Massey Documents by Type
Permanent URI for this communityhttps://mro.massey.ac.nz/handle/10179/294
Browse
11 results
Search Results
Item The "ACT-ive" pursuit of loss and gain : the impact of an acceptance and commitment therapy-based intervention on post weight-loss surgery individuals : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Clinical Psychology at Massey University, Auckland, New Zealand(Massey University, 2021) Damnjanovic, NatalijaObesity prevalence continues to increase at an alarming rate worldwide and poses serious health risks to those affected including increased morbidity, mortality, and psychosocial consequences. Weight-loss surgery is currently the best evidence-based treatment for obesity yet, substantial postoperative weight regain is reported within 2-5 years. Successful weight management is complicated when longstanding psychological difficulties are present, that often require psychological input to address. In response, a private weight-loss surgery clinic has developed an Acceptance and Commitment Therapy-based (ACT) Intervention entitled the Foundations of Healthy Living (FOHL) Retreat with the aim of improving weight-loss surgery outcomes by providing greater support to individuals in the post-operative period. In this thesis, an exploration of the efficacy of the FOHL Retreat is conducted. A quasi-experiment pretest posttest non-equivalent control group design is utilised to investigate the impacts of the intervention on weight-related experiential avoidance, eating behaviour, and body mass index (BMI) over time. An additional supplementary exploration into participants’ relationships with food, eating, and their bodies pre- and post-surgically is undertaken using open-text response format questions. Those who attended the Retreat were also asked to share their perspectives on how their participation in the intervention affected their psychological wellbeing. The main findings of the study showed that the ACT-based intervention demonstrated significant effects on several of the variables of interest, in particular, disordered eating and BMI. These effects were mediated by improvements in weight-related experiential avoidance, suggesting the importance of focussing on targeting experiential avoidance as a key mechanism of change in positive postoperative psychological and weight outcomes. The qualitative component of this study expanded on these findings, identifying several key themes present in the experiences of individuals both prior to, and following, weight-loss surgery. Additionally, qualitative responses provided further insight as to the psychological changes participants experienced. Taken together, these findings highlight firstly, the importance of addressing the psychological needs of weight-loss surgery individuals, and secondly, the value of ACT in augmenting surgical outcomes. The results presented here also offer suggestions for further development and future dissemination of such interventions for this population.Item Perioperative fluid administration to optimise haemodynamics without fluid overload in anaesthetised dogs : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Veterinary Science at Massey University, Manawatu, New Zealand(Massey University, 2021) Sano, HirokiPerioperative fluid therapy is the mainstay of anaesthetic management. Fluid administration improves haemodynamics during anaesthesia as it increases preload and thus cardiac output and blood pressure. However, excessive fluid administration can cause detrimental adverse effects, such as haemodulution and oedema, resulting in prolonged hospital stay and increased morbidity and mortality in people. Therefore, fluid administration should be restricted to those who are able to increase stroke volume or cardiac output in response to the fluid administration (responders) and should not be given to those who are unable to do so (non-responders) based on the famous “Frank–Starling law of the heart” Previously static parameters such as central venous pressure were believed to be a clinical gold standard to estimate preload and fluid responsiveness. Over the last decade, dynamic parameters such as pulse pressure variation and pleth variability index have been shown to be reliable predictors for fluid responsiveness in people. This study found that pulse pressure variation and pleth variability index were more accurate than central venous pressure for predicting fluid responsiveness in dogs. Mini-fluid challenge is another technique that is currently available and can be reliably used to determine fluid responsiveness in human medicine. Mini-fluid challenge is an administration of a small amount of fluid to increase preload. Thus, fluid responsiveness can be assessed based on whether stroke volume increases following mini-fluid challenge according to the Frank-Starling curve. The change in stroke volume of a heart at the steep portion of the Frank-Starling curve will be greater than at the plateau portion after mini-fluid challenge. The studies revealed a percentage change in pulse wave transit time (a surrogate parameter of stroke volume, which was also one of results in this thesis) following mini-fluid challenge could predict fluid responsiveness in mechanically ventilated anaesthetised dogs under an experimental condition, and spontaneously breathing anaesthetised dogs undergoing stifle surgery in clinical setting. Lastly, these methods are still of limited use in veterinary clinical practice because of availability of equipment, difficulty of their interpretation and a cumbersome process. The main purpose of this thesis was to obtain evidence on how to optimise haemodynamics in anaesthetised dogs and prevent excessive fluid administration. The time when most practitioners administer a bolus of fluid during anaesthesia is when hypotension is encountered because of anaesthesia. Thus, prevention of hypotension could avoid excessive fluid administration. Therefore, the study found that prophylactic noradrenaline administration, which counteracts some of the cardiovascular adverse effects of anaesthesia, was able to prevent hypotension, and thus minimise fluid administration in anaesthetised dogs. Although all of these methods tested in this thesis have pros and cons in clinical veterinary practice, they were shown to be able to optimise haemodynamics without fluid overload in anaesthetised dogs.Item Analgesic efficacy and pharmacokinetics of combinations of morphine, dexmedetomidine and maropitant in dogs : a thesis presented in partial fulfilment of the requirement for the degree of Doctor of Philosophy at Massey University, Palmerston North, New Zealand(Massey University, 2020) Karna, Sandeep RajMultimodal analgesia is gaining popularity in veterinary medicine. It is an approach that involves the administration of two or three classes of analgesic drugs with different modes of actions to enhance the analgesic effects and lower the adverse effects associated with high dose of a single drug. In a series of experiments conducted in this thesis, the combinations of morphine, dexmedetomidine and maropitant were evaluated using different pain models with the aim of using them in a multimodal strategy in dogs undergoing ovariohysterectomy or other surgical procedures. Firstly, a pilot study evaluating the efficacy of combinations of the test drugs was performed using a hot-plate test and tail-flick test in rats. The combination of morphine and maropitant showed a significantly higher (p < 0.0001) tail-flick latency compared to all other treatment groups indicating a supra-additive effect of spinal analgesia between morphine and maropitant. A pharmacokinetic study to investigate the disposition of the test drug combinations after intramuscular (IM) administration in dogs under anaesthesia was conducted. The results showed that the elimination half-life of morphine was higher and the clearance rate was lower when combined with dexmedetomidine compared to morphine and maropitant combination or morphine alone at higher doses. This effect may have a clinical advantage of prolonging the dosing interval of morphine. A study to evaluate and compare the analgesic efficacy of the combination of morphine, dexmedetomidine and maropitant in dogs undergoing ovariohysterectomy was conducted. The study showed that dogs receiving the combination of morphine and dexmedetomidine had significantly lower (p < 0.05) pain scores, obtained by the short form of the Glasgow composite measure pain scale and visual analogue pain scale, in the postoperative period. All dogs that received dexmedetomidine showed arrhythmia and second-degree heart block immediately after IM administration. Finally, the efficacy of the test drug combinations was evaluated using changes in electroencephalographic indices of nociception (median frequency, spectral edge frequency and total power) in anaesthetised dogs subjected to a noxious electrical stimulus. The combination of morphine and dexmedetomidine showed a significantly lower change in the post stimulation median and spectral edge frequencies compared to all other treatment groups. The dogs receiving dexmedetomidine also demonstrated arrhythmia and second-degree heart block. In conclusion, the combination of morphine and dexmedetomidine showed a superior analgesic effect compared to morphine alone at higher dose and appeared to be the most effective combination among other combinations of morphine, dexmedetomidine and maropitant. The cardiovascular changes produced by the test drugs may be clinically insignificant in fit and healthy dogs. In future, the efficacy of the combination of morphine, dexmedetomidine and maropitant at other different doses rates and ratios should also be evaluated.Item The prevention of weight regain in bariatric surgery patients at Counties Manukau Health : a thesis completed as part of the requirements for Master of Science in Nutrition and Dietetics at Massey University, Albany Campus Auckland, New Zealand(Massey University, 2019) Billing-Bullen, GypsyBackground: Weight-regain is commonly experienced post-bariatric surgery. This study aimed to assess the impact of a structured eating behaviour group education programme on food intake and eating behaviours which contribute to weight regain. Methods: Participants (n=41) were adults at least 12-months post-bariatric-surgery, recruited through CM Health over six months, representing gender and ethnic diversity. This study evaluated whether the current dietitian-led group education session at 18- months resulted in changes to weight, body composition, quality of life, food intakes and/or eating behaviours. There was also an additional 21-month group session added, which involved a focus group to explore barriers and enablers related to weight management during the bariatric journey. Quantitative measures included body composition analysis using bioelectrical impedance, dietary and eating behaviour measures were conducted utilising validated questionnaires, and data was analysed with Wilcoxin, and Paired T-tests. Thematic analysis was used to evaluate the focus group investigations of participant (n=28) experiences. Results: There were no significant changes in body composition, eating behaviours, and energy or nutrient intakes in the three-day WFRs between 18 and 21-months post- surgery, but food variety scores significantly increased from 51.0 to 59.29 (p= 0.032). Flesh food intakes significantly increased from 2.50 to 7.50 per week between 18 and 21-months, as did savoury snack foods (1.50 to 2.0 per week, p <0.001). Quality of life significantly decreased at 18 and 21-months, compared to 12-months post-surgery (1.91, 0.95, 0.99, respectively, p= 0.002). Thematic analysis revealed five key themes: a life changing health journey, barriers to following a healthy lifestyle, challenges to changing eating behaviour, mindset changes and requiring ongoing support. The focus groups also identified that the participants desired more support throughout the bariatric program. Conclusion: Thematic analysis identified the group education programme was found valuable, providing patients with increased support post-surgery from dietitians and peers. These findings provide important insights into the challenges bariatric patients face and key learnings to develop specific supports in the future. Although quantitative improvements to eating behaviours were not found, some areas of dietary quality improved.Item Bariatric surgery : a literature review and results from the BaSE study : a grounded theory of constructing success for bariatric patients : a thesis presented in partial fulfilment for the requirements of the degree of Master of Science in Human Nutrition at Massey University, Palmerston North, New Zealand(Massey University, 2019) Lake, SaraBackground: In New Zealand, around one-third of adults are categorised as medically ‘obese’ and at risk of related comorbidities such as cardiovascular disease, diabetes, sleep apnoea and certain cancers. Obesity is complex, with an elaborate aetiology that encompasses physical, psychological and socio-economic domains. It has proved a tough challenge for health agencies to address, with lifestyle and pharmaceutical interventions consistently showing underwhelming to nil results, particularly for those classified as having class III obesity. Bariatric surgery is now widely accepted as the only effective treatment for severe obesity and related comorbidities with numbers of surgeries worldwide increasing exponentially each year. Objective: The aim of this review was to document an overview of the current knowledge base around bariatric surgery including its effectiveness, the accepted or proposed mechanisms of action and known issues, while also identifying areas of special interest, findings that could be incorporated into best practice and deficits in the research. Method: A focused non-systematic literature review was conducted through the Web of Science and PubMed databases using keywords relevant to each section of the review. Preference was given to apers that were recent, had large sample numbers, long follow-up times and that had been published in respected journals. Less prestigious papers were also included where they added to the depth and interest of the review. Results: A number of topics were identified which may be of interest to clinicians and provide direction for future research. These included the emerging area of the influence of gut hormones and the microbiome on surgery outcomes, the ongoing problem of pre- and post-surgical nutrient deficiencies and the crucial impact of psychological states and conditions on bariatric outcomes. Recommendations include more intensive physical and psychological screening and preparation, longer and more thorough follow-up protocols, managing patient expectations and expanding the definition of bariatric ‘success’ so that, as well as weight loss and improvement of physical comorbidities, it includes measurable psychological and psychosocial variables as well as subjective eating behaviours.Item Being big, becoming small : conversations with Māori women about weight loss surgery : a thesis presented in partial fulfilment of the requirements for the degree of Master of Arts in Social Anthropology at Massey University, Albany, Aotearoa, New Zealand(Massey University, 2019) Joensen, ClareWeight loss surgery is increasingly being used to combat obesity, resulting in recipients becoming more visible in society. This in turn facilitates the normalising of what once would have been considered a radical medical procedure and the proliferation of discourse that more often than not measures success against models of slimness and appearance and underplays the downsides of surgery. Through the use of a narrative phenomenological approach, this research explores the experiences of surgery recipients, specifically Māori women, and asks the question; ‘how does the embodiment of radical change impact on relationality, interiority, conviviality, and ‘being in the world’?’ Through learning from Māori women, this research also explores how being Māori shapes experience both before and after surgery and in doing so, contrasts to literature which frames experiences of indigenous women through a Foucauldian lens of colonialism. I argue that, as Māori, these women are supported by the collective – significantly so – but also have to grapple with and push back negative discourses that leak into their world. I also argue that life post-surgery is entangled with both liminality and potentialities; precarious, unsettled and unsettling, while being simultaneously imbued with hope and focused towards an extending future. Surgery does transform bodies through enabling tremendous weight loss but also transfigures far more than it is designed to do.Item Efficacy of articaine hydrochloride for disbudding in goat kids and velvet antler removal in red deer, and novel disbudding methods for goat kids : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Veterinary Science at Massey University, Palmerston North, New Zealand(Massey University, 2019) Venkatachalam, DinakaranPainful husbandry procedures are routinely performed in farm animals all over the world. Most of these procedures can be humanely performed under local anaesthesia. Lignocaine is the most commonly used local anaesthetic in veterinary medicine. Even though lignocaine is a cheap and effective local anaesthetic, its use in goat kids and deer has been a concern. In goat kids, lignocaine has been reported to produce toxicity following cornual nerve block. In deer, the presence of lignocaine residue in the harvested velvet antlers following ring block has been a concern as one of its metabolites, 2,6-dimethylaniline (DMA) has been classified as a possible carcinogen in humans. Articaine hydrochloride is an amide-type local anaesthetic with unique pharmacological properties such as rapid hydrolysis in plasma to an inactive metabolite and high lipid solubility. It is widely used in humans for local and regional nerve blocks in dentistry. Several studies in humans suggested that articaine hydrochloride was effective and safer than lignocaine. Given concerns on the use of lignocaine in goat kids and deer, a series of studies were conducted to evaluate the safety and efficacy of articaine hydrochloride as an alternative to lignocaine hydrochloride for disbudding in goat kids and velvet antler removal in deer. As there is a paucity of data on the toxicity of lignocaine in goat kids, the thesis has also investigated the toxicity of lignocaine hydrochloride in goat kids. In addition, novel analgesic and disbudding techniques for goat kids were evaluated. The dose-ranging studies in goat kids suggested that doses up to 8 mg kg–1 and 7 mg kg–1 of articaine hydrochloride and lignocaine hydrochloride, respectively, can be safely used for perineural injections. Pharmacokinetic studies demonstrated that articaine hydrochloride was rapidly hydrolysed and eliminated in goat kids. The elimination half-life of articaine (1.26 ± 0.34 hours) was determined to be shorter than the elimination half-lives of lignocaine (1.71 ± 0.51 hours) and lignocaine’s metabolite, monoethylglycinexylidide (3.19 ± 1.21 hours) in goat kids. The total dose of articaine (16.24 ± 1.79 mg kg–1) required to produce convulsions in goat kids was higher than that of lignocaine (12.31 ± 1.42 mg kg–1). The mean convulsive plasma concentrations of articaine and lignocaine were 9.90 ± 2.38 µg mL–1 and 13.59 ± 2.34 µg mL–1, respectively. Both pharmacokinetic and toxicity data indicate that articaine has a greater margin of safety than lignocaine in goat kids. Cornual nerve block (0.5 mL/site) using articaine hydrochloride (1.5%) and lignocaine hydrochloride (1%) alleviated the acute pain during disbudding in goat kids. However, both the drugs provided analgesia only for a short time which necessitates the use of non-steroidal anti-inflammatory drugs (NSAIDs) for postoperative analgesia. In addition, the injection of these drugs at four sites to anaesthetise both the horn buds caused stress and pain in goat kids. Therefore, it is recommended to use sedatives and NSAIDs along with local anaesthetics for disbudding goat kids. However, future studies should evaluate the safety and efficacy of this protocol for disbudding in goat kids. Similar to goat kids, articaine was rapidly hydrolysed to the inactive metabolite, articainic acid, and rapidly eliminated in red deer. A ring block around the base of the antlers using 4% articaine hydrochloride (1 mL/cm pedicle circumference) provided effective analgesia for velvet antler removal in red deer. The results of the studies in red deer suggested that articaine could be a safe and effective local anaesthetic for velvet antler removal. Residue analysis of harvested antlers using liquid chromatography–mass spectrometry (LC–MS) method revealed that the concentrations of articaine and lignocaine in the harvested velvet antlers were similar. Further studies to evaluate the safety of articaine and its metabolites are warranted in target species before recommending articaine hydrochloride as an alternative to lignocaine hydrochloride for velvet antler removal. The analgesic efficacy of methoxyflurane and a novel topical local anaesthetic formulation for disbudding in goat kids were evaluated. Both methoxyflurane and the novel topical formulation provided cutaneous analgesia but did not provide sufficient analgesia for disbudding in goat kids. Further research is required to evaluate the efficacy of these novel analgesic techniques. The efficacy of mepacrine and eugenol for disbudding in goat kids were investigated following subcutaneous injection (0.2 mL) under the horn buds. Both eugenol and mepacrine produced necrosis of horn buds in goat kids but failed to stop horn bud growth. Injection of these compounds using a needle (26 G) and syringe was painful but no pain-related behaviours were seen after the injection. Future studies should evaluate different injection volumes and different non-invasive or minimally invasive administration techniques to increase the efficacy of this novel technique. Refinement of this novel technique might provide a simple, fast, safe and effective way to stop horn bud growth in goat kids.Item The barriers to surgical patients' oral intake in the acute hospital setting : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Nutrition and Dietetics, Massey University, Albany, New Zealand(Massey University, 2018) Stone, OliviaBackground: Hospital patients worldwide often do not eat all of their meals, resulting in suboptimal food intakes. These patients are more likely to experience numerous undesirable health outcomes as a consequence of not meeting their nutritional requirements. Aim: To investigate the barriers to surgical patients’ oral intake in an acute hospital setting in New Zealand (NZ). Objectives: To conduct a pilot study to test the usability of the validated Patient Mealtime and Nutrition Care Survey (PMNCS) in a NZ setting, and to adapt the PMNCS to include the most relevant barriers to oral intake in NZ. Further, to conduct a feasibility study to test the effectiveness of the NZ-PMNCS independently, and paired with patient meal observations to confirm the effectiveness of the tool. Methods/Design: A single-centre cross-sectional study conducted at North Shore Hospital, NZ. A sample of 100 surgical in-patients participated in the pilot study and 65 patients in the feasibility study. Results: The most frequently reported barriers were food brought into the hospital by visitors (81.5%) and a loss of appetite (70.8%). Six barrier domains were explored revealing significant findings for: younger (<65 years) compared to older (≥65 years) age associated with more hunger domain barriers (1.47 ± 0.81 versus 0.90 ± 0.67, P=0.003); longer (>5 days) versus shorter (≤5 days) length of stay associated with more food quality domain barriers (1.20 ± 1.26 versus 0.40 ± 0.81, P=0.003). Comparing the NZ-PMNCS and meal observation results showed that patients consuming ≤½ of their meals more frequently reported inability to make informed menu choices (50.0%)(P=0.027) and that consumption of their prescribed nutritional supplements affected their food intake negatively (50%)(P=0.001). Conclusion: Compared to earlier studies using previous versions of the PMNCS, the NZ-PMNCS captured similar results in the NZ hospital setting. Key issues identified include a younger age being associated with experiencing more hunger domain barriers, and patients consuming less food experienced difficulty choosing menu options and found prescribed nutritional supplements interfered with their food intake. The NZ-PMNCS was practical to use and feasible in identifying barriers to food intake. These findings could contribute to changing practices to improve hospital food intake. Keywords: barriers, oral intake, foodservice, surgical patients, hospitalItem A study of the effects of total prostatectomy on urethral function of the dog : a thesis ... for the degree of Master of Veterinary Science in Surgery.(Massey University, 1974) Bergman, Marcia McMurdyThe function of the proximal urethra was studied in twelve dogs both before and after prostatectomy by means of repeated intraurethral pressure recordings and micturating cystograms. The animals were destroyed at times from one to three months after surgery and their pelvic urethrae were studied histologically and compared with a further group of intact dogs. Throughout the experiments, a series of routine urine chemical, physical and bacteriological tests and blood chemical and cytological examinations were performed. In addition, daily observations were made of the clinical state of urinary control. A general pattern of intraurethral pressure was found to exist. Although individual variations occurred, the pattern recorded from a given animal was reproducible. In general, pressures were higher within the penile urethra than within the pelvic portion. A small pressure rise occurred at the bladder neck and another near the membranous and prostatic urethral junction. Preoperative intraurethral pressure was relatively constant within the membranous urethra. Micturating cystography revealed the prostatic urethra to be a distensible structure and the penile urethral lumen was generally narrower than the pelvic region both before and after surgery. Following prostatectomy, lower pressures were recorded throughout the pelvic urethra. Mean pre- and postoperative pressures at specific locations were subjected to statistical comparison and a significantly lower pressure was found following surgery at only one of the areas considered, that one near the mid-pelvic urethra. Pressure recordings performed soon after surgery were found to be invalid, probably due to postoperative swelling within the urethra. Areas of postoperative stricture formation, when they occurred, were marked by spikes on the pressure tracing. The histological structure of the pelvic urethra was characterized by a predominant striated muscle component extending from the caudal aspect of the prostate to the urethral bulb. Smooth muscle fibers of the prostate were continuous cranially with the bladder and caudally with the membranous urethra where they formed a minor portion of the wall. After surgical removal of the gland, striated muscle fibers constituted the main urethral muscular component. A highly vascular submucosal layer was conspicuous throughout the pelvic urethra. Diagrams of urethral muscular arrangement were composed from a study of the intact and prostatectomized animals. There were few clinical complications following the initial recovery period after prostatectomy. One dog exhibited mild stress incontinence. Two others developed urethral strictures. All animals were in good physical condition when electively destroyed. The results of the experiment suggest that the prostatic urethra is not an essential structure for urine control although the slightly higher urethral pressures in the caudal prostatic urethra where there is both a smooth and striated muscle component, imply that this region normally plays some role in urethral closure. The function of striated muscle tone in urinary control is probably increased after prostatectomy.Item The applications of sub-Tenon's anaesthesia for canine ophthalmic surgery : a thesis presented in fulfilment of the requirements for the degree of Master of Veterinary Science (MVSc) at Massey University, Manawatu, New Zealand(Massey University, 2016) Bayley, Kellam DavidSub-Tenon's anaesthesia is an indispensable anaesthetic technique in human ophthalmic surgery. It produces highly effective regional anaesthesia and has a significantly lower complication rate than the previously used peribulbar and retrobulbar injections. Although this technique has potential application to veterinary ophthalmology it has not yet been reported in clinical cases. This thesis reviews the literature that references local anaesthesia for ocular surgery in human and veterinary ophthalmology. A sub-Tenon's block technique that was specifically developed for use in dogs is also described. This technique is assessed with a prospective controlled clinical study testing this technique across a variety of ocular surgeries including enucleation, intrascleral prosthesis, keratectomy with a third eyelid flap and cataract surgery. The effect of sub-Tenon's anaesthesia on specific parameters was recorded and compared to the controls such as; globe position and rotation, pupillary dilation, general anaesthetic monitoring parameters, intraocular pressure, vitreal expansion and post-operative pain scores. Analysis of these parameters has indicated that sub-Tenon's anaesthesia was an effective option for controlling post-operative pain when used in conjunction with systemic analgesics and was an excellent alternative to systemic neuromuscular blockade for canine cataract surgery.