The haemodynamic status of cardiac surgical patients in the initial 2-h recovery period

Agitation during anaesthetic emergence: An observational study of adult cardiac surgery patients in two Australian intensive care units

BACKGROUND

Anaesthetic emergence agitation among adult patients being recovered after open cardiac and/or thoracic aorta surgery has not been described.

OBJECTIVES

The objective of this study was to characterise emergence agitation in terms of incidence, clinical features, and consequences in a cohort of cardiac surgery patients being recovered in the intensive care unit (ICU).

METHODS

A prospective, observational pilot study was implemented. Over a 5-week period, the study was conducted in two metropolitan hospitals in Victoria, Australia. The cohort comprised all patients admitted to the ICUs aged ≥18 years, who had undergone cardiac surgery via an open sternotomy with general anaesthetic, and whose emergence was directly observed. Emergence agitation was defined as a Richmond Agitation and Sedation Scale score of ≥+2.

RESULTS

Fifty patients were observed. Emergence agitation occurred in 24/50 (48%) of patients. Patients with emergence agitation experienced more clinical consequences than patients with calm emergence, including a significantly greater number of episodes of airway compromise (12/24, 50%, p < 0.001); ventilator dyssynchrony (23/24, 96%, p = 0.004); and hypertension (13/24, 54%, p = 0.004). Significant treatment interference (potentially dangerous patient movements such as pulling tubes) occurred with 23/24 patients (96%, p < 0.0001). Patients who underwent emergence agitation required significantly more interventions during anaesthetic emergence than patients who underwent a calm emergence. Interventions included extra nursing measures (16/24, 67%, p = 0.001) administration of sedative and/or opioid intravenous boluses (22/24, 92%, p = 0.001) and vasoactive agents (15/24, 63%, p = 0.05).

CONCLUSIONS

In patients recovering from cardiac surgery in the ICU, emergence agitation was clinically important. Immediate interventions were required to prevent and manage complications.

Factors Influencing Pre-Cardiopulmonary Arrest Signs among Post-General Surgery Patients in Critical Care Service System

Health service system factors can lead to pre-cardiopulmonary arrest signs (pre-CA), which refer to a critical condition in the body leading to a circulatory and respiratory system disruption. The purpose of this study was to assess the incidence rate of an event leading to pre-cardiopulmonary arrest signs within the first 24 h, and also to analyze the factors influencing the health service system in critical post-general surgery patients in the intensive care unit. These results of the study found the incidence rate of pre-CA was 49.05 per 1000 person-hours, especially 1 h after admission to the ICU. Hemodynamic instability, respiratory instability, and neurological alteration were the most common pre-CA symptoms. The patient factors associated with high pre-CA arrest sign scores were the age from 18-40 years, with an operation status as emergency surgery, elective surgery compared with urgent surgery, and the interaction of operation status and age in critical post-general surgery patients. The organization factors found advanced hospital level and nurse allocation were associated with pre-CA. To improve quality of care for critical post-general surgery patients, critical care service delivery should be delegated to nurses with nurse allocation and critical care nursing training. Guidelines must be established for critically ill post-general surgery patient care.

Hypotension after intensive care unit drop-off in adult cardiac surgery patients

BACKGROUND

Hypotension is a frequent complication in the intensive care unit (ICU) after adult cardiac surgery.

AIM

To describe frequency of hypotension in the ICU following adult cardiac surgery and its relation to the hospital outcomes.

METHODS

A retrospective study of post-cardiac adult surgical patients at a tertiary academic medical center in a two-year period. We abstracted baseline demographics, comorbidities, and all pertinent clinical variables. The primary predictor variable was the development of hypotension within the first 30 min upon arrival to the ICU from the operating room (OR). The primary outcome was hospital mortality, and other outcomes included duration of mechanical ventilation (MV) in hours, and ICU and hospital length of stay in days.

RESULTS

Of 417 patients, more than half (54%) experienced hypotension within 30 min upon arrival to the ICU. Presence of OR hypotension immediately prior to ICU transfer was significantly associated with ICU hypotension (odds ratio = 1.9; 95% confidence interval: 1.21-2.98; P < 0.006). ICU hypotensive patients had longer MV, 5 (interquartile ranges 3, 15) vs 4 h (interquartile ranges 3, 6), P = 0.012. The patients who received vasopressor boluses (n = 212) were more likely to experience ICU drop-off hypotension (odds ratio = 1.45, 95% confidence interval: 0.98-2.13; P = 0.062), and they experienced longer MV, ICU and hospital length of stay (P < 0.001, for all).

CONCLUSION

Hypotension upon anesthesia-to-ICU drop-off is more frequent than previously reported and may be associated with adverse clinical outcomes.

Competence of nurses in the intensive cardiac care unit

INTRODUCTION

Competence of nurses is a complex combination of knowledge, function, skills, attitudes, and values. Delivering care for patients in the Intensive Cardiac Care Unit (ICCU) requires nurses' competences. This study aimed to explain nurses' competence in the ICCU.

METHODS

This was a qualitative study in which purposive sampling with maximum variation was used. Data were collected through semi-structured interviews with 23 participants during 2012-2013. Interviews were recorded, transcribed verbatim, and analyzed by using the content-analysis method.

RESULTS

The main categories were "clinical competence," comprising subcategories of 'routine care,' 'emergency care,' 'care according to patients' needs,' 'care of non-coronary patients', as well as "professional competence," comprising 'personal development,' 'teamwork,' 'professional ethics,' and 'efficacy of nursing education.'

CONCLUSION

The finding of this study revealed dimensions of nursing competence in ICCU. Benefiting from competence leads to improved quality of patient care and satisfaction of patients and nurses and helps elevate nursing profession, improve nursing education, and clinical nursing.

Predictive factors for bleeding-related re-exploration after cardiac surgery: A prospective cohort study

BACKGROUND

Bleeding-related re-exploration is a life-threatening complication after cardiac surgery. Nurses must be aware of important risk factors for this complication so that their assessment, monitoring and evaluation activities can be prioritized, focused and anticipated.

AIMS

To identify the predictive factors for bleeding-related re-exploration after cardiac surgery and to describe the sources of postoperative bleeding.

METHODS

This is a prospective cohort study at a tertiary cardiac school-hospital in São Paulo/SP, Brazil. Adult patients (n=323) submitted to surgical correction of acquired cardiac diseases were included. Potential risk factors for bleeding-related re-exploration within the 24 hours following admission to the intensive care unit were investigated in the patients' charts. A univariate analysis and a multiple analysis through logistic regression were conducted to identify the outcome predictors. The area under the receiver-operating characteristic curve was calculated as a measure of accuracy considering the cut-off points with the highest sensitivity and specificity.

RESULTS

The univariate factors significantly associated with bleeding-related re-exploration were a lower preoperative platelet count, a lower number of bypasses in coronary artery bypass surgery and postoperatively, a lower body temperature, infusion of lower intravenous volume, a higher positive end-expiratory pressure during mechanical ventilation and transfusion of blood products. The independent predictors of bleeding-related re-exploration included postoperative red blood cell transfusion, and transfusion of fresh frozen plasma, platelet or cryoprecipitate units. These predictors had a sensitivity of 87.5%, a specificity of 99.28% and an accuracy of 97.93%.

CONCLUSIONS

Blood product transfusion postoperatively is an independent predictor of bleeding-related re-exploration. Surgical errors prevailed as sources of bleeding.

A hybrid hierarchical decision support system for cardiac surgical intensive care patients. Part I: Physiological modelling and decision support system design

OBJECTIVE

To develop a clinical decision support system (CDSS) that models the different levels of the clinician's decision-making strategies when controlling post cardiac surgery patients weaned from cardio pulmonary bypass.

METHODS

A clinical trial was conducted to define and elucidate an expert anesthetists' decision pathway utilised in controlling this patient population. This data and derived knowledge were used to elicit a decision-making model. The structural framework of the decision-making model is hierarchical, clearly defined, and dynamic. The decision levels are linked to five important components of the cardiovascular physiology in turn, i.e. the systolic blood pressure (SBP), central venous pressure (CVP), systemic vascular resistance (SVR), cardiac output (CO), and heart rate (HR). Progress down the hierarchy is dependent upon the normalisation of each physiological parameter to a value pre-selected by the clinician via fluid, chronotropes or inotropes. Since interventions at each and every level cause changes and disturbances in the other components, the proposed decision support model continuously refers back decision outcomes back to the SBP which is considered to be the overriding supervisory safety component in this hierarchical decision structure. The decision model was then translated into a computerised decision support system prototype and comprehensively tested on a physiological model of the human cardiovascular system. This model was able to reproduce conditions experienced by post-operative cardiac surgery patients including hypertension, hypovolemia, vasodilation and the systemic inflammatory response syndrome (SIRS).

RESULTS

In all the simulated patients scenarios considered the CDSS was able to initiate similar therapeutic interventions to that of the expert, and as a result, was also able to control the hemodynamic parameters to the prescribed target values.

Haemodynamic instability after cardiac surgery: nurses' perceptions of clinical decision-making

BACKGROUND

Cardiac surgical patients are distinguished by their potential for instability in the early postoperative period, highly invasive haemodynamic monitoring technologies and unique clinical presentations as a result of undergoing cardiopulmonary bypass. Little is known about nurses' perceptions of assuming responsibility for such patients. An understanding of nurses' perceptions may identify areas of practice that can be improved and assist in determining the adequacy of current decision supports.

AIM

The aim of this study was to describe critical care nurses' perceptions of assuming responsibility for the nursing management of cardiac patients in the initial two-hour postoperative period.

DESIGN

An exploratory descriptive study based on naturalistic decision-making.

METHODS

Thirty-eight nurses were interviewed immediately following a two-hour observation of their clinical practice. Content analysis and a systematic thematic analysis process called 'Framework' were used to analyse the interview transcripts.

RESULTS

Nurses described their perceptions of managing patients in terms of how they felt about making decisions for complex cardiac surgical patients and in terms of how clinical processes unique to the admission phase impacted their decision-making. Nurses felt either daunted or stimulated and challenged when making decisions. Nurses identified handover from anaesthetists, settling in procedures and forms of collegial assistance as important processes that impacted their decision-making.

CONCLUSION

Nurses' previous experiences with similar patients influenced how they felt about making decisions during the initial two-hour postoperative period, but did not alter their views about processes important for patient safety during this time.

RELEVANCE TO CLINICAL PRACTICE

Feelings expressed by nurses in this study highlight the need for clinical supervision and appropriate allocation of resources during the immediate recovery period after cardiac surgery. Nurses identified ways to improve clinical processes that impacted their decision-making during the immediate recovery of cardiac surgical patients.