level Paravertebral versus Caudal Block in Paediatric Inguinal Surgery
Authors: Tug R. , Ozcengiz D. , Güneş Y. 
Published: January 2019

Paravertebral block (PVB) has been used for postoperative analgesia in children since 1992. There are no prospective randomised studies comparing the use of PVB versus caudal block (CB) for outpatient inguinal hernia repair surgery. The hypothesis of this study is that a single level, single injection PVB can provide a longer duration of analgesia and less requirement for supplemental analgesia than single shot CB for children undergoing inguinal surgery. Seventy children, aged three to seven, American Society of Anesthesiologists score I to II, having unilateral inguinal surgery were enrolled in the study. The patients were divided into two randomised groups. In group PVB, a single shot of 0.2 ml/kg levobupivacaine was administered via the lumbar paravertebral route and in group CB, patients were given 1 ml/kg levobupivacaine caudally. Sevoflurane concentration was evaluated after induction and recorded during incision, sac traction and closure. Face, legs, activity, cry and consolability (FLACC) scores, heart rate, blood pressure and SpO2 were evaluated postoperatively. Only four (11.4 %) patients in the PVB group needed rescue analgesic drugs compared to 12 (34.3%) patients in the CB group (P=0.044). Patients were given tramadol as rescue analgesia in the first four postoperative hours. No other supplemental analgesic drug was given apart from tramadol. FLACC scores were the same in the both groups. Parental satisfaction was significantly higher in the PVB group compared to the CB group (74.3 vs 40%, P=0.01). This study has demonstrated that a single level single injection paravertebral block provides superior intraoperative and postoperative analgesia when compared to a caudal block for unilateral inguinal hernia repair.
‘Safe’ Methaemoglobin Concentrations are a Mortality Risk Factor in Patients Receiving Inhaled Nitric Oxide
Authors: Rolley L. , Bandeshe H. , Boots R. J. 
Published: January 2019

Inhaled nitric oxide (iNO) can reduce pulmonary arterial hypertension and improve oxygenation in some patients with severe respiratory or heart failure. Despite this, iNO has not been found to improve survival. This study aimed to perform a local practice audit to assess the mortality predictors of critically ill patients who had received iNO as therapy for pulmonary hypertension and respiratory or heart failure. A retrospective audit in a single tertiary centre intensive care unit of patients receiving iNO was conducted between 2004 and 2009. The indications for iNO use, comorbidities, severity of illness, organ function, oxygenation, Sequential Organ Failure Assessment scores, patterns of iNO use, adverse events and outcomes were reviewed. In 215 patients receiving iNO, improvement in oxygenation after one hour from iNO commencement did not predict either intensive care unit (P=0.36) or hospital (P=0.72) mortality. The independent risk factors for intensive care unit mortality were worsening Sequential Organ Failure Assessment scores within 24 hours of commencing iNO (adjusted odds ratio 1.07, 95% confidence interval 1.05 to 1.18), the Charlson Comorbidity Score (adjusted odds ratio 1.49, 95% confidence interval 1.16 to 1.91) and the peak methaemoglobin concentration in arterial blood while receiving iNO (adjusted odds ratio 2.67, 95% confidence interval 1.42 to 4.96). Inhaled nitric oxide as salvage therapy for severe respiratory failure in critically ill patients is not routinely justified. Increased methaemoglobin concentration during iNO therapy, even when predominantly less than 3%, is associated with increased mortality.
A Comparison of Three Minimally Invasive Cardiac Output Devices with Thermodilution in Elective Cardiac Surgery
Authors: Phan T. D. , Kluger R. , Wan C. , Wong D. , Padayachee A. 
Published: January 2019

This study compared the cardiac output responses to haemodynamic interventions as measured by three minimally invasive monitors (Oesophageal Doppler Monitor, the VigileoFlotrac and the LiDCOrapid) to the responses measured concurrently using thermodilution, in cardiac surgical patients. The study also assessed the precision and bias of these monitors in relation to thermodilution measurements. After a fluid bolus of at least 250 ml, the measured change in cardiac output was different among the devices, showing an increase with thermodilution in 82% of measurements, Oesophageal Doppler Monitor 68%, VigileoFlotrac 57% and LiDCOrapid 41%. When comparing the test devices to thermodilution, the kappa statistic showed at best only fair agreement, Oesophageal Doppler Monitor 0.34, LiDCOrapid 0.28 and VigileoFlotrac -0.03. After vasopressor administration, there was also significant variation in the change in cardiac output measured by the devices. Using Bland-Altman analysis, the precision of the devices in comparison to thermodilution showed minimal bias, but wide limits of agreement with percentage errors of Oesophageal Doppler Monitor 64.5%, VigileoFlotrac 47.6% and LiDCOrapid 54.2%. These findings indicate that these three devices differ in their responses, do not always provide the same information as thermodilution and should not be used interchangeably to track cardiac output changes.
Comparison of Fluid Compartments and Fluid Responsiveness in Septic and Non-Septic Patients
Authors: Sánchez M. , Jiménez-Lendínez M. , Cidoncha M. , Asensio M. J. , Herrero E. , Collado A. , Santacruz M. 
Published: January 2019

Our objective was to study the response to a fluid load in patients with and without septic shock, the relationship between the response and baseline fluid distributions and the ratios of the various compartments. A total of 18 patients with septic shock and 14 control patients without pathologies that increase capillary permeability were evaluated prospectively. We used transpulmonary thermodilution to measure the extravascular lung water index, intrathoracic blood volume index and pulmonary blood volume. For the measurement of the initial distribution volume of glucose, plasma volume and extracellular water, we used dilutions of glucose, indocyanine green and sinistrin respectively. Transpulmonary thermodilution and dilutions of glucose were repeated 75 minutes after the beginning of the fluid load.The patients in the septic group had higher volumes of extracellular water (median 295 vs 234 ml/kg, P <0.001), lower intrathoracic blood volume index (median 894 vs 1157 ml/m2, P <0.003), higher pulmonary permeability ratios (extravascular lung water/pulmonary blood volume) (P <0.003) and higher systemic permeability ratios (interstitial/plasma volume) (P <0.04). The intrathoracic blood volume index increase after fluid loading was lower in the septic group (10 vs 145 ml/m2). The pulmonary permeability ratios did not correlate with the systemic permeability ratios, and in the septic group, the percentage volume retained in the intrathoracic blood volumes after fluid loading did not correlate with the systemic permeability ratios. Septic shock can cause a redistribution of fluids. Fluid administration in these patients produced a minimal increase in intrathoracic blood volume, and the percentage of volume retained in this space was not correlated with the interstitial/plasma volume ratio.
Plasma Free Cortisol and B-Type Natriuretic Peptide in Septic Shock
Authors: Sturgess D. J. , Venkatesh B. 
Published: January 2019

Previous studies of patients with septic shock have independently demonstrated alterations in plasma concentrations of B-type natriuretic peptide and plasma free cortisol. Previous data suggest that a reciprocal relationship might exist. However, the relationship between these hormones in patients with septic shock is unclear. We sought to compare paired measurement of both B-type natriuretic peptide and plasma free cortisol in a study of septic shock patients. Twenty-one consecutive adult patients from a tertiary level, multidisciplinary intensive care unit underwent blood collection within 72 hours of developing septic shock. Mean±SD Acute Physiology and Chronic Health Evaluation III score was 80.1±23.8. Hospital mortality was 29%. Log plasma free cortisol demonstrated positive correlation with log B-type natriuretic peptide (r=0.55, P=0.019). Log plasma free cortisol also correlated with Acute Physiology and Chronic Health Evaluation III score (r=0.67, P P=0.01). Acute Physiology and Chronic Health Evaluation III (P=0.001) and noradrenaline dose (P=0.02) were independent predictors of plasma free cortisol. A model incorporating both variables explained 68% of variation in plasma free cortisol (R-square=0.682). This study of patients with septic shock demonstrates a previously unappreciated positive correlation between plasma free cortisol and b-type natriuretic peptide concentration. Acute Physiology and Chronic Health Evaluation III score and noradrenaline dose were independent predictors of plasma free cortisol.
A New Technique for Post-Pyloric Feeding Tube Placement by Palpation in Lean Critically Ill Patients
Authors: Sekino M. , Yoshitomi O. , Nakamura T. , Makita T. , Sumikawa K. 
Published: January 2019

Various techniques have been described for blind bedside placement of a post-pyloric feeding tube. However, there is no universal method and the technique depends on the local institutional resources and expertise. The purpose of this study was to evaluate a simple new technique for the bedside placement of a post-pyloric feeding tube in an intensive care unit using palpation to confirm tube position. We studied 47 consecutive ventilated patients (mean body mass index 22.4±4.2 kg/m2) requiring enteral tube feeding for nutritional support. We monitored the maximum intensity point of injected air ‘bubbling’ by palpation and estimated tube position. We monitored the movement of the maximum intensity point from the left upper quadrant to the right upper quadrant. If the maximum intensity point on the right upper quadrant diminished or weakened, we considered the tube had proceeded beyond the pylorus. By palpation, we could feel the bubbling of the injected air in all patients, but four patients were excluded because of failure to complete the protocol. The overall success rate including the four excluded cases was 85.1% (40/47) on the first attempt and 91.5% (43/47) when we included the second attempt. The median time for 40 successful tube placements on the first attempt was 10 (7 to 23) minutes. Our new palpation technique can successfully detect the position of a feeding tube in the stomach and help guide the tube to the correct location in the post-pyloric portion of the stomach in lean critically ill patients.
Histamine-Releasing and Allergenic Properties of Opioid Analgesic Drugs: Resolving the Two
Authors: Baldo B. A. , Pham N. H. 
Published: January 2019

Opioid analgesics are amongst the most commonly administered drugs in hospitals. Whether natural or synthetic, they show some common structural features, morphine-like pharmacological action and binding specificity for complementary opioid receptors. Tramadol differs from the other opioid analgesics in possessing monoaminergic activity in addition to its affinity for the μ opioid receptor. Many opioids are potent histamine releasers producing a variety of haemodynamic changes and anaphylactoid reactions, but the relationship of the appearance of these effects to the histamine plasma concentration is complex and there is no direct and invariable relationship between the two. Studies of the histamine-releasing effects, chiefly centred on morphine, reveal variable findings and conclusions often due to a range of factors including differences in technical measurements, dose, mode of administration, site of injection, the anatomical distribution of histamine receptors and heterogeneity of patient responses. Morphine itself has multiple direct effects on the vasculature and other haemodynamically-active mediators released along with histamine contribute to the variable responses to opioid drug administration. Despite their heavy use and occasional apparent anaphylactic-like side-effects, immunoglobulin E antibody-mediated immediate hypersensitivity reactions to the drugs are not often encountered. Uncertainties associated with skin testing with these known histamine-releasers, and the general unavailability of opioid drug-specific immunoglobulin E antibody tests contribute to the frequent failure to adequately investigate and establish underlying mechanisms of reactions by distinguishing anaphylactoid from true anaphylactic reactions. Clinical implications for diagnosis of reactions and some speculations on the rarity of true Type 1 allergies to these drugs are presented.
The Influence of Unrestricted Use of Sugammadex on Clinical Anaesthetic Practice in a Tertiary Teaching Hospital
Authors: Watts R. W. , London J. A. , van Wijk R. M. A. W. , Lui Y.-L. 
Published: January 2019

This retrospective casenote audit involving 374 patients requiring intubation for an anaesthetic found that when the availability of sugammadex became unrestricted, its use increased from 7.1 to 65.3% (P P=0.006) but vecuronium use increased (2.1 to 8.3%, P=0.02). Cisatracurium and suxamethonium use were unchanged. Total rocuronium dose (55.9±24.1 vs 60.4±22.3 mg) and the number of doses (1.9±1.48 to 1.96±1.27) were unchanged, but the time between the last dose and reversal decreased (91.7±68.1 to 62±52.4 minutes, P=0.0002). There appeared to be no change in postoperative nausea and vomiting, or post-anaesthesia care unit time or oxygen saturation levels. Anaesthetic theatre time fell from 143.5±85.8 to 120±71.2 minutes (P=0.01) and remained significant when adjusted for confounding variables (ratio of means 1.17, 95% confidence interval 1.03 to 1.34, P=0.02), although inferences in relation to causality are limited by the retrospective and observational design of the study. Hospital stay also appeared to fall (4.2±3.5 to 3.4±3.0 days, P=0.035), but was not statistically significant when adjusted for confounding variables (ratio of means 1.04, 95% confidence interval 0.89 to 1.2, P=0.59). These observations suggest that the unrestricted availability of sugammadex will change how steroid-based neuromuscular blocking drugs are used and reversed, but further research is needed to determine if patient outcomes will improve.
End-tidal Sevoflurane Concentration for ProSeal™ versus Classic™ Laryngeal Mask Airway Insertion in Unpremedicated Anaesthetised Adult Females
Authors: Ghai B. , Jain K. , Bansal D. , Bhatia N. 
Published: January 2019

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