An early scoring system to predict mechanical ventilation for botulism: a single-center-based study

BACKGROUND: Early identification of patients requiring ventilator support will be beneficial for the outcomes of botulism. The present study aimed to establish a new scoring system to predict mechanical ventilation(MV) for botulism patients.METHODS: A single-center retrospective study was conducted to identify risk factors associated with MV in botulism patients from 2007 to 2022. Univariate analysis and multivariate logistic regression analysis were used to screen out risk factors for constructing a prognostic scoring system. The area under the receiver operating characteristic(ROC) curve was calculated.RESULTS: A total of 153 patients with botulism(66 males and 87 females, with an average age of 43 years) were included. Of these, 49 patients(32.0%) required MV, including 21(13.7%) with invasive ventilation and 28(18.3%) with non-invasive ventilation. Multivariate analysis revealed that botulinum toxin type, pneumonia, incubation period, degree of hypoxia, and severity of muscle involvement were independent risk factors for MV. These risk factors were incorporated into a multivariate logistic regression analysis to establish a prognostic scoring system. Each risk factor was scored by allocating a weight based on its regression coefficient and rounded to whole numbers for practical utilization([botulinum toxin type A: 1], [pneumonia: 2], [incubation period ≤1 day: 2], [hypoxia <90%: 2], [severity of muscle involvement: grade Ⅱ, 3;gradeⅢ, 7;grade IV, 11]). The scoring system achieved an area under the ROC curve of 0.82(95% CI 0.75–0.89, P<0.001). At the optimal threshold of 9, the scoring system achieved a sensitivity of 83.7% and a specificity of 70.2%.CONCLUSION: Our study identified botulinum toxin type, pneumonia, incubation period, degree of hypoxia, and severity of muscle involvement as independent risk factors for MV in botulism patients. A score ≥9 in our scoring system is associated with a higher likelihood of requiring MV in botulism patients. This scoring system needs to be validated externally before it can be applied in clinical settings.

A Radio-Telemetry System for Navigation and Recording Neuronal Activity in Free-Roaming Rats

A radio-telemetry recording system is presented which is applied to stimulate specific brain areas and record neuronal ac- tivity in a free-roaming rat. The system consists of two major parts： stationary section and mobile section. The stationary section contains a laptop, a Micro Control Unit （MCU）, an FM transmitter and a receiver. The mobile section is composed of the headstage and the backpack （which includes the mainboard, FM transmitter, and receiver）, which can generate biphasic mi- crocurrent pulses and simultaneously acquire neuronal activity. Prior to performing experiments, electrodes are implanted in the Ventral Posterolateral （VPL） thalamic nucleus, primary motor area （M1） and Medial Forebrain Bundle （MFB） of the rat. The stationary section modulates commands from the laptop for stimulation and demodulates signals for neuronal activity recording. The backpack is strapped on the back of the rat and executes commands from the stationary section, acquires neuronal activity, and transmits the neuronal activity singles of the waking rat to the stationary section. All components in the proposed system are commercially available and are fabricated from Surface Mount Devices （SMD） in order to reduce the size （25 mm×15 mm ×2 mm） and weight （10 g with battery）. During actual experiments, the backpack, which is powered by a rechargeable Lithium battery （4 g）, can generate biphasic microcurrent pulse stimuli and can also record neuronal activity via the FM link with a maximum transmission rate of 1 kbps for more than one hour within a 200 m range in an open field or in a neighboring chamber. The test results show that the system is able to remotely navigate and control the rat without any prior training, and acquire neuronal activity with desirable features such as small size, low power consumption and high precision when compared with a commercial 4-channel bio-signal acquisition and processing system.