Assessment of long-term cognitive dysfunction in older patients who undergo heart surgery.

INTRODUCTION: Older patients are more likely to have cognitive dysfunction, and a great proportion of patients undergone surgical procedures are older adults. Postoperative cognitive dysfunction (POCD) has been shown as a consistent complication after major surgical procedures such as heart surgery. AIM: To determine the presence of long-term POCD in ≥65-year-old patients undergoing coronary artery bypass grafting and aortic valve replacement, and to establish related risk factors. METHODS: We prospectively and sequentially included 44 patients with coronary disease and aortic stenosis scheduled for heart surgery. Follow-up of all patients was standardized and a neurocognitive evaluation were performed preoperatively and at 1, 6 and 12 months after surgery. RESULTS: Patients experienced a significantly postoperative cognitive dysfunction (33.5%, 63.4% and 38.9% at 1, 6 and 12 months, respectively) from baseline (20.5%). Patient-associated aspects such as age (p<0.01), history of smoking (p<0.01), arterial hypertension (p=0.022), diabetes mellitus (p=0.024), heart failure (p=0.036) and preoperative cognitive dysfunction (p<0.01), and surgery-associated aspects such as EuroSCORE (p<0.01) and operation time (p<0.01) were identified as related risk factors. CONCLUSIONS: Older patients who underwent heart surgery had long-term POCD. Both patient- and surgery-related risk factors were established as related risk factors. These findings suggest that the prevalence of cognitive dysfunction after cardiac surgery in older patients could be related to a possible progression to dementia. In addition, many of the risk factors identified may be modifiable but in practice, these patients are not attended to for their possible cognitive impairment.

Assessment of long-term cognitive dysfunction in older patients who undergo heart surgery.

INTRODUCTION: Older patients are more likely to have cognitive dysfunction, and a great proportion of patients undergone surgical procedures are older adults. Postoperative cognitive dysfunction (POCD) has been shown as a consistent complication after major surgical procedures such as heart surgery. AIM: To determine the presence of long-term POCD in ≥65-year-old patients undergoing coronary artery bypass grafting and aortic valve replacement, and to establish related risk factors. METHODS: We prospectively and sequentially included 44 patients with coronary disease and aortic stenosis scheduled for heart surgery. Follow-up of all patients was standardized and a neurocognitive evaluation were performed preoperatively and at 1, 6 and 12 months after surgery. RESULTS: Patients experienced a significantly postoperative cognitive dysfunction (33.5%, 63.4% and 38.9% at 1, 6 and 12 months, respectively) from baseline (20.5%). Patient-associated aspects such as age (p<0.01), history of smoking (p<0.01), arterial hypertension (p=0.022), diabetes mellitus (p=0.024), heart failure (p=0.036) and preoperative cognitive dysfunction (p<0.01), and surgery-associated aspects such as EuroSCORE (p<0.01) and operation time (p<0.01) were identified as related risk factors. CONCLUSIONS: Older patients who underwent heart surgery had long-term POCD. Both patient- and surgery-related risk factors were established as related risk factors. These findings suggest that the prevalence of cognitive dysfunction after cardiac surgery in older patients could be related to a possible progression to dementia. In addition, many of the risk factors identified may be modifiable but in practice, these patients are not attended to for their possible cognitive impairment.

Neurons of the A5 region are required for the tachycardia evoked by electrical stimulation of the hypothalamic defence area in anaesthetized rats.

In order to assess the possible interactions between the pontine A5 region and the hypothalamic defence area (HDA), we have examined the pattern of double staining for c-Fos protein immunoreactivity (c-Fos-ir) and tyrosine hydroxylase, throughout the rostrocaudal extent of the A5 region in spontaneously breathing anaesthetized male Sprague-Dawley rats during electrical stimulation of the HDA. Activation of the HDA elicited a selective increase in c-Fos-ir with an ipsilateral predominance in catecholaminergic and non-catecholaminergic A5 somata (P < 0.001 in both cases). A second group of experiments was done to examine the importance of the A5 region in modulating the cardiorespiratory response evoked from the HDA. Cardiorespiratory changes were analysed in response to electrical stimulation of the HDA before and after ipsilateral microinjection of muscimol within the A5 region. Stimulation of the HDA evoked an inspiratory facilitatory response, consisting of an increase in respiratory rate (P < 0.001) due to a decrease in expiratory time (P < 0.01). The respiratory response was accompanied by a pressor response (P < 0.001) and tachycardia (P < 0.001). After muscimol microinjection within the A5 region, pressor and heart rate responses to HDA stimulation were reduced (P < 0.01 and P < 0.001, respectively). The respiratory response persisted unchanged. Finally, to confirm functional interactions between the HDA and the A5 region, extracellular recordings of putative A5 neurones were obtained during HDA stimulation. Seventy-five A5 cells were recorded, 35 of which were affected by the HDA (47%). These results indicate that neurones of the A5 region participate in the cardiovascular response evoked from the HDA. The possible mechanisms involved in these interactions are discussed.

[Effects of tobacco smoke applied on various levels of the respiratory tract]. / Efecto del humo del tabaco aplicado en distintos niveles de las vías respiratorias.

The respiratory and cardiovascular reflex responses of tobacco smoke inhaled through an isolated larynx and directly into the lungs were studied in cats. The inhalation of tobacco smoke directly into the lungs showed the following: tachypnea (p less than 0.01), an increase in inspiratory and expiratory pleural pressure (p less than 0.01, p less than 0.001) with an increase in total lung resistance (p less than 0.01), a decrease in inspiratory and expiratory subglottic pressure (p less than 0.001, p less than 0.02) and an increase in mean arterial pressure (p less than 0.001) with a non significant slight increase of cardiac rate. The inhalation through an isolated larynx showed: bradypnea (p less than 0.01), a non significative decrease in inspiratory and expiratory pleural pressure with no changes in total lung resistance, and an increase in expiratory subglottic pressure (p less than 0.01) with no changes in inspiratory pressure accompanied by several glottic closures. No changes in arterial pressure and cardiac rate were observed. This study shows the existence of two respiratory reflex responses induced by tobacco smoke depending on the respiratory airway level application.