Number of painful procedures and pain management in a neonatal intensive care unit / A fájdalmas beavatkozások száma és a fájdalomcsillapítás módozatai egy hazai neonatalis intenzív centrumban.

Összefoglaló. Bevezetés: A neonatalis intenzív centrumokban kezelt betegek naponta számos fájdalmas beavatkozáson eshetnek át. A kezeletlen fájdalom következményeinek ismerete ellenére, fájdalmuk csillapítása még messze nem ideális. Célkituzés: Obszervációs tanulmányunk célja az osztályunkon kezelt koraszülötteket és beteg újszülötteket ért fájdalmas beavatkozások gyakoriságának és természetének meghatározása volt. Vizsgáltuk a procedurális fájdalom esetén alkalmazott gyógyszeres és nonfarmakológiai fájdalomcsillapítók használatát, valamint a beavatkozások számát és a fájdalomcsillapítás alkalmazását befolyásoló tényezoket. Módszerek: A vizsgálatba az osztályunkon 2019. 09. 01. és 2019. 12. 31. között kezelt betegeket vontuk be. Prospektív adatgyujtést végeztünk a hospitalizáció elso 14 napján, egy erre a célra kialakított kérdoíven, amelyet az egészségügyi személyzet valós idoben töltött ki. Eredmények: Kutatásunkba 143 gyermeket tudtunk bevonni. A vizsgálati idoszak alatt 43-féle fájdalmas beavatkozás történt, összesen 13 314 alkalommal, amibol 12 953 elso, 361 többszöri kísérlet volt. Gyermekenként átlagosan 93,1 beavatkozást végeztünk a hospitalizáció elso 2 hetében, ami átlagosan 8,2 fájdalmas procedúrát jelentett naponta és gyermekenként. Fájdalomcsillapítás összesen 4190 alkalommal, a beavatkozások 31,5%-ában történt. Ennek 55,5%-a folyamatos gyógyszeres, 40,7%-a nem gyógyszeres, 2,5%-a alkalmi gyógyszeres, 1,3%-a kombinált terápia volt. A legkisebb születési súlyú, legrövidebb gestatiós idore született és a lélegeztetett koraszülöttek szenvedték el a legtöbb fájdalmas beavatkozást. Következtetés: Betegeink nagyszámú fájdalmas beavatkozáson esnek át, és ezek nagyobb részénél nem történik fájdalomcsillapítás. A beavatkozások tervezésével, összehangolásával, a gyógyszeres és nem gyógyszeres fájdalomcsillapítás kiterjedtebb alkalmazásával jobb fájdalommenedzsment lenne elérheto. Orv Hetil. 2021; 162(48): 1931-1939. INTRODUCTION: Preterm infants and sick neonates treated in neonatal intensive care units may undergo numerous painful interventions. Despite rapidly growing knowledge about consequences of untreated pain, pain management of neonates is far from ideal. OBJECTIVE: To determine the frequency and nature of painful procedures and corresponding analgesic therapies in neonates treated in a neonatal intensive care unit of a university teaching hospital in Hungary. METHODS: A prospective observational study was performed between September and December 2019. We collected data of all painful procedures, pharmacological and non-pharmacological analgesic therapy performed on neonates during the first 14 days of hospitalization. For data collection, we used a questionnaire designed for this purpose, which was completed in real time by the medical staff. RESULTS: 143 children were enrolled. 43 types of painful interventions were performed, a total of 13,314 times, of which 12,953 were the first, 361 multiple attempts. Each neonate was subjected to a mean of 93.1 interventions in the first 2 weeks of hospitalization, representing an average of 8.2 painful procedures per day per child. Pain relief was performed a total of 4190 times, in 31.5% of the interventions. Of this, 55.5% were continuous pharmacological, 40.7% non-pharmacological, 2.5% occasional drug, and 1.3% combination therapy. Ventilated neonates and preterm infants with shorter gestational age and lower birth weight had the most painful procedures. CONCLUSION: Patients treated in our unit undergo a large number of painful interventions, most of which are not accompanied by analgesia. Increased efforts are needed to promote our better pain management. Orv Hetil. 2021; 162(48): 1931-1939.

Circulating nucleosomes and severity of illness in children suffering from meningococcal sepsis treated with protein C.

OBJECTIVE: Cell death leading to circulating nucleosomes and histones is a critical step in the pathogenesis of sepsis and contributes to lethality. Activated protein C was demonstrated to attenuate the harmful effects of histones. The objective of this retrospective study was to evaluate whether nucleosomes correlate with the severity of the inflammatory response and mortality in children suffering from severe meningococcal sepsis. Furthermore, we wanted to study the effects of infusion of protein C on nucleosome levels in children with septic purpura. DESIGN: Retrospective analysis of nucleosome levels in children suffering from meningococcal sepsis treated with either placebo or protein C. SETTING: Pediatric intensive care unit of a tertiary care university center. PATIENTS: In a randomized, placebo-controlled study, either protein C or placebo was administered to 38 children suffering from meningococcal sepsis. Nucleosome levels have been measured retrospectively in these 38 children suffering from meningococcal sepsis. MEASUREMENTS AND MAIN RESULTS: Twenty-eight children were treated with protein C and 10 received placebo. Nucleosome levels were significantly higher in nonsurvivors (n = 9) at any time point measured as compared to survivors (n = 29). Nucleosome levels significantly correlated with organ dysfunction scores, cytokines, and parameters for coagulation. Patients treated with protein C had significantly higher activated protein C levels than children receiving placebo. We could not find a clear effect of activated protein C on nucleosome levels in these patients. CONCLUSION: Circulating nucleosomes correlated with the severity of the inflammatory response and were associated with mortality in children suffering from meningococcal sepsis. We show that protein C administration does not decrease nucleosome levels in these patients.

Structure and function of a recombinant von Willebrand factor drug candidate.

The complex structure, large size, and multiple posttranslational modifications of von Willebrand factor (VWF) presented a technological challenge for the production of recombinant VWF (rVWF). Nonetheless, we developed an rVWF product for treating von Willebrand disease, whereupon rVWF is coexpressed with recombinant factor VIII (rFVIII) in Chinese hamster ovary cells used to produce rFVIII for the treatment of hemophilia A. Here we describe the characterization of the structure and function of the rVWF drug product, with a focus on its in vitro platelet aggregation and matrix protein binding functions. Electron microscopy and multimer analysis revealed a highly organized structure for the rVWF protein, with a homogeneous multimer distribution including ultrahigh molecular weight multimers. The specific activity for binding to collagen and platelets mediated by ristocetin is higher in rVWF than in commercial plasma-derived VWF-FVIII complex products. The affinity and binding capacity of rVWF to FVIII is comparable to VWF in plasma. rVWF effectively binds to platelets and promotes platelet adhesion under shear stress similar to VWF in human plasma.

Changes in ADAMTS13 (von-Willebrand-factor-cleaving protease) activity after induced release of von Willebrand factor during acute systemic inflammation.

Von Willebrand factor (VWF) is synthesized in endothelial cells, stored in the form of high molecular weight multimers and released after stimulation. After release, the multimers are cleaved by ADAMTS13 (von-Willebrand-factor-cleaving protease). We studied healthy volunteers in a double-blind, placebo controlled inflammation model. Ten male volunteers received 2 ng/kg endotoxin intravenously, and 5 volunteers placebo. Endotoxin infusion induced systemic inflammation and coagulation activation. After 4 hours the observed increase in neutrophils reached a maximum (273+/-34% of baseline; mean+/-SEM) and the platelet count dropped (81+/-2%). These parameters returned to baseline values after 24 hours. VWF antigen increased to 259+/-16% of baseline after 4 hours, remained elevated (192+/-15%) after 24 hours and returned to baseline after 7 days. Unusually large VWF multimers occurred in the plasma 4 hours after endotoxin infusion. ADAMTS13 activity (measured with a collagen-binding assay) decreased to 64+/-5% of baseline (P<0.001) after 4 hours, was still reduced after 24 hours (86+/- %; P=0.008) and returned to normal after 7 days. VWF multimer analysis showed pronounced satellite bands in the 4-hour samples, indicating cleavage of VWF by ADAMTS13. No apparent changes of the analyzed parameters were observed in the placebo group. The reciprocal course of ADAMTS13 and VWF after short-term VWF release induced by systemic inflammation is similar to that observed after induction of VWF release by desmopressin.

The effects of supra-normal protein C levels on markers of coagulation, fibrinolysis and inflammation in a human model of endotoxemia.

The protein C pathway serves as a modulating system with both anti-inflammatory and anticoagulant properties and is intimately involved in the pathophysiology of inflammation and sepsis. Treatment with recombinant human activated protein C (rhAPC) can reduce the mortality of severe sepsis. We investigated whether an elevation of plasma protein C levels to supra-normal levels by infusion of a protein C zymogen concentrate has an effect on coagulation, protein C activation or inflammation in a human endotoxemia model. Eleven healthy male volunteers were enrolled in a double-blind, placebo-controlled two-way cross-over trial. Ten minutes after infusion of 2ng/kg endotoxin each volunteer received either placebo or a plasma-derived protein C zymogen concentrate (Ceprotin, Baxter) (150 U/kg as a slow bolus infusion followed by 30 U/kg/h continuous infusion until 4 hours after LPS-infusion). Protein C antigen and activity increased 4- to 5-fold after infusion of the concentrate. APC was generated during endotoxin-induced inflammation in the placebo (1.6 fold increase) and the protein C period (4.0-fold increase). The increase of APC levels correlated with the TNF-alpha and IL-6 release in both periods (r = 0.65-0.68; p < 0.05) and paralleled the protein C antigen and activity levels in the period with supranormal protein C levels. Supra normal protein C levels resulted in slightly, although non-significant, lower tissue factor mRNA expression and thrombin generation (TAT, F1+2). Systemic inflammation (TNF-alpha, IL-6) was not influenced by protein C zymogen concentrate administration. Infusion of protein C zymogen was safe and no adverse effects occurred. The increase of protein C levels several fold above the normal range resulted in a proportional increase of the APC levels, but had no major anticoagulant, anti-inflammatory or profibrinolytic effects. Low grade endotoxemia itself induces significant protein C activation, which correlates with the TNF release.

Update on the mechanism of action and future of activated prothrombin complex concentrates.

Activated prothrombin complex concentrates (aPCCs) are an established treatment for bleeding in patients with inhibitors. These products are derived from prothrombin complex concentrates, purified from human plasma with dedicated activation steps included in their manufacturing process. Despite these activation steps, the majority of the prothrombin complex proteins remain as zymogens, with only a relatively small content of activated coagulation enzymes. Among these, the order of concentration based on activity units is the following: factor VIIa to factor Xa to thrombin to factor IXa. Studies in various in vitro and in vivo model systems indicate that the mechanism of action of aPCCs is primarily based on an enzyme-substrate complex consisting of factor Xa and prothrombin. These findings are complemented by others showing that prothrombin is a major procoagulant that is capable of triggering hemostasis under physiologic and pathophysiologic conditions. Despite the findings of the mechanism of action, aPCCs have a long history of successful clinical use, with established dosing regimens, and a relatively low risk of thromboembolic complications compared with other treatment options for patients with inhibitors.

An antibody specific for coagulation factor IX enhances the activity of the intrinsic factor X-activating complex.

During hemostasis the zymogen factor X (FX) is converted into its enzymatically active form factor Xa by the intrinsic FX-activating complex. This complex consists of the protease factor IXa (FIXa) that assembles, together with its cofactor, factor VIIIa, on a phospholipid surface. We have studied the functional properties of a FIXa-specific monoclonal antibody, 224AE3, which has the potential to enhance intrinsic FX activation. Binding of the antibody to FIXa improved the catalytic properties of the intrinsic FX-activating complex in two ways: (i) factor VIIIa bound to the FIXa-antibody complex with a more than 18-fold higher affinity than to FIXa, and (ii) the turnover number (kcat) of the enzyme complex increased 2- to 3-fold whereas the Km for FX remained unaffected. The ability of 224AE3 to increase the FXa-generation potential (called the "booster effect") was confirmed in factor VIII (FVIII)-depleted plasma, which was supplemented with different amounts of recombinant FVIII. In the presence of antibody 224AE3 the coagulant activity was increased 2-fold at physiological FVIII concentration and up to 15-fold at low FVIII concentrations. The booster effect that we describe demonstrates the ability of antibodies to function as an additional cofactor in an enzymatic reaction and might open up a new principle for improving the treatment of hemophilia.

Changes in von Willebrand factor-cleaving protease (ADAMTS13) activity after infusion of desmopressin.

von Willebrand factor-cleaving protease (ADAMTS13) cleaves von Willebrand factor (VWF) and regulates its physiologic function. To investigate the relation between ADAMTS13 activity and VWF, we compared ADAMTS13 activity with the VWF-related parameters VWF antigen (VWF:Ag), VWF collagen-binding activity (VWF:CBA), VWF-propeptide, proVWF, and VWF multimeric composition in 10 healthy volunteers and 3 patients with type 1 von Willebrand disease before and after infusing 0.3 microg/kg desmopressin. The VWF-related parameters in the volunteers increased 60 minutes after start of infusion by 3.7-fold for VWF:Ag, 7.2-fold for propeptide, and 2.2-fold for VWF:CBA. Unusually large VWF multimers and traces of proVWF appeared. The ADAMTS13 activity decreased to about half the initial value. After 24 hours values returned to baseline. Patients with type 1 von Willebrand disease showed similar results. We conclude that the inverse correlation between ADAMTS13 and VWF-related parameters suggests a consumption of ADAMTS13 after the desmopressin-induced release of higher multimers of VWF.

Recombinant von Willebrand factor-insight into structure and function through infusion studies in animals with severe von Willebrand disease.

We used a canine and a murine model of von Willebrand disease (vWD) to study the in vivo effects of recombinant von Willebrand factor (vWF). Two preparations were used: (1) a fully processed mature vWF; this was achieved by coexpression of furin. (2) A preparation containing unprocessed pro-vWF, the propeptide still covalently linked to mature vWF. Both preparations induced an increase in canine and murine factor VIII:C (FVIII), which was sustained even when vWF antigen had been removed from the circulation. vWF multimers were analyzed in the plasma samples after infusion using ultra high-resolution 3% agarose gels to allow the separation of homoforms and heteroforms of the vWF polymers. Administration of pro-vWF to dogs with severe vWD resulted in the removal of the propeptide and maturation of vWF in the circulation, indicating that the propeptide cleavage from unprocessed vWF can occur extracellularly. This suggests that the vWF propeptide, besides being derived from the Weibel-Palade bodies of endothelial cells after stimulation, can also be cleaved by pro-vWF in plasma. Using a murine model of vWD, the involvement of the low-density lipoprotein receptor-related protein (LRP) in the clearance of FVIII was established. The low levels of FVIII observed in the absence of vWF are due to an enhanced clearance of FVIII by binding to LRP and removal from the circulation through endocytosis. Administration of the receptor-associated protein (RAP) as a recombinant fusion protein to vWF knockout mice significantly improved the in vivo recovery of recombinant FVIII and the survival time of otherwise rapidly cleared FVIII.

In vivo and in vitro processing of recombinant pro-von Willebrand factor.

Von Willebrand factor (vWF) is synthesized in endothelial cells as pre-pro-vWF and processed intracellularly to propeptide (vWFpp) and mature vWF. Recombinant pro-vWF when infused into animals can also be processed extracellularly in vivo. Within 1 h of infusion in a dog and mice the multimer pattern changed to that typically seen in mature vWF indicating that propeptide cleavage from unprocessed vWF occurs extracellularly in the circulation. Incubation of a recombinant pro-vWF preparation with canine and human vWF-deficient plasma induced a time-dependent decrease in pro-vWF antigen and an increase in vWFpp antigen without changing total vWF antigen or collagen-binding activity. Multimer analysis showed the gradual transformation of the pro-vWF multimers to mature vWF multimers and cleaved vWFpp was visualized on autoradiograms of SDS-polyacrylamide electrophoresis gels using (125)I-labeled pro-vWF. When recombinant pro-vWF was incubated with increasing amounts of purified thrombin, the extent of pro-vWF processing was dose dependent. The specific cleavage of vWFpp was confirmed by immunoblots using an anti-vWFpp antibody and by amino-terminal amino acid analysis. Hirudin preconditioning of vWF-deficient mice attenuated processing of infused recombinant pro-vWF suggesting that thrombin plays a part in the processing events in vivo.

A fully recombinant partial prothrombin complex effectively bypasses fVIII in vitro and in vivo.

The development of inhibitory antibodies is a serious complication in hemophilic patients, severely compromising therapeutic success. Bleeding episodes in affected patients are controlled by treatment with a plasma-derived prothrombin complex concentrate (PCC), activated PCC (APCC) or recombinant activated factor VII. We hypothesized that a recombinant two-component agent consisting of recombinant prothrombin (rfII) and activated factor X (rfXa) would have substantial fVIII bypassing activity and could be a safe alternative therapeutic option. To test this hypothesis we assembled an agent in vitro solely consisting of rfII and rfXa at a molar ratio of 37,500:1. These factors are believed to be responsible for the activity of APCC preparations. Recombinant fX, used as the source for fXa generation, and rfII were purified from serum-free and protein-free conditioned media of stably transfected CHO and BHK tissue culture cells, respectively. Activation of rfX to rfXa was accomplished by the plant protease ficin, obviating the need for a protease derived from a human or animal source. We found that in vitro the complex reduced the abnormally prolonged activated partial thromboplastin time (APTT) of a high-titer fVIII inhibitor plasma similar to an APCC preparation. Furthermore, addition of increasing amounts of rfII/rfXa to inhibitor plasma resulted in a linear dose-dependent increase in the rate of thrombin generation. In a rabbit fVIII inhibitor model, treatment with rfII/rfXa statistically significantly reduced the intensity of the abnormal cuticle bleeding. In the Wessler test, rfII/rfXa showed no thrombogenicity. These data show that a well-defined, particularly safe and efficacious agent with fVIII bypassing activity can be generated from recombinant fII and fXa.