The American Heart Association (AHA) issued a scientific statement regarding the potentially preventable complications that occur in contemporary cardiac intensive care units (CICUs), which was published in Circulation.
“We review evidence-based practices derived in relevant critical care populations, assess their relevance to CICU practice, and highlight key knowledge gaps warranting further investigation to attenuate patient risk,” noted the AHA’s writing group.
Preventing CICU-Acquired Infections
Infections and sepsis are common in patients in CICU, who are at risk for health care–associated infections (HAIs). “Hand hygiene is critically important, and improved compliance reduces the incidence of HAIs,” noted the statement authors.
The authors provide the following suggestions:
All CICUs should monitor for the presence of preventable HAI and multidrug-resistant pathogens, and use preventive strategies, including meticulous hand hygiene.
The duration of use of invasive medical appliances should be minimized.
All CICUs should use best practice care bundles to prevent common HAIs, including central line-associated bloodstream infection, catheter-associated urinary tract infection, and ventilator-associated pneumonia.
Approach to Analgesia and Sedation, and Diagnosis and Prevention of Delirium
There is an increasing need for CICUs to adopt a structured, evidence-based approach to evaluating patients with physical or cognitive barriers to communication.
“The adoption of best practices for pain, anxiety, agitation, and delirium management in this high-risk cardiovascular population has the potential to minimize missed diagnoses and to reduce excessive sedation and its ancillary complications,” emphasized the authors.
They recommend that all CICUs routinely assess pain with validated instruments, including the Numeric Rating Scale, Critical-Care Pain Observation Tool, or Behavioral Pain Scale (as appropriate), in patients with verbal or cognitive barriers to communication. Pain should be treated before the administration of sedative-hypnotics, and treatment regimens should be individualized to the underlying cause and patient comorbidities.
It is suggested that patients in the CICU undergo routine screening for delirium with either the Intensive Care Delirium Screening Checklist or the Confusion Assessment Method–Intensive Care Unit. Minimizing the use of medications associated with delirium, including benzodiazepines, and implementing early mobilization protocols may reduce the risk for delirium.
The use of antipsychotics in the CICU should be restricted to patients with hyperactive delirium who are at risk for harming themselves or others and have a low risk for long QTc-associated arrhythmias.
It is recommended that patients in the CICU requiring mechanical ventilation (MV) who remain anxious or agitated after appropriate pain or delirium treatment be treated with a sedation protocol that targets light sedation (eg, Richmond Agitation-Sedation Scale score from −1 to 0). Daily sedation interruption (DSI) can be considered in patients requiring deep sedation to facilitate neurological assessments or the suitability for light sedation.
Tailoring of the sedative agent selection to the individual patient’s presenting condition, comorbidities, hemodynamics, and perceived duration of MV is recommended. It is reasonable to avoid intravenous benzodiazepines as a routine first-line sedative-hypnotic given the risk for delirium in the absence of clear medical indications.
Among ventilated patients treated in general medical or surgical ICUs, use of neuromuscular blockers (NMBs) can help improve oxygenation or ventilation in those with acute respiratory distress syndrome (ARDS) or status asthmaticus.
“Although a detailed review of NMB indications, contraindications, pharmacokinetics, and monitoring is beyond the scope of this scientific statement, we concur with guidelines published by other organizations. In the mechanically ventilated CICU population, we suggest that NMB use be restricted to patients with refractory hypoxemia, hypercarbia, dyssynchrony, or targeted temperature management-associated shivering,” noted the authors.
Preventing Ventilator Complications
Complications from MV in the CICU occur in 20% to 30% of ventilated patients in general ICUs and include ventilator-associated lung injury (VALI), muscle weakness, pressure ulcers, tracheal trauma, swallowing dysfunction, and hemodynamic instability.
Routine tidal volume (TV) of 6 to 10 mL/kg ideal body weight in the CICU is recommended, when feasible, with lower TV (6-8 mL/kg ideal body weight) for patients at high risk for VALI or with established ARDS.
Use of applied positive end-expiratory pressure (PEEP) may prevent atelectasis and improve lung recruitment and oxygenation during positive pressure ventilation (PPV). Applied PEEP level should be tailored to each patient’s underlying pathophysiological condition and adjusted to achieve oxygenation and hemodynamic targets. Higher PEEP (eg, 5-10 cm H2O) can be considered in patients with left ventricular dysfunction and elevated filling pressures. A lower PEEP (3-5 cm H2O) may be appropriate for patients with right ventricular dysfunction, pericardial tamponade, constriction, and hypovolemia to prevent hemodynamic instability.
Hyperoxia is associated with adverse outcomes among those who are critically ill, and the optimal approach to oxygen administration continues to evolve.
Close monitoring of oxygenation in the CICU and titration of supplemental oxygen to achieve SpO2 >90% or PaO2 >60 mm Hg; hyperoxia (PaO2 >150 mm Hg) should be avoided.
Spontaneous breathing trials (SBTs) test a patient’s ability to breathe while receiving minimal or no ventilatory support and are safe and efficacious for reducing MV duration.
A daily assessment of readiness for extubation should be conducted on every patient undergoing MV, including a protocolized SBT.
Noninvasive PPV (NI-PPV) use can help reduce in-hospital mortality and the need for invasive, endotracheal intubation in some patients, compared with conventional oxygen supplementation alone.
Use of high-flow nasal cannula (HFNC) or NI-PPV in appropriately selected patients in the CICU with respiratory failure is recommended to reduce morbidity and mortality and to minimize the need for invasive, endotracheal intubation. NI-PPV should be considered after extubation for patients at risk for reintubation.
In patients with tenuous hemodynamics, awake intubation technique performed by an expert in airway management may prevent further decompensation, but this approach has not been evaluated systematically.
The individualization of induction and intubation practices should be performed, based on the patient’s hemodynamics, ventricular function, and loading conditions. Prior stabilization of vital signs, if possible, can mitigate some of the effects of intubation and MV initiation.
Benefits of Early Mobilization
ICU-acquired weakness, which is a clinically appreciable myopathic or neuropathic weakness that develops in the absence of other factors besides critical illness, occurs in up to one-third of patients in the ICU and is associated with decreased survival. Bed rest is a major risk factor for ICU-acquired weakness.
Routine incorporation of early mobilization protocols into management plans for patients in the CICU should be done. Eligibility for early mobilization may be assessed daily with a multidisciplinary team, including physician, nursing, and rehabilitation team members. The majority of patients except those with active ischemia or infarction should be mobilized early. The use of vasoactive agents, MV, intravascular catheters, and mechanical support devices and altered mental status do not preclude early mobilization. Discontinuation of a therapy session is reasonable if significant neurological, cardiovascular, or respiratory derangements occur.
Preventing Gastrointestinal Complications
Patients admitted to the ICU have a high prevalence of malnutrition, which is associated with adverse outcomes. Stress ulcers and upper gastrointestinal tract ulcerations that occur from an illness during hospitalization, are common in the ICU and may be more frequent in the CICU. Hyperglycemia is also common and linked to increased mortality.
Early initiation of enteral nutrition (ie, within 24-48 hours of admission) is suggested for the majority of patients who are unable to eat. Trophic enteral feeding is reasonable in most patients in the CICU, even those with compensated shock, those undergoing targeted temperature management, and those with compensated respiratory failure (including stabilized patients receiving prone positioning or extracorporeal membrane oxygenation).
Prophylaxis for stress ulcers is deemed reasonable for patients at increased risk for gastrointestinal bleeding, including patients on dual antiplatelet therapy with high-risk features, or patients on triple antithrombotic therapy.
Insulin therapy should be initiated early when blood glucose levels are >150 mg/dL (ie, 8.3 mmol/L). Intravenous insulin is recommended over subcutaneous insulin critically ill patients. Insulin therapy titration is preferable to a blood glucose target of 140 to 180 mg/dL (ie, 7.7-10 mmol/L).
Preventing and Recognizing Medication Complications and Errors
Medication use is the most common source of serious medical errors in the ICU setting and is an important target for preventing complications.
For common CICU medications, it is suggested that a routine therapy-specific approach be employed to prevent potential complications
Complications of Invasive Cardiac Procedures and Devices
Specialized use of invasive cardiovascular monitoring and support devices is common in the CICU and is associated with complications relating to placement of the device and its maintenance.
Whenever possible, procedures should be performed before they become emergency, including the routine use of ultrasound and fluoroscopic guidance.
Any invasive catheter or MCS device should be promptly removed when no longer needed.
Transitions of Care Best Practices
Effective communication is important for high-quality health care in the CICU and should include patient care rounds and multidisciplinary rounds.
Structured multidisciplinary rounds should be implemented at a standard time, and daily goals-of-care checklists should be considered.
In addition, palliative care considerations should be incorporated into clinical decisions and should involve palliative care specialists in appropriately selected patient populations.
“Given the substantial heterogeneity in care of critically ill cardiac patients, this document aims to provide standardized approaches to preventive care using the best available evidence,” stated the writing group. “Future research and quality improvement efforts are required to better define the epidemiology of critical illness-related complications in the CICU patient population and to evaluate existing and novel therapies with rigorous multicenter clinical trials and large prospective registries.”
Fordyce CB, Katz JN, Alviar CL, et al. Prevention of complications in the cardiac intensive care unit: A scientific statement from the American Heart Association [published online October 29, 2020]. Circulation. doi: 10.1161/CIR.0000000000000909