Whole blood heparin concentrations do not correlate with plasma antifactor Xa heparin concentrations in pediatric patients undergoing cardiopulmonary bypass

Perfusion ◽  
2000 ◽  
Vol 15 (3) ◽  
pp. 203-209 ◽  
Author(s):  
C Gruenwald ◽  
V de Souza ◽  
A KC Chan ◽  
M Andrew

This study was designed to test the validity of whole blood heparin concentration (WHBC) measurements using an on-site protamine titration assay with the Hepcon instrument (Medtronic Blood Management, Parker, CO, USA) in pediatric patients less than 1 year old undergoing cardiopulmonary bypass (CPB). The validity of the Hepcon measurements was examined via a test of correlation with the gold standard plasma antifactor Xa activity (anti-Xa) assay. Fifty-one patients (23 females and 28 males) under 1 year old (mean age 5.3 months) were studied prospectively. Blood samples were taken at 5 min into CPB and at the end of CPB for the WBHC, plasma anti-Xa activity, and hematocrit (Hct). The WBHC was converted to plasma heparin level using a formula taking into account the collection of blood into citrate solution and the effect of the citrate on the hematocrit. While a nonparametric statistical analysis revealed that the mean corrected values from the Hepcon instrument were not significantly different from the mean anti-Xa values ( p = 0.070 at 5 min on CPB, p = 0.518 at the end of CPB), there was no significant correlation between these values at either 5 min into CPB ( r = 0.113, p = 0.429) or at the end of CPB ( r = -0.247, p = 0.080). The lack of correlation between the two assays may be related to the extreme hemodilution observed during CPB in small children, which leads to very low concentrations of coagulation proteins. Due to this discrepancy, whole blood heparin monitors should be further evaluated in children undergoing CPB.

1993 ◽  
Vol 70 (06) ◽  
pp. 0937-0941 ◽  
Author(s):  
Maureen Andrew ◽  
Brian MacIntyre ◽  
James MacMillan ◽  
William G Williams ◽  
Colleen Gruenwald ◽  
...  

SummaryHeparin therapy for children undergoing cardiopulmonary bypass (CPB) is monitored in the operating room by automated whole blood activated clotting times (ACT). For many years our institution used Hemochron (HC) ACT machines but changed to HemoTec (HT) ACT machines because they required a smaller blood sample and provided results in duplicate. When HemoTec ACT machines were introduced at our institution, the surgical team was concerned that increased amounts of heparin were being administered to our patients during CPB. This study was conducted to investigate the potential mechanisms responsible for these clinical observations. First, we compared ACT values on ex vivo blood samples from 20 consecutive pediatric patients (6 samples each) during CPB. The HC ACT values were significantly and systematically increased over HT ACT values (HC: 750 ± 40 vs HT: 418 ± 26, Mean ± SEM, p <0.01). 94% of all HC ACT values were above 450 s compared to only 27% of HT ACT values. If HT ACT values had been used for patient monitoring, all patients would have received more heparin to achieve ACT values above 450 s. The two machines reported similar ACT values when heparin was added in vitro to whole blood (0.1-5.0 units/ml), (HC: Y = 98X + 104, r2 = 0.93 HT: Y = 82X + 109, r2 = 0.94). Heparin concentrations in our patients following a bolus of 300 U/kg of heparin, but prior to CPB were 3.2 ± 0.07 units/ml. Following the initiation of CPB, heparin concentrations decreased to 1.3 ± 0.05, reflecting, in part, hemodilution by the pump prime (1 U of heparin/ml). In contrast to the in vitro results, there was no relationship between ACT values measured by either machine and plasma heparin concentrations in ex vivo samples. Finally, plasma concentrations of 8 coagulation proteins measured prior to CPB and following CPB were decreased by 27-55%, predominantly reflecting the final dilution by CPB. In conclusion: 1) HT and HC machines cannot be used interchangeably in pediatric patients without risk of altering clinical practice in an uncontrolled fashion; and 2) ACT values from children on CPB correlate poorly with heparin concentrations, likely due to hemodilution. Optimal use of anticoagulant therapy during CPB in children requires further study in clinical trials and ongoing quality control.


1994 ◽  
Vol 72 (04) ◽  
pp. 511-518 ◽  
Author(s):  
Valentine C Menys ◽  
Philip R Belcher ◽  
Mark I M Noble ◽  
Rhys D Evans ◽  
George E Drossos ◽  
...  

SummaryWe determined changes in platelet aggregability following cardiopulmonary bypass, using optical aggregometry to assess macroaggregation in platelet-rich plasma (PRP), and platelet counting to assess microaggregation both in whole blood and PRP. Hirudin was used as the anticoagulant to maintain normocalcaemia.Microaggregation (%, median and interquartile range) in blood stirred with collagen (0.6 µg/ml) was only marginally impaired following bypass (91 [88, 93] at 10 min postbypass v 95 (92, 96] prebypass; n = 22), whereas macroaggregation (amplitude of response; cm) in PRP stirred with collagen (1.0µg/ml) was markedly impaired (9.5 [8.0, 10.8], n = 41 v 13.4 [12.7,14.3], n = 10; p <0.0001). However, in PRP, despite impairment of macroaggregation (9.1 [8.5, 10.1], n = 12), microaggregation was near-maximal (93 [91, 94]), as in whole blood stirred with collagen. In contrast, in aspirin-treated patients (n = 14), both collagen-induced microaggregation in whole blood (49 [47, 52]) and macroaggregation in PRP (5.1 [3.8, 6.6]) were more markedly impaired, compared with control (both p <0.001).Similarly, in PRP, macroaggregation with ristocetin (1.5 mg/ml) was also impaired following bypass (9.4 [7.2, 10.7], n = 38 v 12.4 [10.0, 13.4]; p <0.0002, n = 20), but as found with collagen, despite impairment of macroaggregation (7.2 [3.5,10.9], n = 12), microaggregation was again near-maximal (96 [93,97]). The response to ristocetin was more markedly impared after bypass in succinylated gelatin (Gelo-fusine) treated patients (5.6 [2.8, 8.6], n = 17; p <0.005 v control), whereas the response to collagen was little different (9.3 v 9.5). In contrast to findings with collagen in aspirin-treated patients, the response to ristocetin was little different to that in controls (8.0 v 8.3). Impairment of macroaggregation with collagen or ristocetin did not correlate with the duration of bypass or the platelet count, indicating that haemodilution is not a contributory factor.In conclusion: (1) Macroaggregation in PRP, as determined using optical aggregometry, is specifically impaired following bypass, and this probably reflects impairment of the build-up of small aggregates into larger aggregates. (2) Impairment of aggregate growth and consolidation could contribute to the haemostatic defect following cardiac surgery.


1997 ◽  
Vol 77 (05) ◽  
pp. 0920-0925 ◽  
Author(s):  
Bernd Pötzsch ◽  
Katharina Madlener ◽  
Christoph Seelig ◽  
Christian F Riess ◽  
Andreas Greinacher ◽  
...  

SummaryThe use of recombinant ® hirudin as an anticoagulant in performing extracorporeal circulation systems including cardiopulmonary bypass (CPB) devices requires a specific and easy to handle monitoring system. The usefulness of the celite-induced activated clotting time (ACT) and the activated partial thromboplastin time (APTT) for r-hirudin monitoring has been tested on ex vivo blood samples obtained from eight patients treated with r-hirudin during open heart surgery. The very poor relationship between the prolongation of the ACT and APTT values and the concentration of r-hirudin as measured using a chromogenic factor Ila assay indicates that both assays are not suitable to monitor r-hirudin anticoagulation. As an alternative approach a whole blood clotting assay based on the prothrombin-activating snake venom ecarin has been tested. In vitro experiments using r-hirudin- spiked whole blood samples showed a linear relationship between the concentration of hirudin added and the prolongation of the clotting times up to a concentration of r-hirudin of 4.0 µg/ml. Interassay coefficients (CV) of variation between 2.1% and 5.4% demonstrate the accuracy of the ecarin clotting time (ECT) assay. Differences in the interindividual responsiveness to r-hirudin were analyzed on r-hirudin- spiked blood samples obtained from 50 healthy blood donors. CV- values between 1.8% and 6% measured at r-hirudin concentrations between 0.5 and 4 µg/ml indicate remarkably slight differences in r-hirudin responsiveness. ECT assay results of the ex vivo blood samples linearily correlate (r = 0.79) to the concentration of r-hirudin. Moreover, assay results were not influenced by treatment with aprotinin or heparin. These findings together with the short measuring time with less than 120 seconds warrant the whole blood ECT to be a suitable assay for monitoring of r-hirudin anticoagulation in cardiac surgery.


Reproduction ◽  
2000 ◽  
pp. 331-336 ◽  
Author(s):  
L Holm ◽  
H Ekwall ◽  
GJ Wishart ◽  
Y Ridderstrale

Sperm storage tubules from the utero-vaginal junction of chickens, quails and turkeys were analysed for calcium and zinc using X-ray microanalysis of ultra-rapidly frozen tissue in a scanning electron microscope. This technique enabled the tubular fluid surrounding the stored spermatozoa and the intracellular content of the cells of the sperm storage tubules to be analysed separately and, by using standards with known concentrations, their elemental concentrations were estimated. The mean (+/- SEM) concentration of calcium in the tubular fluid from chickens, quails and turkeys was 17 +/- 3, 19 +/- 3 and 17 +/- 4 mmol kg(-1) wet weight, respectively. The intracellular calcium concentration of the cells of the tubules did not differ significantly from these values and was also similar in the mucosal epithelial cells of the utero-vaginal junction. Zinc was localized in the cells of turkey sperm storage tubules and tubular fluid, but at low concentrations. No zinc could be detected in corresponding structures from chickens and quails. The concentration of calcium in the tubular fluid is within the range known to inhibit the motility of spermatozoa, supporting this function for calcium during storage. Zinc is known to depress turkey sperm metabolism and it may also be involved in inducing quiescence of spermatozoa during storage in this species.


2014 ◽  
Vol 17 (3) ◽  
pp. 173 ◽  
Author(s):  
Murat Ugurlucan ◽  
Eylem Yayla Tuncer ◽  
Fusun Guzelmeric ◽  
Eylul Kafali ◽  
Omer Ali Sayin ◽  
...  

<p><strong>Background</strong>: Although the avoidance of cardiopulmonary bypass during the Fontan procedure has potential advantages, using cardiopulmonary bypass during this procedure has no adverse effects in terms of morbidity and mortality rates. In this study, we assessed the postoperative outcomes of our first 9 patients who have undergone extracardiac Fontan operation by the same surgeon using cardiopulmonary bypass.</p><p><strong>Methods</strong>: Between September 2011 and April 2013,  9 consecutive patients (3 males and 6 females) underwent extra-cardiac Fontan operation. All operations were performed under cardiopulmonary bypass at normothermia by the same surgeon.  The age of patients ranged between 4 and 17 (9.8 ± 4.2) years. Previous operations performed on these patients were modified Blalock-Taussig shunt procedure in 2 patients, bidirectional cavopulmonary shunt operation in 6 patients, and pulmonary arterial banding in 1 patient. Except 2 patients who required intracardiac intervention, cross-clamping was not applied. In all patients, the extracardiac Fontan procedure was carried out by interposing an appropriately sized tube graft between the infe-rior vena cava and right pulmonary artery.</p><p><strong>Results</strong>: The mean intraoperative Fontan pressure and transpulmonary gradient were 12.3 ± 2.5 and 6.9 ± 2.2 mm Hg, respectively. Intraoperative fenestration was not required. There was no mortality and 7 patients were discharged with-out complications. Complications included persistent pleural effusion in 1 patient and a transient neurological event in 1 patient. All patients were weaned off mechanical ventila-tion within 24 hours. The mean arterial oxygen saturation increased from 76.1% ± 5.3% to 93.5% ± 2.2%. All patients were in sinus rhythm postoperatively. Five patients required blood and blood-product transfusions. The mean intensive care unit and hospital stay periods were 2.9 ± 1.7 and 8.2 ±  1.9 days, respectively.</p><p><strong>Conclusions</strong>: The extracardiac Fontan operation per-formed using cardiopulmonary bypass provides satisfactory results in short-term follow-up and is associated with favor-able postoperative hemodynamics and morbidity rates.</p>


2019 ◽  
Vol 24 (5) ◽  
pp. 549-557
Author(s):  
Malia McAvoy ◽  
Heather J. McCrea ◽  
Vamsidhar Chavakula ◽  
Hoon Choi ◽  
Wenya Linda Bi ◽  
...  

OBJECTIVEFew studies describe long-term functional outcomes of pediatric patients who have undergone lumbar microdiscectomy (LMD) because of the rarity of pediatric disc herniation and the short follow-up periods. The authors analyzed risk factors, clinical presentation, complications, and functional outcomes of a single-institution series of LMD patients over a 19-year period.METHODSA retrospective case series was conducted of pediatric LMD patients at a large pediatric academic hospital from 1998 to 2017. The authors examined premorbid risk factors, clinical presentation, physical examination findings, type and duration of conservative management, indications for surgical intervention, complications, and postoperative outcomes.RESULTSOver the 19-year study period, 199 patients underwent LMD at the authors’ institution. The mean age at presentation was 16.0 years (range 12–18 years), and 55.8% were female. Of these patients, 70.9% participated in competitive sports, and among those who did not play sports, 65.0% had a body mass index greater than 25 kg/m2. Prior to surgery, conservative management had failed in 98.0% of the patients. Only 3 patients (1.5%) presented with cauda equina syndrome requiring emergent microdiscectomy. Complications included 4 cases of postoperative CSF leak (2.0%), 1 case of a noted intraoperative CSF leak, and 3 cases of wound infection (1.5%). At the first postoperative follow-up appointment, minimal or no pain was reported by 93.3% of patients. The mean time to return to sports was 9.8 weeks. During a mean follow-up duration of 8.2 years, 72.9% of patients did not present again after routine postoperative appointments. The total risk of reoperation was a rate of 7.5% (3.5% of patients underwent reoperation for the same level; 4.5% underwent adjacent-level decompression, and one patient [0.5%] ultimately underwent a fusion).CONCLUSIONSMicrodiscectomy is a safe and effective treatment for long-term relief of pain and return to daily activities among pediatric patients with symptomatic lumbar disc disease in whom conservative management has failed.


2020 ◽  
Vol 26 (4) ◽  
pp. 353-363 ◽  
Author(s):  
Kathrin Zimmerman ◽  
Bobby May ◽  
Katherine Barnes ◽  
Anastasia Arynchyna ◽  
Elizabeth N. Alford ◽  
...  

OBJECTIVEHydrocephalus is a chronic medical condition that has a significant impact on children and their caregivers. The objective of this study was to measure the quality of life (QOL) of children with hydrocephalus, as assessed by both caregivers and patients.METHODSPediatric patients with hydrocephalus and their caregivers were enrolled during routine neurosurgery clinic visits. The Hydrocephalus Outcomes Questionnaire (HOQ), a report of hydrocephalus-related QOL, was administered to both children with hydrocephalus (self-report) and their caregivers (proxy report about the child). Patients with hydrocephalus also completed measures of anxiety, depression, fatigue, traumatic stress, and headache. Caregivers completed a proxy report of child traumatic stress and a measure of caregiver burden. Demographic information was collected from administration of the Psychosocial Assessment Tool (version 2.0) and from the medical record. Child and caregiver HOQ scores were analyzed and correlated with clinical, demographic, and psychological variables.RESULTSThe mean overall HOQ score (parent assessment of child QOL) was 0.68. HOQ Physical Health, Social-Emotional Health, and Cognitive Health subscore averages were 0.69, 0.73, and 0.54, respectively. The mean overall child self-assessment (cHOQ) score was 0.77, with cHOQ Physical Health, Social-Emotional Health, and Cognitive Health subscore means of 0.84, 0.79, and 0.66, respectively. Thirty-nine dyads were analyzed, in which both a child with hydrocephalus and his or her caregiver completed the cHOQ and HOQ. There was a positive correlation between parent and child scores (p < 0.004 for all subscores). Child scores were consistently higher than parent scores. Variables that showed association with caregiver-assessed QOL in at least one domain included child age, etiology of hydrocephalus, and history of endoscopic third ventriculostomy. There was a significant negative relationship (rho −0.48 to −0.60) between child-reported cHOQ score and child-reported measures of posttraumatic stress, anxiety, depression, and fatigue. There was a similar significant relationship between caregiver report of child’s QOL (HOQ) and caregiver assessment of the child’s posttraumatic stress symptoms as well as their assessment of burden of care (rho = −0.59 and rho = −0.51, respectively). No relationship between parent-reported HOQ and child-reported psychosocial factors was significant. No clinical or demographic variables were associated with child self-assessed cHOQ.CONCLUSIONSPediatric patients with hydrocephalus consistently rate their own QOL higher than their caregivers do. Psychological factors such as anxiety and posttraumatic stress may be associated with lower QOL. These findings warrant further exploration.


Author(s):  
Tran Anh Quynh ◽  
Pham Duy Hien ◽  
Le Quang Du ◽  
Le Hoang Long ◽  
Nguyen Thi Ngoc Tran ◽  
...  

AbstractRobotic surgery offers three-dimensional visualization and precision of movement that could be of great value to gastrointestinal surgeons. There were many previous reports on robotic technology in performing Soave colonic resection and pull-through for Hirschsprung’s disease in children. This study described the follow-up of the Robotic-assisted Soave procedure for Hirschsprung’s disease in children. Robotic-assisted endorectal pull-through was performed using three robotic arms and an additional 5-mm trocar. The ganglionic and aganglionic segments were initially identified by seromuscular biopsies. The rest of the procedure was carried out according to the Soave procedure. We left a short rectal seromuscular sleeve of 1.5–2 cm above the dentate line. From December 2014 to December 2017, 55 pediatric patients were operated on. Age ranged from 6 months to 10 years old (median = 24.5 months). The aganglionic segment was located in the rectum (n = 38), the sigmoid colon (n = 13), and the left colon (n = 4). The mean total operative time was 93.2 ± 35 min (ranging from 80 to 180 min). Minimal blood was lost during the surgery. During the follow-up period, 41 patients (74.6%) had 1–2 defecations per day, 12 patients (21.8%) had 3–4 defecations per day, and 2 patients (3.6%) had more than 4 defecations per day. Fecal incontinence, enterocolitis, and mild soiling occurred in three (5.4%), four (7.3%), and two pediatric patients, respectively. Robotic-assisted Soave procedure for Hirschsprung’s disease in children is a safe and effective technique. However, a skilled robotic surgical team and procedural modifications are needed.


1979 ◽  
Author(s):  
F. Panicucci ◽  
A. Sacripanti ◽  
E. Pinori ◽  
M. Vispi ◽  
B. Conte ◽  
...  

Determinations of AT-III activity, heparin cofactor activity, antifactor Xa activity and AT-III protein were carried out in 200 healthy adults, evenly distributed within age and sex groups, in 60 patients with cerebral thrombosis and in 20 oral contraceptive users. There was a positive correlation between AT-III protein and its activitiesin normal subjects and in patients with cerebral thrombosis. In oral contraceptive users the positive correlation was between AT-III protein and its activities, antifactor Xa activity excepted. The mean AT-III protein and heparin cofactor activity values decreased in males with age and were significantly lower in the groups between 50 and 70 years. The mean AT-III protein and heparin cofactor activity values decreased slightly in women in fertile age and were lower in the 40 to 50 age-group. The mean AT-III protein and its activities values did not show any variation in the patients with cerebral thrombosis. The mean antifactor Xa activity value in the women, taking the pill for 3 months, decreased, whereas the other AT-III activities and AT-III protein were unchanged.


Hand ◽  
2021 ◽  
pp. 155894472110085
Author(s):  
Landis R. Walsh ◽  
Laura C. Nuzzi ◽  
Amir H. Taghinia ◽  
Brian I. Labow

Background Although pediatric hand fractures are common and generally have good outcomes, they remain a considerable source of anxiety for non–hand surgeons, who are less familiar with these injuries. We hypothesized that this anxiety may manifest as inefficiency in referral patterns. Methods The records of pediatric patients with isolated, closed hand fractures without concurrent trauma seen at our institution by a hand surgeon between January 2017 and December 2018 were retrospectively reviewed. Results There were 454 patients included; 62.1% were men, and the mean age was 9.6 years at initial encounter. Most patients (89.6%) were treated nonoperatively and incurred few complications (0.5%). Roughly half of all cases (n = 262) initially presented to an outside provider. Of these, 24.0% (n = 64 of 262) were evaluated by 2+ providers before a hand surgeon. Most commonly, these patients were referred from an outside emergency department (ED) to our ED before hand surgeon evaluation (n = 45 of 64). Forty-seven patients required surgery; however, none were performed urgently. Although a greater proportion of 7- to 11-year-old patients saw 2+ providers prior to a hand surgeon ( P = .007), fewer required surgery ( P < .001). Conclusions Pediatric closed hand fractures are mainly treated nonoperatively and nonemergently with generally excellent outcomes. Our data suggest that many patients continue to be referred through the ED or multiple EDs/providers for treatment. These inefficient referral patterns demonstrate the need for better education for ED and primary care providers, as well as better communication between these providers and local pediatric hand surgeons. Advancements in these areas are likely to improve efficiency of care and decrease costs.


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