Mechanical Ventilation Associated Pneumomediastinum - A Rising Incidence of Cases in an Emergency Hospital During the COVID-19 Pandemics.

Introduction: Mechanical ventilation is a last resort solution for patients presenting with acute respiratory distress syndrome produced by SARS-CoV-2. Spontaneous pneumomediastinum is a rare pathology associated with invasive mechanical ventilation. The objective of our research was to highlight the increased incidence of spontaneous pneumomediastinum during the COVID-19 pandemics in our hospital. Material and method: A retrospective review of the cases in our hospital requiring surgical evaluation was performed. Electronic health records from our institution were searched for nontraumatic pneumomediastinum from October to November 2021. All patients that were identified with pneumomediastinum were included in the review. Results: We identified 12 mechanical ventilated patients that presented with free air in the mediastinum on a computed tomography during the study period. All of the patients had SARS-CoV-2 bronchopneumonia with extensive pulmonary involvement. The mortality rate among these patients was 58.33%. Conclusions: The main take-home message of our study is that the incidence of mechanically ventilation-associated pneumomediastinum was exponentially higher during the fourth wave of COVID-19. There is a need for multicenter data in this pathology for a better approach and to define surgical management options for these patients.

Efficacy of using tidal volume challenge to improve the reliability of pulse pressure variation reduced in low tidal volume ventilated critically ill patients with decreased respiratory system compliance.

BACKGROUND: The prediction accuracy of pulse pressure variation (PPV) for fluid responsiveness was proposed to be unreliable in low tidal volume (Vt) ventilation. It was suggested that changes in PPV obtained by transiently increasing Vt to 8 ml/kg accurately predicted fluid responsiveness even in subjects receiving low Vt. We assessed whether the changes in PPV induced by a Vt challenge predicted fluid responsiveness in our critically ill subjects ventilated with low Vt 6 ml/kg. METHODS: This study is a prospective single-center study. PPV and other parameters were measured at a Vt of 6 mL/kg, 8 mL/kg, and after volume expansion. The prediction accuracy of PPV and other parameters for fluid responsiveness before and after tidal volume challenge was also analyzed using receiver operating characteristic (ROC) curves. RESULTS: Thirty-one of the 76 subjects enrolled in the study were responders (41%). Respiratory system compliance of all subjects decreased significantly (26 ± 4.3). The PPV values were significantly higher in the responder group than the non-responder group before (8.8 ± 2.7 vs 6.8 ± 3.1) or after (13.0 ± 1.7 vs 8.5 ± 3.0) Vt challenge. In the receiver operating characteristic curve (ROC) analysis, PPV6 showed unsatisfactory predictive capability with an area under the curve (AUC) of 0.69 (95%CI, 0.57-0.79, p = 0.002) at a Vt of 6 mL/kg. PPV8 andΔPPV6-8 showed good predictive capability with an AUC of 0.90 (95% CI, 0.81-0.96, p < 0.001) and 0.90 (95% CI, 0.80-0.95, P < 0.001) respectively. The corresponding cutoff values were 11% for PPV8 and 2% for ΔPPV6-8. CONCLUSIONS: PPV shows a poor operative performance as a predictor of fluid responsiveness in critically ill subjects ventilated with a tidal volume of 6 mL/ kg. Vt challenge could improve the predictive accuracy of PPV to a good but not excellent extent when respiratory system compliance decreased significantly.

Guillain Barre Syndrome in the elderly: Experience from a tertiary-care hospital in India.

Age influences incidence and prognosis of Guillain Barre Syndrome (GBS), common cause of ascending areflexic quadriparesis. Dedicated studies on elderly GBS are infrequent. This study aimed to describe clinical features and outcome at hospital-discharge in patients aged≥60years with GBS. Medical records of 70 elderly GBS over 15years were analysed. Mean symptom-duration was 5.78±4.5days and onset-to-peak 5.14±4.4days. Antecedent events preceded GBS by 8.07±9.9days and included: fever (n=19), respiratory infection (n=6), and gastroenteritis (n=5). Clinical features were weakness of facial (n=34), bulbar (n=13), extraocular (n=4) and respiratory (n=20) muscles and recurrence (n=4). Nine had Hughes disability score (HDS) of three or less. Sensory symptoms and signs included paresthesias (n=40), pain (n=24), and impaired kinaesthetic sensation (n=14). Laboratory abnormalities included albumino-cytological dissociation (n=50), hyponatremia (n=36) and elevated creatine kinase (n=18). Electrophysiological subtypes were: primary demyelinating (n=52), inexcitable (n=3), equivocal (n=2) and axonal (n=1). Fifty-seven patients treated with plasmapheresis (n=48) or intravenous immunoglobulin (n=9) had mean HDS of 3.53±0.7 at discharge. Twenty-one were ambulant (HDS≥3), one had persisting respiratory weakness and one died. Striking differences between the 'elderly' and 100 'adults' seen over 20months were shorter symptom-duration, higher frequency of facial palsy and hyponatremia, lower frequency of pain, lower mean MRC sum score and worse HDS at study-entry and discharge (p<0.05). Requirement for mechanical ventilation and cardiac autonomic dysfunction was higher among elderly (p:0.02). In conclusion, in this cohort of elderly GBS, there was a higher frequency severe GBS and demyelinating electrophysiology.

Invasive and non-invasive mechanical ventilation.

Early recognition of patients who might potentially require ventilatory support is a key goal of critical care outreach programmes and an important skill for all hospital medical staff. Decisions about the initiation and timing of invasive ventilation can be difficult, and early discussion with critical care colleagues is essential. Appropriateness of invasive ventilatory support can also require advanced discussion with patients and families. In the past 10-15 years, the role of non-invasive ventilation (NIV) has expanded, not least in an attempt to minimize the complications inherent in invasive ventilation. Indeed, NIV is now considered first-line therapy in some conditions (chronic obstructive pulmonary disease, pulmonary oedema, mild to moderate hypoxaemic respiratory failure in immunocompromised patients), and a 'trial of NIV' is often considered in respiratory failure resulting from an increasingly wide range of causes. With NIV, the importance of the environment (setting, monitoring, experience of staff) and forward planning cannot be overemphasized. When used for other than the standard indications, NIV should be employed in a high-dependency or intensive care setting in patients for whom invasive ventilation would be considered.