Ratios of Plasma and Platelets to Red Blood Cells in Surgical Patients With Acute Intraoperative Hemorrhage.

BACKGROUND: The relationships between the ratios of transfused allogeneic blood products and clinical outcomes in patients with acute intraoperative hemorrhage are poorly defined. METHODS: To better define these ratios, we undertook a single-center, observational cohort study of all surgical patients (≥18 years) who received rapid transfusion defined by a critical administration threshold of 3 or more units of red blood cells (RBCs) intraoperatively within 1 hour between January 1, 2011 and December 31, 2015. Multivariable regression analyses were used to assess relationships between ratios of plasma to RBCs and platelets to RBCs at 3, 12, and 24 hours and clinical outcomes. The primary outcome was hospital mortality, with secondary outcomes of intensive care unit and hospital-free days. RESULTS: The study included 2385 patients, of whom 14.9% had a plasma-to-RBC ratio of 1.0+, and 47.6% had a platelet-to-RBC ratio of 1.0+. Higher plasma-to-RBC and platelet-to-RBC ratios were observed for patients who underwent cardiac, transplant, and vascular surgery and in patients with greater derangements in hemostatic laboratory values. Ratios did not differ by patient age or severity of illness. Higher ratios were not associated with improved clinical outcomes. Mortality differed by platelet-to-RBC but not plasma-to-RBC ratio, with the highest mortality observed with a platelet-to-RBC ratio of 0.1-0.9 at 24 hours (odds ratio, 3.34 [1.62-6.88]) versus no platelets (P= .001). Higher plasma-to-RBC ratios were associated with decreased hospital-free days, although differences in clinical outcomes were not significant after exclusion of patients receiving only RBCs without component therapies. CONCLUSIONS: Transfusion ratios in surgical patients with critical intraoperative hemorrhage were largely related to surgical and hemostatic features rather than baseline patient characteristics. Higher ratios were not associated with improved outcomes.

Naja sputatrix Venom Preconditioning Attenuates Neuroinflammation in a Rat Model of Surgical Brain Injury via PLA2/5-LOX/LTB4 Cascade Activation.

Inflammatory preconditioning is a mechanism in which exposure to small doses of inflammatory stimuli prepares the body against future massive insult by activating endogenous protective responses. Phospholipase A2/5-lipoxygenase/leukotriene-B4 (PLA2/5-LOX/LTB4) axis is an important inflammatory signaling pathway. Naja sputatrix (Malayan spitting cobra) venom contains 15% secretory PLA2 of its dry weight. We investigated if Naja sputatrix venom preconditioning (VPC) reduces surgical brain injury (SBI)-induced neuroinflammation via activating PLA2/5-LOX/LTB4 cascade using a partial frontal lobe resection SBI rat model. Naja sputatrix venom sublethal dose was injected subcutaneously for 3 consecutive days prior to SBI. We observed that VPC reduced brain edema and improved neurological function 24 h and 72 h after SBI. The expression of pro-inflammatory mediators in peri-resection brain tissue was reduced with VPC. Administration of Manoalide, a PLA2 inhibitor or Zileuton, a 5-LOX inhibitor with VPC reversed the protective effects of VPC against neuroinflammation. The current VPC regime induced local skin inflammatory reaction limited to subcutaneous injection site and elicited no other toxic effects. Our findings suggest that VPC reduces neuroinflammation and improves outcomes after SBI by activating PLA2/5-LOX/LTB4 cascade. VPC may be beneficial to reduce post-operative neuroinflammatory complications after brain surgeries.

Plasma bilirubin correlations in non-obstructive cholestasis after partial hepatectomy.

BACKGROUND: The aim of this study was to provide an improved outline of the patterns and correlates of changes in plasma bilirubin after partial hepatectomy. METHODS: A large series of blood measurements and complementary variables were prospectively collected from 85 patients undergoing liver resection, and bilirubin correlations were assessed by regression analysis. RESULTS: Early postoperatively, the best simultaneous correlates of increasing bilirubin were the preoperative value, the duration of surgery, and the number of blood transfusions (r2 = 0.74, p < 0.001). Subsequently, increasing bilirubin became related to the number of resected liver segments, the duration of intraoperative liver ischemia, the use of continuous vs. intermittent ischemia, and the presence of sepsis (r2 = 0.82, p < 0.001); these were also the best simultaneous correlates of peak bilirubin. This pattern was characterized by prominently conjugated hyperbilirubinemia, hypocholesterolemia, and moderately increased alkaline phosphatase, and occurred in the absence of obstructive cholestasis. CONCLUSIONS: Major hepatectomy, parenchymal ischemia, and sepsis have similar and synergistic impacts as determinants of prominently conjugated hyperbilirubinemia after liver resection. This is likely related to impaired hepatocellular bilirubin transport and occurs in the absence of obstructive components.

Intraoperative parathormone measurement from the internal jugular vein predicts post-thyroidectomy hypocalcaemia.

BACKGROUND: The most common significant complication of total thyroidectomy is hypoparathyroidism. Intraoperative prediction of which patients are likely to be affected would allow both intraoperative and postoperative interventions to be utilised in these patients. Selection of these patients is essential if we are to be successful at discharging total thyroidectomy patients on the first postoperative day. We investigated the utility of intraoperative parathormone measurement from the internal jugular vein at predicting postoperative hypocalcaemia. MATERIALS AND METHODS: Prospective collection of data was done on 45 consecutive total thyroidectomy patients. Preoperative calcium, intraoperative parathormone and postoperative calcium and parathormone were collected. The accuracy of intraoperative parathormone in predicting those with postoperative hypocalcaemia was assessed. RESULTS: Intraoperative parathormone of less than 2 pmol l(-1) had a sensitivity of 100% and a specificity of 95% in predicting those with postoperative hypocalcaemia. An intraoperative sample less than 2 pmol l(-1) was a highly significant predictor (p < 0.0001) of postoperative hypocalcaemia. CONCLUSION: Intraoperative assessment of parathormone is an accurate predictor of those patients who will become hypoparathyroid in the postoperative period. Intraoperative prediction allows for targeted autotransplantation of glands in those at risk and selected early institution of postoperative supplementation in these patients. Patients not identified as at risk can be safely discharged.

[Evaluation of perioperative blood loss following total knee arthroplasty].

OBJECTIVE: To evaluate perioperative occult blood loss following total knee arthroplasty (TKA). METHODS: A retrospective analysis of 40 patients undergoing TKA was conducted to calculate the mean blood loss and occult blood loss according to Gross formula. RESULTS: The mean total blood loss was 1538 ml in these cases with occult blood loss of 791 ml. In patients with autologous blood transfusion, the mean total blood loss was 1650 ml with occult blood loss of 786 ml. In patients without autologous blood transfusion, the mean total blood loss was 1370 ml with occult loss of 798 ml. CONCLUSION: TKA often results in large volume of occult blood loss in the perioperative period which can not be fully compensated by autologous blood transfusion, and additional blood supply is needed for maintenance of the circulating volume.

Can the use of methylprednisolone, vitamin C, or alpha-trinositol prevent cold-induced fluid extravasation during cardiopulmonary bypass in piglets?

OBJECTIVE: Hypothermic cardiopulmonary bypass is associated with capillary fluid leakage, resulting in edema and occasionally organ dysfunction. Systemic inflammatory activation is considered responsible. In some studies methylprednisolone has reduced the weight gain during cardiopulmonary bypass. Vitamin C and alpha-trinositol have been demonstrated to reduce the microvascular fluid and protein leakage in thermal injuries. We therefore tested these three agents for the reduction of cold-induced fluid extravasation during cardiopulmonary bypass. METHODS: A total of 28 piglets were randomly assigned to four groups of 7 each: control group, high-dose vitamin C group, methylprednisolone group, and alpha-trinositol-group. After 1 hour of normothermic cardiopulmonary bypass, hypothermic cardiopulmonary bypass was initiated in all animals and continued to 90 minutes. The fluid level in the extracorporeal circuit reservoir was kept constant at the 400-mL level and used as a fluid gauge. Fluid needs, plasma volume, changes in colloid osmotic pressure in plasma and interstitial fluid, hematocrit, and total water contents in different tissues were recorded, and the protein masses and the fluid extravasation rate were calculated. RESULTS: Hemodilution was about 25% after start of normothermic cardiopulmonary bypass. Cooling did not cause any further changes in hemodilution. During steady-state normothermic cardiopulmonary bypass, the fluid need in all groups was about 0.10 mL/(kg.min), with a 9-fold increase during the first 30 minutes of cooling (P <.001). This increased fluid need was due mainly to increased fluid extravasation from the intravascular to the interstitial space at a mean rate of 0.6 mL/(kg.min) (range 0.5-0.7 mL/[kg.min]; P <.01) and was reflected by increased total water content in most tissues in all groups. The albumin and protein masses remained constant in all groups throughout the study. CONCLUSION: Pretreatment with methylprednisolone, vitamin C, or alpha-trinositol was unable to prevent the increased fluid extravasation rate during hypothermic cardiopulmonary bypass. These findings, together with the stability of the protein masses throughout the study, support the presence of a noninflammatory mechanism behind the cold-induced fluid leakage seen during cardiopulmonary bypass.

[Locoregional anesthesia and blood coagulation: impact of new antiplatelet drugs]. / Lokoregionalanästhesie und Blutgerinnung. Behandlung mit Thrombozytenfunktionshemmern.

New antiplatelet drugs such as glycoprotein IIb/IIIa receptor antagonists, thienopyridines (adenosine diphosphate receptor antagonists), inhibitors of cyclooxygenase and phosphodiesterase, and antiaggregatory prostaglandins have been introduced in vascular medicine. This paper reviews the pharmacokinetics, mechanisms of action, indications, and side effects of platelet-inhibiting agents as well as methods for coagulation monitoring. Updated guidelines for the management of locoregional anesthesia in patients receiving new antiplatelet drugs are discussed. In this clinical situation, the decision for or against locoregional anesthesia must be preceded by a risk-benefit analysis based on history of bleeding, physical examination, and coagulation monitoring. Blockade should be performed as atraumatically as possible and specific time intervals must be maintained between the last administration of antiplatelet agents and the performance of the blockade or withdrawal of a catheter in all elective patients.

Life-threatening hyperkalemia: a complication of spironolactone for heart failure in a patient with renal insufficiency.

IMPLICATIONS: Serum potassium concentration should be measured immediately before operation to detect hyperkalemia in heart failure patients treated with spironolactone. Renal insufficiency, advanced age, potassium supplementation, decompensated congestive heart failure, and a spironolactone dose larger than 25 mg/d increase the risk of hyperkalemia as a consequence of spironolactone therapy.

The effects of handholding on anxiety in cataract surgery patients under local anaesthesia.

AIM OF THE STUDY: To assess the effectiveness of handholding on the anxiety of patients undergoing planned cataract surgery under local anaesthesia. BACKGROUND: Anxiety concerning anaesthesia, pain, physical injuries, isolation, prognosis, possibilities of deformity, or loss of self-control may be stressful to patients undergoing surgery. Anxiety activates the sympathetic nervous system, characterized by an increase in catecholamine concentration, heart rate and blood pressure and increased glucocorticoid levels; it also affects immune responses. Therefore, there is a need for nursing interventions to reduce the anxiety of patients under local anaesthesia who are conscious. METHODS: An untreated control group design with pre and post-test was used. Among 62 patients, 30 were randomly assigned to the handholding group and 32 to the control group. Handholding was provided to subjects of the handholding group during surgery. Visual analogue scales and interviews were used to measure anxiety, and pulse rate and systolic and diastolic blood pressure were used as physiological measures of stress. Blood was taken for analysis of levels of epinephrine, norepinephrine, cortisol, neutrophils, lymphocytes and natural killer cells. RESULTS: The number of subjects who reported decreased anxiety during operation was significantly higher in the handholding group compared with the control group and most of the subjects reported that handholding during operation was very helpful in reducing anxiety. Epinephrine levels in the handholding group were significantly lower than in the control group. CONCLUSIONS: Results suggest that this noninvasive intervention has potential for reducing anxiety in patients having cataract surgery under local anaesthesia.

Vascular complications of transsphenoidal surgery.

Vascular complication of transsphenoidal surgery can lead to mortality and serious morbidity. In a series of 3,061 transsphenoidal operations for pituitary disease, 24 such complications were encountered, seven of which were fatal. The anatomic substrate for such complications is discussed, along with technical aspects of surgery and other methods for the avoidance of vascular complications.

A computer model comparing normovolemic hemodilution, hypervolemic hemodilution, and neither on intraoperative blood loss and final hematocrit.

Homologous blood transfusion, while frequently life-saving, is attended by risks and complications. Autologous blood transfusions have become an increasingly common alternative. Volume expansion, which is simpler, also is used. This study was designed to construct computer models of hypervolemic hemodilution and normovolemic hemodilution to compare them with each other and with normal (neither hypervolemic nor normovolemic hemodilution). Each model started with blood volume (BV) equal to 5,000 mL. Initial hematocrits (HCTs) were varied from 25% to 50%. Following phlebotomy and hemodilution or volume expansion, which ranged from 0 to 2,500 mL (50% of initial BV), the models were then bled 250 to 2,500 mL (5% to 50% of initial BV). In the phlebotomy model, the autologous blood was then returned. Final HCTs were then calculated. Preoperative phlebotomy of 500 to 1,000 mL, an amount commonly withdrawn, provides a minimally higher final HTC. Volume expansion by hypervolemic hemodilution provides almost the same low level of benefit. Benefits (3% higher HCT) are not seen until larger volumes are phlebotomized or hemodiluted and accompanied by large intraoperative blood losses. Autologous blood drawn by preoperative phlebotomy for intraoperative transfusion should not be used until studies show that these large volumes are safe and actually save blood.