A large number of patients require cardiac surgery each year and up to 40% of them will experience postoperative delirium . Delirium is a neuropsychological syndrome characterized by fluctuations between acute agitation (hyperactivity) or lethargy (hypoactivity) . According to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-V), patients may be confused and disoriented . Incoherent speech, visual or auditory hallucinations, and labile emotions may also be observed. Delirium usually results from a mix of predisposing and precipitating factors (e.g., older age, tobacco and/or alcohol consumption, and cognitive decline, as well as surgery, pain, dehydration, and social isolation) [3–5]. Some of these factors can be addressed with preventive clinical interventions, but others cannot and require different approaches to manage and monitor the delirium episode.
Hyperactive delirium requires urgent care because patients may pull out endotracheal tubes or chest drains, injure themselves by falling, and sometimes even sustain fractures. On the opposite extreme, hypoactive delirium may interfere with essential care activities, such as daily breathing exercises, to prevent respiratory infections, or walking exercises to prevent loss of functional abilities. Such clinical complications of delirium contribute to longer length of hospital stay, increased mortality risk, and long-term psycho-functional sequelae [1, 2, 5–7]. Family caregivers of patients with delirium are also greatly affected. Witnessing these behavioral and emotional manifestations of delirium in a loved one has been described by caregivers as highly disturbing, with 75% of families reporting anxiety [8–10].
While clinical guidelines on delirium prevention, management, and monitoring have been developed based on meta-analyses, systematic reviews, and clinical studies [2, 11, 12], the level of evidence is much stronger for prevention rather than other interventions. Authors undertaking meta-analyses on delirium prevention have concluded that strategies such as interdisciplinary work and health care staff training focusing on geriatrics and delirium has led to decrease in the delirium incidence (odds ratio: 0.64; 95% confidence interval (CI): 0.46–0.88) . Although less research has focused on the management strategies for delirium, certain strategies have shown efficacy in decreasing mortality, duration of delirium, and length of hospital stay, as well as speeding up post-delirium psycho-functional recovery in older patients hospitalized in medical wards [14, 15]. These later strategies include a combination of pharmacological (e.g., antipsychotics) and non-pharmacological (e.g., reality orientation, reassurance) interventions.
Despite the lack of strong studies in delirium management, guidelines suggest focusing on two main objectives: assessment for probable causes and simultaneous management of delirium manifestations . However, certain settings, such as intensive care units (ICUs), make it more challenging to manage delirium optimally with a non-pharmacological approach. Indeed, ICU patients are in very precarious states, often falling in and out of consciousness, and requiring highly technological and invasive care that needs to be prioritized to insure survival. In this context, it is challenging for nurses to acquire detailed knowledge of patients’ personal backgrounds and personalities, thus limiting the personalization of delirium management interventions with reality orientation and reassurance.
The presence of family members is also central in delirium management guidelines, since familiarity helps patients stay in contact with reality – but the intensive care setting may limit this important aspect of care. Family caregivers’ involvement is a gold standard in other contexts of care such as community health, pediatrics, geriatrics, and palliative care . For example, in patients with dementia (a condition with behavioral manifestations somewhat similar to those accompanying delirium), family caregiver involvement in dementia management has been associated with reduced severity of agitation and aggressive behaviors . However, family caregiver involvement in delirium has been sparsely studied. Black et al.  involved family caregivers in “psychological care” in a comparative time series study with 170 adult acute care patients (87 with facilitated caregiver participation and 83 without facilitated caregiver participation), 77 of which developed delirium. It was hypothesized that having caregivers talk with patients, offer reality orientation, or hold their hand and reassure them at the bedside would potentially prevent delirium and enhance psycho-functional recovery. Results showed no significant difference in delirium prevention with both groups showing similar occurrence, although a superior psycho-functional recovery was observed in patients with facilitated caregiver participation in comparison of those without . In two other studies [12, 14], caregivers were encouraged at the bedside of patients with delirium  and were involved in discussing the discharge plan with the health care team . However, these two studies did not report the results specifically related to caregiver involvement and were not conducted with cardiac surgery patients.
These studies open the door to a novel way of delivering more personalized non-pharmacological delirium management interventions in ICU settings. The involvement of a caregiver who knows about the patients’ personality, life, and family, may offer a reassuring presence, thereby contributing to reality orientation. The present paper describes a study protocol of a delirium management nursing intervention involving caregivers of post-cardiac surgery patients with the hope of diminishing delirium severity and its related clinical complications as well as improving caregiver psychological outcomes. The protocol also tests the validity of regional oximetry (rSO2) measures obtained with near infrared spectroscopy (NIRS) which may provide an objective indicator for early detection and continuous monitoring of delirium. Finally, several feasibility issues such as delirium detection, risk factors for delirium, and ethics challenges with informed consent are discussed.
Study objectives and research hypotheses
The primary objective of this pilot study is to examine the acceptability and feasibility of i) the study design; ii) the experimental nursing intervention; and iii) a novel measure, cerebral rSO2 obtained by NIRS, a non-invasive method to detect cerebral oxygen imbalances among patients with delirium as well as its validity among patients with delirium.
The secondary objective of this pilot study is to examine the preliminary effect of the intervention on patient and caregiver outcomes. The following are the research hypotheses for the study’s secondary objective:
For patient outcomes
Compared with controls, patients in the intervention group will present:
(H1) Less severe delirium in the 3 days following onset;
(H2) Fewer complications (defined as either a sternal wound dehiscence, fall, respiratory tract infection, or accidental removal of urinary catheter, drain, arterial line or endotracheal tube) in the 3 days following onset of delirium;
(H3) Shorter total length of ICU and total hospital stay;
(H4) Enhanced psycho-functional recovery one month after the onset of delirium;
For caregiver outcomes
In comparison with controls, caregivers in the intervention group will present:
(H5) A lower anxiety level after the intervention (Day 4 following delirium onset), at Day 15, and at 1 month following delirium onset;
(H6) A higher sense of self-efficacy after the intervention (Day 4 following delirium onset), at Day 15, and at 1 month following delirium onset.
A randomized pilot study is proposed to test this novel delirium management intervention delivered in collaboration with family caregivers. This pilot study is registered at Controlled Trials (#ISRCTN95736036) and was approved (Reference number: 2012–288, 1420) by the Scientific and Ethics Committee of the Montreal Heart Institute Research Center.