AN ASSESSMENT OF  THE RISK FACTORS ASSOCIATED WITH LONG  INTENSIVE CARE UNIT STAYS IN PATIENTS AFTER CARDIAC SURGERY WITH CARDIOPULMONARY BYPASS

CHAPTER ONE

INTRODUCTION

Background of the study

Cardiac surgery, especially procedures using cardiopulmonary bypass (CPB), has markedly progressed in recent decades, enhancing survival rates and patient outcomes for people with diverse cardiovascular ailments (Loponen et al., 2020). Nonetheless, these operations often need postoperative critical care treatment, and several patients endure extended hospitalisations in the intensive care unit (ICU) owing to problems stemming from the surgery and pre-existing diseases. The duration of ICU stay after heart surgery serves as both an indication of patient recovery and a significant factor influencing healthcare expenses and resource allocation (Brown et al., 2018). The predominant cardiac surgeries conducted using cardiopulmonary bypass (CPB) are heart transplants, combined coronary artery bypass grafts (CABG), and valve surgery [Ailawadi & Zacour, 2019]. Enhancements in the adaptability and safety of CPB have resulted in improved early results. Nonetheless, side effects and postoperative problems related to CPB persist, including pulmonary dysfunction [Almashrafi, Elmontsri & Aylin, 2016], atrial fibrillation, neurocognitive alterations, acute renal damage, inflammation, and coagulation abnormalities. Consequently, it is essential for patients to remain in the ICU postoperatively to observe changes in their state and mitigate problems. Certain patients need an extended length of stay (LOS) in the ICU after cardiopulmonary bypass (CPB). The standard definition of extended ICU length of stay is typically 3 to 7 days [Almashrafi et al, 2016], however to enhance the identification of individuals at elevated risk, a criterion of over 72 hours has been established. Extended ICU length of stay correlates with increased rates of complications, healthcare expenditures, and death rates [Chin-Yee et al, 2017]. Consequently, identifying risk variables linked to extended ICU length of stay after heart surgery with cardiopulmonary bypass may provide several advantages. Multiple factors correlate with extended ICU length of stay, including age, oxygenation index (PaO2/FiO2 ratios), atrial fibrillation classification, type and duration of surgery, pulmonary hypertension, prolonged ventilation, duration of intubation, volume of transfused blood, and inotrope infusion duration in the ICU. Extended ICU length of stay might yield several detrimental impacts on patients; hence, it is crucial to understand the risk factors linked to this metric. Prior research [Almashrafi, Elmontsri & Aylin, 2016] has concentrated on preoperative and intraoperative elements linked to extended ICU length of stay post-surgery; however, there is less understanding of early postoperative aspects. Certain scholars [Meadows, Gibbens, Gerrard & Vuylstek, 2018] in Europe and the United States employ EuroSCORE or Parsonnet to forecast ICU length of stay in patients undergoing cardiac surgery, whereas others have shown that these models are inappropriate for application in various countries [[Meadows, Gibbens, Gerrard & Vuylstek, 2018] due to disparities in medical resource distribution and institutional policies regulating ICU discharge. Therefore, the researcher sought to assess the risk factors associated with long  intensive care unit stays in patients after cardiac surgery with cardiopulmonary bypass. 

Statement of the problem

Cardiac surgery using cardiopulmonary bypass (CPB) is an intricate operation often linked to considerable postoperative problems that might result in extended durations in the intensive care unit (ICU). Prolonged ICU admissions after cardiac surgery are not only expensive but also elevate the likelihood of further complications, such as infections, respiratory issues, and extended mechanical ventilation (Doenst et al., 2019). Determining the risk variables that lead to prolonged ICU admissions is crucial for enhancing patient outcomes and optimising resource distribution. Prior research has identified multiple risk factors that lead to prolonged ICU admissions, including advanced age, preexisting comorbidities (e.g., diabetes and chronic obstructive pulmonary disease), and perioperative variables such as the duration of cardiopulmonary bypass, blood transfusions, and postoperative complications (Ahlsson et al., 2017; Benedetto et al., 2016). Nonetheless, there is an absence of agreement about the relative significance of these characteristics, especially across diverse populations and healthcare environments. The diversity in patient responses to surgical and ICU care regimens further complicates accurate predictions of ICU length of stay (LOS). Hence, the study assess the risk factors associated with long  intensive care unit stays in patients after cardiac surgery with cardiopulmonary bypass. 

1.3 Objective of the study

The broad objective of the study is to assess the risk factors associated with long  intensive care unit stays in patients after cardiac surgery with cardiopulmonary bypass. The specific objectives is as follows

To identify patient-specific factors associated with prolonged ICU stays in patients after cardiac surgery with cardiopulmonary bypass (CPB).

To investigate the impact of postoperative complications on the duration of ICU stays following cardiac surgery with CPB.

To provide recommendations for clinical practice aimed at reducing ICU length of stay and improving postoperative outcomes for patients undergoing cardiac surgery with CPB.

1.4 Research questions

The following questions have been prepared to guide the study

What are the patient-specific factors associated with prolonged ICU stays in patients after cardiac surgery with cardiopulmonary bypass (CPB)?

What is the impact of postoperative complications on the duration of ICU stays following cardiac surgery with CPB?

What are the recommendations for clinical practice aimed at reducing ICU length of stay and improving postoperative outcomes for patients undergoing cardiac surgery with CPB?

1.5 Significance of the study

Findings of the study could influence healthcare policies related to ICU management and cardiac surgery. The findings may support the development of protocols to standardize patient care, reduce ICU congestion, and improve the utilization of intensive care services. This could lead to the establishment of evidence-based guidelines for managing patients undergoing cardiac surgery with CPB. Findings of the study will also be significant to the academic community as it will contribute to the existing literature, add to library resources and serve as a guide to future academic researchers.

1.6 Scope of the study

The study focus on the risk factors associated with long  intensive care unit stays in patients after cardiac surgery with cardiopulmonary bypass. Empirically, the study will  identify patient-specific factors associated with prolonged ICU stays in patients after cardiac surgery with cardiopulmonary bypass (CPB), investigate the impact of postoperative complications on the duration of ICU stays following cardiac surgery with CPB and provide recommendations for clinical practice aimed at reducing ICU length of stay and improving postoperative outcomes for patients undergoing cardiac surgery with CPB.

Geographically, the study will be delimited to Lagos state university teaching hospital (LASUTH)

1.7 Limitation of the study

Like in every human endeavour, the researchers encountered slight constraints while carrying out the study. The significant constraint are: 

Time: The researcher encountered time constraint as the researcher had to carry out this research along side other academic activities such as attending lectures and other educational activities required of her.

Finance: The researcher incurred more financial expenses in carrying out this study such as typesetting, printing, sourcing for relevant materials, literature, or information and in the data collection process.

Availability of Materials: The researcher encountered challenges in sourcing for literature in this study. The scarcity of literature on the subject due to the nature of the discourse was a limitation to this study.

1.8 Definition of terms

Cardiac Surgery: A surgical procedure performed on the heart or its associated blood vessels to treat various cardiovascular conditions, including coronary artery disease, heart valve disorders, and congenital heart defects.

Cardiopulmonary Bypass (CPB): A technique used during certain types of cardiac surgery where a machine temporarily takes over the function of the heart and lungs, allowing the surgeon to operate on a still heart.

Intensive Care Unit (ICU): A specialized hospital unit designed for critically ill patients who require continuous monitoring and advanced medical care, including those recovering from major surgeries like cardiac surgery.

Length of Stay (LOS): The total time a patient spends in the ICU, usually measured in days, from the point of admission to discharge.

Prolonged ICU Stay: A longer-than-expected duration in the ICU following surgery, typically defined as an ICU stay exceeding 48-72 hours, though the exact definition may vary based on the clinical setting.

Preoperative Risk Factors: Conditions or characteristics present before surgery that may increase the likelihood of complications or a prolonged ICU stay, such as advanced age, obesity, or preexisting medical conditions (e.g., diabetes, hypertension).

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