[Antibiotic dosing for renal function disorders and continuous renal replacement therapy]. / Dosierung von Antibiotika bei Nierenfunktionsstörung und kontinuierlicher Nierenersatztherapie.

For patients with acute kidney injury (AKI) and continuous renal replacement therapy, it is essential that the dosing of antibiotics is adequately adjusted in order to achieve an effective drug level above the minimum inhibition concentration but avoiding toxic side effects. In the selection of substances, preference should be given to antibiotics with a broad therapeutic spectrum, low incidence of side effects and, as far as possible, extrarenal elimination. Determination of serum levels should always be carried out, when this is possible. In any case, a sufficiently high loading dose should be included. An accurate as possible estimation of residual renal function and calculation of the mechanical clearance allows determination of the necessary maintenance dosage, which is acceptably accurate for clinical needs. Recent studies have shown that under modern continuous renal replacement therapy, the extent of elimination of antibiotics is regularly underestimated so that nowadays, the risk of antibiotic underdosing is higher than toxicity due to overdosing.

Lung transplantation: how we do it.

Lung transplantation is considered the gold standard for patients with chronic end-stage pulmonary disease. However, due to the complexity of management and relatively lower median survival as compared to other solid organs, many programs across the world have been slow to adopt the same. In our institution, we started lung transplantation in September 1990. And since then, we performed close to 900 lung transplantations. Here, we describe in detail the operative steps adopted in our institution for a successful lung transplantation. There have been very few variations over the years. We believe that having a standardized technique is one of the important features for success of a lung transplant program.

Ex vivo lung perfusion: how we do it.

Lung transplantation is an established treatment for patients with end-stage lung disease. However, a shortage of donors, low lung utilization among potential donors, and waitlist mortality continue to be challenges. In the last decade, ex vivo lung perfusion (EVLP) has expanded the donor pool by allowing prolonged evaluation of marginal donor lungs and allowing reparative therapies for lungs, which are otherwise considered not transplantable. In this review, we describe in detail our experience with EVLP including our workflow, setup, operative technique, and protocols. Our multidisciplinary EVLP program functions with the collaboration of surgeons, pulmonologists, and EVLP nurses who run the pump. EVLP program has been a valuable addition to our program. Since Food and Drug Administration (FDA) approval in 2019, we experienced incremental increased lung transplant volume of 12% annually.

Retrosternal lead placement: an attractive alternative to subcutaneous tunneling.

Complex lead placement is on the rise. When ipsilateral lead placement is unavailable, a retrosternal approach offers minimal cosmetic defects while minimizing lead injury. A retrosternal technique has yet to be described in the literature. Here, we describe our technique, tricks, and pitfalls to performing such an operation in three patients.

What is the Functional Relevance of Prefrontal Cortex Entrainment to Hippocampal Theta Rhythms?

There has been considerable interest in the importance of oscillations in the brain and in how these oscillations relate to the firing of single neurons. Recently a number of studies have shown that the spiking of individual neurons in the medial prefrontal cortex (mPFC) become entrained to the hippocampal (HPC) theta rhythm. We recently showed that theta-entrained mPFC cells lost theta-entrainment specifically on error trials even though the firing rates of these cells did not change (Hyman et al., 2010). This implied that the level of HPC theta-entrainment of mPFC units was more predictive of trial outcome than differences in firing rates and that there is more information encoded by the mPFC on working memory tasks than can be accounted for by a simple rate code. Nevertheless, the functional meaning of mPFC entrainment to HPC theta remains a mystery. It is also unclear as to whether there are any differences in the nature of the information encoded by theta-entrained and non-entrained mPFC cells. In this review we discuss mPFC entrainment to HPC theta within the context of previous results as well as provide a more detailed analysis of the Hyman et al. (2010) data set. This re-analysis revealed that theta-entrained mPFC cells selectively encoded a variety of task-relevant behaviors and stimuli while never theta-entrained mPFC cells were most strongly attuned to errors or the lack of expected rewards. In fact, these error responsive neurons were responsible for the error representations exhibited by the entire ensemble of mPFC neurons. A theta reset was also detected in the post-error period. While it is becoming increasingly evident that mPFC neurons exhibit correlates to virtually all cues and behaviors, perhaps phase-locking directs attention to the task-relevant representations required to solve a spatially based working memory task while the loss of theta-entrainment at the start of error trials may represent a shift of attention away from these representations. The subsequent theta reset following error commission, when coupled with the robust responses of never theta-entrained cells, could produce a potent error-evoked signal used to alert the rat to changes in the relationship between task-relevant cues and reward expectations.