Dysautonomias in Parkinson's disease: cardiovascular changes and autonomic modulation in conscious rats after infusion of bilateral 6-OHDA in substantia nigra

It is important to elucidate the mechanism of dysautonomias in patients with Parkinson's disease; therefore, this study aimed to investigate the cardiovascular and autonomic changes that occur in an animal model of Parkinsonism. Adult male Wistar rats were anesthetized before bilateral microinfusions of 6-hydroxydopamine (6-OHDA) into the substantia nigra. The sham group underwent the same surgical procedure but received vehicle. After 7 days, the mean arterial pressure (MAP) and heart rate (HR) were measured, and various drugs were injected into conscious rats through cannulas previously implanted in the femoral artery and vein. Spectral analyses of systolic arterial pressure (SAP) and pulse interval (PI) were conducted with the CardioSeries software as the spontaneous baroreflex gain and effectivity. The animals were subjected to α-, β-adrenergic, or muscarinic receptor antagonism. For confirmation of the lesion, the levels of dopamine in the striatum were quantified by high-performance liquid chromatography. Animals that underwent 6-OHDA microinfusion had lower MAP and HR compared with those in the sham group. Spectral analysis of SAP showed that 6-OHDA animals exhibited a decrease in the sympathetic component. The PI values did not differ between groups. After the administration of muscarinic and β-adrenergic antagonists, the cardiovascular measures did not differ between the groups. However, upon administration of the α-adrenergic antagonist, the 6-OHDA animals exhibited a lower decrease in the MAP. We report cardiovascular impairments in 6-OHDA animals, possibly due to decreased sympathetic activity. Determination of the origin of these changes (central or peripheral) requires further investigation.

Sedimentation method for preparation of postoperatively salvaged unwashed shed blood in orthopaedic surgery

BACKGROUND

Salvage and return of unwashed shed blood (USB) after total knee replacement (TKR) is an established blood-saving technique, but some authors question its efficacy and safety and suggest that the shed blood be washed before returning. We evaluated a colloid-based sedimentation method for improving and standardizing the quality of USB collected after TKR without the need for washing.

METHODS

Experiments were performed to find the optimal colloid dose and sedimentation time using diluted donated venous blood. USB samples (n=52) were drawn from the reinfusion bag and mixed with hydroxyethyl starch or gelatine solutions (15-30%, colloid solution volume/total volume × 100). USB red blood cells (RBCs) were allowed to settle by gravity for 30 min, supernatant was evacuated from the syringe, and RBC concentrate was analysed. RBC recovery and other blood cell and chemical removal were calculated according to changes in USB volume and haematocrit. Twenty-five samples from leucodepleted packed RBCs were analysed as a comparator group.

RESULTS

Mean haemoglobin (Hb) of USB was 10.9 g dl(-1). After colloid treatment, 90% of RBCs were recovered, and USB Hb was similar to that of leucodepleted packed RBCs (n=25) (18.9 vs 19.6 g dl(-1), respectively; P=NS). In addition, the procedure reduced USB content of leucocytes (60%), platelets (48%), total protein (76%), cytokines (70-77%), and plasma-free haemoglobin (53%), without major differences between colloids.

CONCLUSIONS

Sedimentation of USB with colloid solutions provides a low-cost alternative for improving and standardizing the quality of salvaged USB after TKR.

Which patients are more likely to benefit from postoperative shed blood salvage after unilateral total knee replacement? An analysis of 581 consecutive procedures

INTRODUCTION

Requirements for allogeneic blood transfusion (ABT) after total knee replacement (TKR) are still high (30-50%), and salvage of unwashed filtered postoperative shed blood (USB) may represent an alternative to ABT. We evaluated that patients are more likely to benefit of USB reinfusion after TKR.

PATIENTS AND METHODS

Data from 581 consecutive primary TKR, managed with (reinfusion group, n = 382) or without (control group, n= 199) reinfusion of USB, were retrospectively reviewed.

RESULTS

Patients from reinfusion group received 119 +/- 88 ml of red blood cells from USB, without clinically relevant incidents, and showed a lower ABT rate (30.6% vs. 8.4%, for control and reinfusion groups, respectively; P = 0.001) (transfusion trigger, haemoglobin [Hb] < 9 g/dl). Differences in ABT rate between groups were significant for all preoperative Hb levels, except for Hb < or = 12 g/dl. A lower transfusion threshold (Hb < 8 g/dl) might have further decreased ABT rate (14.6% vs. 5.2%, respectively; P < 0.001), with differences being significant for preoperative Hb between 12 and 15 g/dl. There were no differences with respect to postoperative infection rate, but patients from reinfusion group had a shorter length of hospital stay (11 +/- 4 vs. 13 +/- 4 days, respectively; P= 0.001).

CONCLUSIONS

Return of USB after TKR seems to reduce the need for ABT, especially in patients with preoperative Hb between 12 and 15 g/dl. There is little benefit of USB reinfusion for patients with preoperative Hb > 15 g/dl, whereas patients with preoperative Hb < 12 g/dl would probably benefit from the combination of USB with some other blood-saving method.

Post-operative unwashed shed blood transfusion does not modify the cellular immune response to surgery for total knee replacement

BACKGROUND

In patients undergoing total knee replacement (TKR), most blood loss occurs post-operatively, and the return of unwashed filtered shed blood (USB) from post-operative drainage may represent an alternative to allogeneic blood transfusion (ABT). We evaluated the impact of USB return on the cellular immune response (CIR) after TKR.

PATIENTS AND METHODS

Forty TKR patients, intended to receive post-operative USB, entered the study. Blood samples were obtained before and 6 h, 24 h, 72 h and 7 days after surgery, and from USB, after it had been passed through a 40-microm filter. Full blood cell counts, lymphocyte subsets and immunoglobulins (IgA, IgG, IgM) were measured in all samples. A set of clinical data was collected from each patient.

RESULTS

Twenty-four of the 25 patients received a mean of 1.2 USB units and did not need additional ABT (USB group). Twelve of the 15 remaining patients who received neither USB nor ABT served as a control group for the post-operative CIR study. All patients showed a post-operative decrease in T-cell and natural killer (NK) cell counts, but not B-cell counts, and there were no significant differences between the groups with regard to CIR parameters, post-operative infection or hospital stay.

CONCLUSIONS

Post-operative salvage and return of USB after TKR does not seem to increase the post-operative infection rate or hospital stay, and does not modify CIR induced by surgery. These findings add to the clinical experience that post-operative USB return, as a source of autologous blood, is safe, and questions the beneficial effect of blood washing.

Impact of postoperative shed blood transfusion, with or without leucocyte reduction, on acute-phase response to surgery for total knee replacement

BACKGROUND

In patients undergoing total knee replacement (TKR) most blood loss occurs postoperatively and return of unwashed filtered shed blood (USB) from postoperative drainage may represent an alternative to allogeneic blood transfusion (ABT). We evaluated the impact of USB return, with or without leucocytes, on the acute-phase response (APR) after TKR.

PATIENTS AND METHODS

Forty-eight TKR patients, intended to receive postoperative USB, entered the study. Blood samples were obtained before and 6, 24, 72 h and 7 days after surgery, and from the USB before and after it passed through a 40-microm filter (Group F40) or a leucocyte-reduction filter (Group LRF). Haematimetric parameters, APR proteins (albumin, prealbumin, ceruloplasmin, haptoglobin, C-reactive protein), complement C3 and C4, and cytokines (IL-1beta, IL-6, IL-8, IL-10, and TNF-alpha) were measured in all samples.

RESULTS

Twenty-eight patients (Group F40=14, Group LRF=14) received a mean of 1.2 USB units, without any clinically relevant incident, and did not need additional ABT. Sixteen out of the 20 remaining patients who received neither USB nor ABT served as a control group for the postoperative APR study. All patients showed the typical postoperative APR profile and there were no significant differences between groups for APR parameters, postoperative complications, or hospital stay.

CONCLUSIONS

Postoperative blood salvage and return, with or without a LRF, after TKR does not present any clinically relevant side-effects and does not modify APR induced by surgery. These findings seem to confirm the clinical experience that postoperative USB return is safe and questions the beneficial effect of using LRF.