The history of anaesthetic mortality reporting.

Anaesthetists are acutely aware of the legal constraint of reporting to the coroner deaths in association with anaesthesia. The evolution of the office of the coroner in England is presented and the relationship with the discovery and evolution of anaesthesia is examined. The legal and medical climate in the 19th century is described, with some of the key participants named and their roles explained. The 19th century was an age of questioning and exploration, which led to the elucidation of the problems with chloroform and set the path for progress in monitoring in anaesthesia. Comments are made on the development of anaesthetic mortality reporting into its current system and some of the benefits flowing from it. The collaboration of the various state mortality committees in producing a triennial national report is an important way to ensure that the lessons of the past are kept in mind in the present. The author believes that mortality reporting, the analysis of data and the dissemination of information is a valuable field of research, monitoring and educational tool. Primum non nocere is particularly pertinent in anaesthesia.

Anaphylaxis to Haemaccel and cross reactivity to Gelofusin.

A recent change from Haemaccel to Gelofusin as the preferred colloid for resuscitation in our region caused us to review patients who were known to be allergic to Haemaccel. As Gelofusin and Haemaccel are both modified gelatine, it seemed likely that cross reactivity could occur. Two patients who had been diagnosed previously as having had anaphylactic reactions to Haemaccel were tested intradermally with dilutions of 1/100 of Haemaccel and Gelofusin. Both patients showed similar positive reactions to each agent. It appears that patients who are known to be allergic to Haemaccel are probably allergic also to Gelofusin. Both patients have been given new Medic Alert bracelets stating "Allergic to Haemaccel and Gelofusin".

Post partum subclinical hypocalcaemia and effects on ovarian function and uterine involution in a dairy herd.

Episodes of subclinical hypocalcaemia occurred in the first 6 weeks after calving in 6 out of 12 multiparous Friesian cows calving in the winter period and 7 out of 23 calving in the summer in a subtropical environment. In the winter calving group, there were significant (P< 0.05) decreases in mean plasma calcium concentrations (PTCa) on days 6, 27 and 36 after calving in those animals unable to maintain PTCa >2.0 mmol/L in the first 21 days. These cows had a significantly higher mean body weight and higher mean milk production than normocalcaemic cows. In the summer calving group, the seven cows with episodes of subclinical hypocalcaemia had significantly lower mean PTCa over periods of 21 and 60 days. Intervals until involution of the uterus were negatively (P< 0.05) correlated with mean PTCa over the first 21 and 30 days after calving in the winter and summer calving groups (r = -0.62 and -0.42), respectively. The mean size of the first ovulated follicles was significantly smaller in cows showing episodes of subclinical hypocalcaemia in the winter group and the mean number of ovulatory size follicles was less in these cows at 15 days (P< 0.001) (1.2 +/- 0.17 vs 2.3 +/- 0.21) and at 30 days (P< 0.03) (3.5 +/- 0.43 vs 5.2 +/- 0.54). During the first three dioestrus periods, mean plasma progesterone concentration as a function of corpus luteum area was significantly lower (P< 0.05) in the cows with episodes of subclinical hypocalcaemia in the winter group.

Evaluation of the effect of ketoprofen on experimentally induced ephemeral fever in dairy heifers.

OBJECTIVE: To evaluate ketoprofen for the therapy of ephemeral fever. DESIGN: A blind controlled clinical trial. ANIMALS: Sixteen cattle (one immature Holstein bull, eight Holstein and seven Jersey heifers). PROCEDURE: Ephemeral fever was induced by the intravenous injection of blood leucocyte layer from a clinical case. Ketoprofen solution or a coded placebo was injected intramuscularly at the rate of 3 mg/kg daily for three days. RESULTS: Ketoprofen reversed locomotor dysfunctions significantly compared with controls, but did not have any effect on rectal temperatures, leucocyte counts, plasma fibrinogen concentrations, ionised Ca-concentrations or the presence of dyspnoea. CONCLUSION: Ketoprofen is a safe and effective drug for the treatment of locomotor symptoms of milk fever, but has no effect on the duration of clinical respiratory abnormalities.

Attitudes of veterinarians to undergraduate education in genetics and the use of genetics veterinary occupations.

A questionnaire regarding attitudes to undergraduate education in genetics and the subsequent use of that education was sent to 1000 veterinarians registered in New South Wales. Three hundred replies to the questionnaire were received and analysed. No significant difference in the perceived adequacy of courses at the four universities involved in teaching veterinary science was observed. Opinions on adequacy of education in genetics were not affected by age, sex or years since graduation. The major reason cited for lack of adequacy was that undergraduate genetics courses were not practical. Only 17 respondents stated that they were never approached for information on genetics or animal breeding, while 76 were approached more than 20 times annually for information. Eighty-three respondents claimed to deal with more than 20 cases annually that required some knowledge of genetics. The results of the questionnaire highlight the importance of genetics instruction in undergraduate veterinary education. The questionnaire responses also provide insight into how working veterinarians consider that courses in genetics could be improved.

Medical pregnancy termination in the presence of a massive uterine fibroid.

Surgical termination of pregnancy in the presence of uterine fibroids may be technically difficult resulting in reduced efficacy of the termination procedure. We describe the first documented use of RU486 and gemeprost in the successful medical termination of a pregnancy in a uterus grossly enlarged by fibroids.

Responses of calves to injections of ACTH and their relationship with growth rate.

A study was made of the effects of exogenous adrenocorticotropin (ACTH) on the levels of blood components in 109 dairy replacement calves and the statistical correlations between these effects and the growth rates of the calves from birth to six months. Blood samples were taken from a jugular vein before ACTH was injected and then at two, four, six and eight hours afterwards, and analysed for plasma cortisol concentration, total white cell counts, packed cell volume, haemoglobin, plasma glucose, sodium, potassium, magnesium and inorganic phosphorus, erythrocyte sodium, potassium and magnesium, serum ionised calcium and total protein and total plasma calcium concentration. The injection of 1.1 +/- 0.02 iu/kg of ACTH intramuscularly resulted in a peak plasma cortisol concentration after two hours which had not returned to normal after eight hours. It also resulted in leucocytosis, lymphopenia, neutrophilia, eosinopenia and hypophosphataemia; the mean changes were repeatable (P < 0.05) in 49 of the calves tested two months later. The weight gains to six months of age could be predicted from the degree of the changes in several blood constituents. Significant partial regression coefficients were found for the change in glucose concentration (0 to four hours), absolute neutrophil count (0 to two hours), absolute lymphocyte count (0 to four hours) and loge absolute eosinophil count (0 to two hours). The multiple regression sum of squares was highly significant (P < 0.0001), and the multiple coefficient of determination was 0.305. It was concluded that the changes in these blood components after an injection of ACTH might be used to predict the weight gains of dairy replacement calves.

Limitations to the effectiveness of subcutaneous calcium solutions as a treatment for cows with milk fever.

Serum calcium concentrations were determined in 164 cases of milk fever (mostly Jersey cows) attended in the course of practice in a cold, wet winter rainfall area where the cows calved at pasture. The mean calcium concentration of the cows receiving no calcium therapy subcutaneously before sampling (1.0 mmol/litre) was significantly (P < 0.01) less than the mean of 1.4 mmol/litre for cows receiving 300 ml of 33.3 or 40 per cent calcium borogluconate solution, which was significantly (P < 0.01) less than the mean of 2.1 mmol/litre for those receiving 600 ml subcutaneously. Neither the rectal temperature of the cows nor the average time interval between the injection of the two bottles and blood sampling had any effect on the serum calcium of the latter cows, whereas the rectal temperature but not the time interval had a significant (P < 0.01) effect on the serum calcium of the cows receiving 300 ml; the lower their temperature, the lower the calcium concentration. The mean (+/- sd) interval between treatment by the herdsman and veterinary attention for the cows receiving 300 ml (4.8 +/- 4.9 hours was significantly (P < 0.01) shorter than for the cows receiving 600 ml (12.0 +/- 9.4 hours). At the time of sampling, 48 per cent of the cows receiving 600 ml of calcium borogluconate solution had a serum calcium concentration below 2.0 mmol/litre.

Blood pathophysiological changes in sheep following a prolonged (18-hour) period of hypocalcaemia induced by Na2EDTA solution.

Six aged Merino ewes were used in an experiment in which five were infused with 4.7% Na2EDTA solution intravenously for 18 h at a rate designed to produce hypocalcaemia and maintain recumbency, and five with 0.9% sodium chloride solution at the same rate for the same period (four were infused at different times with both solutions). Blood samples were collected every 3 h and determinations made of plasma Ca, Na, K, Mg, and inorganic P (PiP), erythrocyte Na, K and Mg, and PCV. Three of the hypocalcaemic sheep took 36-64 h to regain their feet. Plasma Ca and K, and erythrocyte Na showed significant (all P less than 0.01) decreases in the group infused with Na2EDTA compared with the group infused with saline while PCVs were significantly (P less than 0.01) greater in the former group. The sheep model used could be suitable for the study of the effects of prolonged hypocalcaemia and recumbency in cows.

A study on the effects of the rapid intravenous infusion of hypertonic Na and K solutions into normal conscious sheep on some cardiac characteristics and blood analytes.

Five normal, conscious, aged Merino ewes were infused with 200 ml of an aqueous solution containing 5% NaCl and 0.25% KCl (HNaK) at a mean rate of 0.024 ml/kg/s and four similar sheep with 0.9% saline at a mean rate of 0.018 ml/kg/s. Five ECG tracings were obtained over a 6-h period--two (20 s each) before, one (continuous tracing) during the infusion, and two (20 s each) afterwards. The heart was auscultated during the infusion. Seven heparinized blood samples were obtained--three before the infusion (1.5 h, 1.0 h, and immediately before), and four afterwards (immediately, 2.5 h, 4.5 h, and 24 h after). Determinations were made of changes in mean PCV, red cell counts, mean corpuscular volumes, plasma Na, K, Ca and Mg, and of erythrocyte Na and K concentrations. Analysis of variance revealed increases in heart rate when the results from both groups were combined, but no significant effects on cardiac rhythm. Auscultation revealed marked fluctuations in cardiac intensity within individual sheep and marked differences between sheep, particularly in those infused with HNaK. In the HNaK group there were significant increases in erythrocyte and plasma Na, and erythrocyte K and decreases in plasma Ca during the infusion. Plasma K increased from the termination of the infusion to 2.5 h afterwards in the saline group but decreased unexpectedly during the same period in the group infused with HNaK [corrected].

The effects of hypocalcaemia due to a 4-hour infusion of Na2EDTA solution on various blood and urine analytes in dairy cows and a comparison of these effects between cows with high and low erythrocyte potassium concentrations.

Six HK (high erythrocyte potassium) and 7 LK (low erythrocyte potassium) dairy cows were subjected to a 4-h intravenous infusion of 4.7% Na2EDTA solution to induce and maintain hypocalcaemia. Blood samples taken immediately before infusion, hourly for 7 h, and at 24 h after commencement of infusion were subjected to determination of concentration (or count) of 16 analytes. The mean changes in concentrations (or counts) of the various blood analytes were calculated for the periods 0-4, 4-7, 7-24, and 0-24 h after commencement of the infusion for all cows combined, and then separately for the HK and LK groups of cows. Plasma Ca(PCa), plasma inorganic phosphorus (PiP) and plasma potassium (PK) showed significant decreases during the 4-h infusion period and were still below pretreatment levels 24 h later. AST, CPK, PCVs and white cell-counts (WCCs) showed significant early increases which were still significantly elevated 24 h later. Plasma magnesium (PMg) and erythrocyte Na(ENa) and K(EK) all showed delayed changes which still persisted 24 h later. Significant between-group differences were present for PCVs which increased significantly more in the LK than the HK group during the infusion period, for PCa which showed a greater increase in the HK cows than the LK cows during the 4-7 h early clinical recovery period, and for plasma bilirubin (PBil) which showed a greater increase from 0 to 24 h in the HK group than in the LK group. Urine samples, collected before infusion, 4-7 h and 24 h after commencement of the infusion, were subjected to analysis for glucose, protein, pH, 'blood' and ketones. Most cows showed increases in urinary glucose, protein and 'blood'.

Investigation of some pathophysiological effects of prolonged hypocalcaemia in sheep induced by infusing Na2EDTA solution for 4 hours daily on three consecutive days.

Hypocalcaemia was induced in a group of five aged Merino ewes (with low erythrocyte potassium status) by the intravenous infusion of 4.7% Na2EDTA solution for 4 h daily on 3 consecutive days. A similar control group was infused with 5.0% dextrose solution (10 ml/h) for the same period. Blood samples were taken immediately before infusion each day, hourly for 7 h, then at 08:00 each morning for a further 5 d. Studies were made on the changes in plasma (P) Ca, PNa, PK, PMg, PProtein (PProt), P inorganic phosphorus (PiP), erythrocyte (E) Na, EK, EMg, PCVs, and mean corpuscular cell volumes (MCV). Significant decreases occurred in PiP concentrations but these were only temporary, which suggests that PiP is unlikely to be involved in the complications of prolonged hypocalcaemia. Significant prolonged decreases in PNa, PK and EK and significant prolonged increases in PCVs suggested that fluid replacement therapy supplemented with Na and K may be worthy of further study in the treatment of ruminants affected by apparent biochemical or physiological complications to prolonged hypocalcaemia.

Monthly variation and distribution of erythrocyte Na, K and Mg concentrations in normal dairy cows.

Blood samples were taken from the caudal vein of 64 normal dairy cows monthly for 12 months and the concentrations of erythrocyte Na (ENa), erythrocyte K (EK), and erythrocyte (EMg) were determined. The overall range of ENa concentrations in the cows was 16 to 176 mmol/l red cells with a grand mean (+/- SD) of 96 +/- 15.4 mmol/l, and a positively skewed distribution with a degree of skewness of 4.4. The overall range of EK concentrations was 13 to 99 mmol/l, with a grand mean (+/- SD) of 32.8 +/- 13.12 mmol/l red cells, and a distribution which suggested bimodality with modes at 26 and 70 mmol/l red cells. The overall range of EMg concentrations was 0.1 to 2.6 mmol/l red cells with a grand mean (+/- SD) of 0.99 +/- 0.12 and mode and median of 0.97 mmol/l red cells; the distribution was that of a normal Gaussian curve. Analysis of variance showed significant effects with respect to cows and calendar months but not lactation months on all cations (all P less than 0.01). The calendar months effects were similar for cows with mean erythrocyte K concentrations below 35 mmol/l for Friesians and Jerseys but not for Australian Illawarra Shorthorn cows. The repeatabilities were 0.4, 0.9 and 0.2 respectively for ENa, EK and EMg. It was concluded that ENa had a moderate genetic component, EK a high, and EMg a low genetic component. There was no significant correlation between plasma Na and ENA or plasma K and EK, but there was between plasma Mg and EMg (r = 0.21, df = 307, P less than 0.01).

Infants and atropine: a dangerous mixture.

Colic in infants is a common but short-lived problem. Many different theories and treatment for this distressing ailment have been tried over the years, yet the definitive cure remains elusive. Although the risks associated with the use of atropine and its derivatives are well known, they are still prescribed by some in the management of colic. We report a case of serious side effects from the treatment of colic with an atropine containing mixture, in which an error in preparation was identified. In view of the potential for serious toxicity resulting from either inappropriate prescription, preparation or administration, alternative methods of treatment should be employed.

The relationship between certain blood constituents in cows with milk fever and the response following treatment with calcium borogluconate solutions.

The association between the concentrations of various blood constituents and the responses of cows with milk fever following calcium borogluconate therapy was determined using analysis of variance. In cows which had not received herdsman treatment prior to sampling (n = 63), plasma potassium was the only constituent with a significant effect (p less than 0.01), the mean concentrations for cows classified as unassisted, assisted, or delayed, recoveries, and deaths ranging down from 4.3 to 2.8 mmol/l, respectively. In cows which had received treatment prior to sampling (n = 55) those making unassisted recoveries had significantly lower mean concentrations of serum total calcium than those making assisted recoveries (1.3 v 1.9 mmol/l, respectively, p less than 0.05), and cows making delayed recoveries had significantly lower mean plasma inorganic phosphate concentrations (0.3 mmol/l) than those making unassisted and assisted recoveries (both 0.7 mmol/l, p less than 0.05) and those subsequently dying (1.2 mmol/l, p less than 0.01). Response was not dependent on plasma potassium concentrations in the treated group of cows, and plasma sodium, serum magnesium, and erythrocyte sodium concentrations were not significant in either group of cows.

Carbon dioxide as a short-term restraint anaesthetic in rats with subclinical respiratory disease.

The use of carbon dioxide (CO2) with, and without, oxygen (O2) as a short-term restraint anaesthetic for Wistar rats in which subclinical respiratory disease was endemic, was assessed in 3 separate experiments. In the first, rats were placed in a CO2 atmosphere generated from solid CO2 chips in a 70 l plastic bin, and removed at time intervals ranging from 0 to 120 s after disappearance of the pedal reflex. Eight of 25 rats died, including 2 which were removed immediately the pedal reflex disappeared; it was concluded that CO2 without O2 was not a suitable short-term anaesthetic for rats. In a second study, rats were anaesthetized in atmospheres of 50:50 and 80:20 (CO2:O2) provided from commercially available cylinders, in 2 different environments--a 3.41 glass jar and a 17 l plastic bin. Rats became excited in the plastic bin but not the glass jar. Rats in the glass jar displayed visible depression and cessation of whiskers movement significantly more quickly in the 80:20 (CO2:O2) than in the 50:50 mixture (4.2 +/- 0.98 s, n = 6, and 66.0 +/- 4.9 s, n = 6 vs 13.8 +/- 2.77 s, n = 5 and 152.0 +/- 20.8 s, n = 5, respectively). Rats in the 17 l plastic bin lost their pedal reflexes in a mean 41.5 +/- 4.55 s (n = 11) in the 50:50 mixture and in a mean 30.9 +/- 6.38 s (n = 11) in the 80:20 (CO2:O2) group. Those left in the 50:50 mixture for 60 s and 180 s after disappearance of their pedal reflexes, recovered these reflexes in 20.2 +/- 0.44 s and 21.5 +/- 7.23 s respectively after removal from the gas. Respiration and heart beat ceased in one rat remaining in the 50:50 mixture after 13 min 10 s. No untoward effects occurred in rats left in the 50:50 mixture for 180 s after disappearance of the pedal reflex, but 2 died when left for an equivalent period in the 80:20 mixture. In the third study, examples of the practical use of a 50:50 mixture as a short term restraint anaesthetic are described. It was concluded that this mixture was a cheap, safe, and effective means of short-term restraint for rats with subclinical respiratory disease, when the minimal time of exposure to the gases was employed.