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There are unanswered questions with regards to acute respiratory outcomes, particularly asthma, due to environmental exposures. In contribution to asthma research, the current study explored a computational intelligence paradigm of artificial neural networks (ANNs) called self-organizing maps (SOM). To train the SOM, air quality data (nitrogen dioxide, sulphur dioxide and particulate matter), interpolated to geocoded addresses of asthmatics, were used with clinical data to classify asthma outcomes. Socio-demographic data such as age, gender and race were also used to perform the classification by the SOM. All pollutants and demographic traits appeared to be important for the correct classification of asthma outcomes. Age was more important: older patients were more likely to have asthma. The resultant SOM model had low quantization error. The study concluded that Kohonen self-organizing maps provide effective classification models to study asthma outcomes, particularly when using multidimensional data. SO2 was concluded to be an important pollutant that requires strict regulation, particularly where frail subpopulations such as the elderly may be at risk.

Background: Delayed tuberculosis (TB) treatment increases the rate of spread of the bacilli in the community and mortality rates. Rapid diagnosis and early TB treatment initiation are crucial to successful outcomes and delays affect TB control programs. In Namibia, there is a paucity of data on the demographic factors affecting TB treatment initiation since GeneXpert MTB/RIF (Xpert) assay was introduced in 2017. Methods: This was a descriptive cross-sectional retrospective study conducted at Katutura Hospital TB clinic from 1st July 2018 to 31st March 2019. A total of seventy-two (72) participants comprising twenty-five (25) rifampicin resistant-TB (RR-TB) and forty-seven (47) non- RR-TB adult patients were enrolled using consecutive sampling. Patients’ medical records, Xpert results and a questionnaire were used to collect data. The data were analyzed using Stata statistical software version 12. Association between socio-demographic factors and treatment initiation delays were established using logistic regression analysis. Results: Staying with a TB patient (AOR=17.22, 95% CI: 2.29-129.773), employment status (AOR=1.23, 95% CI, 002-129), previous TB treatment (AOR=2.19, 95% CI: 0.076-0.86) and being HIV positive (AOR= 1.23, 95% CI: 0.0034-057) were the socio-demographic factors that were significantly associated with treatment initiation delays. Treatment initiation delay median time at Katutura Intermediate Hospital TB Clinic was 10 days (IQR: 1-32) and 3 days (IQR: 0-12) for RR-TB and non- RR-TB respectively. Conclusion: The prolonged treatment initiation delays among HIV positive RR-TB patients might be due to low adherence to HIV care interventions. Staying with a household TB patient and those who were previously treated for TB were also associated with treatment initiation delays. Poor health systems infrastructure and stigma could be the determinants of this delay in these groups. An integrated family-based approach to TB and HIV care involving health care workers can mitigate TB treatment delays post-diagnosis. Further studies should explore the factors associated with late initiation to second-line treatment from a community perspective. Lastly, there is a need to assess the cost-utility of bedaquiline and delamanid drugs roll-out in Namibian health care in comparison with the standard treatment.

Background: Delayed tuberculosis (TB) treatment raises the rate of spread of bacilli in the population and increases mortality rates. Rapid diagnosis and early TB treatment initiation are crucial to successful outcomes and delays affect TB control programs. In Namibia, there is a paucity of data on the demographic factors affecting TB treatment initiation since GeneXpert MTB/RIF (Xpert) assay was introduced in 2017. Methods: This was a descriptive cross-sectional retrospective study conducted at Katutura Hospital TB clinic from 1st July 2018 to 31st March 2019. A total of seventy-two (72) participants comprising twenty-five (25) rifampicin resistant-TB (RR-TB) and forty-seven (47) non- RR-TB adult patients were enrolled using consecutive sampling. Patients’ medical records, Xpert results and a questionnaire were used to collect data. The data were analyzed using Stata statistical software version 12. Association between socio-demographic factors and treatment initiation delays were established using logistic regression analysis. Results: Staying with a TB patient (AOR=17.22, 95% CI: 2.29-129.773), employment status (AOR=1.23, 95% CI, 002-129), previous TB treatment (AOR=2.19, 95% CI: 0.076-0.86) and being HIV positive (AOR= 1.23, 95% CI: 0.0034-057) were the socio-demographic factors that were significantly associated with treatment initiation delays. Treatment initiation delay median time at Katutura Intermediate Hospital TB Clinic was 10 days (IQR: 1-32) and 3 days (IQR: 0-12) for RR-TB and non- RR-TB respectively. Conclusion: The prolonged treatment initiation delays among HIV positive RR-TB patients might be due to low adherence to HIV care interventions. Staying with a household TB patient and those who were previously treated for TB were also associated with treatment initiation delays. Poor health systems infrastructure and stigma could be the determinants of this delay in these groups. An integrated family-based approach to TB and HIV care involving health care workers can mitigate TB treatment delays post-diagnosis. Further studies should explore the factors associated with late initiation to second-line treatment from a community perspective. Lastly, there is a need to assess the cost-utility of bedaquiline and delamanid drugs roll-out in Namibian health care in comparison with the standard treatment. Based on the SEM model, an integrated, family-based approach to TB and HIV care involving health worker needs to be piloted to see its feasibility to reduce treatment initiation. This approach may go a long way in improving the management of TB among women, children, and other vulnerable groups.

Background: Comorbid psychiatric and substance use disorders are common and present several treatment challenges. Aim: The aim of this study was to determine which patient and substance factors are associated with the completion of a substance rehabilitation programme in psychiatric inpatients. Setting: The study was conducted at the Substance Rehabilitation Unit (SRU) at Weskoppies Hospital, a psychiatric training hospital in South Africa, which offers a 6-week programme at the hospital for psychiatric inpatients. Methods: This descriptive, retrospective hospital-based study was carried out comparing completers and non-completers of the SRU programme with respect to patient and substance factors. All patients accepted into the SRU during 2013–2014 were included ( n = 119). Data were collected over a year (2016–2017) from the clinical files, SRU referral forms, SRU attendance register, hospital computerised demographic records, nursing notes and administration files using a data collection sheet designed by the researchers for this study. Comparison between completers and non-completers was performed using Chi-Square or Fisher’s Exact tests. Results: The SRU accepted 119 patients from January 2013 to December 2014. The majority of the sample were involuntary patients ( n = 39), 30–49 years old ( n = 57), male ( n = 89), unmarried ( n = 112), never having received a disability grant ( n = 27), unemployed ( n = 96) and with a Grade 8–11 education ( n = 49). Substance-induced psychotic disorders ( n = 39), schizophrenia ( n = 29) and bipolar disorders ( n = 22) were found to be common. Frequent medical comorbidities included head injury ( n = 27), cardiovascular disease ( n = 18) and HIV reactivity ( n = 7). Cannabis ( n = 98), alcohol ( n = 94) and nicotine ( n = 90) were the most frequently used substances. Level of education ( p = 0.004), disability grant status ( p = 0.004), Nyaope use ( p = 0.001) and nicotine use ( p = 0.049) were statistically seen to be significantly associated with completion. Psychiatric diagnoses and general medical comorbidity were not associated with completion. Conclusions: This study has yielded several results in areas that have not yet been well researched in South Africa. Risk factors for non-completion may include lower levels of education, being on a disability grant and using Nyaope or nicotine, but may vary in different settings. Future research should focus on identifying further factors that may affect completion of substance rehabilitation in psychiatric inpatients, the role of disability grants in patients with co-occurring disorders and the effect of Nyaope and nicotine use on treatment outcomes in this population. Effective and accessible interventions to assist vulnerable patients also need to be identified.

The nature of letsoku and related clayey soils, traditionally used by indigenous Southern African communities for a wide range of purposes, was explored. Thirty nine samples were collected from Botswana, Lesotho, Swaziland, South Africa and Zimbabwe. They were analyzed to determine their composition and physical properties. Analyses involved BET surface area determinations, pH measurements, X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Structured interviews were used to establish the purpose of use and the location of sourcing sites. Most of the samples were in powder form and some were supplied as dry clay balls. Cosmetic applications were almost universally indicated. However, other functions, related to artwork, medicinal use, cultural symbolism and traditional beliefs were also mentioned. The letsoku samples covered a wide range of colors ranging from bright red to yellow but also from off-white to black with some having a light grey color. It was therefore not surprising that the mineral composition of the letsoku samples also varied widely. A black sample, and the yellow and reddish pastel colored samples, contained significant quantities of the corresponding, color imparting, iron oxides. As expected, clay minerals featured prominently although kaolinite was more often encountered than smectites as the dominant minerals. All samples contained silica and in some instances the content exceeded 90% m/m SiO2. The presence of high contents (40% m/m) of gibbsite in samples from Venda represents a new finding for clayey soils in traditional usage.

Objective To determine the minimum infusion rate (MIR) of alfaxalone required to prevent purposeful movement in response to standardized stimulation while co-administered with lidocaine at three different doses by constant infusion rate infusion (CRI) in goats. Study design Prospective, blinded, randomized crossover, experimental. Animals A total of eight healthy goats: four does and four wethers. Methods Anaesthetic induction was with lidocaine at 1 mg kg−1 [low dose of lidocaine (L-Lid)], 2 mg kg−1 [moderate dose (M-Lid)] or 4 mg kg−1 [high dose (H-Lid)] and alfaxalone at 2 mg kg−1. Anaesthetic maintenance was with alfaxalone initially at 9.6 mg kg−1 hour−1 combined with one of three lidocaine treatments: 3 mg kg−1 hour−1 (L-Lid), 6 mg kg−1 hour−1 (M-Lid) or 12 mg kg−1 hour−1 (H-Lid). The MIR of alfaxalone was determined by testing for responses to a stimulation in the form of clamping on a digit with a Vulsellum forceps every 30 minutes during lidocaine CRI. Basic cardiopulmonary parameters were measured. Results The alfaxalone MIRs were 8.64 (6.72–10.56), 6.72 (6.72–8.64) and 6.72 (6.72–6.72) mg kg−1 hour−1 during L-Lid, M-Lid and H-Lid, respectively, without any significant differences among treatments. Compared to the initial rate of 9.6 mg kg−1 hour−1, these reductions in MIR are equivalent to 10, 30 and 30%, respectively. Significant increases in heart rate (HR) and arterial carbon dioxide partial pressure (PaCO2) and decreases in arterial haemoglobin saturation (SaO2), arterial oxygen partial pressure (PaO2) and respiratory frequency (fR) immediately after induction were observed during all lidocaine treatments. Conclusions and clinical relevance Lidocaine reduces the alfaxalone MIR by up to 30% with a tendency towards a plateauing in this effect at high CRIs. Immediate oxygen supplementation might be required to prevent hypoxaemia.

Objective To determine the minimum infusion rate (MIR) of alfaxalone required to prevent purposeful movement of the extremities in response to standardized noxious stimulation during its co-administration with fentanyl at three different doses by constant rate infusion (CRI) intravenously (IV) in goats. Study design Prospective, blinded, randomized crossover, experimental. Animals Eight healthy goats; four does and four wethers. Methods For induction of anaesthesia, a bolus of fentanyl was administered at 0.005 mg kg-1 (LFent), 0.015 mg kg-1 (MFent) or 0.03 mg kg-1 (HFent) followed by alfaxalone at 2.0 mg kg-1. For maintenance, the goats received alfaxalone at an initial infusion rate of 9.6 mg kg-1 hour-1 and one of three fentanyl treatments: 0.005 mg kg-1 hour-1(LFent), 0.015 mg kg-1 hour-1 (MFent) or 0.03 mg kg-1 hour-1 (HFent). The MIR of alfaxalone was determined during fentanyl CRI by testing for responses to stimulation (clamping on a digit with Vulsellum forceps) every 30 minutes. Some cardiopulmonary parameters were measured. Results The alfaxalone MIR median (range) was 6.7 (6.7–8.6), 2.9 (1.0–6.7) and 1.0 (1.0–4.8) mg kg-1 hour-1 during LFent, MFent and HFent, respectively. Alfaxalone MIR was significantly lower during MFENT and HFENT compared to LFENT. Significantly low oxygen haemoglobin saturation (SaO2) and arterial oxygen partial pressure (PaO2), observed 2 minutes into anaesthesia after all fentanyl treatments, were the most remarkable adverse cardiopulmonary effects observed. Recovery from anaesthesia was severely affected by high doses of fentanyl with excitatory behavioural signs predominant for up to 2 hours post-administration after MFent and HFent. Conclusions and clinical relevance Fentanyl reduces alfaxalone MIR in goats in a dose-dependent manner. Immediate oxygen supplementation after induction of general anaesthesia is recommended to prevent hypoxaemia. Doses of fentanyl equal to or greater than 0.015 mg kg-1 hour-1 tend to be associated with severe excitatory behaviour and should be avoided when fentanyl is administered to goats.

Background Low birth weight continues to be a main cause of child morbidity and mortality. Low birth weight can cause complications in adult life, and is therefore a public health concern. In this study, we determined the maternal factors that contribute to low birth weight (LBW) deliveries in Tshwane District, South Africa. Methods We conducted a case control study of 1073 randomly selected mothers who delivered babies in four hospitals in the district. We reviewed antenatal and maternity registers to obtain information about the mothers and their offspring. We fitted a multiple logistic regression to examine relationships between possible factors associated with LBW. Results From the total sample of mothers (n = 1073), 77% (n = 824) were adult women, aged 20 to 35 years. Of the adult mothers, 38.54% (n = 412) delivered low birth weight (LBW) infants. The mean gestational age and weight of all infants at birth was 37.16 weeks (SD 2.92) and 2675.48 grams (SD 616.16) respectively. LBW was associated with prematurity, odds ratio (OR) 7.15, 95% confidence interval (CI) 5.18 to 9.89; premature rupture of membranes OR 7.33, 95% CI 2.43 to 22.12 and attending fewer than five antenatal care (ANC) visits OR 1.30, 95% CI 1.06 to 1.61. Male infants were less likely to be LBW, in this population. Conclusion Women who attended fewer than five ANC visits were predisposed to give birth to low birth weight babies. Mothers should be encouraged to attend ANC visits to detect adverse events like premature rupture of membranes and premature labour timeously.

The effects of midazolam on the minimum alveolar concentration (MAC) of isoflurane in mechanically ventilated goats were evaluated. Six healthy goats (3 does and 3 wethers) were used in a randomized crossover design. General anaesthesia was induced with isoflurane. Endotracheal intubation was performed after which anaesthesia was maintained with isoflurane. Baseline isoflurane MAC was determined. The goats then received, on separate occasions, one of three midazolam treatments intravenously: bolus dose of 0.1 mg/kg followed by a maintenance dose of 0.1 mg/kg/h (Treatment LMID), bolus dose of 0.3 mg/kg followed by a maintenance dose of 0.3 mg/kg/h (Treatment MMID), bolus dose of 0.9 mg/kg followed by a maintenance dose of 0.9 mg/kg/h (Treatment HMID) intravenously. Isoflurane MAC was then re-determined for each midazolam treatment. The baseline [median (inter-quartile range)] isoflurane MAC in goats was 1.40 (1.38–1.41)%. Baseline isoflurane MAC was statistically significantly reduced (P < 0.05) following Treatment LMID, Treatment MMID and Treatment HMID by 16.8%, 35.1% and 54.7%, respectively. Quality of recovery from anaesthesia was good following all midazolam treatments. Midazolam, administered by constant rate infusion, significantly reduces isoflurane MAC in goats.

The effects of fentanyl on the minimum alveolar concentration (MAC) of isoflurane and cardiovascular function in mechanically ventilated goats were evaluated using six healthy goats (three does and three wethers). Following induction of general anaesthesia with isoflurane delivered via a mask, endotracheal intubation was performed and anaesthesia was maintained with isoflurane. The baseline MAC of isoflurane (that is, the lowest alveolar concentration required to prevent gross purposeful movement) in response to clamping a claw with a vulsellum forceps was determined. Immediately after baseline isoflurane MAC determination, the goats received, on separate occasions, one of three fentanyl treatments, administered intravenously: a bolus of 0.005 mg/kg followed by constant rate infusion (CRI) of 0.005 mg/kg/hour (treatment LFENT), a bolus of 0.015 mg/kg followed by CRI of 0.015 mg/kg/hour (treatment MFENT) or a bolus of 0.03 mg/kg followed by CRI of 0.03 mg/kg/hour (treatment HFENT). Isoflurane MAC was redetermined during the fentanyl CRI treatments. Cardiopulmonary parameters were monitored. A four-week washout period was allowed between treatments. The observed baseline isoflurane MAC was 1.32 (1.29 to 1.36) per cent. Isoflurane MAC decreased to 0.98 (0.92 to 1.01) per cent, 0.75 (0.69 to 0.79) per cent and 0.58 (0.51 to 0.65) per cent following LFENT, MFENT and HFENT respectively. Cardiovascular function was not adversely affected. The quality of recovery from general anaesthesia was good, although exaggerated tail-wagging was observed in some goats following MFENT and HFENT. THE depth of anaesthesia during surgery is determined by the interaction of hypnotic drugs, analgesic drugs and the intensity of noxious stimulation (Bouillon and others 2004). General anaesthetic agents, such as isoflurane, primarily contribute to anaesthesia through their hypnotic effects, while opioids, such as fentanyl, contribute through analgesic effects. The interaction of hypnotic agents and opioid analgesics during general anaesthesia can be schematically described by a hierarchical model in which, initially, a noxious stimulus processed at subcortical levels of the CNS has its nociceptive signal attenuated by opioids, and subsequently, when the attenuated signal is projected to the cortical levels, arousal is suppressed by hypnotic agents (Bouillon and others 2004).

Introduction The minimum infusion rate (MIR) of alfaxalone when co-administered with midazolam in goats was evaluated. Materials and methods Eight goats (four does and four wethers) were anaesthetised, on separate occasions, with alfaxalone at an initial dose of 9.6 mg/kg/hour combined with one of three midazolam treatments: a bolus of 0.1 mg/kg followed by constant rate infusion (CRI) of 0.1 mg/kg/hour (treatment LMID), 0.3 mg/kg followed by CRI of 0.3 mg/kg/hour (MMID), 0.9 mg/kg followed by CRI of 0.9 mg/kg/hour (HMID), intravenously. Responses to stimulation (clamping on the proximal part of one digit of the hoof with Vulsellum forceps for 60 seconds) were tested every 30 minutes. In the absence or presence of a response to stimulation, the infusion rate was reduced or increased by 1.9 mg/kg/hour. Alfaxalone MIR was calculated as the mean of the infusion rates that allowed and abolished movement. Cardiopulmonary parameters were measured. Results Alfaxalone MIR was 6.7 (6.7–8.6) mg/kg/hour, 6.7 (4.8–6.7) mg/kg/hour and 2.9 (1.0–4.8) mg/kg/hour for LMID, MMID and HMID respectively. Cardiopulmonary function was minimally affected, with hypoxaemia observed two minutes into anaesthesia during all treatments. Recovery from anaesthesia was excitement-free. Conclusions Midazolam causes a dose-dependent reduction of alfaxalone MIR in goats. Oxygen supplementation is recommended during anaesthesia with alfaxalone and midazolam in goats.

To determine the minimum infusion rate (MIR) of alfaxalone required to prevent purposeful movement of the extremities in response to noxious stimulation.Prospective, experimental.Eight healthy goats; four does and four wethers.Anaesthesia was induced with alfaxalone 3 mg kg(-1) intravenously (IV). A continuous IV infusion of alfaxalone, initially at 0.2 mg kg(-1) minute(-1) , was initiated. Following endotracheal intubation the goats breathed spontaneously via a circle breathing circuit delivering supplementary oxygen. The initial infusion rate was maintained for 30 minutes before testing for responses. The stimulus was clamping on the proximal (soft) part of one digit of the hoof with Vulsellum forceps for 60 seconds. In the absence or presence of purposeful movement of the extremities, the infusion rate was reduced or increased by 0.02 mg kg(-1) minute(-1) and held constant for 30 minutes before claw-clamping again. Alfaxalone MIR was calculated as the mean of the infusion rates that allowed and abolished movement. Cardio-respiratory parameters were measured. Recovery from general anaesthesia was timed and quality scored. Results are presented as median (range).The MIR of alfaxalone was 0.16 (0.14-0.18) mg kg(-1) minute(-1) or 9.6 (8.4-10.8) mg kg(-1) hour(-1) . Induction of and recovery from anaesthesia were excitement-free. Cardio-respiratory changes were minimal, although compared to baseline HR increased, and at 2 minutes post-induction, (prior to oxygen supplementation), PaO2 decreased significantly from 84 (80-88) to 70 (51-72) mmHg [11.2 (10.7-11.7) to 9.3 (6.8-9.6) kPa]. Sporadic muscle twitches, unrelated to depth of anaesthesia, were observed during the period of general anaesthesia. Time (minutes) to sternal recumbency and standing were 4.0 (3.0-10.0) and 41.5 (25.0-57.0) respectively.Alfaxalone can be used for total intravenous anaesthesia (TIVA) in goats and is associated with minimal adverse effects. Oxygen supplementation is advised, especially when working at higher altitudes.

Goats are rarely anaesthetised; consequently, scant information is available on the efficacy of anaesthetic drugs in this species. Alfaxalone is a relatively new anaesthetic agent, of which the efficacy in goats has not yet been studied. In this study, the sedative and alfaxalonesparing effects of midazolam and butorphanol, administered alone or concomitantly, in goats were assessed. Eight clinically healthy goats, four does and four wethers, were enlisted in a randomised crossover manner to receive intramuscular sedative treatments consisting of saline 0.05 mL/kg, or midazolam 0.30 mg/kg, or butorphanol 0.10 mg/kg, or a combination ofmidazolam 0.30 mg/kg with butorphanol 0.10 mg/kg before intravenous induction of general anaesthesia with alfaxalone. Following induction, the goats were immediately intubated and the quality of anaesthesia and basic physiological cardiorespiratory and blood-gas parameters were assessed until the goats had recovered from anaesthesia. The degree of sedation, quality of induction and recovery were scored. When compared with saline (3.00 mg/kg), midazolam,administered alone or with butorphanol, caused a statistically significant increased level of sedation and a reduction in the amount of alfaxalone required for induction (2.00 mg/kg and 1.70 mg/kg, respectively). Butorphanol alone (2.30 mg/kg) did not cause significant changes in level of sedation or alfaxalone-induction dose. During induction and recovery, the goats were calm following all treatments, including the control group. Cardiorespiratory and blood gasparameters were maintained within clinically acceptable limits. The present study showed that midazolam, administered alone or combined with butorphanol, produces a degree of sedation that significantly reduces the dose of alfaxalone required for induction of general anaesthesia in goats, without causing any major adverse cardiorespiratory effects.

Objective To compare the efficacy and cardiopulmonary effects of propofol and fentanyl, with propofol and midazolam for total intravenous anaesthesia. Study design Prospective, randomized, crossover experimental study. Animals Six goats; three does and three wethers. Methods Goats received either fentanyl 0.02 mg kg−1 (treatment FP) or midazolam 0.3 mg kg−1 (treatment MP) intravenously. One minute later anaesthesia was induced with propofol, then maintained by constant rate infusion of propofol 12.0 mg kg−1 hour−1 and fentanyl 0.02 mg kg−1 hour−1 (treatment FP) or propofol 12.0 mg kg−1 hour−1 and midazolam 0.3 mg kg−1 hour−1 (treatment MP) for 90 minutes. Response to noxious stimulus was tested every 10 minutes and propofol dose adjusted to prevent purposeful movement. Cardiopulmonary parameters were measured continuously, and arterial blood-gas analysis performed intermittently. Recovery was timed and quality scored. Results are presented as median (IQR). Results Differences in the propofol induction dose [4.00 (3.96-4.01) and 3.97 (3.91-4.00) mg kg−1 for treatments FP and MP, respectively] were not significant. Quality of induction in both groups was smooth. The median propofol dose for maintenance was less (p = 0.004) with treatment FP (12.0 mg kg−1 hour−1) than MP (18.0 mg kg−1 hour−1). Cardiopulmonary function was well maintained with both treatments. Recovery times in minutes from the end of anaesthetic infusion for treatments FP and MP respectively were; to extubation 3.0 (3.0-3.0) and 4.5 (3.3-5.0); to sternal position, 4.5 (3.3-5.0) and 5.0 (5.0-6.5) and to standing 13.0 (10.3-15.0) and 15.0 (11.3-17.3). Quality of recovery was acceptable in both groups, but abnormal behavioural signs were observed after treatment FP. Conclusions and clinical relevance Total intravenous anaesthesia with propofol and fentanyl or propofol and midazolam, at the doses studied, in spontaneously-breathing, oxygen-supplemented goats is practicable. Recovery from the fentanyl-propofol combination is not always smooth.

The sedative, propofol-sparing and cardiopulmonary effects of acepromazine, midazolam, butorphanol and combinations of butorphanol with acepromazine or midazolam in goats were evaluated. Six healthy Boer - Indigenous African crossbreed goats were by randomised cross-over designated to 6 groups: Group SAL that received saline, Group ACE that received acepromazine, Group MID that received midazolam, Group BUT that received butorphanol, Group ACEBUT that received acepromazine and butorphanol and Group MIDBUT that received midazolam and butorphanol as premedication agents intramuscularly on different occasions at least 3 weeks apart. The degree of sedation was assessed 20 minutes after administration of the premedication agents. Thirty minutes after premedication, the dose of propofol required for induction of anaesthesia adequate to allow placement of an endotracheal tube was determined. Cardiovascular, respiratory and arterial blood-gas parameters were assessed up to 30 minutes after induction of general anaesthesia. Acepromazine and midazolam produced significant sedation when administered alone, but premedication regimens incorporating butorphanol produced inconsistent results. The dose of propofol required for induction of anaesthesia was significantly reduced in goats that received midazolam alone, or midazolam combined with either acepromazine or butorphanol. The quality of induction of anaesthesia was good in all groups, including the control group. Cardiovascular, respiratory and blood-gas parameters were within normal limits in all groups and not significantly different between or within all groups. In conclusion: sedation with midazolam alone, or midazolam combined with either acepromazine or butorphanol significantly reduces the induction dose of propofol with minimal cardiopulmonary effects in goats.

The effects of fentanyl on the minimum alveolar concentration (MAC) of isoflurane and cardiovascular function in mechanically ventilated goats were evaluated using six healthy goats (three does and three wethers). Following induction of general anaesthesia with isoflurane delivered via a mask, endotracheal intubation was performed and anaesthesia was maintained with isoflurane. The baseline MAC of isoflurane (that is, the lowest alveolar concentration required to prevent gross purposeful movement) in response to clamping a claw with a vulsellum forceps was determined. Immediately after baseline isoflurane MAC determination, the goats received, on separate occasions, one of three fentanyl treatments, administered intravenously: a bolus of 0.005 mg/kg followed by constant rate infusion (CRI) of 0.005 mg/kg/hour (treatment LFENT), a bolus of 0.015 mg/kg followed by CRI of 0.015 mg/kg/hour (treatment MFENT) or a bolus of 0.03 mg/kg followed by CRI of 0.03 mg/kg/hour (treatment HFENT). Isoflurane MAC was redetermined during the fentanyl CRI treatments. Cardiopulmonary parameters were monitored. A four-week washout period was allowed between treatments. The observed baseline isoflurane MAC was 1.32 (1.29 to 1.36) per cent. Isoflurane MAC decreased to 0.98 (0.92 to 1.01) per cent, 0.75 (0.69 to 0.79) per cent and 0.58 (0.51 to 0.65) per cent following LFENT, MFENT and HFENT respectively. Cardiovascular function was not adversely affected. The quality of recovery from general anaesthesia was good, although exaggerated tail-wagging was observed in some goats following MFENT and HFENT.