Effects of the sitting position on the distribution of blood volume in patients undergoing neurosurgical procedures

Buhre, W.; Weyland, A.; Buhre, K.; Kazmaier, S.; Mursch, Kay; Schmidt, Michael; Sydow, M.; Sonntag, H.

doi:10.1093/oxfordjournals.bja.a013439

Cited by 96 publications

(37 citation statements)

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“…4). Compared to patients without chronic liver failure [2,15], the total circulating blood volume was significantly higher in these patients even at baseline. Throughout surgery V d circ remained increased and slowly decreased during the first 24 h in intensive care unit (Fig.…”

Section: Blood Volumesmentioning

confidence: 67%

Perioperative monitoring of indocyanine green clearance and plasma disappearance rate in patients undergoing liver transplantation

Spiegel¹,

Scholz²,

Wietasch³

et al. 2002

Anaesthesist

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Section: Blood Volumesmentioning

confidence: 67%

Perioperative monitoring of indocyanine green clearance and plasma disappearance rate in patients undergoing liver transplantation

Spiegel¹,

Scholz²,

Wietasch³

et al. 2002

Anaesthesist

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“…In situations such as when bleeding or during anaesthesia the sitting position reduce venous return (Buhre et al 2000), thoracic electrical impedance (TI) has been used to evaluate the ®lling of the heart (Matzen et al 1990;Hanel et al 1994;Pawelczyk et al 1994;Cai et al 2000a). Using two frequencies, it has been found that TI will distinguish between the extracellular (ECW) and total body water (TBW; Thomasset 1963;Segal et al 1991;Petersen et al 1994).…”

Section: Introductionmentioning

confidence: 99%

An electrical admittance based index of thoracic intracellular water during head-up tilt in humans

Cai

Boesen

Strømstad

et al. 2000

European Journal of Applied Physiology

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During 50 degrees head-up tilt (HUT), the number of erythrocytes within the thorax has been shown to be reduced by approximately 25% and this level is retained during a maintained tilt, whilst that in the thigh increases by approximately 70%. To evaluate whether the electrical admittance of intracellular water (ICW) may be used to monitor this redistribution of red cells in humans, we determined the regional difference in the reciprocal value of the impedance at 1.5 and 100 kHz for the thorax (thoraxICW) and for the leg (legICW). In ten subjects all variables remained unchanged during head-down tilt but during HUT, presyncopal symptoms were induced in eight subjects after a mean of 27 (SEM 7) min as mean heart rate dropped from 85 (SEM 4) to 66 (SEM 3) beats x min(-1), mean arterial blood pressure from 80 (SEM 3) to 60 (SEM 5) mmHg, and mean oxygen saturation of venous blood from 76 (SEM 2)% to 73 (SEM 3)% (P < 0.05). The mean haematocrit increased from 50 (SEM 5)% to 52.5 (SEM 3.5)% (P < 0.01) and mean central venous pressure decreased during tilting (from a mean of 1 (SEM 1) to a mean of -1 (SEM 1) mmHg; P < 0.05) and returned to value at rest during the maintained tilt. Mean thoracic impedances increased by 7.0 (SEM 1.0) ohms (1.5 kHz) and 5.4 (SEM 1.2) ohms (100 kHz), and mean leg impedances decreased by 9.3 (SEM 1.2) ohms (1.5 kHz) and 3.1 (SEM 1.0) ohms (100 kHz) (P < 0.01). Mean thoraxICW decreased at 40 degrees HUT and remained reduced by 11 (SEM 2) S x 10(-4) (P < 0.05) until the presyncopal symptoms developed, at which time it was lower by 16 (SEM 2) S x 10(-4) (P < 0.01). Mean legICW increased from 97 (SEM 15) to 99 (SEM 15) S x 10(-4) (P = 0.08) during HUT but decreased during maintained tilt (to 94 (SEM 15) S x 10(-4); P < 0.05). The results suggested that during HUT, the difference in electrical admittance at a high and a low frequency current reflects the reduced number of red cells within the thorax.

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“…In conscious subjects, sitting position activates the sympathetic nervous system, resulting in an increase of systemic blood pressure associated with increased systemic vascular resistance and sustained reduction in cardiac output. Compensatory increases in sympathetic nervous system activation and systemic vascular resistance are attenuated under general anesthesia causing more pronounced hypotension [26].…”

Section: Discussionmentioning

confidence: 99%

Cerebral oxygen saturation monitoring during hypotensive anesthesia in shoulder arthroscopy: A comparative study between dexmedetomidine and esmolol

Maghawry

Elagamy

Tahir

et al. 2015

Egyptian Journal of Anaesthesia

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Background: Beach chair position (BCP) is used in arthroscopic shoulder operations for its advantages. The BCP together with deliberate hypotension used to decrease intraoperative blood loss during arthroscopic shoulder procedures, this may have risk to cause postoperative neurological insults. Dexmedetomidine and esmolol are used to induce deliberate hypotension. Near-infrared spectroscopy (NIRS) provides a non-invasive technique of continuous monitoring of regional cerebral tissue oxygen saturation (rScO 2 ). In this study we evaluate the prevalence of rScO 2 during hypotensive anesthesia induced by intra-operative infusion of either dexmedetomidine or esmolol in patients undergoing elective arthroscopic shoulder surgery in the BCP. Patients and methods: Fifty patients scheduled for elective arthroscopic shoulder surgery under general anesthesia with hypotensive technique in BCP, randomly assigned into two equal groups, dexmedetomidine group (D Group) and esmolol group (E Group) according to the drug used for deliberate hypotension. MAP, HR, BIS and rS c O 2 were recorded before induction of anesthesia T 0 , post-induction of anesthesia T 1 as baseline, 5 min after BCP T 2 , 5 min after starting the studied drug T 3 , 30 min T 4 , 60 min T 5 , 90 min T 6 , 5 min after stopping the studied drug T 7 , 5 min after return to supine T 8 and after extubation T 9 . Results: In D group there was significant decrease in Lt.rs c o 2 and Rt.rs c o 2 , at T2 to T7 compared to T1. In E group there was significant decrease in Lt.rs c o 2 and Rt.rs c o 2 at T2, to T7 compared to T1. In D group two patients had CDEs compared to five patients in E group. Conclusion: In patients undergoing shoulder arthroscopic surgery under general anesthesia, the BCP significantly decreases rS c O 2 , with further slight decrease of rS c O 2 with dexmedetomidine and esmolol induced hypotension with no affection of postoperative cognitive function with both drugs. Dexmedetomidine and esmolol are safe drugs with better safety of dexmedetomidine over esmolol.

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Effects of the sitting position on the distribution of blood volume in patients undergoing neurosurgical procedures

Cited by 96 publications

References 0 publications

Perioperative monitoring of indocyanine green clearance and plasma disappearance rate in patients undergoing liver transplantation

Perioperative monitoring of indocyanine green clearance and plasma disappearance rate in patients undergoing liver transplantation

An electrical admittance based index of thoracic intracellular water during head-up tilt in humans

Cerebral oxygen saturation monitoring during hypotensive anesthesia in shoulder arthroscopy: A comparative study between dexmedetomidine and esmolol

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