Evaluating the incidence of acute kidney injury and gentamicin synergy dosing for endocarditis.

Objectives: Current infective endocarditis guidelines recommend two different gentamicin synergy dosing strategies for selected Gram-positive organisms. The purpose of this analysis was to evaluate the incidence of acute kidney injury (AKI) with gentamicin synergy dosing, comparing divided-daily and once-daily dosing strategies for infective endocarditis (IE). Methods: Groups were split into patients who received gentamicin divided-daily dosing and once-daily (3 mg/kg) dosing for Gram-positive IE. The primary outcome was the incidence of AKI defined by RIFLE (risk, injury, failure, loss, end-stage renal disease) criteria after starting gentamicin. A multivariable logistic regression analysis was performed to identify possible independent predictors of developing AKI. Notable secondary outcomes included hospital length of stay, need for gentamicin dose adjustments based on therapeutic drug monitoring, and assessment of each case of AKI using the Naranjo algorithm. Results: The incidence of AKI was significantly higher in the divided-daily group compared with the once-daily group (52.5% versus 13%, P < 0.01). The divided-dosing group had significantly longer median [IQR] hospital length of stay (19 days [12:29] versus 13.5 days [9:22], P < 0.01) and a greater number of patients who required dose adjustments (76.2% versus 21.7%, P < 0.01). The multivariable regression analysis showed that the divided-dosing strategy, duration and institution were independently associated with incidence of AKI. Conclusions: This analysis suggests a lower incidence of AKI in the treatment of endocarditis with gentamicin synergy dosed once-daily compared with a divided-daily dosing. Further studies are warranted to assess if there is a difference in efficacy between gentamicin synergy dosing strategies and in gentamicin compared with no gentamicin regimens for IE.

Efficacy of the LouseBuster, a new medical device for treating head lice (Anoplura:Pediculidae).

Human head lice (Pediculus humanus capitis De Geer) occur worldwide and infest millions of children and adults every year. Head lice infestations, which are known as pediculosis capitis, are psychologically stressful, physically irritating, and are one of the leading causes of K-6 school absence. The prevalence of head lice in many countries is increasing rapidly because of resistance to chemicals used in many head lice treatments. We tested the efficacy of an alternative method for controlling head lice, the LouseBuster, a custom-built medical device designed to kill head lice and their eggs using controlled, heated air. A total of 56 infested subjects was treated with the LouseBuster, and the efficacy of the treatment was evaluated by comparing the viability of lice and eggs on randomly assigned pre- and posttreatment sides of each subject's scalp. We evaluate treatment efficacy in the hands of novice versus experienced operators. We also evaluate treatment efficacy on different hair types and at different ambient humidities. Overall mortality of lice and eggs was 94.8% after treatment by experienced operators. Novice operators also achieved good results after a short training session; their results did not differ significantly from those of experienced operators. No adverse events were associated with the LouseBuster treatment. The LouseBuster is efficacious for killing head lice and their eggs. The use of heated air is appealing because it is a fast, safe, nonchemical treatment. Head lice are also unlikely to evolve resistance to desiccation, which is the apparent mode of action.

Na+ currents are required for efficient excitation-contraction coupling in rabbit ventricular myocytes: a possible contribution of neuronal Na+ channels.

Ca2+ transients were activated in rabbit ventricular cells by a sequence of action potential shaped voltage clamps. After activating a series of control transients, Na+ currents (INa) were inactivated with a ramp from -80 to -40 mV (1.5 s) prior to the action potential clamp. The transients were detected with the calcium indicator Fluo-4 and an epifluorescence system. With zero Na+ in the pipette INa inactivation produced a decline in the SR Ca2+ release flux (measured as the maximum rate of rise of the transient) of 27 ± 4% (n = 9, P < 0.001) and a peak amplitude reduction of 10 ± 3% (n = 9, P < 0.05). With 5 mm Na+ in the pipette the reduction in release flux was greater (34 ± 4%, n = 4, P < 0.05). The ramp effectively inactivates INa without changing ICa, and there was no significant change in the transmembrane Ca2+ flux after the inactivation of INa. We next evoked action potentials under current clamp. TTX at 100 nm, which selectively blocks neuronal isoforms of Na+ channels, produced a decline in SR Ca2+ release flux of 35 ± 3% (n = 6, P < 0.001) and transient amplitude of 12 ± 2% (n = 6, P < 0.05). This effect was similar to the effect of INa inactivation on release flux. We conclude that a TTX-sensitive INa is essential for efficient triggering of SR Ca2+ release. We propose that neuronal Na+ channels residing within couplons activate sufficient reverse Na+-Ca2+ exchanger (NCX) to prime the junctional cleft with Ca2+. The results can be explained if non-linearities in excitation-contraction coupling mechanisms modify the coupling fidelity of ICa, which is known to be low at positive potentials.

HIV-1 Virologic Rebound Due to Coadministration of Divalent Cations and Bictegravir.

A potential drug-drug interaction exists between divalent and trivalent cations (Ca2+, Fe3+, Mg2+, Al3+, Zn2+) and HIV-1 integrase strand transfer inhibitors (INSTIs). There are limited case reports describing the clinical significance of this potential interaction and none to our knowledge identifying zinc co-administration with INSTIs. In this report we present a patient taking bictegravir/emtricitabine/tenofovir alafenamide who became viremic after ingesting zinc and calcium supplements and later was able to obtain virologic re-suppression after discontinuing supplements. This case represents a potential significant drug interaction between a commonly prescribed antiretroviral drug class and readily available over-the-counter divalent cation products.

Transcervical ultrasonography in the diagnosis of pediatric peritonsillar abscess.

OBJECTIVES/HYPOTHESIS: Pediatric peritonsillar abscess (PTA) is a common infection, particularly in the adolescent population. Physical examination alone is not always sufficient to diagnose this pathology, and thus, computed tomography is often utilized as a diagnostic adjunct. With growing concern over radiation exposure in the pediatric population, we conducted a prospective study to investigate the use of ultrasonography in the detection of pediatric PTA. STUDY DESIGN: Prospective single arm cohort study. METHODS: Pediatric patients examined in consultation for concern for PTA were prospectively enrolled in the study. Patients were managed based on clinical symptoms and presentation. Transcervical ultrasonography of the peritonsillar region was performed on all patients. Clinical outcomes were reviewed retrospectively and compared to ultrasound findings. RESULTS: Forty-three patients (age range, 2-20 years) were enrolled in the study. The sensitivity and specificity of transcervical ultrasound when compared to clinical outcomes were 100% and 76.5%, respectively. The positive and negative predictive values were 52.9% and 100%, respectively. Fisher exact test showed a statistically significant association (P < .01) between negative ultrasonography and successful medical management, and multivariate regression analysis showed a strong correlation between ultrasound findings and presence/absence of purulence during surgical intervention (P = .01). CONCLUSIONS: Transcervical ultrasonography is a useful tool in diagnosing pediatric PTA. This imaging modality not only avoids undue radiation exposure, but it also proves to be an excellent tool at identifying patients who will not need surgical intervention. To our knowledge, this is the first study to explore this technique for the diagnosis of pediatric PTA. LEVEL OF EVIDENCE: 2b.

Three-dimensional direct laryngoscopy and bronchoscopy: enhanced visualization of the airway.

IMPORTANCE: This is the first description of 3-dimensional (3D) pediatric airway endoscopy in the otolaryngology literature detailing the superior visualization with this technology. Ultimately, enhanced optics may further improve the treatment of airway pathology. OBJECTIVE: To report the first case series examining the use of 3D direct laryngoscopy and bronchoscopy (DLB) in the diagnosis and management of laryngotracheal pathology. DESIGN: Case series. SETTING: Tertiary care pediatric hospital. PARTICIPANTS: Three patients underwent both telescopic 2-dimensional (2D) and 3D DLB for comparison purposes: a 12-year-old boy for visualization of complete tracheal rings, a 23-year-old man for dilation of tracheal stenosis, and a 4-month-old boy for resection of subglottic cysts. MAIN OUTCOME MEASURES: Enhanced visualization of laryngotracheal pathology and facilitated endoscopic surgery. RESULTS: To our knowledge, this is the first case series in the otolaryngology literature examining the use of 3D DLB for the resection of subglottic cysts, dilation of tracheal stenosis, and visualization of complete tracheal rings. We believe that the 3D view offers qualitatively improved depth perception, accuracy of balloon placement, and appraisal of subglottic cyst resection margins. CONCLUSIONS AND RELEVANCE: This emerging technology has vast potential for improving endoscopy, surgical precision in airway interventions, tissue preservation, and methods of teaching. More research is needed in this area regarding the benefits and advantages of 3D compared with 2D endoscopy.