bluuebunny/crossref_metadata_2025_split huggingface dataset:
Systemic Anticoagulant Effect of Low-Dose Subcutaneous Unfractionated Heparin as Determined Using Thrombelastography
Authors: Matzelle S. J. , Gibbs N. M. , Weightman W. , Sheminant M. , Rowe R. , Baker S. 
Published: January 2019

In an observational study using heparinase-modified thrombelastography, we investigated the percentage of elective cardiothoracic surgical patients receiving low-dose unfractionated heparin (5000 IU 12 hourly subcutaneously) who had a demonstrable systemic heparin effect. Blood samples were obtained at induction from 40 adult elective cardiothoracic surgical patients who had received 5000 IU unfractionated heparin subcutaneously within six hours. Simultaneous kaolin and heparinase-modified thrombelastographies were run on all samples. Fourteen patients (35%; 95% CI: 20 to 50%) had a demonstrable heparin effect(defined as a kaolin thrombelastography R time >25% longer than the heparinase-modified control). Their mean±SD kaolin thrombelastography R time was 13.6±5.9 minutes (normal range 4 to 8 minutes) vs. 7.1±2.0 minutes for the heparinase-modified controls. In 10 patients the thrombelastography R times were >50% longer and in four patients >100% longer, than their respective heparinase-modified controls. In a post hoc analysis, there was little correlation between the extent of the prolongation and patient age (r=0.02), weight (r=-0.31), preoperative creatinine (r=-0.17), or time since administration of heparin (r=0.14). These results indicate that about one third of patients who have received low-dose unfractionated heparin subcutaneously within six hours have a demonstrable heparin effect. The potential for this effect should be considered if central neural blockade is planned.
Airway Management Equipment in a Metropolitan Region: An Audit
Authors: Baker P. A. , Hounsell G. L. , Futter M. E. , Anderson B. J. 
Published: January 2019

Difficult airway equipment containers are commonly found in operating rooms, but the availability of airway equipment beyond that environment is unknown. Using the Difficult Airway Society (U.K.) and American Society of Anesthesiologists’ guidelines, we conducted an inspection audit of airway equipment at all anaesthetic sites in our region. Staff knowledge about the equipment was assessed and feedback was provided to each site. Eighteen of the 42 sites had an airway container. Equipment for an unexpected difficult intubation, according to the guidelines, was deficient at all sites. Equipment to detect oesophageal intubation was inadequate. Locations remote from the operating suite lacked emergency invasive airway equipment and were, on average, a 4.3 minute walk from the nearest appropriate equipment. Two clinics had no emergency invasive airway equipment. Half of the airway containers with check lists had items missing. One third of the items with an expiry date were expired. Quality control and implementation of airway guidelines could rectify these deficiencies. Anaesthesia organisations should be encouraged to publish detailed equipment guidelines.
Difficult Decisions in the Intensive Care Unit: An Illustrative Case
Authors: Freshwater-Turner D. A. , Boots R. J. , Bowman R. N. , Healy H. G. , Klestov A. C. 
Published: January 2019

Difficult clinical decision-making is a common experience in intensive care units. There is often considerable pressure on time and decisions may have to be made in a stressful environment. Patients in the intensive care unit not infrequently present with extreme or rare manifestations of a disease process. Clinical evidence to guide management of such patients may be incomplete, non-existent, or its relevance to the problem at hand may be questionable. In this context, formal decision-making analytical tools are often impractical. Unconscious cognitive biases have been shown to play an important role in medical decision-making, particularly in these settings. While mostly these contribute to doctors making appropriate and timely decisions, occasionally they lead to errors. Despite 30 years of research into models of clinical reasoning, most doctors are unaware of how biases affect their thinking and are unfamiliar with techniques of detecting and neutralising bias in clinical practice. We present the case of a patient with Wegener's granulomatosis, which highlights many of the difficulties outlined above. We review the clinical evidence for our decisions at each stage and explain the rationale for our choices, highlighting the many situations for which high quality evidence was lacking. Examples of cognitive bias are identified and techniques of metacognition (thinking about thinking) that can be useful in limiting the effects of bias on complex decision-making are reviewed. The intensivist's evaluation of management alternatives has an important role in steering medical management towards optimal patient outcomes.
Computerised Tomography for the Detection of Pulmonary Emboli in Intensive Care Patients—a Retrospective Cohort Study
Authors: Licht A. , Sibbald W. J. , Levin P. D. 
Published: January 2019

Pulmonary emboli are frequently considered as a cause for respiratory deterioration in intensive care unit (ICU) patients, however empirical observation suggests that computerised tomographic (CT) angiography is infrequently positive after the first 24 hours. This study aimed to determine the rate and risk factors for detection of pulmonary emboli by CT angiography in ICU patients. All patients undergoing CT angiography >24 hours after ICU admission for respiratory deterioration from April 2000 until January 2004 were included. The positivity rate for pulmonary emboli was determined and risk factors analysed. Seven (6%) out of 113 CT angiograms were positive for pulmonary emboli. All were found in trauma patients. Comparing positive to negative scans, predefined risk factors including head injury (5/7 positive scans, 71% vs. 23/106 negative scans, 22%, P=0.005), spine injury with neurological impairment (4/7, 57% vs. 9/106, 8%, P=0.002) and lower limb injury (3/7, 43% vs. 12/106, 9%, P=0.039) were significantly more frequent in patients with positive scans. Deep vein thrombosis prophylaxis was employed less frequently prior to a positive scan (in 3/7, 43% patients with positive scans vs. 91/106, 86% patients with negative scans P=0.015). Only the predefined risk factors were independently associated with positive CT angiography on limited logistic regression (OR 24.7 per risk factor, 95% CI 2.38 to 255.1, P=0.007). Pulmonary emboli were infrequently diagnosed using CT angiography in ICU patients admitted for more than 24 hours and found only in patients with recognised risk factors.
Hyperglycaemia upon Onset of Icu-Acquired Bloodstream Infection is Associated with Adverse Outcome in a Mixed Icu Population
Authors: Vandijck D. M. , Oeyen S. G. , Buyle F. M. , Claus B. O. , Blot S. I. , Decruyenaere J. M. 
Published: January 2019

This study aimed to assess whether a relationship exists between hyperglycaemia and outcome in a mixed cohort of critically ill patients with nosocomial bloodstream infection (BSI), and to evaluate patterns of blood glucose levels between survivors and non-survivors. A historical observational cohort study was conducted in the intensive care unit (ICU) of a tertiary care referral centre. One-hundred-and-thirty patients with a microbiologically documented ICU-acquired BSI (period 2003 to 2004) were included. For the study, morning blood glucose levels were evaluated from one day prior until five days after onset of BSI. The contribution of hyperglycaemia, divided in three subgroups (≥150 mg/dl, ≥175 mg/dl and ≥200 mg/dl), to in-hospital mortality was estimated by logistic regression. In-hospital mortality was 36.2%. Over the seven study days, no differences were found in daily morning blood glucose levels between survivors (n=83) and non-survivors (n=47). Nevertheless, the trend of blood glucose levels upon onset of BSI showed a remarkable increase in the non-survivors, whereas it decreased in the survivors. Hyperglycaemia (≥175 mg/dl and ≥200 mg/dl) was observed more often among the non-survivors. Multivariate logistic regression showed that APACHE II (P=0.002), antibiotic resistance (P=0.004) and hyperglycaemia (≥175 mg/dl) upon onset of BSI (P=0.017) were independently associated with in-hospital mortality, whereas a history of diabetes (P=0.041) was associated with better outcome. Hyperglycaemia (≥175 mg/dl) upon onset of ICU-acquired BSI is associated with worse outcome in a heterogeneous ICU population. Patterns of morning blood glucose levels have only limited value in the prediction of the individual course.
Pre-Existing Cardiac Disease, Troponin I Elevation and Mortality in Patients with Severe Sepsis and Septic Shock
Authors: Scott E. C. , Ho H. C. , Yu M. , Chapital A. D. , Koss W. , Takanishi D. M. 
Published: January 2019

A prospective, observational study was undertaken to determine the frequency of troponin I elevation and the incidence of pre-existing cardiac disease in patients with severe sepsis and septic shock, and to determine their relationship to mortality. The setting was the surgical intensive care unit of a tertiary care medical centre. Sixty-six consecutive patients admitted with severe sepsis or septic shock requiring pulmonary artery catheterisation for haemodynamic monitoring were studied. Measurement of troponin I was done at the time of pulmonary artery catheterisation and every six to eight hours if there was ongoing tachycardia, hypotension or arrhythmias requiring treatment. Preexisting cardiac disease was determined from the patient and/or family members as well as from the medical record. Significant cardiac history was defined as prior myocardial infarction; abnormal treadmill report, nuclear medicine study or coronary angiogram; history of congestive heart failure or arrhythmia requiring treatment. Forty-two patients (64%) had elevated troponin I at study entrance and 23 patients (35%) had pre-existing cardiac disease. History of cardiac disease was associated with reduced cardiac index and oxygen delivery, and a nearly three-fold increase in mortality (44% vs. 16%, P=0.03), irrespective of elevated troponin I levels. Troponin I elevation alone was not associated with increased mortality. We conclude that pre-existing cardiac disease and elevated troponin I are commonly found in surgical patients with severe sepsis and septic shock. In our study, pre-existing cardiac disease, and not troponin I elevation, was associated with increased mortality.
The Use of Epidural Analgesia in a New Zealand Tertiary Hospital before and after Publication of the Master Study
Authors: Werrett G. C. , Horton H. , Craig R. , French R. A. 
Published: January 2019

We audited the total number of perioperative epidural techniques performed at Christchurch Hospital, New Zealand, for three years, before and after The Lancet published the MASTER Anaesthesia Trial in 2002. We also looked specifically at the number of epidural anaesthetic and analgesic techniques performed in combination with general anaesthesia for colonic surgery over the same period. In both cases we found a statistically significant fall in epidural rate in the years after the publication (P<0.001). A subsequent survey of local specialist anaesthetists, who have worked throughout this period, revealed the majority (75%) were knowingly performing fewer epidural techniques and that the findings of the MASTER Anaesthesia Trial had influenced their decisions.
In Vitro Effects of Propofol on Gravid Human Myometrium
Authors: Thind A. S. , Turner R. J. 
Published: January 2019

The aim of this study was to evaluate the direct effect of propofol (di-isopropyl phenol) on the contractile properties of gravid human uterine muscle. Six specimens of uterine muscle were obtained from term parturients undergoing elective lower segment caesarean section. Small strips (1 × 2 x 12 mm) of muscle were prepared and suspended in an organ bath containing oxygenated Kreb's solution at 36.5°C. Following preparation, spontaneous regular contractions developed at a rate of one contraction every six to 10 minutes. Force of contraction was recorded continuously using an isometric tension transducer. Following baseline measurements, propofol was introduced into the bath at concentrations corresponding to 2 /μg/ml, 5 /μg/ml and 8 /μg/ml. The specimens were also exposed to intralipid in concentrations equivalent to that found in the 8 μ/ml solution of propofol to determine whether this additive influenced uterine contractility. Contractility (defined as area under the tension/time curve) was decreased to 89 ± 6.5% of control at 2 μg/ml 53±4.3% at 5 μ/ml and 45 ± 4.1% at 8 μg/ml. This decrease in contractility was statistically significant at concentrations >2 μg/ml. Intralipid did not significantly affect uterine contractility. The results of this study show that propofol decreases isolated human uterine muscle contractility in a dose-dependent manner.
Airway Assessment Based on a three Column Model of Direct Laryngoscopy
Authors: Greenland K. B. 
Published: January 2019

Airway assessment has remained a problematic area, largely due to the low sensitivities, specificities and/or positive predictive values of most bedside tests. In this paper, a structured overview of the common preoperative airway assessment tests is presented, based on a model for direct laryngoscopy that has been previously described. This model is composed of three columns: anterior, middle and posterior. The anterior column tests are classified into the assessment of volume and compliance of the submandibular space, the range of movement of the temporomandibular joints and the flexibility of the stylohyoid ligament. Reductions in volume of the anterior column may be absolute or relative. An absolute reduction may occur with shortening of either the incisor-hyoid distance, the temporomandibular joint-incisor distance or the temporomandibular joint-temporomandibular joint distance. A relative reduction may be seen with either prominent upper front incisors or large tongues. Testing of the middle column includes a history and physical examination of the upper respiratory system, imaging of the airway (such as X-ray, computed tomography scans and/or magnetic resonance imaging scans) and nasopharyngoscopy. The posterior column may be assessed by the range of movement of the neck, especially the range of extension of the occipito-atlanto-axial complex. By integrating common tests of the anterior, middle and posterior columns within this three-column model, the practitioner may be better positioned to understand the complexity of direct laryngoscopy in both normal and difficult airway scenarios.
Practice Patterns for Predicted Difficult Airway Management and access to Airway Equipment by Anaesthetists in Queensland, Australia
Authors: Zugai B. M. , Eley V. , Mallitt K. A. , Greenland K. B. 
Published: January 2019

A postal survey was conducted to investigate difficult airway management, training and equipment availability among Fellows of the Australian and New Zealand College of Anaesthetists in Queensland. The survey aimed to determine practise patterns for predicted difficult airways and investigate equipment availability. Participants were asked to nominate an induction method, intubation method and airway adjunct for each of the five difficult airway scenarios. The cases consisted of one elective and four emergency scenarios. Availability of difficult airway devices in their institution was also assessed, as well as demographics of practice and airway-related maintenance of professional standards participation. There were 454 surveys distributed and 250 returned (response rate 55%). Direct laryngoscopy and flexible fibreoptic intubation were the most commonly selected techniques for all five cases. Difficult intubation trolleys were available to 98% of responders. Certain types of equipment (such as fibreoptic bronchoscopes and cricothyroidotomy kits) were available less frequently in private institutions. We recommend a standardisation of difficult airway management equipment and an on-going training program to provide support for anaesthetists in all locations.
Patient- and Operator-Related Factors Associated with Successful Glidescope® intubations: A Prospective Observational Study in 742 Patients
Authors: Siu L. W. L. , Mathieson E. , Naik V. N. , Chandra D. , Joo H. S. 
Published: January 2019

The Glidescope® Video Laryngoscope (Glidescope, Verathon Medical, Bothell, WA, USA) is a relatively new intubating device. It has been proposed to be useful for securing both routine airways and those where direct laryngoscopy may be difficult. In this prospective observational study, data for 742 intubations using the Glidescope were collected to investigate whether four factors are associated with successful tracheal intubation at first attempt using the Glidescope: previous Glidescope experience, previous direct laryngoscopy experience, level of anaesthesia training and clinical airway assessment. The likelihood of successful tracheal intubation at first attempt using the Glidescope increased with increasing previous Glidescope experience. Similarly, success was more likely in airways that were assessed as normal compared with those where direct laryngoscopies were either predicted or known to be difficult. Subgroup analysis indicated 83% first attempt success by ‘experienced’ Glidescope users in patients with documented difficult direct laryngoscopies. This supports its use as an adjunct device for management of airways where direct laryngoscopies prove difficult. With regard to the level of anaesthesia training, only medical students were more likely to fail with the Glidescope. Success was not associated with previous experience in direct laryngoscopy. The lack of association with direct laryngoscopy experience and level of anaesthesia training (beyond student level) suggests that expertise with traditional airway tools is not necessary to become proficient with the Glidescope.
An Evaluation of P Wave Dispersion, QT, Corrected QT and Corrected QT Dispersion Intervals on the Electrocardiograms of Malnourished Adults
Authors: Hanci V. , Ayoğlu H. , Yurtlu S. , Yildirim N. , Okyay R. D. , Erdoğan G. , Sayin E. , Turan I. O. 
Published: January 2019

The aim of our study was to investigate P wave dispersion (Pwd), QT, corrected QT (QTc), QT dispersion (QTd) and corrected QT dispersion (QTcd) intervals in subjects with malnutrition diagnosed in the pre-anaesthetic assessment, compared to those without malnutrition. A total of 76 adult patients were included. Main diagnoses, anthropometric measurement, body mass index, electrocardiogram and serum sodium, potassium, chloride, magnesium and calcium levels were recorded for all patients. Pwd, QT and QTd intervals were measured on all electrocardiogram records and QTc and QTcd intervals determined with the Bazett formula. Protein-energy malnutrition was diagnosed with the nutritional risk index. No statistically significant difference was found between the age, gender and malignant cancer diagnosis rates between patients with malnutrition (group M) and those not suffering from malnutrition (group N) (P >0.05). Serum albumin, total protein, potassium, calcium, magnesium and chloride values of group M were found to be significantly lower than group N (P <0.05). In group M, Pwd, QT, QTc, QTd and QTcd intervals were significantly longer than in group N (P <0.001). Patients diagnosed with malnutrition during pre-anaesthetic assessment had significantly longer Pwd, QTc and QTcd interval durations than the control group. We attribute such extended Pwd, QTc and QTcd durations in these patients to malnutrition and malnutrition-related electrolyte imbalance.
Magnesium Sulphate for Treatment of Tetanus in Adults
Authors: Mathew P. J. , Samra T. , Wig J. 
Published: January 2019

There are reports that suggest that magnesium sulphate alone may control muscle spasms thereby avoiding sedation and mechanical ventilation in tetanus, but this has not been confirmed. We examined the efficacy and safety of intravenous magnesium sulphate for control of rigidity and spasms in adults with tetanus. A prospective clinical study of intravenous magnesium sulphate was carried out over a period of two years in a tertiary care teaching hospital. In addition to human tetanus immunoglobulin and parenteral antibiotics, patients with tetanus received magnesium sulphate 70 mg/kg intravenously followed by infusion. The infusion was increased by 0.5 g/hour every six hours until cessation of spasms or abolishment of patellar tendon jerk. The primary outcome measure was efficacy determined by control of spasms. Secondary outcomes included frequency of autonomic instability, duration of ventilatory support, hospital stay and mortality. Thirty-three patients were enrolled. At presentation, the incidence of severity of tetanus was as follows: Grade I: 5 (15%), Grade II: 13 (39%), Grade III: 14 (42%) and Grade IV: 1 (3%). Rigidity and mild spasms were controlled with magnesium therapy alone in six patients; all were Grades I or II. Additional sedatives were required in severe forms of tetanus. The average duration of ventilatory support was 18.3±16.0 days and the overall mortality was 22.9%. Asymptomatic hypocalcaemia was a universal finding. Magnesium sulphate therapy alone may not be efficacious for the treatment of severe tetanus.
Bedside Percutaneous Tracheostomy: A Prospective Randomised Comparison of PercuTwist® versus Griggs’ Forceps Dilational Tracheostomy
Authors: Montcriol A. , Bordes J. , Asencio Y. , Prunet B. , Lacroix G. , Meaudre E. 
Published: January 2019

Tracheostomy is considered the airway management of choice for patients who require prolonged mechanical ventilation. The development of percutaneous techniques offers many advantages including the ability to perform the procedure in the intensive care unit. The aim of this study was to compare the controlled rotating dilation method (PercuTwist®) and the Griggs’ forceps dilational tracheostomy. Patients over 18 years of age undergoing tracheostomy in the intensive care unit were included in the study. They were divided in two random samples – either PercuTwist or forceps dilational tracheostomy. Data collected prospectively included demographic characteristics, procedure duration, blood gas analysis, intracranial pressure, arterial blood pressure and heart rate before and after the procedure. Any complications during or after the procedure due to the tracheostomy were also recorded. Contrary to the main hypothesis, PercuTwist technique took significantly longer to perform than forceps dilational tracheostomy technique (five minutes [2 to 25] vs three minutes [1 to 17][P=0.006]). A significant increase in PaCO2 and decrease in arterial pH were observed in both groups between the pre-tracheostomy and post-tracheostomy blood gas analysis. Haemodynamic tolerance was good. Our results show that intracranial pressure is affected by the procedure whatever the technique used. However we did not observe a decrease in cerebral perfusion pressure. The incidence of complications was 23% (20/87). These complications were minor in 18/20 and were not significantly different between the two groups. In conclusion, we consider that the PercuTwist technique is safe despite the longer duration of the procedure. Nevertheless the forceps dilational technique remains our routine procedure.