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Relationship between intraoperative regional cerebral oxygen saturation trends and cognitive decline after total knee replacement: a post-hoc analysis.

Salazar F, Doñate M, Boget T, Bogdanovich A, Basora M, Torres F, Gracia I, Fàbregas N - BMC Anesthesiol (2014)

Bottom Line: We observed no differences in baseline rSO2 values; rSO2 decreased significantly in all patients during surgery (P < 0.0001).The mean right-left difference in rSO2 was also significant in these patients (-2.87% [4.73%], lower on the right, P = 0.0034).Detection of a trend to asymmetry in rSO2 values can warn of possible postoperative onset of memory decline.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Anesthesia, Hospital Clinic de Barcelona, (Universitat de Barcelona), Barcelona, Spain.

ABSTRACT

Background: Bilateral regional brain oxygen saturation (rSO2) trends, reflecting intraoperative brain oxygen imbalance, could warn of brain dysfunction. Various types of cognitive impairment, such as memory decline, alterations in executive function or subjective complaints, have been described three months after surgery. Our aim was to explore the potential utility of rSO2 values as a warning sign for the development of different types of decline in postoperative psychological function.

Methods: Observational post-hoc analysis of data for the patient sample (n = 125) of a previously conducted clinical trial in patients over the age of 65 years undergoing total knee replacement under spinal anesthesia. Demographic, hemodynamic and bilateral rSO2 intraoperative values were recorded. An absolute rSO2 value of <50% or a reduction of >20% or >25% below baseline were chosen as relevant cutoffs. Composite function test scores were created from baseline to three months for each patient and adjusted for the mean (SD) score changes for a control group (n = 55). Tests were used to assess visual-motor coordination and executive function (VM-EF) (Wechsler Digit Symbol-Coding and Visual Reproduction, Trail Making Test) and memory (Auditory Verbal Learning, Wechsler Memory Scale); scales were used to assess psychological symptoms.

Results: We observed no differences in baseline rSO2 values; rSO2 decreased significantly in all patients during surgery (P < 0.0001). Seventy-five patients (60%) had no sign of cognitive decline or psychological symptoms. Twenty-one patients (16.8%) had memory decline, 3 (2.4%) had VM-EF decline, and 33 (26.4%) had psychological symptoms. Left and right rSO2 values were asymmetric in patients who had memory decline (mean [SD] left-right ratio of 95.03 [8.51] vs 101.29 [6.7] for patients with no changes, P = 0.0012). The mean right-left difference in rSO2 was also significant in these patients (-2.87% [4.73%], lower on the right, P = 0.0034).

Conclusions: Detection of a trend to asymmetry in rSO2 values can warn of possible postoperative onset of memory decline. Psychological symptoms and memory decline were common three months after knee replacement in our patients over the age of 65 years.

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Least mean squares estimates of regional cerebral oxygen saturation (rSO2) in each hemisphere over time for all patients (n = 125). rSO2 values for both hemispheres were seen to decrease over the course of study (P < 0.0001). The largest rSO2 decline coincided with tourniquet deflation and reperfusion of the extremity. Three hours after surgery rSO2 had not recovered to baseline (59.46% [95% CI, 58.25%–60.66%] and 59.20% [95% CI, 58.14%–60.27%] (P < 0.001) for right and left hemispheres respectively. CI = confidence interval. Ind = induction. Tourn = tourniquet. Postop = postoperative.
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Figure 1: Least mean squares estimates of regional cerebral oxygen saturation (rSO2) in each hemisphere over time for all patients (n = 125). rSO2 values for both hemispheres were seen to decrease over the course of study (P < 0.0001). The largest rSO2 decline coincided with tourniquet deflation and reperfusion of the extremity. Three hours after surgery rSO2 had not recovered to baseline (59.46% [95% CI, 58.25%–60.66%] and 59.20% [95% CI, 58.14%–60.27%] (P < 0.001) for right and left hemispheres respectively. CI = confidence interval. Ind = induction. Tourn = tourniquet. Postop = postoperative.

Mentions: The mean (SD) baseline absolute rSO2 values in the study group were 65% (7.3%) (range, 44%–87%) for the right hemisphere and 65% (6%) (range, 47%-80%) for the left hemisphere. rSO2 values for both hemispheres were seen to decrease over the course of study (P < 0.0001) (Figure 1), and the largest declines coincided with cuff deflation and reperfusion of the extremity. The mean right and left absolute rSO2 values three hours after surgery (59.46% [95% confidence interval, 58.25%–60.66%] and 59.20% [95% confidence interval, 58.14%–60.27%], respectively) had not recovered to baseline levels (P < 0.001). No correlations between changes in rSO2 and blood loss, hemodynamic or other respiratory variables were found. Baseline absolute rSO2 values of <50% were observed only in two patients (in one hemisphere).


Relationship between intraoperative regional cerebral oxygen saturation trends and cognitive decline after total knee replacement: a post-hoc analysis.

Salazar F, Doñate M, Boget T, Bogdanovich A, Basora M, Torres F, Gracia I, Fàbregas N - BMC Anesthesiol (2014)

Least mean squares estimates of regional cerebral oxygen saturation (rSO2) in each hemisphere over time for all patients (n = 125). rSO2 values for both hemispheres were seen to decrease over the course of study (P < 0.0001). The largest rSO2 decline coincided with tourniquet deflation and reperfusion of the extremity. Three hours after surgery rSO2 had not recovered to baseline (59.46% [95% CI, 58.25%–60.66%] and 59.20% [95% CI, 58.14%–60.27%] (P < 0.001) for right and left hemispheres respectively. CI = confidence interval. Ind = induction. Tourn = tourniquet. Postop = postoperative.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4109378&req=5

Figure 1: Least mean squares estimates of regional cerebral oxygen saturation (rSO2) in each hemisphere over time for all patients (n = 125). rSO2 values for both hemispheres were seen to decrease over the course of study (P < 0.0001). The largest rSO2 decline coincided with tourniquet deflation and reperfusion of the extremity. Three hours after surgery rSO2 had not recovered to baseline (59.46% [95% CI, 58.25%–60.66%] and 59.20% [95% CI, 58.14%–60.27%] (P < 0.001) for right and left hemispheres respectively. CI = confidence interval. Ind = induction. Tourn = tourniquet. Postop = postoperative.
Mentions: The mean (SD) baseline absolute rSO2 values in the study group were 65% (7.3%) (range, 44%–87%) for the right hemisphere and 65% (6%) (range, 47%-80%) for the left hemisphere. rSO2 values for both hemispheres were seen to decrease over the course of study (P < 0.0001) (Figure 1), and the largest declines coincided with cuff deflation and reperfusion of the extremity. The mean right and left absolute rSO2 values three hours after surgery (59.46% [95% confidence interval, 58.25%–60.66%] and 59.20% [95% confidence interval, 58.14%–60.27%], respectively) had not recovered to baseline levels (P < 0.001). No correlations between changes in rSO2 and blood loss, hemodynamic or other respiratory variables were found. Baseline absolute rSO2 values of <50% were observed only in two patients (in one hemisphere).

Bottom Line: We observed no differences in baseline rSO2 values; rSO2 decreased significantly in all patients during surgery (P < 0.0001).The mean right-left difference in rSO2 was also significant in these patients (-2.87% [4.73%], lower on the right, P = 0.0034).Detection of a trend to asymmetry in rSO2 values can warn of possible postoperative onset of memory decline.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Anesthesia, Hospital Clinic de Barcelona, (Universitat de Barcelona), Barcelona, Spain.

ABSTRACT

Background: Bilateral regional brain oxygen saturation (rSO2) trends, reflecting intraoperative brain oxygen imbalance, could warn of brain dysfunction. Various types of cognitive impairment, such as memory decline, alterations in executive function or subjective complaints, have been described three months after surgery. Our aim was to explore the potential utility of rSO2 values as a warning sign for the development of different types of decline in postoperative psychological function.

Methods: Observational post-hoc analysis of data for the patient sample (n = 125) of a previously conducted clinical trial in patients over the age of 65 years undergoing total knee replacement under spinal anesthesia. Demographic, hemodynamic and bilateral rSO2 intraoperative values were recorded. An absolute rSO2 value of <50% or a reduction of >20% or >25% below baseline were chosen as relevant cutoffs. Composite function test scores were created from baseline to three months for each patient and adjusted for the mean (SD) score changes for a control group (n = 55). Tests were used to assess visual-motor coordination and executive function (VM-EF) (Wechsler Digit Symbol-Coding and Visual Reproduction, Trail Making Test) and memory (Auditory Verbal Learning, Wechsler Memory Scale); scales were used to assess psychological symptoms.

Results: We observed no differences in baseline rSO2 values; rSO2 decreased significantly in all patients during surgery (P < 0.0001). Seventy-five patients (60%) had no sign of cognitive decline or psychological symptoms. Twenty-one patients (16.8%) had memory decline, 3 (2.4%) had VM-EF decline, and 33 (26.4%) had psychological symptoms. Left and right rSO2 values were asymmetric in patients who had memory decline (mean [SD] left-right ratio of 95.03 [8.51] vs 101.29 [6.7] for patients with no changes, P = 0.0012). The mean right-left difference in rSO2 was also significant in these patients (-2.87% [4.73%], lower on the right, P = 0.0034).

Conclusions: Detection of a trend to asymmetry in rSO2 values can warn of possible postoperative onset of memory decline. Psychological symptoms and memory decline were common three months after knee replacement in our patients over the age of 65 years.

Show MeSH
Related in: MedlinePlus