Surgical management of catheter tip thrombus: surgical therapy for right atrial thrombus and fungal endocarditis (Candida tropicalis) complicating paediatric sickle-cell disease.

The use of indwelling central catheters for long-term administration of hyperalimentation, chemotherapy or other intravenous therapies is increasing. This unusual presentation of a catheter-induced right atrial thrombus was complicated by fungal infection. We present a case of a paediatric sickle-cell patient who underwent surgical removal of a right atrial thrombus secondary to fungal (Candida tropicalis) endocarditis from an indwelling catheter. Successful thrombus removal utilizing cardiopulmonary bypass and subsequent discharge underscores the importance of surgical therapy in treating this important complication.

The significance of ductal shunting during extracorporeal membrane oxygenation.

The purpose of this study was to evaluate the significance and direction of shunts at the level of the foramen ovale or ductus arteriosus in full-term newborns with neonatal respiratory failure who were placed on extracorporeal membrane oxygenation (ECMO). A decrease in left ventricular dimension was expected when infants were placed on ECMO but did not occur. A left-to-right shunt was demonstrated at the ductal level in nine of 12 infants early in the course of ECMO before pulmonary resistance decreased. Presumably, the lack of change in the left ventricular dimension when infants were placed on bypass was due to a left-to-right shunt at the ductal level with ductal flow replacing the right heart output, being drawn into the bypass circuit.

Noninvasive determination of effective (nonshunted) pulmonary blood flow in normal and injured lungs.

PEEP is utilized in acute respiratory failure to decrease intrapulmonary shunting and improve oxygenation. Despite these beneficial effects, PEEP may adversely affect cardiac output, thus reducing oxygen delivery. To monitor some of the cardiopulmonary effects of PEEP, we utilized a noninvasive rebreathing technique to measure effective (nonshunted) pulmonary blood flow (Qepr) and compared the results to those measured by thermodilution (Qepi) in normal and oleic acid-injured canine lungs. Qepr was highly correlated with Qepi (r = .92, r2 = .85, p less than .001) despite large variations in PEEP before lung injury (0 to 15 cm H2O) and after lung injury (0 to 20 cm H2O). This close correlation was found even with wide ranges in cardiac output (1.01 to 6.45 L/min) and intrapulmonary shunt fractions (0.03 to 0.67). This technique may prove valuable as a noninvasive method by which to monitor and adjust PEEP therapy in patients with acute lung injury.

Acyclovir and vidarabine monophosphate: comparison of iontophoretic and intravenous administration for the treatment of HSV-1 stromal keratitis.

We determined the therapeutic efficacy of iontophoretic application of acyclovir and vidarabine monophosphate (ara-AMP) for the treatment of herpes simplex virus (HSV) type 1-induced stromal keratitis in rabbits. The therapeutic efficacy of intravenous administration of acyclovir was assessed in the same model. Stromal keratitis was produced by intrastromal injection of 10 microliters purified HSV-1, McKrae strain. Treatment began the first day after intrastromal injection. Iontophoresis (0.5 mAmp for four minutes) of 3.4 percent (0.1 M) ara-AMP and 5.0 percent (0.22 M) acyclovir was performed once daily for five consecutive days in two treatment groups. Intravenous administration of 50 mg acyclovir/kg was performed twice daily for eight consecutive days. Intravenous administration of NaCl (0.14 M) and ocular iontophoresis of NaCl (0.14 M) were performed as controls in the two treatment groups. At least two scorers performed a single masked evaluation of the disease severity (lesion scoring) of the conjunctiva, corneal epithelium, stroma, and iris by still lamp examination. The eyes were scored daily for 12 consecutive days, and then every other day up to day 22. Iontophoresis of acyclovir or ara-AMP significantly reduced the course of the disease compared with iontophoresis of NaCl. Intravenous administration of acyclovir significantly reduced the disease compared with intravenous NaCl. This suggests that iontophoresis of acyclovir or ara-AMP either alone or in combination with intravenous administration of acyclovir may be of value in the treatment of HSV-1 stromal keratitis.

Induction of ocular herpes simplex virus shedding by iontophoresis of epinephrine into rabbit cornea.

Ocular herpes simplex virus type 1 (HSV-1) shedding from the latently infected rabbit was induced by iontophoresis of 0.01% epinephrine into the eye. The iontophoresis of epinephrine was at 0.8 mAmp for 8 min once a day for 3 consecutive days. Shedding was determined by the presence of HSV-1 in the tear film obtained with eye swabs. Unilateral epinephrine iontophoresis performed 60 days after inoculation of the virus resulted in ipsilateral HSV-1 shedding in all cases (7/7). Bilateral epinephrine iontophoresis performed on selected days during 170 to 365 days after inoculation resulted in HSV-1 shedding in 75% of the eyes (21/28) and 100% of the rabbits (14/14). All shedding was initiated within 3 days after the third treatment with epinephrine iontophoresis. The shedding frequency induced by epinephrine iontophoresis was significantly higher (pb less than 0.05) than that induced by the other methods employed. HSV-1 was detected in one or both cocultivated explants of trigeminal and superior cervical ganglia for every eye in all experimental groups, indicating that all eyes had the potential to shed. In conclusion, epinephrine iontophoresis induced ocular HSV-1 shedding reliably and with a high frequency in the latently infected rabbits. Furthermore, we suggest that this easily reproducible model of viral shedding offers a system for studying the factors involved in recurrent HSV-1 ocular infections.