Clinical Practices in Central Venous Catheter Mechanical Adverse Events.

Background: Over 5 million central venous catheters (CVCs) are placed annually. Pneumothorax and catheter malpositioning are common adverse events (AE) that requires attention. This study aims to evaluate local practices of mechanical complication frequency, type, and subsequent intervention(s) related to mechanical AE with an emphasis on catheter malpositioning. Methods: This is a retrospective review of CVC placements in a tertiary hospital setting from 1/2013 to 12/2013. Pneumothorax and CVC positioning were evaluated on post-insertion chest x-ray (CXR). Malposition was defined as unintended placement of the catheter in a vessel other than the intended superior vena cava on CXR. Catheter reposition was defined as radiographic evidence of a new catheter with removal of the old catheter less than 24hrs after initial placement. Data points analyzed included pneumothorax and thoracostomy rate, CVC malposition frequency, catheter reposition rate, catheter duration, and incidence of complications such as catheter associated venous thrombosis. Result: Among 2045 eligible CVC insertions, pneumothoraces occurred in 14 (0.7%; 95%CI 0.38, 1.17) and malpositions were identified in 275 (13.4%; 95% CI 12.3, 15.3). The proportion of pneumothoraces that required tube thoracostomy was 57%. The proportion of CVCs with malposition that were removed or replaced within 24h was 32.7%. "Malpositioned" catheters that were left in place by the clinical team (n = 185) had an average catheter duration of 8.2 days (95% CI 7.2, 9.3) versus 7.2 days (95% CI 6.17, 8.23) for catheters that were replaced after initial malposition (p = 0.14, t test). The incidence of venous thrombosis in repositioned "malpositioned" catheters was 7.8% versus 4.9% for "malpositioned" catheters that were left in place. Conclusions: Clinically significant catheter malposition and pneumothorax after CVC insertion are low. In this study, replaced and non-replaced "malpositioned" catheters had similar catheter duration and rates of complications, challenging the current dogma of CVC malposition practice.

Pharmacokinetic modulation of radiolabeled chelates facilitated by phosphonate ester coordinating groups.

Chelates are an important part of metal based radiopharmaceuticals. This study examines the possible application of phosphonate ester moieties incorporated into chelates, where the ester group can be changed to modulate the pharmacokinetics of the radiopharmaceutical, while the phosphonate stably binds the metal radioisotope. Two phosphonate ester containing chelates, PCTMB and PCTM(F)E, were compared to the carboxylate containing analogue, p-Bn-PCTA, with respect to radiochemistry with several radionuclides (In-111, Ga-68, Ga-67, Cu-64). The phosphonate ester derivatives were similar to p-Bn-PCTA with respect to efficient radiolabeling with each of the radiometals under mild, aqueous conditions. Each of the radiolabeled phosphonate esters was also shown to be stable under physiological conditions in vitro. The phosphonate ester moieties did exhibit a propensity to degrade under more acidic conditions. Biodistribution studies in mice with the In-111 radiolabeled versions of PCTMB, PCTM(F)E and p-Bn-PCTA demonstrated the ability of the phosphonate ester functionalities to change the pharmacokinetics of the BFCs. With increasing lipophilicity, the phosphonate ester derivatives showed increasing hepatic clearance; but no significant increase in background tissue uptake (bone, muscle) was observed, and all the In-111 radiolabeled BFCs were substantially cleared within 24 h. The substitution of phosphonate ester for carboxylate functional groups in chelates may be an effective strategy to assist in optimizing the pharmacokinetics of radiopharmaceuticals through varying of the ester group.

Heterotopic Pregnancy Diagnosed with Point-of-care Ultrasound in the Emergency Department: A Case Report.

INTRODUCTION: Heterotopic pregnancies are rare. However, they are occurring with increasing frequency. Unfortunately, diagnosis is frequently delayed, with patients presenting in extremis. CASE REPORT: We present a case of a heterotopic pregnancy diagnosed by point-of-care ultrasound (POCUS) in a woman presenting with lower abdominal pain, who had a documented normal first trimester ultrasound the day prior to presentation. DISCUSSION: Given the increasing rates of heterotopic pregnancies, we can no longer be reassured by the presence of an intra-uterine pregnancy (IUP) in a patient with concerning signs and symptoms of a ruptured ectopic pregnancy. A thorough POCUS evaluation of the uterus and adnexa is essential for the diagnosis of heterotopic pregnancy in the emergency department. CONCLUSION: This case highlights the value POCUS brings to the emergency department evaluation of patients in early pregnancy.