PhD Thesis / Background: The home care population is a cohort of medically complex older adults at risk for cardiac arrest and poor post-cardiac arrest health outcomes. Research Question: What is the prognosis of cardiac arrest among patients receiving home care, and what pre-arrest features and geriatric syndromes (e.g., frailty) are prognostic of survival and post-cardiac arrest health? Methods: Following a systematic review and meta-analysis that evaluated the prognostic association between frailty and post-cardiac arrest outcomes, a population-based retrospective cohort was created of adults (≥18 years) who received cardiac arrest care at a hospital in Ontario, Canada, between 2006 and 2018. Patients receiving home care and nursing home residents were identified using the Home Care Dataset and the Continuing Care Reporting System. Arrests were analyzed overall and within distinct sub-groups of in-hospital (IHCA) and out-of-hospital cardiac arrests (OHCA). The primary outcome for this thesis was 30-day survival post-cardiac arrest. Frailty was measured using the Clinical Frailty Scale and a valid frailty index. The odds of survival from cardiac arrest were estimated using multivariable logistic regression. Prognostic models were internally validated using bootstrap resampling (n= 2000). Results: We found high certainty evidence for an association between the Clinical Frailty Scale and death prior to hospital discharge after IHCA (OR = 2.93; 95% CI = 2.43 – 3.53) after adjusting for age as a minimum confounder. Our retrospective cohort contained 86,836 unique adult cardiac arrests, of which 39,610 were OHCA and 47,226 were IHCA. Patients receiving home care represented 10.7% of the cohort and were less likely to survive to hospital discharge (RD = -6.4; 95%CI = -7.4– -5.2) and one-year (RD = -12.8; 95%CI = -14.6 – -10.9) post-cardiac arrest compared to community-dwelling individuals receiving no support in the community. Frail patients receiving home care had worse odds of 30-day survival when measured with the CFS (OR=0.78; 95%CI = 0.61-0.98) and a frailty index (OR=0.89; 95%CI = 0.85-0.95), after adjusting for age, sex, and arrest setting. My prognostic model out-performed the two valid frailty measures and demonstrated fair discriminative accuracy (AUROC = 0.66; 95%CI=0.65-0.65) and good calibration (Slope = 0.95) for group-level prognostication when internally validated among patients receiving home care. Conclusion:Patients receiving home care have a worse absolute risk of death when compared to community-dwelling individuals receiving no community-based support services. Frailty is associated with survival and post-cardiac arrest declines in cognition and function when evaluated in patients receiving home care. The prognostic model developed within my thesis outperformed the ability of frailty to predict 30-day survival and is suitable for group-level prognostication. / Dissertation / Doctor of Philosophy (PhD) / The proportion of older adults receiving home care is growing. The home care population is frail and medically complex, with a greater risk for cardiac arrest. This thesis aims to evaluate the prognosis and prognostic factors influencing survival and other health outcomes, to develop a statistical model that can predict 30-day survival post-cardiac arrest. Findings from my research demonstrate that patients receiving home care have worse survival outcomes post-cardiac arrest compared to well-being older adults living in the community. In my research, frailty was associated with survival and declines in post-cardiac arrest functional independence and cognitive performance among patients receiving home care. Our statistical model performed better than valid frailty measures and had respectable accuracy for group-level prognostication. The home care population is ideally positioned for proactive and shared decision-making about end-of-life care preferences, bearing in mind their receipt of detailed and routine health assessments.

Out-of-hospital cardiac arrest (OHCA) is a significant public health problem in most westernized industrialized nations. In spite of national and international guidelines for cardiopulmonary resuscitation and emergency cardiac care, the overall survival of patients with OHCA was essentially unchanged for 30 years--from 1978 to 2008 at 7.6%. Perhaps a better indicator of Emergency Medical System (EMS) effectiveness in treating patients with OHCA is to focus on the subgroup that has a reasonable chance of survival, e.g., patients found to be in ventricular fibrillation (VF). But even in this subgroup, the average survival rate was 17.7% in the United States, unchanged between 1980 and 2003, and 21% in Europe, unchanged between 1980 and 2004. Prior to 2003, the survival of patients with OHCA, in VF in Tucson, Arizona was less than 9% in spite of incorporating previous guideline recommendations. An alternative (non-guidelines) approach to the therapy of patients with OHCA and a shockable rhythm, called Cardiocerebral Resuscitation, based on our extensive physiologic laboratory studies, was introduced in Tucson in 2003, in rural Wisconsin in 2004, and in selected EMS areas in the metropolitan Phoenix area in 2005. Survival of patients with OHCA due to VF treated with Cardiocerebral Resuscitation in rural Wisconsin increased to 38% and in 60 EMS systems in Arizona to 39%. In 2004, we began a statewide program to advocate chest compression-only CPR for bystanders of witnessed primary OHCA. Over the next five years, we found that survival of patients with a shockable rhythm was 17.7% in those treated with standard bystander CPR (mouth-to-mouth ventilations plus chest compression) compared to 33.7% for those who received bystander chest-compression-only CPR. This article on Cardiocerebral Resuscitation, by invitation following a presentation at the 2011 Danish Society Emergency Medical Conference, summarizes the results of therapy of patients with primary OHCA treated with Cardiocerebral Resuscitation, with requested emphasis on the EMS protocol.

Aims The aim of this thesis was to describe out-of-hospital cardiac arrest (OHCA) due to drowning from the following angles. In Paper I: To describe the characteristics of OHCA due to drowning and evaluate factors of importance for survival. In Paper II: To describe lifesaving skills and CPR competence among surf lifeguards. In Paper III: To describe the characteristics of interventions performed by the Swedish fire and rescue services (SFARS) and evaluate survival with or without rescue diving units. In Paper IV: To describe the prevalence of possible confounders for death due to drowning. In Paper V: To describe changes in characteristics and survival over time and again to evaluate factors of importance for survival Methods Papers I and III-V are based on retrospective register data from the Swedish OHCA Register reported by Emergency Medical Service (EMS) clinicians between 1990-2011. In addition, in Paper III, the data have been analysed and compared with the SFARS database for rescue characteristics. In Paper IV, the data have been compared with those of the National Board of Forensic Medicine (NBFM). Paper II is a descriptive study of 40 surf lifeguards evaluating delay and CPR quality as peformed on a manikin. Results Survival in OHCA due to drowning is about 10% and does not differ significantly from OHCA with a cardiac aetiology. The proportion of witnessed cases was low. Survival appears to increase with a short EMS response time, i.e. early advanced life support. Surf lifeguards perform CPR with sustained high quality, independent of prior physical strain. In half of about 7,000 drowning calls, there was need for a water rescue by the fire and rescue services. Among the OHCA in which CPR was initiated, a majority were found floating on the surface. Rescue diving took place in a small percentage of all cases. Survival when using rescue divers did not differ significantly from drownings where rescue diving units were not used. No survivors were found after &gt;15 minutes of submersion in warm water. After submersion in cold water, survival with a good neurological outcome was extended. Among 2,166 autopsied cases of drowning, more than half were judged as accidents and about one third as intentional suicide cases. Among accidents, 14% were found to have a cardiac aetiology, while the corresponding figure among suicides was 0%. In a 20-year follow-up of OHCA due to drowning in Sweden, both bystander CPR and early survival to hospital admission are increasing. The proportion of cases alive after one month has not changed significantly during the period. Conclusions Survival from OHCA due to drowning is low. A reduction in the EMS response time appears to have high priority, i.e. early ALS is important. The quality of CPR among surf lifeguards appear to be high and not affected by prior physical strain. In all treated OHCA cases, the majority were found at the surface and survival when rescue diving took place did not appear to be poorer than in non-rescue diving cases. In a minor proportion of cases, cardiac disease could be a confounder for death due to drowning. Bystander CPR in OHCA due to drowning has increased over a 20-year period and the proportion of early survivors to hospital admission is increasing. We speculate that our studies were underpowered with regard to the opportunity adequately to assess the effects of bystander CPR on survival to hospital discharge. A uniform Swedish definition of drowning based on the recommended international terms should be implemented throughout Swedish authorities and health care, in order to enhance the quality of data and improve the potential for future research. / <p>Disputationen sker Fredagen den 20 September 2013, kl. 13.00 Sahlgrens aula, Blå stråket 5, Sahlgrenska universitetssjukhuset, Göteborg.</p>

M.A. / The study investigated the effects of cardiac arrest and myocardial infarction on long-term memory function. Given that anoxia has more serious neuropsychological ramifications than hypoxia, it was hypothesized that the cardiac arrest group would perform poorer than the myocardial infarction group in visuo-spatial and auditory-verbal recall and recognition memory. When brain insult prevails, affective changes may occur and may reflect the trauma related to the illness and partly to the cognitive dysfunction. Thus it was hypothesized that the Beck Depression Inventory scores would be significantly elevated in the cardiac arrest group. Each group consisted of 15 participants. The mean age for the cardiac arrest group and myocardial infarction group was 59.47 years (SD = 9.24) and 58.87 years (SD = 7.22), respectively. Sex, age, education, hypertension, diabetes mellitus, and smoking were controlled. However, the analysis did not reveal any significant between-group differences. There was no significant difference on the BDI, and both groups were moderately depressed, the cardiac arrest (BDI: mean score = 17.07, SD = 16.97) and myocardial infarction (BDI: mean score = 18.33, SD = 18.35). The researchers acknowledged the potential effects that beta-adrenoceptor antagonists and diuretics, and angiotensin-converting enzyme have on memory and cognitive performance, respectively. However, the analysis did not reveal a significant between-group difference for these variables. The neuropsychological test battery comprised: Rey-Auditory Verbal Learning Test (RAVLT), Rey-Osterreith Complex Figure Test (ROCFT), Wechsler Memory Scale-Revised (WMS-R), Wechsler Adult Intelligence Test (WAIS) Symbol Search and Digit Symbol Substitution Test, Raven’s Standard Progressive Matrices, and the Oral Word Controlled Test (FAS). The memory function of the cardiac arrest group was characterized by deficits in visuo-spatial and auditory-verbal recall and recognition memory. In addition, the retention intervals were not mediating factors. This group was also impaired in visuo-spatial perception, constructional and organizational ability, and psychomotor speed. The impairment that characterized the myocardial infarction group converged on all auditory-verbal attentional tasks, indicating that this group has a selective impairment in auditory-verbal attention. Moreover, both groups exhibited equal levels of impairment in orientation, and uniform performance in executive function and verbal fluency. The memory function after cardiac arrest is characterized by deficits in visuo-spatial and auditory-verbal deficits in recall and recognition memory as well as impairment in visual perception, constructional ability, and psychomotor speed. By contrast, myocardial infarction patients are specifically impaired in auditory-verbal attention.

名古屋大学博士学位論文 学位の種類 : 博士(医学)(論文) 学位授与年月日:平成5年4月6日 氏平伸子氏の博士論文として提出された

Thesis (Ph. D.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references (leaves 405-423). Available also in a digital version from Dissertation Abstracts.

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The purpose of this study was to investigate a resuscitation algorithm that calculates the value of AMSA in real-time to direct the duration of post-shock chest compressions. We hypothesized that such an algorithm would shorten the time to achieve ROSC in swine. Swine were randomized into normal or infarcted myocardia and waveform guided or traditional resuscitation algorithm groups. VF was induced electrically and left untreated for 10minutes. Resuscitation was commenced with 1minute of compressions, resumption of mechanical ventilation, shock and epinephrine. In the traditional group, all shocks were followed by 2minutes of post-shock compressions. In the waveform guided group, AMSA was measured prior to shocks. If AMSA>20mV-Hz, post shock compression duration was shortened to 1minute.This study found that the waveform guided resuscitation algorithm to direct the duration of post-shock chest compressions had no significant effect on time to ROSC or AMSA values when compared to the traditional resuscitation algorithm.

Hyperglycaemia is prevalent in critical care and increases the risks of further complications and mortality. Glycaemic control has shown benefits in reducing mortality. However, due in parts to excessive metabolic variability, many studies have found it difficult to reproduce these results. Out-of-Hospital Cardiac Arrest (OHCA) patients have low survival rates and often experience hyperglycaemia. However, these patients belongs to one group who has shown benefit from accurate glycaemic control (AGC), but can be highly insulin resistant and variable, particularly on the first two days of stay. Hypothermia is often used to treat post-cardiac arrest patients or out of hospital cardiac arrest (OHCA) and these same patients often simultaneously receive insulin. In general, it leads to a lowering of metabolic rate that induces changes in energy metabolism. However, its impact on metabolism and insulin resistance in critical illness is unknown, although one of the adverse events associated with hypothermic therapy is a decrease in insulin sensitivity and insulin secretion. However, this decrease may not be notable in the cohort that is already highly resistant and variable. Hence, understanding metabolic evolution and variability would enable safer and more accurate glycaemic control using insulin in this cohort. OHCA patients were undergone preliminary analysis during cool and warm, which includes insulin sensitivity (SI), blood glucose (BG), and exogenous insulin and dextrose. Patients were analysed based on overall cohort, sub-cohorts, and 6 and 12 hour time block. Generally, the results show that OHCA patients had very low metabolic activity during cool period but significantly increased over time. In contrast, BG is higher during cool period and decreased over time. The analysis is equally important as the controller development since it provides scientific evidence and understanding of patients’ physiology and metabolic evolution especially during cool and warm. Model-based methods can deliver control that is patient-specific and adaptive to handle highly dynamic patients. A physiological ICING-2 model of the glucose-insulin regulatory system is presented in this thesis. This model has three compartments for glucose utilisation, effective interstitial insulin and its transport, and insulin kinetics in blood plasma, with emphasis on clinical applicability. The predictive control for the model is driven by the patient-specific and time-varying insulin sensitivity parameter. A novel integral-based parameter identification enables fast and accurate real-time model adaptation to individual patients and patient condition. Stochastic models and time-series methods for forecasting future insulin sensitivity are presented in this thesis. These methods can deliver probability intervals to support clinical control interventions. The risk of adverse glycaemic outcomes given observed variability from cohort-specific and patient-specific forecasting methods can be quantified to inform clinical staff. Hypoglycaemia can thus be further avoided with the probability interval guided intervention assessments. Simulation studies of STAR-OHCA control trials on ‘virtual patients’ derived from retrospective clinical data provided a framework to optimise control protocol design in-silico. Comparisons with retrospective control showed substantial improvements in glycaemia within the target 4 - 7 mmol/L range by optimising the infusions of insulin. The simulation environment allowed experimentation with controller parameters to arrive at a protocol that operates within the constraints found earlier during patient analysis. Overall, the research presented takes model-based OHCA glycaemic control from concept to proof-of-concept virtual trials. The thesis employs the full range of models, tools and methods to optimise the protocol design and problem solution.

Thesis (M.S.)--Auburn University, 2008. / Abstract. Vita. Includes bibliographical references (p. 38-39).