Temporal Changes in the Oxyhemoglobin Dissociation Curve of Critically Ill COVID-19 Patients.

Critical COVID-19 is a life-threatening disease characterized by severe hypoxemia with complex pathophysiological mechanisms that are not yet completely understood. A pathological shift in the oxyhemoglobin curve (ODC) was previously described through the analysis of p50, intended as the oxygen tension at which hemoglobin is saturated by oxygen at 50%. The aim of this study was to analyze Hb-O2 affinity features over time in a cohort of critically ill COVID-19 patients, through the analysis of ODC p50 behavior. A retrospective analysis was performed; through multiple arterial blood gas (ABG) analyses, each p50 was calculated and normalized according to PaCO2, pH and temperature; patients' p50 evolution over time was reported, comparing the first 3 days (early p50s) with the last 3 days (late p50s) of ICU stay. A total of 3514 ABG analyses of 32 consecutive patients were analyzed. The majority of patients presented a left shift over time (p = 0.03). A difference between early p50s and late p50s was found (20.63 ± 2.1 vs. 18.68 ± 3.3 mmHg, p = 0.03); median p50 of deceased patients showed more right shifts than those of alive patients (24.1 vs. 18.45 mmHg, p = 0.01). One-way ANOVA revealed a p50 variance greater in the early p50s (σ2 = 8.6) than in the late p50s (σ2 = 3.84), associated with a reduction over time (p < 0.001). Comparing the Hb-O2 affinity in critically ill COVID-19 patients between ICU admission and ICU discharge, a temporal shift in the ODC was observed.

Platypnea-Orthodeoxia Syndrome Caused by an Intracardiac Shunt.

Platypnea-orthodeoxia syndrome, a rare condition characterized by posture-related dyspnea, is usually caused by an intracardiac shunt, hepatopulmonary syndrome, or shunting resulting from severe pulmonary disease. We report the case of a 33-year-old woman who presented with increasing dyspnea and oxygen desaturation when she sat up or arose. Our diagnosis was platypnea-orthodeoxia syndrome. A lead of a previously implanted pacemaker exacerbated a severe tricuspid regurgitant jet that was directed toward the patient's intra-atrial septum. Percutaneous closure of a small secundum atrial septal defect eliminated right-to-left shunting and substantially improved the patient's functional status. In addition to this case, we discuss this unusual condition.

Endovascular Stenting in 2 Patients with Benign Superior Vena Cava Syndrome.

Superior vena cava syndrome has typically been associated with malignant conditions; however, the number of benign cases has started to grow as the use of upper-extremity venous lines and implantable cardiac devices increases. Whereas endovascular techniques are standardly used to treat patients with malignancies, the optimal care of patients with benign causes is less clear because they typically have longer life expectancies. We describe 2 cases of benign superior vena cava syndrome successfully managed with endovascular stenting, and we review the relevant literature. Of 145 cases in 10 series (average follow-up time, 24 mo), 96% of patients experienced symptomatic relief after endovascular management, with a primary patency rate of 66% and a secondary rate of 93%. Although few data exist to compare open surgical and endovascular techniques directly, both approaches appear to produce similar rates of patency. Both approaches frequently necessitate secondary intervention to maintain patency, but endovascular management is associated with fewer complications. We conclude that endovascular management of benign superior vena cava syndrome is a safe, effective, and reasonable initial management approach.

Platypnea-Orthodeoxia Syndrome: Diagnostic Challenge and the Importance of Heightened Clinical Suspicion.

Platypnea-orthodeoxia syndrome is an uncommon condition of positional dyspnea and hypoxemia; symptoms occur when the patient is upright and resolve with recumbency. Causes can be broadly categorized into 4 groups: intracardiac shunting, pulmonary shunting, ventilation-perfusion mismatch, or a combination of these. Platypnea-orthodeoxia syndrome should be suspected when normal arterial oxygen saturations are recorded while an individual is supine, followed by abrupt declines in those saturations when upright. Further investigations with use of imaging and cardiac catheterization aid in the evaluation. When platypnea-orthodeoxia syndrome is due to intracardiac shunting without pulmonary hypertension, intracardiac shunt closure can be curative. In this article, we report a case of platypnea-orthodeoxia syndrome in an 83-year-old woman who was successfully treated by means of percutaneous transcatheter closure of an atrial septal defect.

Percepção de dispneia em repouso e em atividades físicas habituais em diferentes graus de obesidade / Perception of dyspnea at rest and in daily physical activities in varying degrees of obesity

JUSTIFICATIVA E OBJETIVO: Dispneia é uma experiência subjetiva de desconforto respiratório, cujos mecanismos fisiopatológicos e de percepção são complexos. O objetivo deste estudo foi avaliar a percepção de dispneia dos obesos em repouso e em atividades físicas habituais, utilizando três escalas de dispneia, e verificar a influência do peso corporal na percepção de dispneia crônica. MÉTODOS: Estudo transversal, incluindo 140 pacientes com peso normal e sobrepeso (grupo controle) e obesidade graus I, II e III, que foram subdivididos em seis subgrupos. Dispneia crônica foi avaliada utilizando-se descritores de dispneia e percepção de dispneia em repouso e em atividades físicas habituais por meio três escalas de dispneia: Escala Analógica Visual, Escala de Diagrama de Custo de Oxigênio e Medical Research Council modificada. RESULTADOS: Os grupos tiveram distribuição homogênea quanto a gênero, idade, cor da pele, altura, status tabágico e atividade física. O peso corporal médio foi 109,5±30,9kg e o índice de massa corporal de 39,91±10,57kg/m², com diferenças significativas entre os grupos (p<0,001). Nenhum dos pacientes referiu dispneia em repouso em posição sentada, nas três escalas utilizadas. Houve diferenças significativas entre os grupos quanto à percepção de dispneia em atividades físicas habituais, que se intensificaram nos grupos com o índice de massa corporal mais elevada (p<0,0001). CONCLUSÃO: Indivíduos obesos livres de comorbidades que influenciam a percepção de dispneia não demonstram dispneia em repouso; todavia, apresentaram dispneia crônica em atividades físicas habituais da vida diária, que sofre influência do aumento progressivo do peso corporal...

BACKGROUND AND OBJECTIVE: Dyspnea is a subjective experience respiratory distress whose pathophysiological mechanisms and perception are complex. The objective of this study was to evaluate the perception of dyspnea in obese at rest and in habitual physical activities, using three scales of dyspnea, and check the influence of body weight on the perception of chronic dyspnea. METHDOS: Cross-sectional study including 140 patients with normal weight and overweight (control group) and obesity grades I, II and III, which were subdivided into six subgroups. Chronic dyspnea was assessed using descriptors of dyspnea and perception of dyspnea at rest and in daily physical activities through three dyspnea scales: Visual Analog Scale, Oxygen Cost Diagram scale and modified Medical Research Council. RESULTS: The groups were homogeneous distributed according to gender, age, skin color, height, smoking status and physical activity. The average body weight was 109.5±30.9kg and body mass index 39.91±10.57kg/m², with significant differences between groups (p<0.001). None of the patients reported dyspnea at rest in a sitting position according to the three scales used. There were significant differences between the groups regarding the perception of dyspnea in daily physical activities, which were intensified in the groups with higher body mass index (p<0.0001). CONCLUSION: Obese individuals with no comorbidities which can influence the perception of dyspnea had no dyspnea at rest; however, they presented with chronic dyspnea in daily physical activities of daily living, influenced by the progressive increase in body weight...

Early hemi-diaphragmatic plication through a video assisted mini-thoracotomy in postcardiotomy phrenic nerve paresis.

New symptom onset of respiratory distress without other cause, and new hemi-diaphragmatic elevation on chest radiography postcardiotomy, are usually adequate for the diagnosis of phrenic nerve paresis. The symptom severity varies (asymptomatic state to severe respiratory failure) depending on the degree of the lesion (paresis vs. paralysis), the laterality (unilateral or bilateral), the age, and the co-morbidity (respiratory, cardiac disease, morbid obesity, etc). Surgical treatment (hemi-diaphragmatic plication) is indicated only in the presence of symptoms. The established surgical treatment is plication of the affected hemidiaphragm which is generally considered safe and effective. Several techniques and approaches are employed for diaphragmatic plication (thoracotomy, video-assisted thoracoscopic surgery, video-assisted mini-thoracotomy, laparoscopic surgery). The timing of surgery depends on the severity and the progression of symptoms. In infants and young children with postcardiotomy phrenic nerve paresis the clinical status is usually severe (failure to wean from mechanical ventilation), and early plication is indicated. Adults with postcardiotomy phrenic nerve paresis usually suffer from chronic dyspnoea, and, in the absence of respiratory distress, conservative treatment is recommended for 6 months -2 years, since improvement is often observed. Nevertheless, earlier surgical treatment may be indicated in non-resolving respiratory failure. We present early (25(th) day postcardiotomy) right hemi-diaphragm plication, through a video assisted mini-thoracotomy in a high risk patient with postcardiotomy phrenic nerve paresis and respiratory distress. Early surgery with minimal surgical trauma, short operative time, minimal blood loss and postoperative pain, led to fast rehabilitation and avoidance of prolonged hospitalization complications. The relevant literature is discussed.

Arteria lusoria aneurysm with truncus bicaroticus: surgical resection without restoring blood supply to the right arm.

Arteria lusoria, an aberrant or anomalous right subclavian artery, is the most common anomaly of the aortic arch. It may be associated with other congenital anomalies of the heart and great vessels-including, rarely, truncus bicaroticus (a common trunk of both common carotid arteries), and, even more rarely, aneurysmal formation.Herein, we report the case of a 72-year-old man who had both an atherosclerotic aneurysm of an aberrant right subclavian artery and truncus bicaroticus. We resected the aneurysm through a posterolateral thoracotomy and did not restore the distal pulsatile blood supply to the right arm. During long-term clinical follow-up, the patient experienced no arm ischemia or cerebrovascular insufficiency.Aneurysm of arteria lusoria should be suspected in the presence of a right superior mediastinal mass on chest radiographs and should be considered as a cause of new-onset dyspnea, chest pain, or dysphagia. Symptomatic right arteria lusoria aneurysm should be removed promptly after diagnosis. Despite disagreement among investigators regarding the need to restore pulsatile blood flow to the right arm, we recommend reconstructing that flow, when possible.

Mesothelial cyst of the pericardium, absent on earlier computed tomography.

Pericardial cysts are benign intrathoracic lesions that are considered to be congenital. They are usually found incidentally upon chest radiography and typically cause few symptoms. Their true incidence is unknown. Herein, we describe the case of a 41-year-old man who, over nearly a decade, had undergone frequent hospital admissions for fever and thoracic pain. Computed tomography had shown no evidence of any intrathoracic mass. He was admitted to the hospital with fever, chest pain, tachycardia, dyspnea, and cough. The symptoms persisted despite medical therapy. Computed tomography revealed a pericardial cyst on the right side of the anterior mediastinum, near the confluence of the brachiocephalic vein and the superior vena cava and very close to the ascending aorta. The mass compressed the right main bronchus. Due to the cyst's unusual location and the ineffectiveness of medical therapy, we excised the tumor via median sternotomy. We found a large (7 x 4-cm), well-circumscribed, unilocular cyst, which unexpectedly involved the outside pericardial surface and the phrenic nerve. Histopathologic examination confirmed that the lesion was a simple mesothelial cyst of the pericardium. After the surgery, the patient's fever and chest pain resolved. We know of no other report of a pericardial cyst that had gone undetected upon earlier computed tomography. We believe that surgical treatment of pericardial cysts should be reserved for patients who have severe symptoms due to complications, or when diagnosis is uncertain and malignancy is suspected.

Two scimitar veins in an adult: repair through a right thoracotomy without cardiopulmonary bypass.

Scimitar syndrome is a rare but serious congenital condition that consists of anomalous pulmonary venous drainage of the right lung to the inferior vena cava. The appearance on chest radiography resembles a curved Turkish sword, or scimitar. Scimitar syndrome is associated with other anomalies, including hypoplasia of the right lung, dextroposition of the heart, anomalous systemic arterial supply to the right lung, and atrial septal defect. Clinical manifestations in infants include severe tachypnea and cyanosis. Adult patients may present with dyspnea and increased fatigue. Few adult cases have been reported in the medical literature. Classical surgical repair involves diversion of the scimitar venous flow into the left atrium with a baffle, requiring the use of cardiopulmonary bypass and deep hypothermic circulatory arrest. Herein, we report the case of a 42-year-old woman with 2 scimitar veins who underwent corrective surgery at our center without the use of cardiopulmonary bypass. We also comment on the importance of a patient's lung hypoplasia in the decision to repair the defect through a right thoracotomy.