Prophylactic treatment with desmopressin does not reduce postoperative bleeding after coronary surgery in patients treated with aspirin before surgery

The synthetic vasopressin analog desmopressin has hemostatic properties and may reduce postoperative bleeding after coronary artery bypass grafting (CABG). A study on the effects of recent aspirin ingestion on platelet function in cardiac surgery showed a greater impairment of platelet function in patients treated with aspirin <2 days before the operation. We evaluated the effects of desmopressin on postoperative bleeding in CABG patients who were treated with aspirin 75 or 160 mg until the day before surgery. The study was a prospective, randomized, double-blinded, placebo-controlled, parallel group trial. One-hundred patients were included and divided into two groups. One group received desmopressin 0.3 micro g/kg and the other received placebo (0.9% NaCl) after the neutralization of heparin with protamine sulfate. Postoperative blood loss was recorded for 16 h. The mean (SD) bleeding was 606 (237) mL in the desmopressin group and 601 (301) mL in the placebo group (P = 0.93), representing no significant difference (95% confidence interval, -107 to 117 mL). We conclude that desmopressin does not reduce postoperative bleeding in CABG patients treated with aspirin until the day before surgery. IMPLICATIONS: Continuation of aspirin until the day before coronary artery bypass grafting may increase postoperative bleeding. The administration of desmopressin to these patients after the neutralization of heparin with protamine sulfate does not reduce postoperative bleeding.     

Single-dose tranexamic acid reduces postoperative bleeding after coronary surgery in patients treated with aspirin until surgery

Tranexamic acid reduces postoperative bleeding after coronary artery bypass grafting. We evaluated the effects of a single dose of tranexamic acid given immediately before cardiopulmonary bypass (CPB) in patients treated with aspirin until the day before surgery. The study was a prospective, randomized, double-blinded, placebo-controlled, parallel-group trial. Eighty patients were included and divided into two groups: one group received tranexamic acid 30 mg/kg, and one group received placebo (0.9% NaCl) as a bolus injection before CPB. Postoperative blood loss was recorded for 16 h. Transfusions of blood products were recorded for the whole hospital stay. Transfusions of packed red cells were given when the hematocrit value was less than 20% during CPB and less than 25% after surgery. The patients in the tranexamic acid group had significantly less postoperative bleeding compared with the patients in the placebo group (mean [SD]) (475 [274] mL versus 713 [243] mL; P < 0.001). An effective inhibition of fibrinolysis was found in patients receiving tranexamic acid. Tranexamic acid reduces postoperative bleeding in coronary artery bypass grafting patients treated with aspirin until the day before surgery. IMPLICATIONS: Continuation of aspirin medication until the day before coronary artery bypass grafting may increase postoperative bleeding. The administration of a single dose of tranexamic acid (30 mg/kg) immediately before cardiopulmonary bypass significantly reduced postoperative bleeding and inhibited fibrinolysis in these patients.     

A case of unexpected difficult airway due to lingual tonsil hypertrophy

Clinical value of preoperative bedside screening tests for predicting difficult airway remains limited. Asymptomatic lingual tonsil hypertrophy is a known cause of unexpected difficult airway. We report a case as a reminder of this.     

Prediction of postoperative pain after percutaneous nephrolithotomy: can preoperative experimental pain assessment identify patients at risk?

Postoperative pain remains a significant problem and the individual variance in postoperative pain is not fully understood. In recent years, there has been focus on identifying risk factors predicting patients with high postoperative pain intensity or consumption of analgesics, which may facilitate an improvement in rehabilitation. This study evaluates the relationship between preoperative experimental pain assessment and postoperative pain and opioid consumption. Forty-four patients with uni- or bilateral kidney stone disease scheduled for percutaneous nephrolithotomy were included. The preoperative pain thresholds were measured using electrical (single and 5 repeated) and pressure pain stimulation over the flank bilaterally (stone-side = operation side and control-side = non-operation side). Postoperative pain scores were recorded on a numerical rating scale and analgesic consumption was registered. The responses to repeated electrical stimuli (temporal summation) were preoperatively increased on the stone-side compared to the control-side (P = 0.016). Preoperative electrical pain thresholds from the control-side correlated inversely with postoperative opioid consumption (single stimuli: ρ = ?0.43, P < 0.01; repeated stimuli: ρ = ?0.45, P < 0.005). This correlation was more pronounced for the 22 patients with unilateral renal calculi (single stimuli: ρ = ?0.54, P < 0.02; repeated stimuli: ρ = ?0.58, P < 0.01). There were no other correlations between the preoperative sensory tests and postoperative pain or opioid consumption. This study showed a correlation between the preoperative electrical pain thresholds on the control-side and postoperative opioid consumption after percutaneous nephrolithotomy. Preoperative measurement of the electrical pain thresholds may, therefore, be useful as a screening tool to identify patients at high risk of postoperative pain.     

Hyperoxia but not ambient pressure decreases tetrahydrobiopterin level without affecting the enzymatic capability of nitric oxide synthase in human endothelial cells

Nitric oxide (NO) seems to be related to bubble formation and endothelial dysfunction resulting in decompression sickness. Bubble formation can be affected by aerobic exercise or manipulating NO. A prior heat stress (HS) has been shown to confer protection against decompression sickness in rats. An important question was if the oxidative environment experienced during diving limits the availability of the nitric oxide synthase (NOS) cofactor tetrahydrobiopterin (BH4). Human endothelial cells were used to investigate how HS and simulated diving affected NO synthesis and defense systems such as heat shock protein 70 (HSP70) and glutathione (GSH). BH4 was measured using a novel LC–MS/MS method and NOS by monitoring the conversion of radiolabeled l-arginine to l-citrulline. Increased pO₂ reduced BH4 levels in cells in a dose-dependent manner independently of high pressure. This effect may result in decreased generation of NO by NOS. The BH4 decrease seemed to be abolished when cells were exposed to HS prior to hyperoxia. NOS enzyme was unaffected by increased pO₂ but substantially reduced after HS. The BH4 level seemed to a minor extent to be dependent upon GSH and probably to a higher degree dependent on other antioxidants such as ascorbic acid. A simulated dive at 60 kPa O₂ had a potentiating effect on the heat-induced HSP70 expression, whereas GSH levels were unaffected by hyperoxic exposure. HS, hyperoxia, and dive affected several biochemical parameters that may play important roles in the mechanisms protecting against the adverse effects of saturation diving.     

Diagnosis of autoimmune pancreatitis by core needle biopsy: application of six microscopic criteria

Autoimmune pancreatitis (AIP) has been established as a special entity of chronic pancreatitis (CP). However, its clinical distinction from pancreatic cancer and other types of CP is still difficult. The aim of this study was to evaluate the efficacy of pancreatic core needle biopsy for the diagnosis of AIP. In 44 core needle biopsy specimens, we assessed the following microscopic features: granulocytic epithelial lesions (GELs), more than ten IgG4-positive plasma cells/HPF, more than ten eosinophilic granulocytes/HPF, cellular fibrosis with inflammation, lymphoplasmacytic infiltration, and venulitis. All biopsies that showed four or more of the six features (22 of 44) were obtained from 21 of 26 patients whose clinical diagnosis and follow-up were consistent with AIP. All non-AIP CP patients (n = 14) showed three or less than three of the features in their biopsies. GELs were only observed in biopsy specimens from AIP patients. In conclusion, our data indicate that the six criteria we applied were able to recognize AIP in 76% of biopsy specimens using a cut-off level of four. When the specimens that revealed only three features but showed GELs were added, the sensitivity rose to 86%. Pancreatic core needle biopsy can therefore make a significant contribution to the diagnosis of AIP.