Delirium in octogenarians undergoing cardiac surgery or intervention (CARDELIR), is the first study that systematically determined the occurrence, development and consequences of postoperative delirium in patients of 80 years or older with severe aortic stenosis, who have been treated with traditional aortic valve replacement surgery (AVR), or transcatheter aortic valve implantation (TAVI). The project leader for the CARDELIR study is professor Tone M. Norekvål.
Delirium can be found in all age groups, but older patients are especially vulnerable. Increasingly, older people are being offered advanced cardiac treatments like AVR and TAVI, and healthcare personnel more often experience patients who develop delirium after such treatments. Studies have shown that delirium in the oldest patients is associated with unfortunate consequences like reduced physical and cognitive functions, increased hospital readmissions, and death. Increased knowledge about delirium could, in cases like these, contribute to preventing the condition.
Delirium, also known as acute confusion, is characterized by sudden and shifting disturbances in attention, consciousness and cognitive function. The condition is a sign of a serious underlying medical condition. Several causes can contribute to make some patients more vulnerable to developing delirium than others.
Delirium is classified into three forms; hyperactive, hypoactive, and mixed delirium.
Patients with hyperactive delirium can be restless and agitated and remove oxygen masks, urinary catheters or peripheral venous catheters. Patients with hypoactive delirium can seem distant or apathetic, and struggle to keep awake during conversations. They may also have problems following instructions from healthcare personnel. Most patients shift between experiencing hypo- and hyperactive delirium through several hours or days.
In the CARDELIR study, data material from patients of 80 years and older who have been treated with either AVR or TAVI, was collected over a period of two years. The aim of the study is, to identify the occurrence of delirium in these patients, and to examine risk factors for developing delirium after AVR and TAVI and its longterm consequences including hospital readmissions and mortality.
Comparison of Frequences, Risk Factors, and Time Course of Postoperative Delirium in Octogenarians After Transcatheter Aortic Valve Implantation Versus Surgical Aortic Valve Replacement
The study included 143 patients of 80 years and older. The patients were screened for delirium daily for the five first post-operative days, using the Confusion Assessment Method (CAM). Of the patients in the AVR group, 66% developed delirium, compared to 44% of the patients in the TAVI group.
This was despite that the patients in the TAVI group were older, had a lower cognitive score at baseline, and more comorbidities. Patients who were treated with TAVI, and who did not develop post-operative delirium after two days, had a low risk of developing the condition in the following days in the course of the treatment.
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Delirium as a predictor of physical and cognitive function in individuals at the age of 80+ after TAVI or AVR.
This sub-study showed that the patients who developed post-operative delirium after TAVI or AVR had poorer short-term instrumental activities of daily living (IADL) function. Even so, the study showed that delirium did not seem to lead to a long-term reduction in physical, mental or self-reported health in the same patients.
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Eide LSP, Ranhoff, AH, Fridlund B, Haaverstad R, Hufthammer KO, Kuiper KKJ, Nordrehaug JE, Norekvål TM. Delirium as a Predictor of Physical and Cognitive Function in Individuals Aged 80 and Older After Transcatheter Aortic Valve Implantation or Surgical Aortic Valve Replacement. Am J Cardiol. 2015 Mar 15;115(6):802-9.
Readmission and death after AVR and TAVI
The study showed that delirium in patients at the age of 80+ can be a serious risk factor for post-operative morbidity and mortality. The results showed the effect of delirium on readmissions and mortality was greatest during the first 2 months after discharge.
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Eide LSP, Ranhoff, AH, Fridlund B, Haaverstad R, Hufthammer KO, Kuiper KKJ, Nordrehaug JE, Norekvål TM. Readmissions and Mortality in Delirious Versus Non-Delirious Octogenarian Patients After Aortic Valve Therapy: A Prospective Cohort Study. BMJ Open. 2016 Oct 5;6(10):e012683.
Indwelling urinary catheter use, aortic valve treatment and delirium
The study shows the connection between urinary catheter and delirium is stronger in patients at the age of 80+ who have undergone TAVI, compared to patients who have undergone AVR. These results show a previously unknown association between the number of hours with an indwelling urinary, and post-operative delirium in patients who have been treated with TAVI.
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Eide LSP, Lauck S, Ranhoff, AH, Fridlund B, Haaverstad R, Hufthammer KO, Kuiper KKJ, Nordrehaug JE, Norekvål TM. Indwelling Urinary Catheters, Aortic Valve Treatment and Delirium: A Prospective Cohort Study. BMJ Open. 2018 Nov 1;8(11):e021708.
Sleep in patients 80+ after TAVI or AVR
The study showed that patients of 80 years or older who have been treated with AVR or TAVI, experienced disturbances in self-reported sleep and insomnia, and had a disturbed sleep-wake pattern in the post-operative phase. The study also showed that the patients experienced reduced sleep during the nighttime, and increased sleep during the daytime, where they were immobile and mostly slept during the daytime in the five first days after surgery, while they were still admitted to the hospital.
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Amofah HA, Broström A, Fridlund B, Bjorvatn B, Haaverstad R, Hufthammer KO, Kuiper KK, Ranhoff AH, Norekvål TM. Sleep in Octogenarians During the Postoperative Phase After Transcatheter or Surgical Aortic Valve Replacement. Eur J Cardiovasc Nurs. 2016 Apr;15(2):168-77.
The experiences of the patients with post-operative delirium
The study showed that patients in the age group 80+ had clear memories of their delirium experiences for a long time after the operation (for up to 12 months). These memories were usually experienced as unpleasant and troublesome. This is new information that could contribute to an improved health services for this patient group.
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How patients experiences interactions with Healthcare Professionals and Relatives after Aortic Valve Therapy
The study found that next of kin and health personnel play an important part in the rehabilitation phase after AVR. Thoughtless comments communicated to older patients during this phase increases the feeling of discomfort, also in a long-term perspective. Attentive support with a focus on dignity and integrity is essential in the care of this patient group.
Tone M. Norekvål, PhD, RN, Professor, University of Bergen and the Western Norway University of Applied Sciences. Chair of PROCARD research group, Department of Heart Disease, Haukeland University Hospital.
Leslie SP Eide; Nurse, Gerontologist, PhD, Associate professor at the Western Norway University of Applied Sciences.