Base teórica: Muitos pacientes internados em Unidade de Terapia Intensiva (UTI) necessitam da instituição da ventilação mecânica invasiva (VM). Porém esta pode trazer efeitos deletérios como: alteração na higiene brônquica e pneumonia associada à ventilação mecânica (PAV). Devido a isso, faz-se necessária avaliação de técnicas de higiene brônquicas eficazes e o menos deletérias possíveis. Objetivos: Comparar a eficácia das técnicas em estudo: vibrocompressão (VB) (G1), hiperinsuflação com o ventilador mecânico (HMV) (G2) VB + HMV (G3) na quantidade de secreção aspirada (SEC), no tempo de VM, na incidência de PAV, na reintubação orotraqueal (Re-IoT) e na mortalidade de pacientes em VM. Método: Ensaio clínico randomizado, realizado no Centro de Terapia Intensiva do Hospital de Clínicas de Porto Alegre (HCPA). Foram incluídos no estudo 93 pacientes (29 G1, 32 G2 e 32 G3) em VM por mais de 24 horas. Foram aplicadas as seguintes técnicas: aspiração isolada (ASP), VB, HMV e VB + HMV. Foram medidas as seguintes variáveis: frequência cardíaca (FC), frequência respiratória (FR), pressão arterial média (PAM), saturação arterial periférica de oxigênio (SpO2), pressão inspiratória de pico (PIP), volume corrente (VC), complacência dinâmica (Cdyn), peso da SEC; tempo de VM, Re-IoT, incidência de PAV e mortalidade na VM. Conclusão: O grupo 3 foi o único que apresentou aumento significativo da SEC, quando comparado à ASP (0,7 g (0,1-2,5) vs 0,2 g (0,0-0,6) – p = 0,006). Em comparação com os demais grupos, o grupo 2 apresentou aumento significativo na incidência de PAV (22% - p = 0,003) e Re-IoT (21,9% - p = 0,048), demonstrando assim, na amostra estudada, que VB + HMV é mais eficaz quanto à quantidade de SEC e exerce efeito protetor, juntamente com a VB, na incidência de PAV e Re-IoT. / Background: Many patients admitted to the Intensive Care Unit (ICU) require the institution of invasive Mechanical Ventilation (MV). However, this can bring harmful effects such as changes in mucociliary transport and cough capacity, leading to bronchial obstruction and Ventilator Associated-Pneumonia (VAP). Objective: To compare the efficacy of the techniques: Vibrocompression (G1), Hyperinflation with Mechanical Ventilation (G2) Vibrocompression + Hyperinflation with Mechanical Ventilation (G3) in the amount of Aspirated Secretions (AS), MV time, the incidence of VAP, Re-intubation tracheal (Re-IoT) and mortality of patients on MV. Method: Randomized clinical trial, conducted at the Intensive Care Unit, of the Hospital de Clinicas de Porto Alegre (HCPA). 93 patients were included in the study (29 G1, 32 G2 and 32 G3) in mechanical ventilation for more than 24 hours. The following techniques were applied: Isolated Aspiration (ASP), Vibrocompression (VB), Hyperinflation with Mechanical Ventilation (HMV) Vibrocompression + Hyperinflation with Mechanical Ventilation (HMV + VB). The following variables were measured: Heart Rate (HR), Respiratory Rate (RR), Mean Arterial Pressure (MAP), Peripheral Arterial Oxygen Saturation (SpO2); Peak Inspiratory Pressure (PIP), Tidal Volume (TV); Dynamic Compliance (Cdyn); weight of the AS; VM time; Re-IoT; VAP incidence and mortality in the VM. Conclusion: The HMV + VB (G3) was the only group that showed significant increase in the AS (0.7 g (0.1-2.5) vs 0.2 g (0.0-0.6) – p = 0.006) when compared to ASP. Compared with the other groups G2 showed a significant increase in the incidence of VAP (22% - p = 0.003) and Re-IoT (21.9% - p = 0.048). Thus demonstrating in the sample, which HMV + VB is more effective as the amount of secretion aspirated and has a protective effect, along with the VB, the incidence of VAP and Re-IoT.

Base teórica: Muitos pacientes internados em Unidade de Terapia Intensiva (UTI) necessitam da instituição da ventilação mecânica invasiva (VM). Porém esta pode trazer efeitos deletérios como: alteração na higiene brônquica e pneumonia associada à ventilação mecânica (PAV). Devido a isso, faz-se necessária avaliação de técnicas de higiene brônquicas eficazes e o menos deletérias possíveis. Objetivos: Comparar a eficácia das técnicas em estudo: vibrocompressão (VB) (G1), hiperinsuflação com o ventilador mecânico (HMV) (G2) VB + HMV (G3) na quantidade de secreção aspirada (SEC), no tempo de VM, na incidência de PAV, na reintubação orotraqueal (Re-IoT) e na mortalidade de pacientes em VM. Método: Ensaio clínico randomizado, realizado no Centro de Terapia Intensiva do Hospital de Clínicas de Porto Alegre (HCPA). Foram incluídos no estudo 93 pacientes (29 G1, 32 G2 e 32 G3) em VM por mais de 24 horas. Foram aplicadas as seguintes técnicas: aspiração isolada (ASP), VB, HMV e VB + HMV. Foram medidas as seguintes variáveis: frequência cardíaca (FC), frequência respiratória (FR), pressão arterial média (PAM), saturação arterial periférica de oxigênio (SpO2), pressão inspiratória de pico (PIP), volume corrente (VC), complacência dinâmica (Cdyn), peso da SEC; tempo de VM, Re-IoT, incidência de PAV e mortalidade na VM. Conclusão: O grupo 3 foi o único que apresentou aumento significativo da SEC, quando comparado à ASP (0,7 g (0,1-2,5) vs 0,2 g (0,0-0,6) – p = 0,006). Em comparação com os demais grupos, o grupo 2 apresentou aumento significativo na incidência de PAV (22% - p = 0,003) e Re-IoT (21,9% - p = 0,048), demonstrando assim, na amostra estudada, que VB + HMV é mais eficaz quanto à quantidade de SEC e exerce efeito protetor, juntamente com a VB, na incidência de PAV e Re-IoT. / Background: Many patients admitted to the Intensive Care Unit (ICU) require the institution of invasive Mechanical Ventilation (MV). However, this can bring harmful effects such as changes in mucociliary transport and cough capacity, leading to bronchial obstruction and Ventilator Associated-Pneumonia (VAP). Objective: To compare the efficacy of the techniques: Vibrocompression (G1), Hyperinflation with Mechanical Ventilation (G2) Vibrocompression + Hyperinflation with Mechanical Ventilation (G3) in the amount of Aspirated Secretions (AS), MV time, the incidence of VAP, Re-intubation tracheal (Re-IoT) and mortality of patients on MV. Method: Randomized clinical trial, conducted at the Intensive Care Unit, of the Hospital de Clinicas de Porto Alegre (HCPA). 93 patients were included in the study (29 G1, 32 G2 and 32 G3) in mechanical ventilation for more than 24 hours. The following techniques were applied: Isolated Aspiration (ASP), Vibrocompression (VB), Hyperinflation with Mechanical Ventilation (HMV) Vibrocompression + Hyperinflation with Mechanical Ventilation (HMV + VB). The following variables were measured: Heart Rate (HR), Respiratory Rate (RR), Mean Arterial Pressure (MAP), Peripheral Arterial Oxygen Saturation (SpO2); Peak Inspiratory Pressure (PIP), Tidal Volume (TV); Dynamic Compliance (Cdyn); weight of the AS; VM time; Re-IoT; VAP incidence and mortality in the VM. Conclusion: The HMV + VB (G3) was the only group that showed significant increase in the AS (0.7 g (0.1-2.5) vs 0.2 g (0.0-0.6) – p = 0.006) when compared to ASP. Compared with the other groups G2 showed a significant increase in the incidence of VAP (22% - p = 0.003) and Re-IoT (21.9% - p = 0.048). Thus demonstrating in the sample, which HMV + VB is more effective as the amount of secretion aspirated and has a protective effect, along with the VB, the incidence of VAP and Re-IoT.

Bakgrund: Intuberade patienter inom intensivvården har en hög risk för att erhålla en ventilator-associerad pneumoni (VAP). Det finns evidensbaserade riktlinjer för vuxna somförebygger VAP. För barn behövs det däremot mer forskning för att klargöra vilka omvårdnadsåtgärder som kan standardiseras. Syfte: Syftet är att beskriva vilka omvårdnadsåtgärder som förebygger VAP hos barn inom intensivvården, en litteraturöversikt. Metod: En deskriptiv litteraturstudie med kvantitativ induktiv ansats valdes. 16 kvantitativa studier analyserades med en innehållsanalys. Det samlade materialet kvalitetsgranskades med hjälp av GRADE. Resultat: Fem huvudteman identifierades utifrån studiernas resultat. Huvudteman var VAP-omvårdnadspaket, munvård med klorhexidin, skötsel av endotrakealtub, olika nutritionssonder, omvårdnadsutbildning. VAP-omvårdnadspaket och omvårdnadsutbildning visade sig statistiskt signifikant sänka VAP-prevalensen hos barn. Munvård med klorhexidin kunde inte sänka VAP-prevalensen. Slutsats: Med rätt evidensbaserad vård kan VAP-prevalensen sänkas. Forskning kring VAP-prevention till barn saknar evidens i nuläget och kan ej anses vara evidensbaserad vård. För att göra vården evidensbaserad, rekommenderas att globala riktlinjer för VAP-prevention till barn tas fram. / Background: Intubated patients admitted to an intensive care unit have a higher risk ofacquiring ventilator-associated pneumonia (VAP). There are evidence-based guidelines for adults that prevent VAP. For children there is a need for more research in this area to clarifywhich nursing methods can be standardized. Aim: The aim was to describe which nursing care measures prevent VAP in children admitted to the intensive care unit, a literature review. Method: A descriptive literature study with a quantitative inductive approach was used. A total of 16 quantitative studies was analysed with a content analysis. A GRADE system was used to assess the quality of the included studies. Results: Five main themes were identified from the study’s results. The main themes where VAP-care bundles, oral care with chlorhexidine, care of endotracheal tube, different nutritional catheters, and nursing care education. VAP-care bundles and nursing care education showed to have statistically and significantly lowered the prevalence of VAP in children. Oral care with Chlorhexidine did not lower the prevalence significantly of VAP. Conclusion: The prevalence of VAP can be lowered with the right evidence-based practice. At the current situation research on preventing VAP in children lack evidence and can’t be considered as evidence-based practice. To make the nursing care evidence based, it´s recommended to create global guidelines of VAP-prevention for children.

OBJETIVOS: Estimar a taxa de falência de desmame, identificar fatores de risco para a falência, estimar a taxa de mortalidade na unidade de terapia intensiva e hospitalar em um grupo heterogêneo de pacientes com ventilação mecânica prolongada. MÉTODOS: Trata-se de um estudo de coorte prospectivo de pacientes adultos consecutivamente internados em 11 unidades de terapia intensiva e que receberam ventilação mecânica por 3 dias ou mais. As variáveis de desfecho incluíram o resultado do desmame (falência ou sucesso) e o desfecho da UTI (alta ou óbito).RESULTADOS: Dos 189 pacientes incluídos, 149 (79%) foram desmamados com sucesso e 40 (21%) necessitaram de reintubação dentro de 48 horas, constituindo o grupo falência.Através da análise de regressão logística, o sexo feminino foi identificado como fator independentemente associado com a falência do desmame. Os pacientes com falência permaneceram por mais tempo na UTI (p < 0,01). A freqüência de traqueostomia foi maior no grupo com falência (p < 0,01). A taxa de mortalidade na UTI foi de 21%; IC de 95%: 15-27%. O modelo de regressão de Cox ajustado para a gravidade à admissão na UTI identificou que a falência do desmame aumentou o risco de morte na UTI (RR: 3,08; p < 0,01). CONCLUSÔES: Após o controle para variáveis clínicas e gravidade à internação na UTI, o sexo feminino apresentou associação independente com a falência do desmame. Pacientes com falência apresentaram maior tempo de internação na UTI, maior taxa de traqueostomia e maior risco de morte na UTI / OBJECTIVE: To determine the rate of weaning failure, risk factors, intensive care unit (ICU) and hospital outcomes in a number of heterogeneous patients with prolonged MV. DESIGN, SETTING, AND SUBJECTS: Prospective cohort of consecutive adult patients admitted to 11 ICU who received MV (³ 72 hours). Study endpoints included weaning failure vs success and ICU death vs survival. RESULTS: Of 189 intubated patients, 149 (79%) were succesfully extubated, and 40 (21%) required reintubation within 48 hours.Using multiple logistic regression, female gender was an independent predictor of weaning failure. The mean ICU length of stay was significantly longer in weaning failure group (p < 0.01). The rate of tracheostomy was higher in the failure group (p < 0.01). The ICU mortality rate was 21%; 95% CI, 15 - 27%. In a Cox model adjusting on severity at ICU admission, weaning failure increased the risk of death in the ICU (RR: 3.08; p < 0,01). CONCLUSION: After adjusting for severity of ilness and medical conditions, female gender had a significant independent association with increased risk of weaning failure (WF). WF had association with prolonged ICU stay and higher rate of tracheostomy. Patients with weaning failure were 3 times more likely to die in the ICU

OBJETIVOS: Estimar a taxa de falência de desmame, identificar fatores de risco para a falência, estimar a taxa de mortalidade na unidade de terapia intensiva e hospitalar em um grupo heterogêneo de pacientes com ventilação mecânica prolongada. MÉTODOS: Trata-se de um estudo de coorte prospectivo de pacientes adultos consecutivamente internados em 11 unidades de terapia intensiva e que receberam ventilação mecânica por 3 dias ou mais. As variáveis de desfecho incluíram o resultado do desmame (falência ou sucesso) e o desfecho da UTI (alta ou óbito).RESULTADOS: Dos 189 pacientes incluídos, 149 (79%) foram desmamados com sucesso e 40 (21%) necessitaram de reintubação dentro de 48 horas, constituindo o grupo falência.Através da análise de regressão logística, o sexo feminino foi identificado como fator independentemente associado com a falência do desmame. Os pacientes com falência permaneceram por mais tempo na UTI (p < 0,01). A freqüência de traqueostomia foi maior no grupo com falência (p < 0,01). A taxa de mortalidade na UTI foi de 21%; IC de 95%: 15-27%. O modelo de regressão de Cox ajustado para a gravidade à admissão na UTI identificou que a falência do desmame aumentou o risco de morte na UTI (RR: 3,08; p < 0,01). CONCLUSÔES: Após o controle para variáveis clínicas e gravidade à internação na UTI, o sexo feminino apresentou associação independente com a falência do desmame. Pacientes com falência apresentaram maior tempo de internação na UTI, maior taxa de traqueostomia e maior risco de morte na UTI / OBJECTIVE: To determine the rate of weaning failure, risk factors, intensive care unit (ICU) and hospital outcomes in a number of heterogeneous patients with prolonged MV. DESIGN, SETTING, AND SUBJECTS: Prospective cohort of consecutive adult patients admitted to 11 ICU who received MV (³ 72 hours). Study endpoints included weaning failure vs success and ICU death vs survival. RESULTS: Of 189 intubated patients, 149 (79%) were succesfully extubated, and 40 (21%) required reintubation within 48 hours.Using multiple logistic regression, female gender was an independent predictor of weaning failure. The mean ICU length of stay was significantly longer in weaning failure group (p < 0.01). The rate of tracheostomy was higher in the failure group (p < 0.01). The ICU mortality rate was 21%; 95% CI, 15 - 27%. In a Cox model adjusting on severity at ICU admission, weaning failure increased the risk of death in the ICU (RR: 3.08; p < 0,01). CONCLUSION: After adjusting for severity of ilness and medical conditions, female gender had a significant independent association with increased risk of weaning failure (WF). WF had association with prolonged ICU stay and higher rate of tracheostomy. Patients with weaning failure were 3 times more likely to die in the ICU

Abstract Professional practice in critical care settings is characterized by the application of relevant theories, research and evidence-based guidelines to clinical practice. However, critical care nurses’ knowledge and skills in adhering to evidence-based protocols and guidelines for avoiding ventilator-associated pneumonia are inadequate. The aim of the study was to evaluate critical care nurses’ knowledge and skills in adhering to best-practice endotracheal suctioning recommendations and ventilator bundles, to develop and validate instruments to evaluate the care of mechanically ventilated patients, and to evaluate the effectiveness of continuing education on critical care nurses’ knowledge and skills, with a focus on ventilator bundles. In the first study, a descriptive and cross-sectional correlation study was conducted to evaluate critical care nurses’ (n&#160;=&#160;40) endotracheal suctioning practices in relation to current best-practice recommendations. In the second study, a descriptive design with a literature review was conducted to assess the effectiveness of educational programmes in preventing ventilator-associated pneumonia. In the third study, an instruments validation study was conducted to develop and test the psychometric properties of the Ventilator Bundle Questionnaire (VBQ) and Observation Schedule (VBOS). In the fourth study, the effectiveness of human patient simulation education was evaluated among thirty (n&#160;=&#160;30) critical care nurses who were randomly allocated to intervention and control groups (n&#160;=&#160;15 each). Critical care nurses’ knowledge and skills in adhering to best-practice endotracheal suctioning recommendations and ventilator bundles continues to be inadequate. However, educational programmes were linked to significant improvements in learning and clinical outcomes. The VBQ and VBOS were developed and shown to have acceptable psychometric properties (CVI 0.99–1.0, ICC 0.93–1.0). After human patient simulation education, the mean skill scores of the intervention group increased significantly (pt*g&#160;=&#160;0.02). Educational programmes may have a significant impact on clinical outcomes and thus, patients’ safety and quality of care, through improvements in nurses’ knowledge and skills in adhering to evidence-based guidelines in critical care settings. The VBQ and VBOS can provide an objective method measuring whether evidence-based guidelines are being used in clinical practice. In addition, there was a significant transfer of learned skills to clinical practice following human patient simulation education. / Tiivistelmä Teho-osastoilla ammatillinen erityisosaaminen edellyttää tutkitun tiedon, teorioiden sekä näyttöön perustuvien hoitosuositusten soveltamista kliiniseen käytäntöön. Kuitenkin tehohoitajien tiedot ja taidot noudattaa näyttöön perustuvia hoitokäytäntöjä ja suosituksia hengityslaitehoitoon liittyvän keuhkokuumeen ehkäisyksi ovat olleet puutteellisia. Tutkimuksen tarkoituksena oli arvioida tehohoitajien tietoa ja taitoa noudattaa hyväksi havaittuja hengitysteiden imukäytäntöjä sekä hengityslaitehoitoon liittyviä hoitosarjakäytäntöjä, kehittää ja validoida mittareita hengityslaitehoitoa saavien potilaiden hoidon laadun arvioimiseksi sekä arvioida täydennyskoulutuksen vaikuttavuutta tehohoitajien tietoihin ja taitoihin noudattaa hengityslaitehoitoon liittyviä hoitosarjakäytäntöjä. Ensimmäisessä osatyössä arvioitiin kuvailevan ja korrelatiivisen tutkimusasetelman avulla tehohoitajien (n = 40) alahengitysteiden imukäytäntöjä suhteessa hyväksi havaittuihin toimintakäytäntöihin. Toisessa osatyössä arvioitiin kuvailevan kirjallisuuskatsauksen avulla koulutusinterventioiden vaikuttavuutta hengityslaitehoitoon liittyvän keuhkokuumeen ehkäisyssä. Kolmannessa osatyössä kehitettiin ja testattiin hengityslaitehoitoon liittyvä hoitosarjakysely (VBQ) sekä havainnointimittari (VBOS). Neljännessä osatyössä arvioitiin simulaatiokoulutuksen vaikuttavuutta satunnaistetussa koeasetelmassa interventio- (n&#160;=&#160;15) ja kontrolliryhmän (n&#160;=&#160;15) välillä. Tehohoitajien tiedot ja taidot noudattaa hyväksi havaittuja hengitysteiden imukäytäntöjä sekä hengityslaitehoitoon liittyviä hoitosarjakäytäntöjä olivat edelleen puutteellisia. Kuitenkin koulutusinterventioiden vaikuttavuus kliinisiin hoitotuloksiin sekä oppimistuloksiin oli merkittävä. VBQ- ja VBOS-mittareiden psykometriset ominaisuudet osoittautuivat hyväksyttäviksi (CVI 0,99–1,0, ICC 0,93–1,0).Simulaatiokoulutuksen jälkeen interventioryhmän taidot noudattaa hoitosuosituksia lisääntyivät merkittävästi (pt*g&#160;=&#160;0,02). Koulutusinterventioiden kliininen vaikuttavuus potilasturvallisuuden ja hoidon laadun kehittämisessä voi olla merkittävää, kun hoitajien tietoa ja taitoa noudattaa näyttöön perustuvia hoitosuosituksia lisätään kliinisessä tehohoitotyössä. VBQ- ja VBOS-mittarit voivat tarjota objektiivisen tavan arvioida tutkitun tiedon siirtymistä kliiniseen käytäntöön. Simulaatiokoulutuksen jälkeen opittujen taitojen siirtovaikutus kliiniseen käytäntöön oli merkittävä.

Thesis (MCur)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: Ventilator-Associated Pneumonia (VAP) is a hospital acquired infection, not present or incubating at the time of admission and developing in patients during the process of care within the hospital setting. Between nine and twenty-seven percent of patients who are mechanically ventilated will develop ventilator-associated pneumonia. Mortality rates for ventilated patients who develop ventilator-associated pneumonia are estimated to be between 33-50%. The Institute for Healthcare Improvements (IHI) in 2006 recommended the use of ‘care bundles’ to reduce VAP but no statistically significant decline has been noted. Despite the completion of an extensive literature search for purposes of this review, no statistical data on nosocomial infections or nosocomial pneumonia relevant to South Africa was found. Mechanical ventilation, a support therapy used in approximately one third of patients, significantly increases the patient’s risk of developing this nosocomial pneumonia. Critically ill patients are by virtue of their critical illness more prone to the development of infections, especially ventilator-associated pneumonia. Consistent evidence suggests that oropharyngeal colonization can be associated with the development of VAP. Studies focusing on standard oral care, with or without the concurrent use of chlorhexidine, have not provided sufficient evidence for the use of chlorhexidine in VAP prevention. Chlorhexidine is an antiseptic agent, which when tested, proved to reduce total respiratory tract infections by up to 69% (DeRiso et al, 1996:1558). Objective: The aim of this study was to systematically appraise and review evidence on the effectiveness of chlorhexidine in reducing the incidence of ventilator-associated pneumonia in adult patients. The secondary aim was to systematically summarize evidence on the use of chlorhexidine in reducing mortality. Methodology: An extensive literature search of studies published in English was undertaken. Electronic databases searched were CENTRAL, CINAHL, EMBASE and MEDLINE. Reference lists of articles, textbooks and conference summaries were examined. Literature searches were conducted using Medical Subject Headings (MeSH). These included: Ventilator-associated pneumonia, chlorhexidine, VAP and oral care. Eight randomized controlled trials, investigating the efficacy of Chlorhexidine in ventilator-associated pneumonia prevention in adults met the inclusion criteria. The effect measure of choice was Risk ratio with 95% confidence intervals for dichotomous data using the random effects (Mantel-Haenszel) model; (p=value of 0.05). Heterogeneity was assessed using the Cochrane Q statistic and I². Results: Eight randomized controlled trials met the inclusion criteria for this review. Pooled risk ratio for the incidence of ventilator-associated pneumonia was 0.64 (95% CI; 0.44-0.91; p =0.18). Treatment with chlorhexidine decreased the risk of ventilator-associated pneumonia by 36%. There was no evidence of Chlorhexidine reducing mortality. Conclusions: Chlorhexidine is a cost effective safe treatment in the prevention of VAP. The use of 2% chlorhexidine may be more effective in reducing the incidence of VAP. No studies were found conducted in developing countries. More rigorously designed trials using 2% chlorhexidine are recommended. / AFRIKAANSE OPSOMMING: Agtergrond Ventilator-Geassosieerde Longontsteking (VAP) is 'n hospitaal verkry infeksie, nie teenwoordig met toelating nie. Ventilator-geassosieerde longontsteking word ontwikkel in pasiënte tydens die proses van sorg in die hospitaal. Tussen nege en sewe en twintig persent van pasiënte wat meganies geventileer word kry ventilator-geassosieerde pneumonie. Sterftesyfers vir geventileerde pasiënte wat ventilator-geassosieerde pneumonie ontwikkel is na raming tussen 33- 50%. Die Institute for Healthcare Improvements (IHI) het in 2006 die gebruik van 'sorg bundels' aanbeveel om VAP te verminder, maar geen statisties beduidende daling is aangeteken nie. Ten spyte van 'n uitgebreide literatuur soek, is geen statistiese data op nosokomiale infeksies of nosokomiale longontsteking toepaslik tot Suid-Afrika gevind nie. Meganiese ventilasie, 'n ondersteuningsterapie wat gebruik word in ongeveer een derde van die pasiënte, verhoog aansienlik die pasiënt se risiko vir die ontwikkeling van hierdie nosokomiale longontsteking. Kritiek siek pasiënte is op gronde van hul kritieke toestand meer geneig tot die ontwikkeling van infeksies, veral ventilator-geassosieerde pneumonie. Konsekwente bewyse dui daarop dat orofaringeale kolonisasie kan met die ontwikkeling van VAP geassosieer word. Studies wat fokus op standaard mond sorg, met of sonder die gelyktydige gebruik van chlorhexidine, het nie voldoende bewyse vir die gebruik van chlorhexidine in VAP voorkoming nie. Chlorhexidine is 'n antiseptiese agent, wat wanneer in een verewekansigde gekontroleerde studies (VGS) getoets was die totale respiratoriese kanaal infeksies verminder deur tot 69%. Doel: Die doel van hierdie sistematiese literatuuroorsig was om stelselmatig te evalueer en bewyse oor die effektiwiteit van chlorhexidine in die vermindering en voorkoms van ventilatorgeassosieerde pneumonie in volwasse pasiënte te hersien. Die sekondêre doel was om stelselmatig bewyse op te som op die gebruik van chlorhexidine in die vermindering van sterfte. Metodiek: 'n Uitgebreide literatuursoektog van studies wat in Engels gepubliseer is was onderneem. CENTRAL, CINAHL, EMBASE en MEDLINE was deursoek. Naslaanlyste van artikels, handboeke en konferensie opsommings is ondersoek. Die literatuur soektog is uitgevoer met behulp van Medical Subject Headings (MeSH). Dit sluit in: ventilator-geassosieerde pneumonie, chlorhexidine, VAP en mond sorg. Agt verewekansigde gekontroleerde studies (VGS), wat die doeltreffendheid van Chlorhexidine in ventilator-geassosieerde pneumonie voorkoming in volwassenes ondersoek, was ingesluit vir hierdie studie. Die effek mate van keuse was risiko ratio (RR) met 95% vertrouensintervalle met behulp van die ewekansige effekte (Mantel-Haenszel) model; (p = 0.05). Heterogeniteit is bepaal deur gebruik te maak van die Cochrane Q- statistiek en I². Hoof resultate: Agt verewekansigde gekontroleerde studies (VGS) het die insluiting kriteria vir hierdie oorsig gepas. Gepoelde risiko ratio vir die voorkoms van ventilator-geassosieerde pneumonie: Risiko Ratio (RR) was 0.64 (95% CI; 0.44-0.91; p=0.18). Gevolgtrekkings: Behandeling met chlorhexidine het die risiko van ventilator-geassosieerde pneumonie met 36% gedaal. Daar was geen bewyse van Chlorhexidine op die vermindering van mortaliteit nie. Chlorhexidine is 'n koste-effektiewe veilige behandeling in die voorkoming van VAP. Die gebruik van 2% chlorhexidine kan moontlik meer effektief wees in die vermindering van die voorkoms van VAP. Meer streng ontwerp studies met 2% chlorhexidine word aanbeveel.

Stockpiling resources is a pervasive way to handle demand uncertainty and future demand surges. However, stockpiling is subject to costs, including warehousing costs, inventory holding costs, and wastage of expired resources. Hence, how to stockpile in an economically efficient manner is an important topic to study. Furthermore, if the inventoried supply is insufficient for a surge in demand, how to best allocate available resources becomes a natural question to ask. In this dissertation, we consider three applications of stockpiling and resource allocation: (i) we stockpile ventilators both centrally and regionally for an influenza pandemic; (ii) we allocate limited vaccine doses of various types to target populations for an influenza pandemic; and, (iii) we investigate inventory needs for low cost, high usage (class C) parts in an engine assembly plant. First, we describe and analyze a model for estimating the number of ventilators that the Texas Department of State Health Services (DSHS), and eight health service regions in Texas, should stockpile for an influenza pandemic. Using a probability distribution governing peak-week demand for ventilators across the eight health service regions, an optimization model allows investigation of the tradeoff between the cost of the total stockpile and the expected shortfall of ventilators under mild, moderate, and severe pandemic scenarios. Our analysis yields the surprising result that there is little benefit to DSHS holding a significant stockpile, even when those centrally held ventilators can be dispatched to regions after observing the peak-week demand realization. Three factors contribute to this result: positively correlated regional demands, a relatively low coefficient of variation, and wastage of the central stockpile once it is dispatched to the regions. Second, we formulate an optimization model for allocating various types of vaccines to multiple priority groups in 254 counties in the state of Texas that DSHS can use to distribute its vaccines for an influenza pandemic. For reaching the public, vaccines are allocated to the state’s Registered Providers (RPs), Local Health Departments (LHDs), and Health Service Regions (HSRs). The first two allocations are driven by requests from RPs and LHDs while HSR allocation is at DSHS’s discretion. The optimization model aims to achieve proportionally fair coverage of priority groups across the 254 counties, as informed by user-specified weights on those priority groups, using the HSR doses. With proportional fairness as our primary goal, the optimal allocation also counts policy simplicity and regional equity. Sensitivity analysis on the portion of the state’s vaccines reserved for HSRs shows that a small portion can effectively shrink the gap of vaccination coverage between urban and rural counties. Finally, we derive short-cut formulae for estimating the extra inventory needed for managing class C parts in units of bins that an engine assembly plant can use to achieve a desired fill rate at workstations. The plant orders a class C part from its supplier based on the part’s aggregated next-day demand across all workstations. After receiving the part, the plant first stores the supply in the warehouse and delivers the part to workstations in bins whenever the line-side inventory at a workstation is empty. We study four cases of various information availability in the order quantity calculation and derive associated formulae for estimating the extra inventory needed due to demand aggregation and bin delivery. We demonstrate the performance of our short-cut formulae, showing the tradeoff between extra inventory needed and the associated risk of not satisfying all workstation requests. Our sensitivity analysis shows that workstation demand variation and bin size have little or no influence on the performance of our short-cut formulae. / text

Mechanical ventilation (MV) is a system that partially or fully assists patients whose respiratory system fails to achieve a gas exchange function. However, MV can cause a ventilator-associated lung injury (VALI) or even contribute to a multiple organ dysfunction syndrome (MODS) in acute respiratory distress syndrome (ARDS) patients. Despite advances in today technologies, mortality rates for ARDS patient are still high. A better understanding of the interactions between airflow from mechanical ventilator and the airway could provide useful information used to develop a better strategy to ventilate patients. The mechanisms, which mechanical ventilation induces airway inflammation, are complex processes and cover a wide range of spatial scales. The multiscale model of the airway have been developed combining the computational models at organ, tissue, and cellular levels. A model at the organ level was used to study behaviors of the airway during mechanical ventilation. Strain distributions in each layer of the airway were investigated using a model at the tissue level. The cellular inflammatory responses during mechanical ventilation were investigated through the cellular automata (CA) model incorporating all biophysical processes during inflammatory responses. The multiscale modeling framework started by obtaining airway displacements from the organ-level model. They were then transferred to the tissue-level model for determining the strain distributions in each airway layer. The strain levels in each layer were then transferred to the cellular-level model for inflammatory responses due to strain levels. The ratio of the number of damage cells to healthy cells was obtained through the cellular-level model. This ratio, in turn, modulated changes in the Young’s modulus of elasticity at the tissue and organ levels. The simulation results showed that high tidal volume (1400 cc) during mechanical ventilation can cause tissue injury due to high concentration of activated immune cells and low tidal volume during mechanical ventilation (700 cc) can prevent tissue injury during mechanical ventilation and can mitigate tissue injury from the high tidal volume ventilation. The multiscale model developed in this research could provide useful information about how mechanical ventilation contributes to airway inflammation so that a better strategy to ventilate patients can be developed.

The thesis is focused on ventilator-associated pneumonia and its possible preventive measures during nursing care. In the theoretical part of the work we have included chapters on nosocomial infections emphasizing on the etiology and epidemiology of ventilator-associated pneumonia and its clinical manifestations. We have analyzed the issues of artificial airway management with a detailed focus on the peculiarities of nursing care of the ventilated patients. There, we focus primarily on the care of the patients oral cavity, respiratory tract and the ventilation circuit. A big chapter is dedicated to preventive measures and to the possibilities of prevention in the nursing practice. The empirical part includes research on preventive measures that are implemented in practice and comparative analysis of the measures between different facilities as well as their compliance to the guidelines. We have also determined the level of VAP awareness and its prevention among the nurses. KEYWORDS nosocomials infections, nursing care, prevention, ventilator-associated pneumonia