-
Frontiers in Veterinary Science 2023Pulmonary atelectasis is a commonly occurs during anesthesia. In these cases, mechanical ventilation (MV) associated with alveolar recruitment maneuvers (ARMs) and...
BACKGROUND
Pulmonary atelectasis is a commonly occurs during anesthesia. In these cases, mechanical ventilation (MV) associated with alveolar recruitment maneuvers (ARMs) and positive end-expiratory pressure (PEEP) is indicated to reverse the condition, ensure adequate gas exchange and improve oxygenation. ARMs can trigger volutrauma, barotrauma, and atelectrauma. Therefore, computed tomography (CT) is the gold-standard method for monitoring lung aeration after ARM.
OBJECTIVE
To evaluate lung volume distribution after stepwise ARMs using computed tomography (CT).
METHODS
Twelve dogs weighing 24.0 ± 6.0 kg, aged 3 ± 1 years, of both sexes and different breeds, underwent orchiectomy or ovariohysterectomy. The animals were anesthetized and ventilated in volume-controlled mode. ARMs were then initiated by positive end-expiratory pressure (PEEP) titration (5, 10, 15, and 20 cmHO). CT scans, cardiovascular parameters, and ventilatory mechanics were evaluated at all time points. Data were assessed for normality using the Shapiro-Wilk test and a two-way analysis of variance, followed by a Bonferroni test to identify differences between time points. Statistical significance was attributed to a value of of <0.05.
RESULTS
CT demonstrated that the ARMs increased ventilation throughout the lung, including the dependent regions, with volumes that increased and decreased proportionally with PEEP titration. When they reached PEEP 10 and 5 cmHO descending (d), they remained significantly higher than those in PEEP 0 cmHO (baseline). Static compliance improved about 40% at PEEP 10d and PEEP 5d compared to baseline. There was an increase in heart rate (HR) from PEEP 15 increasing (i) (74.5%) to PEEP 10d (54.8%) compared to baseline. Mean arterial blood pressure (MABP) decreased approximately 9% from PEEP 15i to PEEP 15d compared to baseline.
CONCLUSION
Lung attenuation and regional and global volumes assessed by CT showed that maximum pulmonary aeration distribution followed by PEEP titration occurred at PEEP 20 cmHO, maintaining the lungs normoaerated and without hyperaeration.
PubMed: 38292132
DOI: 10.3389/fvets.2023.1232635 -
Rozhledy V Chirurgii : Mesicnik... 2023The incidence of explosions in large agglomerations is high even during peacetime and continues rising. Blast syndrome injuries are complex, with shock wave causing... (Review)
Review
The incidence of explosions in large agglomerations is high even during peacetime and continues rising. Blast syndrome injuries are complex, with shock wave causing severe injuries of multiple organ systems. In situations with large numbers of injured persons, effective triage allows an early diagnosis and treatment of the highest number of victims. Treatment is challenging, and potentially conflicting therapeutic goals may alternate. This review provides an overview of the pathophysiology of blast injuries, current diagnostic algorithms and therapeutic procedures.
Topics: Humans; Blast Injuries; Explosions; Incidence
PubMed: 38286652
DOI: 10.33699/PIS.2023.102.6.236-243 -
The Laryngoscope Jul 2024To understand the role of a single laryngologist, Andrew Heermance Smith, in elucidating the mechanisms of Caisson Disease and controlling it effects on bridge workers. (Review)
Review
OBJECTIVE
To understand the role of a single laryngologist, Andrew Heermance Smith, in elucidating the mechanisms of Caisson Disease and controlling it effects on bridge workers.
DATA SOURCES
Scientific and lay publications, letters and records of the Roebling family, obituaries and internet sources.
REVIEW METHODS
Historical review.
RESULTS
AH Smith combined physiological observations and experiments in the Brooklyn Bridge caissons with a review of the existing engineering and medical literature to describe the Caisson Disease and to devise strategies to ameliorate its effects.
CONCLUSION
Despite an incorrect conclusion about the pathophysiology of decompression sickness, Smith's stringent standards and timely interventions allow completion of the masonry towers of the Brooklyn Bridge.
LEVEL OF EVIDENCE
NA Laryngoscope, 134:3044-3048, 2024.
Topics: Humans; History, 19th Century; History, 20th Century; Otolaryngology; Decompression Sickness
PubMed: 38284795
DOI: 10.1002/lary.31306 -
The Journal of Emergency Medicine Mar 2024Although common in pediatric airway equipment, positive-pressure relief ("pop-off") valves are also present on some adult resuscitator bags. These valves are designed to...
BACKGROUND
Although common in pediatric airway equipment, positive-pressure relief ("pop-off") valves are also present on some adult resuscitator bags. These valves are designed to decrease barotrauma but, in doing so, limit the airway pressure provided during manual bag-assisted ventilation. In critically ill adult patients with high airway pressures, these valves can be detrimental and result in hypoventilation and subsequent hypoxemia.
CASE REPORTS
In the 7 days after an unannounced introduction of new resuscitator bags with pop-off valves in the emergency department, there were 3 adult patients for whom an open pop-off valve resulted in hypoventilation and hypoxemia. These cases involved both medical and traumatic pathologies. In each case, there was a delay in discovering the change to a resuscitator bag equipped with a pop-off valve. Once the emergency physicians noticed the pop-off valve and closed them, there was significant improvement in ventilation and oxygenation. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Hand-operated resuscitator bags are an essential tool for airway management. These cases represent two main lessons: changing airway equipment without notifying staff is dangerous, and an open pop-off valve will result in inadequate ventilation when patients have high airway pressures, without the tactile feedback of difficult bagging. Emergency physicians should be aware of equipment changes and know to disable the pop-off valve on resuscitator bags if they find them in their departments.
Topics: Adult; Humans; Child; Hypoventilation; Respiration, Artificial; Cardiopulmonary Resuscitation; Lung; Hypoxia
PubMed: 38278680
DOI: 10.1016/j.jemermed.2023.10.016 -
Frontiers in Medicine 2023Tracheobronchial diverticulum (TBD) is an asymptomatic, benign cystic lesion outside the lumen of the trachea and bronchus. This is the first report case of a SCUBA...
Tracheobronchial diverticulum (TBD) is an asymptomatic, benign cystic lesion outside the lumen of the trachea and bronchus. This is the first report case of a SCUBA (self contained underwater breathing apparatus) diver diagnosed with TBD, which is a potential risk to diving. No literature or guideline is available so far on the diving fitness for patients with congenital or acquired TBD condition. A healthy 26-year-old male professional diver has records of SCUBA diving up to a depth of 40 meters sea water. He did not have any diving-related injuries or symptoms during his career and had no history of smoking, drinking, or other special illnesses except for a COVID-19 infection. A tracheal diverticulum was found accidentally by computed tomography (CT), but its communication with the trachea was not clear initially. Therefore, high-resolution CT and electronic bronchoscopy were done to clarify the situation of the diverticulum and identify the diving risk. High-resolution CT showed a possible opening in the diverticulum, but this was not seen under electronic bronchoscopy. Although a potential opening was shown in high-resolution CT, the lack of visual bronchoscopic evidence made it likely to be a dead cavity. As there is a higher theoretical risk of barotrauma during decompression, leading to pneumomediastinum, hemorrhage, or arterial gas embolism, the current clinical consensus is that air-containing tissue should be regarded as a relative contraindication for diving. Overall, it is recommended that the diver should dive carefully and avoid ascending too rapidly.
PubMed: 38274443
DOI: 10.3389/fmed.2023.1340974 -
Journal of Neurotrauma Jun 2024Blast-induced traumatic brain injury is typically regarded as a signature medical concern for military personnel who are exposed to explosive devices in active combat...
Blast-induced traumatic brain injury is typically regarded as a signature medical concern for military personnel who are exposed to explosive devices in active combat zones. However, soldiers as well as law enforcement personnel may be repeatedly exposed to low-level blasts during training sessions with heavy weaponries as part of combat readiness. Service personnel who sustain neurotrauma from repeated low-level blast (rLLB) exposure do not display overt pathological symptoms immediately but rather develop mild symptoms including cognitive impairments, attention deficits, mood changes, irritability, and sleep disturbances over time. Recently, we developed a rat model of rLLB by applying controlled low-level blast pressures (≤ 70 kPa) repeated five times successively to mimic the pressures experienced by service members. Using this model, we assessed anxiety-like symptoms, motor coordination, and short-term memory as a function of time. We also investigated the role of the NLRP3 inflammasome, a complex involved in chronic microglial activation and pro-inflammatory cytokine interleukin (IL)-1β release, in rLLB-induced neuroinflammation. NLRP3 and caspase-1 protein expression, microglial activation, and IL-1β release were examined as factors likely contributing to these neurobehavioral changes. Animals exposed to rLLB displayed acute and chronic short-term memory impairments and chronic anxiety-like symptoms accompanied by increased microglial activation, NLRP3 expression, and IL-1β release. Treatment with MCC950, an NLRP3 inflammasome complex inhibitor, suppressed microglial activation, reduced NLRP3 expression and IL-1β release, and improved short-term memory deficits after rLLB exposure. Collectively, this study demonstrates that rLLB induces chronic neurobehavioral and neuropathological changes by increasing NLRP3 inflammasome protein expression followed by cytokine IL-1β release.
Topics: Animals; NLR Family, Pyrin Domain-Containing 3 Protein; Indenes; Blast Injuries; Rats; Memory Disorders; Neuroinflammatory Diseases; Male; Microglia; Sulfonamides; Rats, Sprague-Dawley; Furans; Disease Models, Animal; Brain Injuries, Traumatic; Inflammasomes
PubMed: 38269433
DOI: 10.1089/neu.2023.0444 -
International Journal of Molecular... Jan 2024Blast-induced neurotrauma has received much attention over the past decade. Vascular injury occurs early following blast exposure. Indeed, in animal models that... (Review)
Review
Blast-induced neurotrauma has received much attention over the past decade. Vascular injury occurs early following blast exposure. Indeed, in animal models that approximate human mild traumatic brain injury or subclinical blast exposure, vascular pathology can occur in the presence of a normal neuropil, suggesting that the vasculature is particularly vulnerable. Brain endothelial cells and their supporting glial and neuronal elements constitute a neurovascular unit (NVU). Blast injury disrupts gliovascular and neurovascular connections in addition to damaging endothelial cells, basal laminae, smooth muscle cells, and pericytes as well as causing extracellular matrix reorganization. Perivascular pathology becomes associated with phospho-tau accumulation and chronic perivascular inflammation. Disruption of the NVU should impact activity-dependent regulation of cerebral blood flow, blood-brain barrier permeability, and glymphatic flow. Here, we review work in an animal model of low-level blast injury that we have been studying for over a decade. We review work supporting the NVU as a locus of low-level blast injury. We integrate our findings with those from other laboratories studying similar models that collectively suggest that damage to astrocytes and other perivascular cells as well as chronic immune activation play a role in the persistent neurobehavioral changes that follow blast injury.
Topics: Animals; Humans; Blast Injuries; Endothelial Cells; Brain Concussion; Vascular System Injuries; Astrocytes; Inflammation
PubMed: 38256223
DOI: 10.3390/ijms25021150 -
Clinical Case Reports Jan 2024Color changes of the tympanic membranes without an inflammatory component or perforation are rarely described. They may result from hemorrhage after barotrauma or...
KEY CLINICAL MESSAGE
Color changes of the tympanic membranes without an inflammatory component or perforation are rarely described. They may result from hemorrhage after barotrauma or spontaneously. Other explanatory models include discoloration due to otomycosis.
ABSTRACT
This is a case of a 61-year-old patient with an unexplained incidental of black dots located almost symmetrically on the antero-inferior quadrant of both tympanic membranes. This harmless anatomical rarity has not been published before. Underlying pathologies should be excluded in the case of discoloration of the tympanic membranes.
PubMed: 38223514
DOI: 10.1002/ccr3.8292 -
JPMA. the Journal of the Pakistan... Jan 2024To identify that incidence of pulmonary barotrauma secondary to mechanical ventilation for the management of acute respiratory distress syndrome associated with...
OBJECTIVES
To identify that incidence of pulmonary barotrauma secondary to mechanical ventilation for the management of acute respiratory distress syndrome associated with coronavirus-disease-2019, and to compare it with the incidence of pulmonary barotrauma trauma secondary to mechanical ventilation associated with all the other causes.
METHODS
The retrospective case-control study was conducted at the Aga Khan University Hospital, Karachi, and comprised data from October 2020 to March 2021 of patients who underwent mechanical ventilation. The data was divided into two groups. Data of acute respiratory distress syndrome associated with coronavirus-disease-2019 was in group 1, and that of acute respiratory distress syndrome associated with any other cause in control group 2. Medical records were reviewed to obtain demographic and clinical data, while the institutional picture archiving and communication system was used to review radiological images. Data was analysed using SPSS 24.
RESULTS
Of the 261 cases, 115(44%) were in group 1; 87(75.6%) males and 28(24.3%) females. There were 146(56%) controls in group 2; 96(65.7%) males and 50(34.2%) females. There were 142(54.4%) subjects aged >60 years; 61(43%) in group 1 and 81(57%) in group 2. The incidence of pulmonary barotrauma in group 1 was 39(34%) and 8(5.5%) in group 2 (p<0.0001).
CONCLUSIONS
Mechanical ventilation in the management of acute respiratory distress syndrome associated with coronavirusdisease- 2019 was found to be associated with a significantly higher incidence of pulmonary barotrauma than acute respiratory distress syndrome associated with any other cause.
Topics: Male; Female; Humans; Respiration, Artificial; Retrospective Studies; Case-Control Studies; COVID-19; Lung Injury; Respiratory Distress Syndrome; Pneumonia; Barotrauma
PubMed: 38219163
DOI: 10.47391/JPMA.7900