Hoskote, Sumedh S.

Abstract Introduction Phrenic neuropathies (PN) are an important cause of dyspnea and hypercapnic respiratory failure. A crucial yet often overlooked symptom is dyspnea associated with water immersion activities. This symptom which is frequently documented in patients with PN, carries a serious risk of drowning and should serve as a key clinical clue for underlying diaphragmatic weakness. This report details a case of severe unilateral diaphragmatic paralysis, where immersion dyspnea served as the respiratory harbinger guiding the diagnosis in a competitive athlete. Case Description A 47-year-old male athlete training for an Ironman triathlon, presented with exercise-induced dyspnea, wheezing and orthopnea following a major bike accident involving left sided trauma (rib fractures, pneumothorax, left clavicle/scapula fracture). Notably he reported difficulty swimming or water immersion dyspnea even before the accident. Chest x-ray revealed an elevated right hemidiaphragm. Pulmonary Function Tests (PFTs) showed normal baseline spirometry and diffusing capacity but Maximal Inspiratory Pressure (MIP) was reduced (51 cmH2O), indicating neuromuscular weakness. Cardiopulmonary Exercise Testing (CPET) demonstrated supranormal exercise capacity (Peak VO2 4.13 L/min, 122% predicted, Peak Work Rate 385 W, 170% predicted) with reduced breathing reserve of 2.4%, arguably normal with the other supranormal exercise parameters in a highly conditioned athlete. Electromyography (EMG) and nerve conduction studies revealed an absent right phrenic motor response while diaphragmatic ultrasound confirmed severe right hemidiaphragm atrophy (thickness 0.05 cm; normal >0.15 cm) and a poor thickening ratio (0.5; normal >1.2). Discussion Immersion dyspnea should immediately raise suspicion for phrenic neuropathy (PN) even in otherwise healthy and athletic individuals. In a Mayo Clinic study of 535 PN patients, only 4% (22 of 535) reported dyspnea triggered specifically by water immersion underscoring the rarity of this symptom. For 36% (8 of 22) immersion dyspnea was the first respiratory symptom and in 4.5% (1 of 22) it was the only symptom. Notably 18% (4 of 22) experienced near-drowning incidents. The hydrostatic pressure exerted by water worsens the mechanical disadvantage caused by a paralyzed diaphragm making immersion dyspnea a vital diagnostic warning sign. Because of its rarity but serious risks patients with diaphragmatic paralysis should be advised to avoid immersion activities particularly diving. This abstract is funded by: nnone

The human voice is an important medium of communication and expression of feelings or thoughts. Disruption in the regulatory systems of the human voice can be analyzed and used as a diagnostic tool, labeling voice as a potential “biomarker”. Conversational artificial intelligence is at the core of voice-powered technologies, enabling intelligent interactions between machines. Due to its richness and availability, voice can be leveraged for predictive analytics and enhanced healthcare insights. Utilizing this idea, we reviewed artificial intelligence (AI) models that have executed vocal analysis and their outcomes. Recordings undergo extraction of useful vocal features to be analyzed by neural networks and machine learning models. Studies reveal machine learning models to be superior to spectral analysis in dynamically combining the huge amount of data of vocal features. Clinical applications of a vocal biomarker exist in neurological diseases such as Parkinson’s, Alzheimer’s, psychological disorders, DM, CHF, CAD, aspiration, GERD, and pulmonary diseases, including COVID-19. The primary ethical challenge when incorporating voice as a diagnostic tool is that of privacy and security. To eliminate this, encryption methods exist to convert patient-identifiable vocal data into a more secure, private nature. Advancements in AI have expanded the capabilities and future potential of voice as a digital health solution.

BACKGROUND: Residual volume (RV) is a derived lung compartment that correlates with air trapping in the context of air flow obstruction on spirometry. The significance of an isolated elevation in RV in the absence of other pulmonary function test (PFT) abnormalities is not well defined. We sought to assess the clinical and radiologic findings associated with isolated elevation in RV. METHODS: We searched our out-patient PFT database at Mayo Clinic (Rochester, Minnesota) from 2016–2018 for adult patients with isolated elevation in RV. We defined isolated elevation in RV as RV ≥ upper limit of normal or ≥ 130% predicted with normal total lung capacity (TLC), spirometry, and diffusion capacity of the lung for carbon monoxide (D LCO ). We then matched this high-RV group by age and sex to an equal number of individuals with normal RV, TLC, spirometry, and D LCO (normal-RV group). RESULTS: We identified 169 subjects with isolated elevation in RV on PFTs, with a median age of 73 y; 55.6% were female, and median body mass index was 26.8 (vs 29.8 in the normal-RV group). The median RV was 3.08 L (134% predicted, interquartile range [IQR] 130–141) in the high-RV group and 2.26 L (99% predicted, IQR 90–109) in the normal-RV group (P < .001). Subjects with high RV were more likely to have smoked (54% vs 40%, P = .01) and almost twice as likely to have a maximum voluntary ventilation < 30 times the FEV 1 (21% vs 12%, P = .02). Clinically, asthma (21% vs 11%, P = .01) and non–tuberculous mycobacterial lung infections (12% vs 2%, P = .001) were more prevalent in the high-RV group. On chest computed tomography, bronchiectasis (31% vs 15%, P = .008), bronchial thickening or mucus plugging (46% vs 22%, P < .001), and emphysema (13% vs 5%, P = .046) were more common in the high-RV group. CONCLUSIONS: Isolated elevation in RV on PFTs is a clinically relevant abnormality associated with airway-centered diseases.