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A Quality Assurance Framework For Sulphonic Acid-Coated Sand Used In 3D Printing Applications
Get PDFArticleThe need for companies to adopt a quality management strategy has significantly increased in recent times as a result of global competition and more demanding customers. It is important to integrate quality throughout the product lifecycle, which includes the design phase. The purpose of the paper is to develop a quality assurance framework for the local production of chemical-coated sand used in the Voxeljet VX1000 printing process. The framework could be used as a basic structure to develop the necessary processes, procedures, and work instructions to ensure the quality of local chemical-coated sand
Efficacy of Different Disinfectants on Isolated and Biofilmbiofilm-Associated Yeast from a Beverage Production Facility
No full textThesisIn the food industry, disinfectants are routinely used to sanitize and disinfect product contact surfaces. These disinfectants provide a necessary and required step to ensure that the foods produced and consumed are as free as possible from microorganisms that can cause foodborne illness and spoilage. Disinfection is the reduction, by means of chemical agents and/or physical methods, of the number of microorganisms in the environment to a level that does not compromise food safety or suitability.
Disinfection can be inadequate and cause unwanted issues such as spoilage which can result in product recalls. Factors which can cause inefficient disinfection include: incorrect dilution of chemicals, inadequate contact time, not cleaning the surface before the disinfection stage or not using a suitable disinfectant. Other factors can include and the presence of biofilms which make the process more challenging or the development of resistance to disinfectant actions.
Sometimes, it is thought that microbial resistance is present when actually the organisms are avoiding contact with the disinfectant because a biofilm is present. Biofilms are polysaccharides that allow attachment to most surfaces. Over time, the film becomes enhanced and may contain different species of bacteria or yeast yielding a constant source of contamination which then reflects as ineffective disinfection is taking place.
In a previous study, 20 yeast species were isolated from final concentrated beverage products and on direct food contact surfaces after the disinfection process, alluding to the fact that the disinfection process was insufficient for a processing facility producing concentrated beverages. Eight disinfectants displaying oxidative and non-oxidative modes of action with active ingredients including peracetic acid, didecyl dimethyl ammonium chloride, iodine and potassium iodide, chlorine and oxygen dissolved and volatile secondary metabolites were tested using the minimum inhibitory concentration (MIC) 96 well broth dilution laboratory protocol. The MIC was performed by five minutes contact time on the 20 yeast isolates at uniform growth numbers against the eight disinfectants, followed by incubation and visual determination of the point where inhibition stopped. The MIC results yielded two disinfectants with didecyl dimethyl ammonium chloride (DDAC2) active ingredient which displayed 100% inhibition at a maximum concentration of 0.1% usage against the 20 yeast isolates tested compared to ranges of 0% to a maximum of only 20% inhibition achieved by the remaining disinfectants.
The two disinfectants, being quaternary ammonium compounds (QAC’s) which had only different concentrations of the active ingredient, were then subjected to facility trial protocols for a period of six months to determine if the action displayed in the laboratory results was also applicable on industrial scale application. The facility trial sampling focused on the direct food contact surfaces which would promote biofilm development, namely the filler line nozzles. Sampling included swabs of nozzles, before disinfectant changeover, two weeks, two months and six months after changeover respectively.
Both disinfectants used during the facility trial showed positive results in terms of yeast growth reductions where one disinfectant which contained a higher concentration of DDAC2 in particular showed 94.5% reduction in number of colonies counted obtained from nozzle swabs within two months of use. Both disinfectants would also result in a significant cost saving initiative for the facility.
Culturable yeast diversity changes during the trial were studied using denaturing gel electrophoresis (DGGE). DGGE results provided further information on which yeasts both or one of the disinfectants tested were able to inhibit. These included Candida sojae, Pichia occidentalis, Rhodotorula dairenensis, Sporidiobolus sp. and Rhynchogastrema noutii as well as an uncultured isolate. Lodderomyces elongisporus and Kazachstania exigua however, were not inhibited during the facility trial by both disinfectants.
The industrial trial demonstrated that QAC disinfectant rather than an acid based product yielded better disinfection in the particular facility. The study identified shortcomings in protocols where an unsuitable growth medium was utilized which caused an underestimation of yeast load present in nozzles. The identification of these aspects will prove advantageous to the facility to improved monitoring protocols and provide a true representation of the yeast load in filler nozzles. In conclusion the more efficient disinfectant with capabilities to better prevent biofilm development was identified. L. elongisporus and K. exigua were however not inhibited by these disinfectants and further exposure is necessary to determine the extent of tolerance/resistance. The findings of the study will assist to prevent the occurrences of spoilage experienced by the facility resulting in reduced financial losses and brand protection and provides opportunities for further studies
Chemistry And Biotransformation Of Uapaca kirkiana Pulp In Development Of A Functional Food Using A Probiotic
Get PDFThesisModern advances in understanding the relationship between nutrition and health have resulted in the development of the concept of functional foods, which is a new practical approach earmarked to promote optimal health status. Underutilised wild fruits have great potential to improve overall human nutrition and help to mitigate malnutrition related problems faced by most communities in Sub-Saharan Africa. This research focused on the chemistry and biotransformation of Uapaca kirkiana pulp in the development of a functional food using a probiotic, Lactobacillus rhamnosus yoba. Lactobacillus rhamnosus yoba is a Gram negative, lactic acid bacterium, and generic probiotic of L. rhamnosus GG. The specific objectives of the study were the following: to determine the bioactive compounds, physiochemical properties, and functional potential of a highly nutritious, but underutilized U. kirkiana Muell. Arg (wild loquat) fruit; to produce a probiotic jam; to determine the functional properties of the jam and the bioaccessibility of iron and zinc, and its sensorial qualities. Ripe fruits were obtained from the Bikita, Gokwe, and Kazangarare areas in Zimbabwe and the bioactive phytochemical constituents, physicochemical properties and functional characteristics of the fruit pulp were analysed. The total soluble sugars, individual sugars and mineral contents in the fruit pulp were determined. Ascorbic acid was determined using the 2,6-Dichlorophenolindophenol (DCPIP) titration test. The total phenolic, tannin, and flavonoid contents were analysed using the Folin-Ciocalteu test, tannin binding test, and vanillin test, respectively. A composite pulp sample was obtained and its physicochemical properties (vitamin C, total titratable acid (TTA), pH, total soluble solids (TSS), antioxidant activity (AOA), moisture, and % pectin) were analysed before jam making. A probiotic jam was developed using the formulation- 55 % (wt/vol) pulp, 46 % (wt/vol) sugar, 1.5 % (wt/vol) pectin, and 0.5 % (wt/vol) citric acid. After preparation of the jam, the probiotic, L. rhamnosus yoba was inoculated into the jam, and the control jam sample was inoculated with distilled water. The viability of L. rhamnosus yoba in the jam was determined before consumption. Functional properties (vitamin C, total titratable acid (TTA), pH, total soluble solids (TSS), antioxidant activity (AOA), and moisture) of the jam inoculated with L. rhamnosus yoba were determined. Iron and zinc bioaccessibility in the probiotic jam were analysed using the in vitro simulated digestion protocol. The sensory evaluation of the jam was conducted by trained (n = 20) and untrained (n = 130) panellists. Sensory attributes, including taste, appearance, aroma, spreadability, mouthfeel, and texture were scored using a 9 point hedonic scale. A triangle test and preference test for overall acceptance were conducted. Pulp yield ranged from 12.15 ± 0.16 g/100 g to 15.09 ± 0.27 g/100 g and was significantly different (F = 158.71, p < 0.0001) in all fruits from the three study areas, and accounted for 96 % of the variation in the fruit. The TTA (0.3–0.48 g/kg) and pH (4.3–4.6) values of the pulp were significantly different (F = 12.58; P<0.0001 and F = 15.66, P< 0.0001, respectively) in fruits obtained from the three sampling areas. Fruit properties varied amongst the three study site and this was contributed by pH (74 %) level and TTA (69 %) content. The TSS (sugar content) was significantly different (F = 4.66, P < 0.0071) and accounted for 45 % of the fruit variation. There was a strong relationship between TTA and pH (r2 = 0.79); TTA and antioxidant (r2 = 0.72); and pH and phosphorus (r2 =0.81). The iron content ranged between 11.25 ± 0.52 mg/100 g to 12.16 ± 0.54 mg/100 g. Phosphorus, sodium and iron accounted for approximately 73 %, 50 %, and 43 % of the variation, respectively. The vitamin C content accounted for 27 % of the variation. Fructose was the dominant sugar. Tannins, flavonoids, and gallotannins were present. The fruit pulp had a total phenolic content of 67.0–82.5 μg GAE/g. Principal components 1 and 2 which represented physiochemical and functional properties of the pulp had eigenvalues of 5.59 and 2.13, and a variability of 37.31 % and 14.17 %, respectively. The jam inoculated with L. rhamnosus yoba had a vitamin, TTA, brix, and moisture content of 0.34 ±0.02 mg/100 g, 2.2 ± 0.11, 68.5 ± 0.2, and 34.8 ± 1.2, respectively. The fruit pulp had an antioxidant activity of 35 ± 1.02 %. Immediately after production, the jam inoculated with L. rhamnosus yoba had an iron and zinc content of 4.13 ± 0.52 mg/100 g and 0.36 ± 0.02 mg/100 g, respectively. The jam inoculated with L. rhamnosus yoba exhibited high fructose and sucrose content of 12.84 ± 0.21 g/100 g and 24.61 ± 0.12 g/100 g, respectively. Further, the jam inoculated with L. rhamnosus yoba had a TTA content of 2.2 at d 0 (after production), 2.37 ± 0.01 at d 4, and 2.48 ± 0.02 at d 7 of storage (25 °C). The jam inoculated with L. rhamnosus yoba had an iron bioaccessibility of 6.55 ± 0.36 % and a zinc bioaccessibility of 16.1 ± 0.50 %. The use of L. rhamnosus yoba in the jam showed a 4 % and 2 % increase in the iron and zinc bioaccessibility, respectively. L. rhamnosus yoba jam had mean scores of 7.5, 7.0, 6.0, and 6.5 for spreadability, taste, appearance, and mouthfeel, respectively. The jam inoculated with L. rhamnosus yoba had an overall acceptance score of 7.5 (n = 120). The good chemical and functional properties of the fruit pulp resulted in the utilisation of the fruit pulp in producing a probiotic jam through the biotransformation of nutrients. The fruit jam was able to deliver 6.2 ± 0.2 log CFU/mL live L. rhamnosus yoba cells, which make it a good probiotic food with possible functional benefits
An Artificial Intelligence Energy Management System For An Education Building
Get PDFThe study of energy demand and consumption has become a topic of increasing importance as a result of the growing interest in energy sustainability. In the present energy crisis of South Africa, where Eskom is currently the only electricity provider, it cannot always meet the electricity needs of the customers. Therefore, the consideration of electrical power savings in education buildings can play a huge role, which was implemented in this study.
University campuses represent a specific group of various buildings with significant energy demands and consumptions. Due to the various buildings, a University campus can be seen as a small town on its own, therefore, it offers an excellent test bed to monitor energy consumption and to understand the demand for electricity of the different buildings.
In addition, it was possible to predict with an artificial intelligence concept using different prediction models when peak load will occur and to determine a maximum demand. A suitable database for the Engineering Technology Building (ETB) at the Central University of Technology (CUT), Free State, was created and available data of the electricity energy usage were collected and analysed for this purpose, with the aid of utilising methods, namely Moving Average, Straight Line and Kalman Filter. The available data were tested and evaluated by the switchgear, according to the priority list, and it proved to be successful. There was a total saving of approximately 5.83% on the power consumption per day. This proved to work well and a greater percentage of savings could be achieved by switching another circuit breaker according to the priority list
Assessment Of Moringa Oleifera And Xylopia Aethiopica Extracts For Their Preservative Potential In Fruit Juice
Get PDFDissertationThe chemical compounds used as preservatives in fruit juices have been associated with many health problems. Hence, it is imperative to find safer alternatives from natural sources such as plants. This study assessed Moringa oleifera and Xylopia aethiopica extracts for their preservative potential in fruit juice based on their phytochemical contents, antioxidant activities and anti-yeast properties. Qualitative phytochemical analysis showed that M. oleifera extracts contained alkaloids, tannins, saponins, glycosides, terpenoids and flavonoids but the water extracts lacked alkaloids. The same phytochemicals, except terpenoids, were also found in all X. aethiopica extracts. The antioxidant activity determined using 2, 2- dipheny- 1- picrylhydrazyl (DPPH) and the total phenolic content expressed as Gallic Acid Eqivalent (GAE/g), indicated that the plant extract with the highest antioxidant activity (IC50) also had the highest total phenolic content (GAE/g). The methanol extract of M. oleifera had IC50 of 48.09 μg/mL and GAE/g of 110.0 mg while the acetone extract of X. aethiopica had IC50 of 19.10 μg/mL and GAE/g of 173.2 mg. The agar dilution assay was used to evaluate the anti-yeast activity of the extracts in vitro against fruit juice spoilage yeasts. The methanol extract of M. oleifera had the strongest anti-yeast activity and was specifically fungicidal against the CY0757 and IGC4242 strains of Zygosaccharomyces bailii and Wickerhamomyces anomalus. The acetone and water extract were poor growth inhibitors. All M. oleifera extracts showed stimulatory activity on Yarrowia lipolytica which has been reported as beneficial in biofuel production. The best anti-yeast activity for X. aethiopica was shown by the methanol extract which was fungicidal against Zygosaccharomyces bailii IGC4242 and Cryptococcus laurentii. The acetone extract of X. aethiopica exerted inhibitory activity against most of the yeasts. The water extract showed the least bioactivity. The anti-yeast activity of plant extracts in fresh grape and orange juice showed microbial overgrowth in the untreated fruit juices used as controls, indicating the presence of contaminants in treated fruit juices. The Hoechst 33342 and propidium iodide dual staining procedure showed that M. oleifera extracts were not cytotoxic on normal Vero cells. The water extract of X. aethiopica also did not show toxicity on the cells. The methanol and acetone extract were, however, very toxic on the cells. This study demonstrates that although M. oleifera and X. aethiopica extracts have limited potential as natural preservatives in fruit juice, the growth stimulatory activity of M. oleifera extracts on Y. lipolytica may be useful in biofuel production and this requires further investigation
Profile Of Coronary Artery Disease Patients At Universitas Academic Hospital: 1994 Versus 2014
Get PDFDissertationIntroduction
Coronary artery disease (CAD) is a condition that decreases the flow of blood through the coronary arteries around the heart (Merriam-Webster Incorporated, 2019) that can lead to a heart attack (Yayan, 2014). It is the leading cause of death worldwide (Nowbar et al., 2019) and there are several risk factors that contribute to its development (Fuster and Kelly, 2010). Non-modifiable risk factors are age, gender and ethnicity/race and family history, while modifiable risk factors include hypertension, hypercholesterolemia, obesity and sedentary lifestyle, diabetes mellitus and smoking (Jaggi & Kearns, 2012; Winham et al., 2014; Yayan, 2014; Papadakis & McPhee, 2016; Nowbar et al., 2019).
While it is reported that CAD in Sub-Saharan Africa is rare (Forouzanfar et al., 2012) reports from the World Health Organization (WHO) African region suggest that non-communicable diseases in this region are on the rise (World Health Organization African Regional Office, 2018). However, epidemiological data of this region is scanty. The only major studies available for South Africa (SA) are the Heart of Soweto study and the work of Prof. Bongani M Mayosi which report that the prevalence of modifiable risk factors for CAD is high and rising, especially in the black African population (Sliwa et al., 2008; Tibazarwa et al., 2009; Mayosi et al., 2009; Pretorius et al., 2011; Mayosi et al., 2012; Mayosi & Benatar, 2014), emphasizing the need for epidemiological studies into this phenomenon (Stewart et al., 2006; Sliwa & Mocumbi, 2010; Senkubuge & Mayosi, 2013).
No CAD data exists for central SA. The profile of patients of patients presenting with CAD at Universitas Academic Hospital (UAH) have not been documented in the past.
Aim
To document the profile of public sector patients who had confirmed CAD (on coronary angiography) in central SA and determine if there was a change over twenty years.
Methods
This was a retrospective single-centre observational cohort comparing two time periods, twenty years apart, conducted at UAH, Bloemfontein. The main inclusion criterion was confirmed atherosclerotic CAD as reported on coronary angiography. Medical records/data of all public sector patients who underwent coronary angiography during 1994 and 2014 were evaluated. Demographic data, which forms part of the non-modifiable risk factors for CAD, and other relevant clinical information was recorded. Results
Acute coronary syndrome (ACS) increased over the study period (p<0,0001) and this can be attributed to a notable increase in both Non-ST-Elevation Myocardial Infarction (NSTEMI) (p<0,0001) and ST-Elevation Myocardial Infarction (STEMI) (p<0,0001). Unstable angina decreased significantly over the study period (p<0,0001). There was a significant increase in the number of African patients who experienced STEMI over the study period (p<0,0001) and there was a substantial decrease in Caucasian patients who had ACS (p=0,0015). While NSTEMI increased significantly in Caucasian patients (p<0,0001), unstable angina in this group decreased significantly (p<0,0001).
Females with ACS presented 4 years earlier in 2014 than those in 1994 (1994 median age = 66 years vs. 2014 median age = 62 years) (p=0,0031, 95% CI 1,3941; 6,7202). This trend was predominantly demonstrated in Caucasian females only (1994 median age = 66 years vs. 2014 median age = 62 years; p=0,04811, 95% CI 0,0276; 6,5743). The age of females with STEMI decreased significantly from 1994 (median age 69 years) to 2014 (median age 60 years) (p=0,0119; 95% CI 1,4195; 10,8305). Females with unstable angina were six years younger in 2014 (median age 60 years) than in 1994 (median age 66 years) (p=0,0269, 95% CI 0,5800; 9,1978). Caucasian females with NSTEMI was markedly older in 2014 (median age 66 years) than in 1994 (median age 50 years) (p<0,0001, 95% CI -19,7368; -12,8882), while those with STEMI became younger (1994 median age = 69 years vs. 2014 median age = 60 years, p=0,0269; 95% CI 0,9640; 14,6464).
Conclusions
There was an epidemiological change in public sector patients who had confirmed CAD in central SA with CAD increasing in patients of African and mixed ethnicity. ACS rose significantly over time with females presenting at a significantly younger age. STEMI became the most important presenting condition in patients of African ethnicity whilst NSTEMI increased in Caucasian patients. These findings have important implications for central SA public sector patients presenting with chest pain – the risk of STEMI in patients of African ethnicity is increasing and should not be ignored by clinicians
An Investigation Of The Phytochemistry And Biological Activity Of Tulbaghia Violacea
Get PDFDissertationMedicinal plants are the most important source of life saving drugs for most of the world’s population. The aim of this study was to assess Tulbaghia violacea as an anticancer agent, to determine the antimicrobial activity, anticancer activity, antioxidant and total polyphenol activity, cytotoxicity and genotoxicity effects to be used in the development of a novel anticancer remedy. Tulbaghia violacea bulb, root and leaf extracts were collected, dried and finely ground with aqueous and methanol/dichloromethane solvents. The extracts were tested for their growth inhibitory effects using the sulforhodamine B assay; genotoxicity activity was determined using NucRed Live 647; antimicrobial activity was determined using p-Iodonitrotetrazolium chloride assay; antioxidant activity was determined using 2,2-diphenyl-1-picrylhydrazyl assay; and the gallic acid method was used to determine the concentration of phenols. The extracts from T. violacea were classified as weak or inactive against the human cell lines TK-10 (renal), PC3 (prostate) and HeLa (cervix) cancer. Aqueous and methanol/dichloromethane extracts of T. violacea were both non-toxic when tested against the WI-38 cell line. The result of the test for genotoxicity determination showed that leaf water extract induced the formation of micronuclei and could be considered genotoxic. The extract of T. violacea exhibited high antioxidant activity compared to the standard. Total phenolic determination showed that water leaf extract had the highest concentration of phenolics and bulb methanol/dichloromethane extract the lowest. The antibacterial activity showed interesting results with certain plant extracts, indicating Gram specificity. Water leaf extracts and water bulb extract from T. violacea both showed activity against Klebsiella pneumoniae (Gram-negative) but not against Staphylococcus aureus (Gram-positive). Root water extract showed a similar result at the lower concentrations. The high concentrations of root methanol/dichloromethane extract showed a more drastic increase in the percentage cell death of S. aureus than that of K. pneumoniae. Methanol/dichloromethane bulb extract also seemed to be effective against S. aureus. The extracts of T. violacea have the potential to be developed as an antimicrobial agent, but the standard has higher antimicrobial activity. These results indicated the safety and importance of T. violacea as a potential for the development of a novel drug
Assessing Technology Adoption At A University Of Technology: A Case Study Of Electronic Response System
Get PDFDissertationTechnology adoption is defined as accepting and using a new technology in order to improve delivery, service or performance. One such new technology is an Electronic Response System, called clickers that may be used to leverage classroom participation. ERS is a system that consists of a device used by students in conjunction with an electronic USB transceiver, connected to a personal computer. One of the advantages of ERS is to help passive students become more actively engaged with course material during classroom time, while helping academics to monitor student learning. Despite the advantages of using ERS in education, some academics fail to adopt this new technology into their teaching practice. This study aims to present factors that may help to promote the use and adoption of an ERS at a University of Technology. A non-experimental research design, incorporating a descriptive case study with quantitative data is used with convenient sampling. A small-scale preliminary study was undertaken in order to test the questionnaire as the main data collection instrument. A convenient sample of 20 academics from the Central University of Technology participated in this. A total of 57 academics then participated in the main study, using a questionnaire structured around the four main constructs of Venkatesh’s Unified Theory of Acceptance and Use of Technology (UTAUT) model.
The four constructs are Performance Expectancy, Effort Expectancy, Facilitating Conditions and Social Influence. Performance Expectancy is the level to which an individual believes that using the system will help him or her to achieve achievements in job performance. Effort Expectancy is defined by the level of ease regarding the use of technology sustained in systems. Social Influence is defined as the level to which an individual perceives the importance of a technology, based on the perceptions of others. Facilitating Conditions refers to the extent to which a person perceives that a technical and organizational infrastructure is available for the intended system. The UTAUT model aims to explain user intentions to use an information system. The main advantage of this model is that it focuses on user behaviour towards new technologies. Three of the four variables in the UTAUT model were selected, being age, experience and gender. The fourth variable, voluntariness of use, was not included as it is associated with mandatory use of a new technology. This is not applicable to this study as academics have the freedom to choose whether to adopt ERS or not, into their teaching practice. Statistical results suggest that there is a strong relationship between Performance Expectancy, Effort Expectancy and Facilitating Conditions towards the use of ERS. Social Influence has a moderate relationship in this regard. The results also indicate that age, experience or gender, play no significant role in the adoption of such a system. Based on these results, there is a need to create awareness among all academics, irrespective of their age, experience or gender, of the importance of adopting ERS in their teaching practice to further student learning
Supplemental Oxygen Therapy in COVID-19
Get PDFArticleSouth Africa face a significant shortage of ventilator-supported intensive care (ICU) beds during the peak phase of the COVID-19 pandemic, further exacerbated by severe ICU-staff shortages. It is also recognised that the mortality rate for ventilated patients might be as high as 88%. In the absence of a vaccine and proven effective pharmacotherapy, it is important to understand the pathophysiological processes causing progression. Early type-L COVID-19, associated with pulmonary thrombo-embolism, may be amenable to treatment with careful anti-coagulation and supplementary oxygenation strategies. This could attenuate the severe hyperventilation phase causing patient self-inflicted lung injury (P-SILI) that contributes to the development of type-H COVID-19 pneumonia. Type-H is an ARDS variant requiring intubation and ventilation and is associated with a very high mortality rate. Stepwise non-invasive positive pressure ventilation strategies (NIPPV) providing supplementary oxygen have shown benefit and, in the South African context, may be the only realistic strategy to deal with high numbers of patients during the early type-L phase of the disease. To address this, a mobile wall unit has been created that allows for stepwise supplementary oxygen therapy according to protocol – including NIPPV as well as standard ventilation. The unit can support modified wards, field hospitals or high care areas in existing facilities. It allows for NIPPV support within a hood system linked to scavenger lines addressing aerolisation. Standard humidification, flow regulators, vacuum systems, HFNC and CPAP systems, as well as monitoring equipment that are readily available in South Africa, can be linked to the system addressing availability issues
A Comparison Of Preoperative Hypoalbuminaemia With The NNIS And SENIC Risk Scores For The Prediction Of Surgical Site Infection In A South African Setting
Get PDFArticleIntroduction: Preoperative hypoalbuminaemia is a risk factor for surgical site infection (SSI) in the South African (SA) setting. However,
the predictive accuracy of preoperative hypoalbuminaemia has not been tested against established SSI risk stratification models in
our setting, which could have important implications for SSI prevention strategies. With reference to SSI in SA settings, the study
objective was to compare the overall predictive accuracy of preoperative hypoalbuminaemia with that obtained for the SENIC/NNIS
risk scores.
Method: This was a sub-analysis of a pre-existing laparotomy patient registry (N = 439). Variables collected as part of the registry
included preoperative serum albumin measurements and all parameters of the SENIC/NNIS risk scores. Preoperative hypoalbuminaemia
was defined as preoperative serum albumin of < 30 g/L. The study outcome was SSI up to 30 days postoperatively. Overall predictive
accuracy was determined through a receiver-operator-characteristic (ROC) curve analysis, with results presented as C-statistics (95%
confidence intervals [CI]).
Results: The C-statistics obtained for preoperative hypoalbuminaemia, the SENIC risk score, and the NNIS risk score were 0.677
(CI: 0.609–0.746), 0.652 (CI: 0.582–0.721), and 0.634 (CI: 0.563–0.705).
Conclusion: All three methods display similar predictive accuracy for SSI. However, preoperative hypoalbuminaemia has several
practical advantages over the SENIC/NNIS scores which must be considered