Faecal egg counts in Australian pasture-based dairy herds.

In Australian pastoral dairy systems, a variety of 'routine' anthelmintic programs are used in lactating cows varying from nil anthelmintic use to bi-annual application. Anthelmintic resistance has been repeatedly diagnosed on dairy farms and studies have indicated variable milk production benefits from anthelmintics internationally. We aimed to identify the predominant gastrointestinal parasites in recently calved dairy cows in south-west Victoria and examined the relationship between individual faecal egg counts (FEC) and other cow and management factors such as body condition score, age, and historical anthelmintic use. This study included 18 pasture-based dairy farms in south-west Victoria. FECs were measured in recently calved primiparous and multiparous cows. Individual FEC tests with a minimum detectable FEC of 2.5 eggs per gram of faeces (epg) and group larval cultures were completed. Farm management data and cow information was recorded for data analysis with the Jamovi statistical package. Overall, 35% of all cows had FEC ≥ 2.5 epg (26% of multiparous and 45% of primiparous). Ostertagi ostertagi was the predominant gastrointestinal nematode in all cohorts. Cooperia pectinata or C. punctata were also present in mixed infestations alongside C. oncophora. Multiparous cows in low body condition score post calving (<4) were more likely to have a FEC of >5 epg. Faecal egg counts at a minimum detectable FEC of 2.5 epg are effective indicators of parasitism in recently calved primiparous and poorly conditioned multiparous dairy cows. Increasing the test sensitivity (minimum detectable count) of FECs from 10 epg to 2.5 epg resulted in increasing the overall positive FEC rate from 15% to 35%. Further investigation of sensitive FECs and their relevance to production along with the timing and value of anthelmintic use in dairy cattle is warranted.

Overview of the introduction of neuromuscular monitoring to clinical anaesthesia.

Muscle relaxants were introduced into clinical practice in the early 1940s. From 1949, assessments were being made of the efficacy of various agents in awake volunteers, usually the researchers themselves. From the early to mid 1950s, while interest in using muscle relaxants was keen, concern emerged in the surgical literature that there was a higher mortality rate seen in patients receiving muscle relaxants. In fairness, the major article highlighted lack of randomisation, bias and confounding variables but this was largely regarded as showing a toxicity associated with muscle relaxants. By 1961 the matter had been settled that muscle relaxants were not toxic but required careful management and administration. Perhaps fortuitously, measurement of the degree of muscle relaxation was introduced to clinical practice with the use of nerve stimulation. These were measured responses to single twitch stimulus or tetanic stimulation. In 1970, train-of-four ratio was introduced, then in 1981 post-tetanic count, and in 1989 double burst stimulation. This article reviews the introduction of these techniques.

Comparison of the Bonfils and Levitan optical stylets for tracheal intubation: a clinical study.

The Bonfils and Levitan FPS scopes are rigid fibreoptic stylets that may assist routine or difficult intubation. This study compared the effectiveness of each in patients with predicted normal airways when used by specialist anaesthetists with no prior experience using optical stylets. Twelve anaesthetists and 324 elective surgical patients participated. Six anaesthetists were randomised to first intubate 20 patients with the Levitan scope (Phase 1) followed by a further seven patients with the Bonfils scope (Phase 2). The other six participating anaesthetists undertook their first 20 intubations with the Bonfils (Phase 1), followed by seven intubations with the Levitan (Phase 2). Outcomes recorded were success rate, total time to intubation, number of attempts, ease of intubation score and incidence of complications. Overall failure rates were similar for the two scopes with 5.6% of patients not intubated after three attempts. Median total times to intubation were similar for the Levitan (44 seconds) and Bonfils (36 seconds) (P = 0.11). Participants using the Bonfils in Phase 1 had significantly higher chance of success on first attempt (73%) compared to Levitan users during Phase 1 (57%) (P = 0.008). These differences were not significant in the second phase and ease of intubation scores were similar for both scopes (P = 0.9). This study showed the two scopes were comparable but the high failure rate amongst novice users demonstrated the importance of familiarity and skill development prior to their introduction to a difficult airway cart.

Assessing the accuracy of self-reported height and weight in an elective surgical population in a Melbourne metropolitan hospital.

A Health Questionnaire serves as a screening form as part of our Hospital Preadmission process and is completed by all patients scheduled for elective surgery. We reviewed the completed Health Questionaires of 444 patients. Completion of the Health Questionnaire requires patients to record their height and weight. At the time of admission their actual height and weight was measured and recorded by nursing staff as part of the preoperative assessment. We compared their estimated body mass index (BMI) from self-reported height and weight, with their actual BMI calculated from height and weight measured upon admission. The measured BMI accorded well with that calculated from reported values and showed no systematic over- or under-reporting. Of 70 patients with a BMI greater than 35, only ten estimated their BMI less than 35 and only five of these had more than a two unit difference. Perioperative patients appear to be more accurate at providing height and weight than previously analysed non-patient groups. However there is not complete accuracy and some patients still provide unreliable information. Whether or not individual practitioners utilize BMI from self-reported height and weight will depend on the accuracy that they require for their purposes. Of note there was greater accuracy in prediction of height and weight than in the derived variable of BMI due to the calculations required.

Sevoflurane versus propofol for induction of anaesthesia for electroconvulsive therapy: a randomized crossover trial.

Propofol is often used to induce anaesthesia for electroconvulsive therapy. Some patients who receive propofol have fits of poor quality or inadequate duration despite increasing electroconvulsive therapy doses. Sevoflurane has been reported to exhibit pro-convulsant properties in some "at-risk" patients during anaesthesia for other procedures. The purpose of this study was to perform a randomized crossover trial in patients undergoing electroconvulsive therapy, comparing the effects on seizure parameters of propofol versus sevoflurane induction. Patients were randomly allocated to receive either sevoflurane or propofol for their first treatment. In the subsequent treatment the alternative agent was used. Patients in both treatment groups exhibited equally good fits, with those in the sevoflurane group having slightly better morphology, which is the most subjective of the parameters measured. The sevoflurane administrations were associated with slightly higher pulse rates and blood pressures. Sevoflurane provides a suitable alternative to propofol for anaesthesia in patients undergoing electroconvulsive therapy, although the slightly greater pulse rate rise and blood pressure rise should be considered in patients with ischaemic heart disease.

A comparison of carbon dioxide monitoring and oxygenation between facemask and divided nasal cannula.

The divided nasal cannula is a device recently released in Australia that couples oxygen delivery and end-tidal carbon dioxide (PETCO2) monitoring. This study compares the accuracy of PETCO2 measurements by the divided nasal cannula and those measured by a modified facemask (as currently used in this institution), with arterial partial pressure of carbon dioxide (PaCO2). In this crossover study, 30 patients who had arterial lines as part of their routine monitoring were given oxygen via nasal cannula and facemask preoperatively. The PETCO2 was measured with each device and a simultaneous PaCO2 and PaO2 measured after equilibration. The results demonstrate a significant difference between the PETCO2 as measured by each technique. The divided nasal cannula more accurately reflects PaCO2 (mean arterial to end expired gradient of 5 mmHg) and provides a more representative trace when compared to a traditional facemask system. Both methods provided adequate oxygenation.

A re-evaluation of the role of tracheostomy in Ludwig's angina.

Ten cases of Ludwig's angina that required surgical decompression in addition to intravenous antibiotic therapy are reviewed. The vocal cords were visualized in all ten patients following deep inhalational anesthesia to relieve trismus. Only one case required tracheostomy, which has previously been recommended as the treatment of choice for airway management; the other nine were intubated under direct vision.

Ludwig's angina. The anaesthetic management of nine cases.

We reviewed nine patients with Ludwig's angina who required surgical drainage over a 24-month period. This represents the largest series reported in world literature. All of these patients were managed successfully by a combination of tracheal intubation and early surgical intervention. None required tracheostomy, which is the previously recommended procedure of choice for airway management.