A major portion of spinal cord injury (SCI) cases occur in the cervical region, where essential components of the respiratory neural circuitry are located. Phrenic motor neurons (PhMNs) housed at cervical spinal cord level C3-C5 directly innervate the diaphragm, and SCI-induced damage to these cells severely impairs respiratory function. In this study, we tested a biomaterial-based approach aimed at preserving this critical phrenic motor circuitry after cervical SCI by locally delivering hepatocyte growth factor (HGF). HGF is a potent mitogen that promotes survival, proliferation, migration, repair, and regeneration of a number of different cell and tissue types in response to injury. We developed a hydrogel-based HGF delivery system that can be injected into the intrathecal space for local delivery of high levels of HGF without damaging the spinal cord. Implantation of HGF hydrogel after unilateral C5 contusion-type SCI in rats preserved diaphragm function, as assessed by in vivo recordings of both compound muscle action potentials and inspiratory electromyography amplitudes. HGF hydrogel also preserved PhMN innervation of the diaphragm, as assessed by both retrograde PhMN tracing and detailed neuromuscular junction morphological analysis. Furthermore, HGF hydrogel significantly decreased lesion size and degeneration of cervical motor neuron cell bodies, as well as reduced levels surrounding the injury site of scar-associated chondroitin sulfate proteoglycan molecules that limit axon growth capacity. Our findings demonstrate that local biomaterial-based delivery of HGF hydrogel to injured cervical spinal cord is an effective strategy for preserving respiratory circuitry and diaphragm function.

OBJECTIVE: To report a case of systemic gas embolism associated with removal of a chest drain perforating a lung lobe in a dog undergoing sternotomy under general anesthesia and intermittent positive pressure ventilation.
METHODS: An 8-year-old Cocker Spaniel underwent an exploratory thoracotomy via median sternotomy for surgical management of pyothorax that was treated conservatively for 7 days prior to referral following bilateral chest drain placement. The surgical procedure consisted of a subphrenic mediastinectomy and pericardiectomy. During surgery, it became apparent that the right drain was perforating the right middle lung lobe. Sudden desaturation and rapid hemodynamic deterioration occurred after the drain was removed. A systemic gas embolism was suspected on the basis of clinical signs and results of an arterial blood gas analysis, and immediate supportive treatment was started with an adequate response. Once the surgical procedure was completed, a clear \"mill wheel\" sound was audible on cardiac auscultation and point-of-care cardiac ultrasound confirmed the presence of gas bubbles in the cardiac chambers. The dog recovered from anesthesia and was managed in the intensive care unit where arterial blood gas analyses were nearly normal and the dog made a full recovery.
CONCLUSIONS: In people, there are reports of fatal air embolism related to the use of chest drains. To our knowledge, this is the first case report in dogs of a systemic gas embolism during open-chest surgery caused by a chest drain perforating a lung lobe. Immediate recognition and aggressive treatment of this life-threatening condition should be provided in order to achieve a favorable outcome.

UNASSIGNED: We describe two cats that had episodic tachypnoea and increased respiratory effort during periods of paroxysmal supraventricular tachycardia (SVT). Thoracic radiographs at the time of clinical signs were consistent with cardiogenic pulmonary oedema. Echocardiography following stabilisation revealed a hypertrophic cardiomyopathy phenotype with normal left atrial size in both cats. The first cat was initially treated with diltiazem, but this did not reduce the frequency of the clinical episodes. Diltiazem was switched to atenolol and the cat remained well without further recurrence. At the time of writing, the cat was reported to be well, 3 years after the initial diagnosis of SVT. The second cat was first managed with diltiazem and was then transitioned to atenolol due to recurrent clinical episodes. The episodes were less frequent with atenolol but still present. Therefore, atenolol was changed to sotalol. The cat remained well on sotalol for 2 years with only one recurrent episode during a painful event. The patient then suffered a sudden cardiac death, 5 years after the initial diagnosis of SVT.
UNASSIGNED: To our knowledge, this is the first report that describes flash pulmonary oedema developing secondary to episodic paroxysmal SVT in cats. Despite the severity and speed of respiratory compromise, prognosis may be good with an adequate arrhythmia control.

Stiff person syndrome (SPS) spectrum disorders (SPSSD) cause spasms and rigidity throughout different body regions and can be associated with apnea and acute respiratory failure. There are limited data on the prevalence and predictors of respiratory symptoms with spasms (RSwS) in SPSSD. We sought to characterize the spirometry patterns and the frequency and predictors of RSwS in a large SPSSD cohort.
Participants were recruited from the Johns Hopkins SPS Center between 1997 and 2021, as part of an ongoing, longitudinal observational study. Medical records were reviewed to assess demographics and clinical characteristics. Data were analyzed using descriptive statistics and multivariable logistic regression models.
One-hundred ninety-nine participants (mean age = 53.4 ± 13.6 years, median time to diagnosis = 36 [IQR 66] months, 74.9% women, 69.8% White, 62.8% classic SPS phenotype) were included in final analyses; 35.2% of participants reported RSwS, of whom 24.3% underwent spirometry as part of routine clinical care. Obstructive (23.5%) and restrictive (23.5%) patterns were most commonly observed in those with SPSSD. An increasing number of body regions involved predicted the presence of RSwS (odds ratio [OR] = 1.95, 95% confidence interval [CI] = 1.50-2.53); those with ≥5 body regions involved (vs. ≤4) had higher odds (OR = 6.19, 95% CI = 2.81-13.62) of experiencing RSwS in adjusted models. Two patients died from SPSSD-associated respiratory compromise.
RSwS are common in SPSSD and may be predicted by an increasing number of body regions involved by SPSSD. Close clinical monitoring and having a low threshold to obtain spirometry should be considered in people with SPSSD.

Our institution implemented a post-anesthesia care unit (PACU) extended-stay model (Grey Zone model), where the post-operative level of care for high-risk adenotonsillectomy patients (general care vs. intensive care unit) was decided based on the clinical course of 2-4 h of PACU admission.
To assess the correlation between post-tonsillectomy respiratory compromise and the need for respiratory support during an extended stay at PACU. To identify comorbidities associated with a need for intensive care after extended observation.
A retrospective cohort study of high-risk children who underwent adenotonsillectomy and were admitted to the Grey Zone following surgery.
274 patients met inclusion criteria. 262 (95.6%) met criteria for general care unit transfer (mean oxygen saturation 94.4 ± 5.1%). Twelve (4.4%) patients were transferred from the PACU to the ICU due to respiratory distress (mean oxygen saturation 86.8 ± 11%). Of the patients admitted to general care, 4 (1.5%) secondarily developed respiratory compromise, requiring escalation of care. Three of these maintained oxygen saturation ≥95% throughout the PACU period. There was no difference between the groups with respect to demographic data, rates of morbid obesity, and severity of obstructive sleep apnea. Neuromuscular disease, chronic lung disease, seizure disorder, and gastrostomy-tube status were more prevalent in those requiring ICU level of care compared to the general care unit.
The Grey Zone model accurately identifies patients requiring ICU-level care following adenotonsillectomy, allowing for a safe reduction in the utilization of ICU resources. Due to rare delayed respiratory events, overnight observation in this cohort is recommended.
4 Laryngoscope, 133:3582-3587, 2023.

UNASSIGNED: We performed a real-world data analysis to evaluate the relationship between simulated ketamine exposures and oxygen desaturation in children.
UNASSIGNED: A previously developed population pharmacokinetic model was used to simulate exposures and evaluate target attainment, as well as the association with oxygen desaturation in children ≤17 years treated with intravenous ketamine.
UNASSIGNED: In 2022 children, there was no significant association between simulated plasma ketamine concentrations and oxygen saturation; however, a higher cumulative area under the curve was associated with increased odds of progression to significant desaturation (<85%), though magnitude of effect was small.
UNASSIGNED: By leveraging a population pharmacokinetic model and real-world data, we confirmed there is no relationship between simulated ketamine plasma concentration and oxygen desaturation.

Extracorporeal membrane oxygenation for the purpose of intervening upon profound cardiovascular or pulmonary compromise has proven to be a worthy intervention. Technological advancements have allowed this mode of therapy to become more effective and widespread. Veno-venous extracorporeal membrane oxygenation (VV-ECMO) is a commonly used strategy to help manage patients with pulmonary dysfunction refractory to traditional management methods. This review intends to focus upon common indications and the clinical considerations for the institution of VV-ECMO as well as some of its known complications.

Esophageal atresia (EA) with tracheoesophageal fistula (TEF) is among the most common congenital anomalies requiring surgical intervention in infancy. General surgeons practicing in rural or austere environments may encounter emergency situations requiring their involvement. Respiratory emergencies can arise in the neonatal period; the recommended approaches are the ligation of the fistula through the chest or occlusion of the distal esophagus through the abdomen. As survivors of the condition reach late adulthood, general surgeons can anticipate encountering these patients. An understanding of risk factors, common symptoms, associated anomalies, and the appropriate diagnostic evaluation will facilitate care.

[This corrects the article DOI: 10.3389/fmed.2022.867536.].

UNASSIGNED: Review the incidence and factors associated with respiratory compromise requiring intensive care unit level interventions in children with planned admission to the pediatric intensive care unit (PICU) following tonsillectomy or adenotonsillectomy (T/AT).
UNASSIGNED: Retrospective cohort study.
UNASSIGNED: Review of all patients with PICU admissions following T/AT from 2015 to 2020 at a tertiary care pediatric hospital. Patient demographics, underlying comorbidities, operative data, and respiratory complications during PICU admission were extracted.
UNASSIGNED: Seven hundred and seventy-two patients were admitted to the PICU following T/AT, age 6.1 ± 4.6 years. All children were diagnosed with obstructive sleep apnea or sleep-disordered breathing (mean pre-operative apnea-hypopnea index 29 ± 26.5 and O2 nadir 77.1% ± 11.1). Neuromuscular disease, enteral feed dependence, and obesity were common findings (N = 240 (31%), N = 106 (14%), and N = 209 (27%) respectively). Overall, 29 patients (3.7%) developed respiratory compromise requiring PICU-level support, defined as new-onset continuous or bilevel positive airway pressure support (n = 25) or reintubation (n = 9). Three patients were diagnosed with pulmonary edema. Multivariable regression analysis demonstrated pre-operative oxygen nadir and enteral feed dependence were associated with respiratory compromise (OR = 0.97, 95% CI 0.94-0.99, P = .04; OR = 6.3, 95% CI 2.36-52.6, P = .001 respectively).
UNASSIGNED: Our study found respiratory compromise in 3.7% of patients with planned PICU admissions following T/AT. Oxygen nadir and enteral feeds were associated with higher respiratory compromise rates. Attention should be given to these factors in planning for post-operative disposition.