Using post-grazing sward height to impose dietary restrictions of varying duration in early lactation: its effects on spring-calving dairy cow production.

The objective of this study was to investigate the immediate and carryover effects of imposing two post-grazing sward heights (PGSH) for varying duration during early lactation on sward characteristics and dairy cow production. The experiment was a randomised block design with a 2×2 factorial arrangement of treatments. A total of 80 spring-calving (mean calving date - 6 February) dairy cows were randomly assigned, pre-calving, to one of the two (n=40) PGSH treatments - S (2.7 cm) and M (3.5 cm) - from 13 February to 18 March, 2012 (P1). For the subsequent 5-week period (P2: 19 March to 22 April, 2012), half the animals from each P1 treatment remained on their treatment, whereas the other half of the animals switched to the opposing treatment. Following P2, all cows were managed similarly for the remainder of the lactation (P3: 23 April to 4 November, 2012) to measure the carryover effect. Milk production, BW and body condition score were measured weekly, and grass dry matter intake (GDMI) was measured on four occasions - approximately weeks 5, 10, 15 and 20 of lactation. Sward utilisation (above 2.7 cm; P1 and P2) was significantly improved by reducing the PGSH from 3.5 (0.83) to 2.7 cm (0.96). There was no effect of PGSH on cumulative annual grass dry matter (DM) production (15.3 t DM/ha). Grazing to 2.7 cm reduced GDMI by 1.7 and 0.8 kg DM/cow in P1 and P2, respectively, when compared with 3.5 cm (13.3 and 14.0 kg/cow per day, respectively). Cows grazing to 2.7 cm for both P1 and P2 (SS) tended to have reduced cumulative 10-week milk yield (-105 kg) and milk solids yield (-9 kg) when compared with cows grazing to 3.5 cm for both periods (MM; 1608 and 128 kg/cow, respectively). Treatments that alternated PGSH at the end of P1, SM and MS had intermediate results. There was no interaction between P1 and P2 treatments. There was also no carryover effect of early lactation grazing regime on milk and milk solids production in P3, given the reduction in early lactation milk yield. The results indicate that the diet of dairy cows should not be restricted by imposing a severe PGSH for all of the first 10 weeks of lactation, cows should graze to 3.5 cm for at least 5 of these weeks.

The aetiology and prevention of peri-operative corneal abrasions.

Corneal abrasion is the most frequent ocular complication to occur during the peri-operative period. This review describes the aetiology of corneal abrasions and evaluates the current methods of prevention. Most abrasions are caused by lagophthalmos (failure of the eyelids to close fully) during general anaesthesia, resulting in corneal drying. General anaesthesia reduces both the production and the stability of tears and therefore increases the incidence of this painful condition. Taping the eyelids closed, soft contact lenses, the instillation of aqueous gels or paraffin-based ointments are all effective in preventing corneal abrasions, but ointments are associated with significant morbidity.

A study of the incorrect use of ventilator disconnection alarms.

Pressure-sensitive ventilator disconnection alarms may fail to function correctly when used with discharging compliance ventilators such as the Manley Blease. The increase in gas flow on disconnection generates raised pressure owing to the resistance provided by components of the breathing system. Thirty-four anaesthetists, who were unaware of the nature of the survey, were observed to see if previous recommendations for the correct adjustment of the ventilator alarm were being followed. It was found that 77% of alarms were incorrectly adjusted and would not have alarmed in the event of a true disconnection occurring.

Availability and appropriateness of allogeneic bone marrow transplantation for chronic myeloid leukemia in 10 countries.

BACKGROUND: Allogeneic bone marrow transplantation, a sophisticated and expensive procedure, is the only curative therapy for chronic myeloid leukemia (CML). We examined the availability and appropriateness of allogeneic bone marrow transplantation for CML in 10 economically advanced countries with diverse health care systems. For each country we obtained data on the likelihood of transplantation to treat CML in patients under the age of 55 years, the length of time from diagnosis to transplantation, and the stage of disease at the time of transplantation. METHODS: Data were collected on 9873 allogeneic bone marrow transplantations performed at 208 centers in 10 countries from 1989 through 1991. Data were acquired from transplantation registries and by means of a mailed survey of all centers and teams that did not contribute data to registries. Data on the incidence of disease were drawn from national and regional cancer registries. RESULTS: Among the 10 countries there was a twofold difference between the lowest and highest rates of transplantation to treat CML (0.26 to 0.54 per 100,000 population per year); Swedish patients were the most likely to receive a transplant, and German patients the least likely. The median length of time from diagnosis to transplantation ranged from 6.8 to 15.4 months. In all countries, most transplantations were performed in the chronic phase of the disease, but as many as a third of patients received transplants in the less favorable accelerated or blast phase. The values for the United States fell near the middle of those for the 10 countries on all measures. CONCLUSIONS: Our findings challenge the assumption that the United States is unique in providing broad access to high-technology treatments. On no measure of the availability or appropriateness of transplantation for CML did it surpass the other nine countries studied.

Non-invasive monitoring of cardiac output changes during aortic cross-clamping for infrarenal reconstruction--a new technique using suprasternal Doppler-derived cardiac output.

There is a significant morbidity and mortality associated with elective infrarenal aortic reconstruction. To examine the value of continuous cardiac output monitoring for predicting those at risk, 40 consecutive patients were monitored using Doppler-derived cardiac output. The anaesthetist was blind to all information from the monitor and managed the patients using standard techniques. In 28 patients there were no observed changes, while in seven, cardiac output rose after aortic cross-clamping. In five patients a fall in cardiac output occurred after cross-clamping. No cardiac events or cardiac deaths occurred in the 35 patients who showed a rise or no change in cardiac output. However, there were three cardiac events, including one cardiac death in the group of five patients in whom a fall in cardiac output was observed. It would appear that intraoperative non-invasive Doppler-derived cardiac output monitoring successfully predicts high-risk patients who would perhaps benefit from more intensive pre-, peri- and postoperative care.

Postoperative analgesia for haemorrhoidectomy. A comparison between caudal and local infiltration.

This study compared the analgesic effectiveness of local infiltration of bupivacaine with caudal extradural bupivacaine in the first 48 hours after haemorrhoidectomy. Surgical and anaesthetic protocol was rigidly standardised. The caudal group had significantly less pain in the first 6 hours after haemorrhoidectomy, and on first bowel opening, when compared to those who received local infiltration of bupivacaine. There was no significant difference between the two groups with respect to further analgesic requirements, complications, time to first bowel action, and duration of hospital stay. The definite advantage of caudal extradural bupivacaine for haemorrhoidectomy must be balanced against the rare but potentially serious complications associated with its use.

Ventilator disconnexion alarm failures. The role of ventilator and breathing system accessories.

Pressure-sensitive ventilator disconnexion alarms do not always alarm during disconnexion of a discharging compliance ventilator such as Manley Blease, unless accurately adjusted. High flows during disconnexion result in significant pressure generation caused by outflow resistance of catheter mounts, heat and moisture exchangers, capnometer cuvettes, and angled connectors; this may lead to alarm failure because of incorrectly adjusted pressure alarm limits. The exact position of the disconnexion is critical and if the alarm's pressure sensor is placed in either the inspiratory or expiratory limb of the ventilator it makes no difference to its correct function. Nine different heat and moisture exchanges were compared in the same breathing system. Those with 15-mm male connectors generate the highest pressures on disconnexion (1.1 kPa). It is suggested that the low pressure alarm limit is set only marginally below the peak inspiratory pressure, and that it is readjusted for every patient and after every change in ventilation. Most importantly, the alarm should be shown to be functional by a trial disconnexion at the tracheal tube.

A plea for noradrenaline.

Hypotension induced by nifedipine and chlorpromazine is discussed, together with the role of noradrenaline in the correction of this problem, which was resistant to other forms of therapy.

Ischaemic pain in Buerger's disease. Report of a female patient receiving long-term local analgesia.

A female patient with Buerger's disease developed severe ischaemic pain in her left index finger which was refractory to several therapeutic measures. A silastic catheter inserted in the region of the median nerve at the elbow was topped up intermittently with local anaesthetic for 6 weeks and effected excellent analgesia. The catheter was removed when the pain had abated, and the finger tip later amputated.

Anaesthetic problems in cross clamping of the thoracic aorta.

Cross clamping of the descending thoracic aorta is performed in this hospital for graft replacement of suprarenal aneurysms or during endarterectomy for extensive aortic occlusive disease. The anaesthetic management of nine patients is described and the surgical results are presented. Proximal aortic clamping and declamping lead to profound haemodynamic changes. Myocardial infarction, ventricular failure and even death may result. Renal preservation during clamping and massive blood transfusion are also problems of this surgical approach. The measures taken to ameliorate the consequences of proximal aortic clamping are discussed in detail.