Innovative treatment of hypercapnia with soda lime in COVID-19: a case report.

One of the rare consequences of COVID-19 is increasing blood carbon dioxide, which can lead to unconsciousness, dysrhythmia, and cardiac arrest. Therefore, in COVID-19 hypercarbia, non-invasive ventilation (with Bi-level Positive Airway Pressure, BiPAP) is recommended for treatment. If CO2 does not decrease or continues rising, the patient's trachea must be intubated for supportive hyperventilation with a ventilator (Invasive ventilation). The high morbidity and mortality rate of mechanical ventilation is an important problem of invasive ventilation. We launched an innovative treatment of hypercapnia without invasive ventilation to reduce morbidity and mortality. This new approach could open the window for researchers and therapists to reduce COVID death. To investigate the cause of hypercapnia, we measured the carbon dioxide of the airways (mask and tubes of the ventilator) with a capnograph. Increased carbon dioxide inside the mask and tubes of the device was found in a severely hypercapnic COVID patient in the Intensive Care Unit (ICU). She had a 120kg weight and diabetes disease. Her PaCO2 was 138mmHg. In this condition, she had to be under invasive ventilation and accept its complication or lethal risk but we decreased her PaCO2 with the placement of a soda lime canister in the expiratory pathway to absorb CO2 from the mask and ventilation tube. Her PaCO2 dropped from 138 to 80, and the patient woke up from drowsiness completely without invasive ventilation, the next day. This innovative method continued until PaCO2 reached 55 and she was discharged home 14 days later after curing her COVID. Soda lime is used for carbon dioxide absorption in anesthesia machines and we can research its application in hypercarbia state in ICU to postpone invasive ventilation for treatment of hypercapnia.

Nasal high-flow versus noninvasive ventilation in patients with chronic hypercapnic COPD.

Background: Despite the encouraging results of noninvasive ventilation (NIV) in chronic hypercapnic COPD patients, it is also evident that some patients do not tolerate NIV or do not benefit from it. We conducted a study in which COPD patients with stable, chronic hypercapnia were treated with NIV and nasal high-flow (NHF) to compare effectiveness. Methods: In a multi-centered, randomized, controlled, cross-over design, patients received 6 weeks of NHF ventilation followed by 6 weeks of NIV ventilation or vice-versa (TIBICO) between 2011 and 2016. COPD patients with stable daytime hypercapnia (pCO2≥50 mmHg) were recruited from 13 German centers. The primary endpoint was pCO2 changes from baseline blood gas, lung function, quality of life (QoL), the 6 min walking test, and duration of device use were secondary endpoints. Results: A total of 102 patients (mean±SD) age 65.3±9.3 years, 61% females, body mass index 23.1±4.8 kg/m2, 90% GOLD D, pCO2 56.5±5.4 mmHg were randomized. PCO2 levels decreased by 4.7% (n=94; full analysis set; 95% CI 1.8-7.5, P=0.002) using NHF and 7.1% (95% CI 4.1-10.1, P<0.001) from baseline using NIV (indistinguishable to intention-to-treat analysis). The difference of pCO2 changes between the two devices was -1.4 mmHg (95% CI -3.1-0.4, P=0.12). Both devices had positive impact on blood gases and respiratory scores (St. George's Respiratory Questionnaire, Severe Respiratory Insufficiency Questionnaire). Conclusions: NHF may constitute an alternative to NIV in COPD patients with stable chronic hypercapnia, eg, those not tolerating or rejecting NIV with respect to pCO2 reduction and improvement in QoL.

Electrical stimulation influences chronic intermittent hypoxia-hypercapnia induction of muscle fibre transformation by regulating the microRNA/Sox6 pathway.

Chronic obstructive pulmonary disease can cause muscle fibre transformation due to chronic intermittent hypoxia-hypercapnia (CIHH). Studies have shown that high expression of Sox6 in muscle could suppress type-I fibres through downregulating the PPARß (peroxisome proliferator-activated receptor ß)/ERRγ (oestrogen-related receptor γ)/microRNA pathway. However, whether this pathway is involved in CIHH-induced muscle fibre transformation is unknown. Electrical stimulation (ES) is an effective approach to ameliorate muscle dysfunction. Here, we explored the effects of ES on CIHH-induced muscle fibre transformation and the microRNA/Sox6 pathway. After CIHH exposure, both the soleus (SOL) and gastrocnemius (GC) muscles showed decreased type-I fibres. The PPARß/ERRγ/mir-499&208b (PEM, for GC) and PPARß/mir-499&208b (PM, for SOL) signalling cascades were suppressed, followed by elevated Sox6 expression. Low frequency electrical stimulation (LFES) activated the PEM/PM pathway and enhanced type-I fibre numbers through suppressing Sox6 in SOL and GC. High frequency electrical stimulation (HFES) promoted type-I fibre expression through activating the PEM pathway in GC. Although PPARß expression and type-I fibres were suppressed in SOL after HFES, no significant change was found in mir-499&208b/Sox6 expression. These results suggest that the microRNA/Sox6 pathway is disturbed after CIHH. Both low and high frequency electrical stimulations induce muscle fibre transformation partly through regulating the microRNA/Sox6 pathway.

The use of equine surfactant and positive pressure ventilation to treat a premature alpaca cria with severe hypoventilation and hypercapnia.

A 5-hour-old, premature alpaca cria was presented with failure to nurse, weakness, hypoglycemia, hypercapnia, and respiratory distress. The cria was treated with 3 doses of fresh, crude equine surfactant, positive pressure ventilation, and supplemental intranasal oxygen. Recovery to discharge was uneventful, and the cria regained apparently normal respiratory function. Three years after hospital discharge, the alpaca was a healthy adult.

Utilisation du surfactant équin et de la ventilation à pression positive pour traiter un jeune alpaga atteint d'hypoventilation grave et d'hypercapnie. Un jeune alpaga né prématurément et âgé de 5 heures a été présenté pour une absence d'allaitement, une faiblesse, l'hypoglycémie, l'hypercapnie et la détresse respiratoire. Le jeune a été traité à l'aide de 3 doses de surfactant équin frais et brut, une ventilation à pression positive et de l'oxygène intranasal supplémentaire. Le rétablissement et le congé se sont bien passés et la fonction respiratoire normale du jeune s'est apparemment rétablie. Trois ans après le congé de l'hôpital, l'alpaga était un adulte en santé.(Traduit par Isabelle Vallières).

High pressure versus high intensity noninvasive ventilation in stable hypercapnic chronic obstructive pulmonary disease: a randomized crossover trial.

BACKGROUND: High-intensity (high-pressure and high backup rate) noninvasive ventilation has recently been advocated for the management of stable hypercapnic chronic obstructive pulmonary disease (COPD). However, the relative contributions of high inspiratory pressure and high backup rate to ventilator adherence and physiological outcome have not been investigated. METHODS: Patients with stable hypercapnic COPD (daytime PaCO(2) > 6 kPa) and nocturnal hypoventilation were enrolled. Patients were randomly allocated to high-pressure and high backup rate (high-intensity) and high-pressure and low backup rate (high-pressure) for a 6-week period. At the end of the first treatment period, patients were switched to the alternative treatment. The primary outcome measure was mean nightly ventilator usage. RESULTS: Twelve patients were recruited, with seven completing the 12-week trial protocol. The mean patient age was 71 ± 8 years, with a forced expiratory volume in one second (FEV(1))/forced vital capacity (FVC) of 50% ± 13% and FEV(1) of 32% ± 12%. The baseline PaCO(2) and PaO(2) were 8.6 ± 1.7 kPa and 7.3 ± 1.4 kPa, respectively. There was no significant difference demonstrated in mean nightly ventilator usage between the high-intensity and high-pressure groups (difference of 4 minutes; 95% confidence interval -45 to 53; P = 0.9). Furthermore, there were no differences in any of the secondary endpoints, with the exception of the respiratory domain of the Severe Respiratory Insufficiency questionnaire, which was lower in the high-intensity arm than in the high-pressure arm (57 ± 11 versus 69 ± 16; P < 0.05). CONCLUSION: There was no additional benefit, in terms of night-time ventilator adherence or any of the other measured parameters, demonstrated by addition of a high backup rate to high-pressure noninvasive ventilation. These data suggest that it is the high-pressure component of the high-intensity noninvasive ventilation approach that plays the important therapeutic role in the management of hypercapnic respiratory failure in COPD patients.

[Non-invasive mechanical ventilation in COPD]. / Nichtinvasive Beatmung bei COPD.

Non-invasive mechanical ventilation is the preferred method for the treatment of acute respiratory failure in patients with chronic obstructive pulmonary disease (COPD). Primary contraindications and stopping criteria must be regarded to avoid delaying endotracheal intubation. The primary interface is usually a nasal-oral mask. Cautious sedation can facilitate non-invasive ventilation in some patients. Under certain circumstances non-invasive ventilation may enable successful extubation in COPD patients with prolonged weaning. COPD patients can also benefit from preventive non-invasive ventilation in order to avoid re-intubation after a planned extubation. Domiciliary nocturnal non-invasive ventilation is an option for some patients with COPD in chronic hypercapnic respiratory failure. This treatment should be established in a specialised unit.

Active cycle of breathing techniques in non-invasive ventilation for acute hypercapnic respiratory failure.

We hypothesised that applying the active cycle of breathing techniques (ACBT) in patients with acute hypercapnic respiratory failure undergoing non-invasive ventilation would improve patient outcome. Thirty-four patients were randomised so that 17 patients with acute hypercapnic respiratory failure received the ACBT and non-invasive ventilation (ACBT group), and 17 patients received non-invasive ventilation alone (control group). The primary outcome measure was length of time requiring non-invasive ventilation, and secondary outcome measures were change in acute physiology score, change in arterial blood gas values, total duration of non-invasive ventilation, and length of stay in the intensive care unit. Although not significant, there was a greater decrease in arterial carbon dioxide pressure in the ACBT group compared to the control group (-21.41 mmHg vs -17.45 mmHg, p = 0.27). Total duration of ventilation tended to be shorter in the ACBT group than in the control group (64.9 hours vs 84.1 hours, p = 0.15). Length of time in need of non-invasive ventilation was significantly lower in the ACBT group than in the control group (5.0 days vs 6.7 days, p = 0.03). There was no significant difference in length of stay in the intensive care unit between the two groups (8.0 vs 9.4 days, p = 0.31). The use of ACBT may have positive effects in the treatment of patients with acute hypercapnic respiratory failure, resulting in a shorter length of time requiring non-invasive ventilation.

Feedback-controlled negative pressure ventilation in patients with stable severe hypercapnic chronic obstructive pulmonary disease.

BACKGROUND: In recent studies, the efficacy of intermittent rest of the inspiratory muscles as an option of treating patients with severe chronic obstructive pulmonary disease (COPD) has become questionable. OBJECTIVE: The aim of our study was to analyze the effects of feedback-controlled intermittent negative pressure ventilation (INPV) on stable, but severely hypercapnic COPD patients. METHODS: 21 clinically stable, hypercapnic patients with severe COPD underwent INPV with chest shells for 3 weeks, 6 h a day. The INPV sessions were optimized by a visual biofeedback system, which enabled control over the decrease in diaphragmatic activity. Respiratory muscle (RM) function parameters, lung function parameters, blood gases and exercise capacity were analyzed. RESULTS: In the end, 19 patients concluded INPV treatment. They had PaO(2) of 56.5 +/- 11.8 mm Hg, PaCO(2) of 50.2+/-2.7 mm Hg (mean +/- SD) and FEV(1) of 27.8 +/- 4.3% predicted before treatment. There was no statistically significant change in lung function parameters, RM function parameters, physical performance and level of dyspnea after 3 weeks of INPV. CONCLUSION: We conclude that intermittent RM rest induced by INPV can relax inspiratory muscles in most patients with stable severe COPD, but fails to improve RM function and exercise capacity.

[Human resistance to decompression sickness and nonspecific methods of its elevation]. / Ustoichivost' liudei k dekompressionnoi bolezni i nespetsificheskie metody ee povysheniia.

The object of this study was the dependence of decompression sickness (DCS) tolerance determined by the intensity of venous gas embolism on functioning of the cardiovascular and respiratory systems, and micro-circulation which predetermine wash-out of an indifferent gas. Efficiency of nonspecific methods, e.g. hypercapnic training, hyperbaric oxygenation, exposures to pulse current to enhance human tolerance to DCS was experimentally substantiated.

[Control of respiration in patients with respiratory insufficiency in chronic obstructive lung disease]. / Kontrola oddychania u chorych z niewydolnoscia oddychania w przebiegu przewleklej obturacyjnej choroby pluc.

Twenty eight COPD patients with respiratory insufficiency were studied. These included: 12 hypoxemic and normocapnic patients, 16 hypoxemic and hypercapnic patients, and 22 healthy volunteers. During at rest respiration both COPD groups differed from the control group--demonstrating a higher respiratory incidence, VT/Ti and PO2 values. During hypercapnic stimulation using the rebreathing method the ventilatory response to CO2 in the COPD patients was lowered in comparison with the control. Increase of occlusion pressure as a response to the increasing hypercapnia was lowered in both groups, significantly in patients with hypercapnia.