Mono- and bi-plane sonographic approach for difficult accesses in the emergency department - A randomized trial.

BACKGROUND: The insertion of peripheral intravenous (PIV) catheters is one of the most performed invasive procedures in acute healthcare settings. However, peripheral difficult vascular access (PDVA) is not uncommon and can lead to delays in administering essential medications. Ultrasound (US) has emerged as a valuable tool for facilitating PIV cannulation. Advancements in technology have introduced a technique known as bi-plane imaging, allowing the simultaneous display of both longitudinal and transverse views of vessels. We aimed to investigate whether the utilization of bi-plane imaging, as opposed to the single-plane approach, would yield superior results for PDVA in the emergency department (ED). METHODS: This study was a single-center randomized controlled trial. We included adult patients admitted to the ED who required PIV cannulation. Patients were randomly assigned to undergo cannulation using either the mono-plane or bi-plane approach, both performed by skilled providers. The primary outcome of the study was to compare the first attempt success rates between the two techniques. RESULTS: A total of 442 patients were enrolled, with 221 undergoing cannulation attempts using the mono-plane approach. Successful placement of a functioning PIV catheter was achieved in a single attempt for 313 out of 442 patients (70.8%). There was no significant difference in the success rates between the two study groups: 68.3% in the mono-plane group and 73.3% in the bi-plane group (p = 0.395). The median time required for a successful attempt differed between the groups, with 45 s (range 18-600) in the mono-plane group and 35 s (range 20-600) in the bi-plane group (p = 0.03). CONCLUSIONS: Our study confirms that US is a highly effective tool for facilitating PIV cannulation in patients with PDVA presenting to the ED. However, our investigation into the use of bi-plane imaging did not reveal a significant improvement when compared to mono-plane imaging.

Population spiking and bursting in next-generation neural masses with spike-frequency adaptation.

Spike-frequency adaptation (SFA) is a fundamental neuronal mechanism taking into account the fatigue due to spike emissions and the consequent reduction of the firing activity. We have studied the effect of this adaptation mechanism on the macroscopic dynamics of excitatory and inhibitory networks of quadratic integrate-and-fire (QIF) neurons coupled via exponentially decaying post-synaptic potentials. In particular, we have studied the population activities by employing an exact mean-field reduction, which gives rise to next-generation neural mass models. This low-dimensional reduction allows for the derivation of bifurcation diagrams and the identification of the possible macroscopic regimes emerging both in a single and in two identically coupled neural masses. In single populations SFA favors the emergence of population bursts in excitatory networks, while it hinders tonic population spiking for inhibitory ones. The symmetric coupling of two neural masses, in absence of adaptation, leads to the emergence of macroscopic solutions with broken symmetry, namely, chimera-like solutions in the inhibitory case and antiphase population spikes in the excitatory one. The addition of SFA leads to new collective dynamical regimes exhibiting cross-frequency coupling (CFC) among the fast synaptic timescale and the slow adaptation one, ranging from antiphase slow-fast nested oscillations to symmetric and asymmetric bursting phenomena. The analysis of these CFC rhythms in the θ-γ range has revealed that a reduction of SFA leads to an increase of the θ frequency joined to a decrease of the γ one. This is analogous to what has been reported experimentally for the hippocampus and the olfactory cortex of rodents under cholinergic modulation, which is known to reduce SFA.

Immediate provisional restoration of postextraction implants for maxillary single-tooth replacement.

The timing of implant placement and loading following tooth extraction has recently undergone substantial reconsideration. The authors tested a protocol of immediate loading of single implants placed at the time of tooth extraction in a consecutive case series. Thirty-three patients received a single implant-supported crown to replace a maxillary anterior tooth at the time of extraction. Regular recalls were planned for the following 4 years. One implant did not integrate, and another became unstable secondary to facial trauma. Overall patient satisfaction and clinical and radiographic parameters were good.