Simplified point-of-care ultrasound protocol to confirm central venous catheter placement: A prospective study.

BACKGROUND: The current standard for confirmation of correct supra-diaphragmatic central venous catheter (CVC) placement is with plain film chest radiography (CXR). We hypothesized that a simple point-of-care ultrasound (POCUS) protocol could effectively confirm placement and reduce time to confirmation. METHODS: We prospectively enrolled a convenience sample of patients in the emergency department and intensive care unit who required CVC placement. Correct positioning was considered if turbulent flow was visualized in the right atrium on sub-xiphoid, parasternal or apical cardiac ultrasound after injecting 5 cc of sterile, non-agitated, normal saline through the CVC. RESULTS: Seventy-eight patients were enrolled. POCUS had a sensitivity of 86.8% (95%CI 77.1%-93.5%) and specificity of 100% (95%CI 15.8%-100.0%) for identifying correct central venous catheter placement. Median POCUS and CXR completion were 16 minutes (IQR 10-29) and 32 minutes (IQR 19-45), respectively. CONCLUSION: Ultrasound may be an effective tool to confirm central venous catheter placement in instances where there is a delay in obtaining a confirmatory CXR.

Simplified point-of-care ultrasound protocol to confirm central venous catheter placement:A prospective study / 世界急诊医学杂志（英文）

@#BACKGROUND: The current standard for confirmation of correct supra-diaphragmatic central venous catheter (CVC) placement is with plain film chest radiography (CXR). We hypothesized that a simple point-of-care ultrasound (POCUS) protocol could effectively confirm placement and reduce time to confirmation. METHODS: We prospectively enrolled a convenience sample of patients in the emergency department and intensive care unit who required CVC placement. Correct positioning was considered if turbulent flow was visualized in the right atrium on sub-xiphoid, parasternal or apical cardiac ultrasound after injecting 5 cc of sterile, non-agitated, normal saline through the CVC. RESULTS: Seventy-eight patients were enrolled. POCUS had a sensitivity of 86.8% (95%CI 77.1%–93.5%) and specificity of 100% (95%CI 15.8%–100.0%) for identifying correct central venous catheter placement. Median POCUS and CXR completion were 16 minutes (IQR 10–29) and 32 minutes (IQR 19–45), respectively. CONCLUSION: Ultrasound may be an effective tool to confirm central venous catheter placement in instances where there is a delay in obtaining a confirmatory CXR.

Thrombosis of Inferior Vena Cava Diagnosed Using Point-of-Care Ultrasound After Pediatric Near-Syncope.

BACKGROUND: Venous thromboembolism (VTE) is extremely rare but under recognized in the pediatric population. Although the literature on the use of ultrasound to detect VTEs in adults is plentiful, little has been documented on its use in the pediatric population. CASE REPORT: We present a case of a healthy 16-year-old female who presented to our emergency department with 3 months of dyspnea on exertion and one episode of near-syncope. Point-of-care cardiac ultrasound identified an inferior vena cava thrombosis. Subsequent computed tomography angiography diagnosed concurrent bilateral pulmonary emboli (PE). The patient's identical twin sister presented with similar symptoms shortly thereafter and was also diagnosed with VTE and bilateral PE. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case demonstrates an instance of VTE and pulmonary embolism in twin adolescent girls. Physical examination findings, electrocardiogram, chest x-ray study, and several previous evaluations did not reveal the diagnosis. Point of care ultrasound was used to correctly diagnosis VTE and for heightened concern for a pulmonary embolism.

Spontaneous twin anemia-polycythemia sequence complicated by recipient placental vascular thrombosis and hydrops fetalis.

Twin anemia-polycythemia sequence (TAPS) is an atypical form of twin-twin transfusion syndrome (TTTS) that presents as a large intertwin hemoglobin difference with one twin developing anemia and the other developing polycythemia, without oligohydramnios-polyhydramnios sequence (Lopriore et al., Placenta 2007;28:47-51). The prenatal diagnostic criteria for TAPS require that the middle cerebral artery-peak systolic velocity (MCA-PSV) measure greater than 1.5 multiples of median (MoM) in the donor twin and less than 0.8 MoM in the recipient twin (Robyr et al., Am J Obstet Gynecol 2006;194:796-803; Klaritsch et al., Ultrasound Obstet Gynecol 2009;34:149-154; Mari et al., N Engl Med 2000;342:9-14). The presumed etiology of TAPS involves the presence of small caliber arteriovenous anastomoses, which generate a slow transfusional process allowing for hemodynamic compensation (Lopriore et al., Placenta 2007;28:47-51; Lopriore et al., Placenta 2009;30:223-225; Lewi et al., Am J Obstet Gynecol 2006;194:790-795; Lopriore et al., Am J Obstet Gynecol 2008;112:753-758; Van den Wijngaard et al., Placenta 2007;28:611-615). The resulting polycythemia in the recipient twin is a risk factor for fetal and placental thrombosis (Van den Wijngaard et al., Am J Physiol 2005;288:R799-R814). We present a case of spontaneous TAPS complicated by a large placental vessel thrombosis and hydrops fetalis. Treatment via selective laser photocoagulation of communicating vessels (SLPCV) resulted in normalization of the MCA-PSV discordance.

Postoperative middle cerebral artery peak systolic velocity changes confirm physiological principles of the sequential laser technique for twin-twin transfusion syndrome.

INTRODUCTION: Treatment of the twin-twin transfusion syndrome (TTTS) via sequential selective laser photocoagulation of communicating vessels (SQLPCV) mandates ablation of donor-to-recipient arteriovenous anastomoses first. It is hypothesized that SQLPCV facilitates intraoperative transfusion to the donor, thereby minimizing donor hypovolemia and anemia. We sought to determine if postoperative changes in fetal middle cerebral artery-peak systolic velocities (MCA-PSV) support this hypothesis. MATERIALS AND METHODS: Patients undergoing preferential SQLPCV for TTTS had MCA-PSV measured 1 day before surgery and on postoperative day 1 (POD-1). Fetal anemia was defined as an MCA-PSV ≥1.5 multiples of the median (MoM). Exclusions included: POD-1 demise, missing MCA-PSV data, or gestational age <18 weeks. RESULTS: Study criteria were met by 139 patients. Mean MCA-PSV in recipients increased from 0.97 to 1.15 MoM postoperatively (p < 0.0001). Donor mean MCA-PSV remained stable at 1.00 MoM preoperatively and 0.98 MoM postoperatively (p = 0.272). Nine fetuses, 6 donors and 3 recipients, had preoperative anemia; SQLPCV was not attempted in the 3 anemic recipients. Postoperatively, the proportion of donors with anemia remained stable (increase 3.6%, p = 0.419), and the proportion of recipients with anemia increased (increase 12.2%, p = 0.009). DISCUSSION: Our findings confirm the presumed physiological basis for the SQLPCV treatment of TTTS.

Normalization of amniotic fluid levels after fetoscopic laser surgery for twin-twin transfusion syndrome.

OBJECTIVE: The purpose of this study was to describe amniotic fluid (AF) normalization after laser surgery for twin-twin transfusion syndrome (TTTS). METHODS: Patients with TTTS (n = 174) who had laser surgery from 2006 through 2009 underwent serial measurements of the AF maximum vertical pockets (MVPs) during postoperative weeks 1 through 10. A normal MVP was defined as greater than 2 cm and less than 8 cm. Postoperative TTTS criteria required an MVP of 2 cm or less in one sac and 8 cm or greater in the other sac. Patients with septostomy, immediate fetal death, or missing MVP values were excluded. RESULTS: Inclusion criteria were met by 115 patients. Normalization of the MVP occurred by week 5 in donors and week 8 in recipients in approximately 95% of the cases. Recipient fetuses with Quintero stage 3 or 4 TTTS (J Perinatol 1999; 19:550-555) were more likely to have an abnormal MVP than those with stage 1 or 2 TTTS during weeks 3 and 4 (P = .0049) and 5 and 6 (P = .0239). The criteria for TTTS were met in 6 cases (6.9%) in week 1: 5 resolved spontaneously, and 1 (1.2%) had persistent TTTS and required a second laser surgery. After week 1, 6 additional patients had abnormal MVP values for both fetuses simultaneously: 1 met TTTS criteria in week 3; 2 had oligohydramnios in week 2; and 3 had polyhydramnios in weeks 2, 4, and 7; none of these patients required further interventions. CONCLUSIONS: Although the AF of individual donor and recipient fetuses may take several weeks to normalize after laser surgery for TTTS, it is rare for both fetuses to meet TTTS criteria beyond the first postoperative week.

Discordant blood chimerism in dizygotic monochorionic laser-treated twin-twin transfusion syndrome.

BACKGROUND: Twin-twin transfusion syndrome occurs in 10% of monozygotic monochorionic twin gestations and results from an unbalanced exchange of blood from the donor to the recipient fetus through placental anastomoses. CASE: We present a case of twin-twin transfusion syndrome with differing fetal sex treated with in utero laser surgery. Genetic analyses showed 46,XX/46,XY hematologic chimerism in both twins at birth and at 6 months, with the recipient twin being significantly more chimeric than the donor. Placental pathologic examination confirmed monochorionicity and laser ablation of all anastomoses. CONCLUSION: Despite in utero separation of the fetal circulations remote from delivery, hematologic chimerism persisted after birth. We speculate that the greater degree of blood chimerism in the recipient compared with the donor was related to the pathophysiology of twin-twin transfusion syndrome before laser surgery.

Amniopatch as a treatment for rupture of membranes following laser surgery for twin-twin transfusion syndrome.

OBJECTIVE: The risk of iatrogenic rupture of membranes (IROM) is 5-30% after operative fetoscopy. The aim of this study was to describe outcomes of patients with IROM following selective laser photocoagulation of communicating vessels (SLPCV) for twin-twin transfusion syndrome (TTTS) who were subsequently treated with amniopatch therapy. METHODS: A review of patients who underwent treatment for mid-trimester TTTS between March 2006 and February 2008 with IROM within 7 days of SLPCV was performed. IROM patients without evidence of preterm labor or chorioamnionitis were offered expectant management, pregnancy termination, or amniopatch therapy. RESULTS: Ninety-three patients were treated with SLPCV, of which three (3.2%) had IROM within 7 days. All three opted for amniopatch therapy which was performed at 18 2/7, 23 1/7, and 22 6/7 weeks' gestation in patients 1, 2 and 3, respectively. In patients 1 and 2, amniopatch therapy sealed membranes within 7 days. A second amniopatch was required for patient 3 before IROM resolved. Gestational ages at delivery were 38 2/7, 37 5/7 and 30 2/7 weeks, respectively. CONCLUSION: Amniopatch is a viable treatment option for iatrogenic ROM following SLPCV.