Pneumomediastinum and pneumoretroperitoneum after COVID-19: concealed intestinal perforation.

BACKGROUND: With the prevalence of coronavirus disease 2019 (COVID-19), many severe cases have been discovered worldwide. Here, a case of concurrent pneumomediastinum, pneumoretroperitoneum, and intestinal perforation was reported. This case was the first report on COVID-19-induced related complications. CASE PRESENTATION: A 74-year-old female patient was hospitalized for COVID-19. Air leakage was unexpectedly found during imaging reexamination. Considering the unobvious subjective feeling of the patient, a conservative treatment was given at the early stage, and finally, sigmoid colon perforation was surgically confirmed. The family gave up the treatment at last, because the patient could not be taken off the ventilator. Coincidentally, the patient also had abnormal renal anatomical position. This situation led to an abnormal air leakage direction and the atypical manifestations of peritonitis. It was also one of the important reasons for the delayed diagnosis and treatment of the disease. CONCLUSIONS: Clinicians should be vigilant for spontaneous gastrointestinal perforation in patients with COVID-19, particularly those undergoing treatment with glucocorticoids and tocilizumab. The case is shared to highlight this rare and fatal extrapulmonary manifestation of COVID-19 and further assist clinicians to raise their awareness and timely implement imaging investigation and multidisciplinary intervention so as to facilitate early discovery, diagnosis and treatment and reduce the mortality.

Short-term changes in chest CT images among individuals at low altitude after entering high-altitude environments.

Objective: To investigate the short-term changes in chest CT images of low-altitude populations after entering a high-altitude environment. Methods: Chest CT images of 3,587 people from low-altitude areas were obtained within one month of entering a high-altitude environment. Abnormal CT features and clinical symptoms were analyzed. Results: Besides acute high-altitude pulmonary edema, the incidence of soft tissue space pneumatosis was significantly higher than that in low-altitude areas. Pneumatosis was observed in the mediastinum, cervical muscle space, abdominal cavity, and spinal cord epidural space, especially the mediastinum. Conclusion: In addition to acute high-altitude pulmonary edema, spontaneous mediastinal emphysema often occurs when individuals in low-altitude areas adapt to the high-altitude environment of cold, low-pressure, and hypoxia. When the gas escapes to the abdominal cavity, it is easy to be misdiagnosed as gastrointestinal perforation. It is also not uncommon for gas accumulation to escape into the epidural space of the spinal cord. The phenomenon of gas diffusion into distant tissue space and the mechanism of gas escape needs to be further studied.

Patient self-inflicted lung injury associated pneumothorax/pneumomediastinum is a risk factor for worse outcomes of severe COVID-19: a case-control study.

We aimed to determine the clinical characteristics of patient self-inflicted lung injury (P-SILI)-associated pneumothorax/pneumomediastinum, to reveal its risk factors, and to assess its impact on severe COVID-19 cases. In total, 229 patients were included in this case-control study. They were randomly divided into either the case group or the control group as per the inclusion and exclusion criteria. The two groups were further analyzed to reveal the risk factors of spontaneous pneumothorax/pneumomediastinum (SP/P). Finally, risk factors for death were analyzed in the case group and the relationship between death and SP/P was also analyzed among all patients. The mean age of patients was 59.69 ± 17.01 years, most of them were male (74.2%), and 62.0% of them had comorbidities upon admission. A respiratory rate higher than 30 BPM was a risk factor for SP/P (OR 7.186, 95% CI 2.414-21.391, P < 0.001). Patients with delayed intubation due to early application of HFNC or NIV had a higher mortality rate when they developed SP/P (P < 0.05). Additionally, advanced age increased the risk of death (P < 0.05). Finally, SP/P may be a risk factor for death among patients with severe COVID-19 (OR 2.047). P-SILI occurs in severe COVID-19 with acute respiratory failure. It is necessary to identify the risk factors of P-SILI, the indicators of severe P-SILI, and the preventive measures.

Spontaneous pneumomediastinum and surgical emphysema presenting as rhinolalia following ecstasy ingestion: a case report.

BACKGROUND: We present a unique case of rhinolalia as the first recognizable sign of spontaneous pneumomediastinum and surgical emphysema following drug use. CASE PRESENTATION: This case presents a 17-year-old white male experiencing rhinolalia following ecstasy ingestion at a rave. Subsequent chest X-ray revealed extensive surgical emphysema, along with a continuous diaphragm sign indicative of pneumomediastinum. Computed tomography confirmed the diagnosis. The patient was managed conservatively with strict monitoring and 6 hourly electrocardiograms. Follow-up computed tomography on day 3 showed resolution of pneumomediastinum and surgical emphysema, and the patient was safely discharged. Notably, the patient experienced a temporary rhinolalia during the acute phase, which resolved spontaneously as his condition improved. CONCLUSIONS: This case underscores the importance of considering spontaneous pneumomediastinum and surgical emphysema in the differential diagnosis of young individuals presenting with acute symptoms after drug use.

Pan pneumo: an unusual complication following pacemaker implantation.

Implantation of cardiac devices is usually considered to be a safe procedure. Rare complications, such as pneumothorax, may occur after the procedure. The association with pneumopericardium or pneumomediastinum is even more uncommon. We present the case of a patient in his 70s, on haemodialysis, admitted for complete atrioventricular block. He underwent implantation of a dual-chamber pacemaker. He presented with chest pain the day after implantation. Chest CT scan revealed a pneumothorax associated with a pneumopericardium and pneumomediastinum 'pan pneumo', due to an atrial perforation. We opted for a conservative management strategy. Repeat CT scan of the chest 8 days after the procedure showed a complete resorption of the 'pan pneumo'. The objective of this case report is to describe this rare complication and provide further insight into its management, particularly in the absence of specific guidelines.

Spontaneous pulmonary interstitial emphysema, pneumomediastinum and cervical subcutaneous emphysema secondary to the Macklin effect in dogs with no clinical signs: 12 cases.

Pneumomediastinum denotes the presence of gas within the mediastinum and generally occurs by leakage of air from an aerated viscus that traverses or abuts the mediastinal plane. The Macklin effect has been described in several veterinary studies and describes gas tracking along the perivascular interstitium following alveolar rupture causing interstitial emphysema, pneumomediastinum and subsequently cervical subcutaneous emphysema. This retrospective case series describes incidental spontaneous pulmonary interstitial emphysema, pneumomediastinum and cervical subcutaneous emphysema secondary to the Macklin effect in dogs with no related clinical signs. Twelve dogs were identified from the author's institution, of which 75 % were Sighthounds (Greyhounds, Whippets or Lurchers). Pulmonary interstitial emphysema had a predominantly paravascular distribution, although in some cases a parabronchial distribution was also identified. We conclude that incidental pulmonary interstitial emphysema, pneumomediastinum and secondary cervical subcutaneous emphysema can be incidental, presumed secondary to the Macklin effect and that Sighthound breeds may be overrepresented.

Pneumomediastinum in COVID-19: Risk factors and outcomes from a multicentre case-control study.

BACKGROUND: An increased incidence of pneumomediastinum has been observed among patients hospitalized with coronavirus disease 2019 (COVID-19) pneumonia. The study aimed to identify risk factors for COVID-19-associated pneumomediastinum and investigate the impact of pneumomediastinum on clinical outcomes. METHODS: In this multicentre retrospective case-control study, we included consecutive patients with COVID-19 pneumonia and pneumomediastinum hospitalized from March 2020 to July 2020 at ten centres; then, we identified a similarly sized control group of consecutive patients hospitalized with COVID-19 pneumonia and respiratory failure who did not develop pneumomediastinum during the same period. Clinical, laboratory, and radiological characteristics, as well as respiratory support and outcomes, were collected and compared between the two groups. Risk factors of pneumomediastinum were assessed by multivariable logistic analysis. RESULTS: Overall 139 patients with pneumomediastinum and 153 without pneumomediastinum were analysed. Lung involvement ≥75 %, consolidations, body mass index (BMI) < 22 kg/m2, C-reactive protein (CRP) > 150 mg/L, D-dimer >3000 ng/mL FEUs, and smoking exposure >20 pack-year were all independently correlated with the occurrence of pneumomediastinum. Patients with pneumomediastinum had a longer hospital stay (mean ± SD 31.2 ± 20.2 days vs 19.6 ± 14.2, p < 0.001), higher intubation rate (73/139, 52.5 % vs 27/153, 17.6 %, p < 0.001), and in-hospital mortality (68/139, 48.9 % vs 36/153, 23.5 %, p < 0.001) compared to controls. CONCLUSIONS: Extensive lung parenchyma involvement, consolidations, low BMI, high inflammatory markers, and tobacco exposure are associated with a greater risk of pneumomediastinum in COVID-19 pneumonia. This complication significantly worsens the outcomes.

Conservative Management of Large Post-Intubation Tracheal Laceration.

ABSTRACT: Tracheal rupture is a very rare but life-threatening complication of endotracheal intubation. It is more common in women and patients older than 50 years old. Overinflation of endotracheal tube cuff and tracheal wall weakening are the most important pathogenetic mechanisms. Laceration sites are located in the posterior membranous wall in most cases. Subcutaneous and mediastinal emphysema and respiratory distress are the most common manifestations. A 55-year-old female presented with postoperative subcutaneous and mediastinal emphysema without dyspnea because of a tear in the posterior tracheal wall. The diagnosis was based on clinical manifestation, chest computer tomography scans (CT), and endoscopic findings. A conservative approach by broad-spectrum antibiotic therapy was decided because of patients' vital signs stability and the absence of esophageal injury. The follow-up showed that there was no lesion in the posterior tracheal wall. Our case showed that in clinically stable patients without mediastinitis and with spontaneous breathing, conservative management of tracheal tears is a safe procedure.

Spontaneous pneumomediastinum - Hamman´s syndrome.

This case study presents a rare case of a 29-year-old woman with spontaneous pneumomediastinum who was treated in the emergency department for subjective dyspnea, rhinitis, and a subjectively reported increasing swelling of the throat. The clinical presentation was only characterized by crepitus in the neck and supraclavicular areas. CT scan of the neck and chest revealed massive emphysema of the soft tissues of the neck, chest, the right side of the face, and pneumomediastinum extending to the diaphragm. Based on the clinical presentation and imaging findings, which were consulted with thoracic surgeons, we assessed the condition as benign spontaneous pneumomediastinum. The patient was treated conservatively and discharged from the hospital on the third day of hospitalization with the need of aftercare.

Cervicofacial Subcutaneous Emphysema and Pneumomediastinum Following Class V Resin Restoration: A Case Report.

Air can become trapped within the subcutaneous layer of the cervicofacial area, a condition known as subcutaneous emphysema (SE), unexpectedly after routine dental procedures. SE can worsen by extending superiorly to the peri-orbital region and inferiorly to the thorax and abdomen along the fascial planes. Upward progression can result in cavernous sinus thrombosis. Conversely, downward progression can cause a variety of complications such as pneumothorax, mediastinitis, and compression of the venous trunks. The presence of these conditions highlights the significance of prompt identification, precise diagnosis to ascertain the need for immediate intervention, and suitable management to prevent additional unfavorable consequences.

Air leak syndrome in animals: definition and pathogenesis.

Air leak syndrome (ALS) is described in human medicine as a constellation of clinical disorders including pneumomediastinum, pneumopericardium, pulmonary interstitial emphysema, pneumothorax, pneumoperitoneum, pneumoretroperitoneum and subcutaneous emphysema. The pathogenesis of ALS depends on the anatomy of the mediastinum and its associations with thoracic, abdominal and cervical connective tissues, as well as a physical phenomenon referred to as the Macklin effect. Various animal species develop diverse combinations of these lesions, although ALS has not been recognized in animals. However, this term aids pathologists in addressing this disease compilation. The aim of this retrospective study is to illustrate examples of ALS in animals by arbitrarily selecting 13 cases in dogs, cats, pinnipeds, sea otters and harbour porpoises. ALS can be classified into three groups based on aetiology: iatrogenic, secondary or spontaneous. Iatrogenic ALS was diagnosed in two cats with tracheal laceration following endotracheal intubation. Secondary ALS was identified in two dogs, one with acute respiratory distress syndrome and the other due to grass awn migration. Secondary ALS in pinnipeds was diagnosed following severe pulmonary parasitism, uraemic pneumonia and oesophageal perforation. The other marine mammals developed ALS following trauma. Spontaneous ALS was also diagnosed in one cat and one dog without any apparent predisposing causes.

Hemodynamic instability caused by pneumorrachis and pneumomediastinum following epidural analgesia: a case report.

BACKGROUND: Pneumomediastinum and pneumorrachis are rare complications following epidural analgesia, that can either be asymptomatic or rarely can produce mild to moderate severity symptoms. Most reported cases regarding the presentation of these two entities with epidural analgesia concern asymptomatic patients, however there are cases reporting post-dural puncture headache and respiratory manifestations. CASE PRESENTATION: We present a case where a combined lumbar epidural and spinal anesthesia was performed using the loss of resistance to air technique (LOR), on a 78-year-old Greek (Caucasian) male undergoing a total hip replacement. Despite being hemodynamically stable throughout the operation, two hours following epidural analgesia the patient manifested a sudden drop in blood pressure and heart rate that required the administration of adrenaline to counter. Pneumomediastinum, pneumorrachis and paravertebral soft tissue emphysema were demonstrated in a Computed Tomography scan. We believe that injected air from the epidural space and surrounding tissues slowly moved towards the mediastinum, stimulating the para-aortic ganglia causing parasympathetic stimulation and therefore hypotension and bradycardia. CONCLUSION: Anesthesiologists should be aware that epidural analgesia using the LOR to technique injecting air could produce a pneumomediastinum and pneumorrachis, which in turn could produce hemodynamic instability via parasympathetic stimulation.

Retrospective evaluation of traumatic pneumomediastinum in dogs and cats (2005-2022): 52 cases.

OBJECTIVE: To describe the incidence, etiology, clinical signs, diagnostics, treatments, and outcome of noniatrogenic traumatic pneumomediastinum (TPM) in dogs and cats. DESIGN: Retrospective study of cases (2005-2022). SETTING: University veterinary teaching hospital. ANIMALS: Fifty-two patients (29 dogs, 23 cats). MEASUREMENTS AND MAIN RESULTS: Data collected from the medical records included signalment, physical examination findings, animal trauma triage (ATT) score, clinicopathological data, imaging data, surgical intervention, length of hospitalization, supportive care, complications, and outcome. Most dogs presented with tachycardia and tachypnea, while cats presented with hypothermia and tachypnea. Subcutaneous emphysema, pneumothorax, and dyspnea were the most common clinical signs for both species. The median calculated ATT score was 3.5 in dogs and 4 in cats. The most common radiographic abnormalities other than pneumomediastinum were pneumothorax and lung contusions. The overall mortality rate was 18%, with a significantly higher survival rate in dogs (26/28 dogs [93%], 15/22 cats (68%); P = 0.03). Outcome was unknown in 1 dog and 1 cat. The only significant difference in treatment between survivors and nonsurvivors was the requirement in dogs for positive pressure ventilation. The median hospitalization period was 2 days for both species, with a shorter hospitalization in the nonsurvivors (0.6 vs 2 days, respectively; P = 0.006). CONCLUSIONS: TPM is an infrequent pathology in veterinary medicine and may be seen without an externally obvious injury. The most common causes for TPM in dogs were vehicular trauma and bite wounds, while high-rise syndrome was the most common cause in cats. Most of the cases have concurrent pneumothorax and require thoracocentesis; however, direct intervention to treat TPM is not usually required. The vast majority of cases did not undergo surgery to treat TPM. The prognosis for dogs with TPM was good but was guarded for cats.

Neumomediastino espontáneo: una manifestación extramuscular de la dermatomiositis anti-MDA5. Reporte de 2 casos / Spontaneous pneumomediastinum: An extra muscular manifestation of anti-MDA5 dermatomyositis. Report of 2 cases

El uso de anticuerpos específicos en miopatías inflamatorias ha mejorado la caracterización de esta enfermedad identificando distintos fenotipos clínicos. Los pacientes con dermatomiositis y anticuerpos anti-MDA5 muestran síntomas típicos en la piel, un menor compromiso muscular y una prevalencia de enfermedad pulmonar intersticial de hasta el 91%. Además de la enfermedad pulmonar intersticial, se ha identificado el neumomediastino espontáneo como una manifestación pulmonar rara pero potencialmente mortal. Se reportan 2 casos de esta manifestación en pacientes con dermatomiositis anti-MDA5.(AU)

The use of specific antibodies in inflammatory myopathies has improved the characterization of this disease, identifying different clinical phenotypes. Patients with dermatomyositis and anti-MDA5 antibodies display typical skin symptoms, lesser muscular involvement, and a prevalence of interstitial lung disease of up to 91%. Beyond interstitial lung disease, spontaneous pneumomediastinum has been identified as a rare but potentially fatal pulmonary manifestation. Two cases of this complication in patients with anti-MDA5 dermatomyositis are reported.(AU)

Extracorporeal membrane oxygenation versus invasive ventilation in patients with COVID-19 acute respiratory distress syndrome and pneumomediastinum: A cohort trial.

BACKGROUND: Patients with severe respiratory failure due to COVID-19 who are not under mechanical ventilation may develop severe hypoxemia when complicated with spontaneous pneumomediastinum (PM). These patients may be harmed by invasive ventilation. Alternatively, veno-venous (V-V) extracorporeal membrane oxygenation (ECMO) may be applied. We report on the efficacy of V-V ECMO and invasive ventilation as initial advanced respiratory support in patients with COVID-19 and acute respiratory failure due to spontaneous PM. METHODS: This was a retrospective cohort study performed between March 2020 and January 2022. Enrolled patients had COVID-19 and acute respiratory failure due to spontaneous PM and were not invasively ventilated. Patients were treated in the intensive care unit (ICU) with invasive ventilation (invasive ventilation group) or V-V ECMO support (V-V ECMO group) as the main therapeutic option. The primary outcomes were mortality and ICU discharge at 90 days after ICU admission. RESULTS: Twenty-two patients were included in this study (invasive ventilation group: 13 [59%]; V-V ECMO group: 9 [41%]). The V-V ECMO strategy was significantly associated with lower mortality (hazard ratio [HR] 0.33 [95% CI 0.12-0.97], p = 0.04). Five (38%) patients in the V-V ECMO group were intubated and eight (89%) patients in the invasive ventilation group required V-V ECMO support within 30 days from ICU admission. Three (33%) patients in the V-V ECMO group were discharged from ICU within 90 days compared to one (8%) patient in the invasive ventilation group (HR 4.71 [95% CI 0.48-45.3], p = 0.18). CONCLUSIONS: Preliminary data suggest that V-V ECMO without invasive ventilation may improve survival in COVID-19-related acute respiratory failure due to spontaneous PM. The study's retrospective design and limited sample size underscore the necessity for additional investigation and warrant caution.

Pulmonary interstitial emphysema and spontaneous pneumomediastinum are more prevalent in sighthounds than other dog breeds undergoing thoracic CT.

Spontaneous pneumomediastinum is an uncommon condition described in veterinary medicine with concurrent respiratory disease. It can be caused by the Macklin effect, which is when gas leaks from the alveoli into the surrounding interstitial lung tissue. Pulmonary interstitial emphysema (PIE) is the presence of gas within the pulmonary vascular sheaths and indicates the presence of the Macklin effect. In the authors' experience, spontaneous pneumomediastinum and PIE are more prevalent in sighthound dogs than in other breeds and are often considered incidental findings. This retrospective, observational, cross-sectional study compared the prevalence of PIE and subsequent pneumomediastinum in sighthound with other purebred dogs. It characterized the appearance of PIE in CT and analyzed a possible association with concomitant pulmonary pathologies or with the use of general anesthesia. Medical records and thoracic CTs of sighthounds and nonsighthound dogs from two institutions were reviewed. A total of 256 dogs, comprising 127 sighthounds and 129 other purebred dogs, were included. The prevalence of PIE and pneumomediastinum was statistically higher in sighthound (14.2%) compared with other nonsighthound dogs (2.2%). There was no statistical association between the presence of PIE and pneumomediastinum with different age and weight groups or with sex. There was no statistical difference in the prevalence of PIE and pneumomediastinum between dogs with and without pulmonary pathology or in dogs undergoing CT with sedation or general anesthesia. Spontaneous pneumomediastinum in sighthounds is more prevalent than in other breeds, and its prevalence is not associated with the presence of pulmonary pathology or the use of general anesthesia.