CPAP Pressure Prediction Calculation. An Alternative to the Difficulty of Performing a Titration Within the Context of the COVID19 Pandemic

Abstract Introduction: The treatment of choice for the obstructive sleep apnea-hypopnea syndrome (OSAHS) is continuous positive air pressure in the airway (CPAP), titrating the effective pressure that eliminates obstructive events through validated methods. From the beginning of the COVID 19 pandemic, it has been recommended that conventional titration should be postponed, replacing it with self-adjusting equipment. In our population, access to these devices is difficult. Objective: To show whether there is a difference between the CPAP pressure level calculated through a prediction formula and the pressure determined by titration under polysomnography. Materials and Methods: We included patients with OSAHS who underwent effective CPAP titration and compared it with the cal culated CPAP by the Miljeteig and Hoffstein formula. Results: We included medical records of 583 patients, (56%) men, 51 years (41-61), apnea-hypopnea index (AHI) of 51.3 (29.2 -84.4), calculated CPAP, 9.3 cm H2O vs. effective CPAP, 8 cm H2O (p < 0.0001). Comparing according to the degree of severity of the OSAHS, the average difference between calculated CPAP and effective CPAP was 0.24, 0.21, and 0.41 (non-significant differences) for mild, moderate and severe, up to an AHI < 40; in patients with an AHI ≥ 40 this difference was 1.10 (p < 0.01). We found an ac ceptable correlation between the calculated CPAP and the effective CPAP, with an intraclass correlation coefficient of 0.621, p < 0.01. Conclusion: We could use CPAP pressure prediction calculations to start treatment in patients with OSAHS who don't have access to self-adjusting therapies within the context of the pandemic, until standard calibration measures can be taken.

Clinical Observation of Nasal Continuous Positive Airway Pressure Ventilation in the Treatment of Neonatal Respiratory Failure / 现代医院

Objective To explore the clinical efficacy of nasal continuous positive airway pressure ventilation and conventional mechanical ventilation in the treatment of neonatal respiratory failure (NICU).Methods 68 cases of neonatal respiratory failure in our hospital from June, 2014 to June, 2016 in neonatal intensive care unit, according to the random number table method were divided into two groups: The observation group involved 34 patients with nasal continuous positive airway pressure, the control group 34 patients with conventional mechanical ventilation treatment.The changes of arterial blood gas analysis, clinical effect and complication were compared between the two groups.Results The PCO2 of the two groups was significantly decreased (P0.05).However, pH value was significantly increased, and the observation group was smaller than the control group (P<0.05).The total effective rate was 94.12% in the observation group and 67.65% in the control group (P<0.05).The time of ventilation and incidence of comorbidities in the observation group was significantly shorter than that in the control group (P<0.05).Conclusion Nasal continuous positive airway pressure ventilation for treatment of neonatal respiratory failure can more significantly improve the efficacy than conventional mechanical ventilation, shorten the time on the machine and reduce the relevant complications.So it is worth promoting.

Factores subjetivos asociados a la no adherencia a la CPAP en pacientes con síndrome de apnea hipopnea de sueño / Subjective factors associated with cpap non-adherence in patients with sleep apnea hypopnea syndrome

Introducción: los beneficios de la CPAP dependen del número de horas que el paciente la use. El objetivo del estudio fue establecer, en pacientes con apnea del sueño (SAHS), si hay adecuada adherencia a la CPAP y determinar qué factores referidos por el paciente se relacionan a la no adherencia. Métodos: estudio observacional analítico transversal en pacientes tratados con CPAP. Se definió buena adherencia como uso mínimo de cuatro horas al menos el 70% de los días (registro del dispositivo). Análisis de regresión logística para evaluar los factores relacionados a la no adherencia: presión, resequedad de la vía aérea, problemas con la máscara y falta de educación en el uso de CPAP. Resultados: de 160 pacientes, 88 (55%) tuvieron mala adherencia. La edad, peso, talla, cuello e índice de apneas fueron similares en los grupos con buena y mala adherencia. El Epworth y la presión de CPAP fueron significativamente mayores en el grupo de mala adherencia (p<0.05). El promedio de horas de uso de CPAP en el grupo con buena adherencia fue de 5.1 ± 1.7 horas y en el grupo con mala adherencia fue de 1.9 ± 1.5 horas. Los pacientes sobreestimaron el uso de la CPAP en 2.0 horas: reportadas por el paciente 5.3 horas frente a 3.3 horas según la tarjeta del equipo (p<0.001). El único factor referido por el paciente que se relacionó con la mala adherencia fue la presión de CPAP (OR ajustado: 3,34 [1,34 a 8,30]). Conclusiones: la adherencia al tratamiento con CPAP en pacientes con SAHS es subóptima (mala adherencia en 55% de los pacientes). La principal causa relacionada con la no adherencia según los pacientes fue la intolerancia a la presión del dispositivo. Los pacientes sobreestiman las horas reales de uso del CPAP.

Introduction: the benefits of CPAP depend on the number of hours being used by the patient. The aim of the study was to establish, in patients with sleep apnea (SAHS), if there is adequate adherence to CPAP and to determine what factors reported by the patient are related to non-adherence. Methods: an analytical observational cross-sectional study in patients treated with CPAP. Good adherence was defined as a minimum of 4 hours use at least 70% of days (device score). Logistic regression analysis to assess factors related to non-adherence: pressure, airway dryness, mask problems and lack of education in the use of CPAP. Results: of 160 patients, 88 (55%) had poor adherence. Age, weight, height, neck and apnea index were similar in the groups with good and poor adherence. The Epworth and CPAP pressure were significantly higher in the group of poor adherence (p <.05). The average hours of use of CPAP in the group with good adherence was 5.1 ± 1.7 hours and the poor adherence group was 1.9 ± 1.5 hours. The patients overestimated the use of CPAP in 2.0 hours: 5.3 hours reported by the patient versus 3.3 hours according to the device card (p <0.001). The only factor reported by the patient that was associated with poor adherence was CPAP pressure (adjusted OR: 3.34 [1.34 to 8.30]). Conclusions: adherence to CPAP in patients with SAHS is suboptimal (poor adherence in 55% of patients). The main cause related to non-adherence according to patients was intolerance to the pressure device. Patients overestimate the real hours of CPAP use.

Continuous Positive Airway Pressure during Bronchoalveolar Lavage in Patients with Severe Hypoxemia / 결핵

BACKGROUND: A bronchoalveolar lavage(BAL) is useful in diagnosing the etiology of bilateral pulmonary infiltrations, but may worsen the oxygenation and clinical status in severely hypoxemic patients. This study assessed the safety and efficacy of the continuous positive airway pressure(CPAP) using a conventional mechanical ventilator via a face mask as a tool for maintaining the oxygenation level during BAL. METHODS: Seven consecutive patients with the bilateral pulmonary infiltrates and severe hypoxemia (PaO2/FIO2 ratio

Continuous Positive Airway Pressure during Bronchoalveolar Lavage in Patients with Severe Hypoxemia / 결핵

BACKGROUND: A bronchoalveolar lavage(BAL) is useful in diagnosing the etiology of bilateral pulmonary infiltrations, but may worsen the oxygenation and clinical status in severely hypoxemic patients. This study assessed the safety and efficacy of the continuous positive airway pressure(CPAP) using a conventional mechanical ventilator via a face mask as a tool for maintaining the oxygenation level during BAL. METHODS: Seven consecutive patients with the bilateral pulmonary infiltrates and severe hypoxemia (PaO2/FIO2 ratio

The Effects of High Frequency Jet Ventilation to the Collapsed Lung on Systemic Oxygenation during One Lung Ventilation / 대한마취과학회지

BACKGROUND: In some cases of one-lung ventilation (OLV), hypoxemia may occur secondarily to the obligatory right to left transpulmonary shunt through the collapsed lung. We investigated the efficacy of high frequency jet ventilation (HFJV) to the non-dependent lung which rendered to be manually collapsed by surgeon and not to be reinflated, in improving systemic oxygenation and ventilation during OLV while ventilating the dependent lung with intermittent positive pressure ventilation. METHODS: Investigation was carried out on 20 ASA 2 or 3 patients who underwent thoracotomy in lateral decubitus position. The patients were randomly allocated into HFJV group (n = 11) or CPAP group (n = 9). In HFJV group, 20 minutes after OLV began, HFJV with driving pressure 1.0 bar, Ti 30%, and frequency 150 cycles/min, was applied to the non-dependent lung. In CPAP group, 5 cmH2O of CPAP was applied to the non-dependent lung without re-inflation. We compared the changes of PaO2, PaCO2, AaDO2 and pulmonary shunt, before and after HFJV or CPAP was applied to the non-dependent lung during OLV. RESULTS: AaDO2 and pulmonary shunt were decreased significantly and therefore, PaO2 was increased significantly when HFJV was applied to the non-dependent lung (P < 0.05, respectively). PaO2, AaDO2 and pulmonary shunt were not improved after 5 cmH2O of CPAP was applied to the non-dependent lung without re-inflation. In HFJV group, PaCO2 measured after HFJV was not decreased significantly compared with that before HFJV. CONCLUSIONS: HFJV to the non-dependent lung during OLV improved systemic oxygenation, even after the non-dependent lung collapsed completely but did not enhance CO2 elimination. 5 cmH2O of CPAP to the non-dependent lung, which was completely collapsed and not re-inflated, did not improve systemic oxygenation.

The Effects of Isoflurane on the Expression of iNOS mRNA in Endotoxemic Rats / 대한마취과학회지

BACKGROUND: It has been known that alveolar macrophage exposed to bacterial lipopolysaccharide (LPS) induces a lots of nitric oxide (NO) and inducible nitric oxide synthase (iNOS) mRNA expression. The Authors elucidated the effects of iNOS mRNA expression by inhalational anesthetics (isoflurane) on endotoxemic rats and positive pressure ventilation with and without LPS. METHODS: Fifty Sprague-Dawley rats (250 - 270 g) were anesthesized with urethane injected in the peritoneal cavity. Then the expression of iNOS mRNA in the alveolar macrophages of the rats were measured after injection of LPS, 2 hours of isoflurane (0.5 - 2.5%) anesthesia, and 2 hours of positive pressure ventilation. The activities of iNOS in macrophages were measured by analysing iNOS mRNA expression by Northern blot analysis with autoradiography using the polymerase chain reaction (PCR) method. RESULTS: The size and patterns of the iNOS mRNA band in the 0.5 - 2% isoflurane group were almost same as with the control group. The size of the iNOS mRNA band in the 2.5% isoflurane group increased more than in the control group. In the continous positive-pressure ventilation with LPS group, the iNOS mRNA band was slightly increased compared to the normal lung and the continous positive-pressure ventilation without LPS group. CONCLUSIONS: Higher concentrations of isoflurane anesthesia may evoke the expression of iNOS mRNA in a septic model. Positive pressure ventilation in sepsis may induce iNOS mRNA production.

General Anesthesia for Patient with Broncho-gastric Fistula: A case report / 대한마취과학회지

Broncho-gastric fistula caused by benign gastric ulcer perforation after esophagectomy is very rare. In general anesthesia of a patient with broncho-gastric fistula, in spite of hyperventilation, leakage of the anesthetic gases through fistula may make the patient hypercapneic, and positive pressure ventilation may increase the risk of the pulmanary aspiration by the regurgitation of gastric fluid by stomach distension. For that reason, in this patient, denitrogenation was performed during patient's voluntary respiration with 100% oxygen for 5 minutes, and induction was performed without positive pressure ventilation, and one lung ventilation was carried out. Hypoxemia was followed by one lung ventilation because his pulmonary function was moderate obstructive type and his lung was damaged by aspiration of gastric fluid via broncho-gastric fistula. A low level of continuous positive airway pressure (CPAP) has no significant hemodynamic effect and can maintain the patency of nonventilated lung, so hypoxemia induced by one lung ventilation may be reduced. Thus we carried out one lung ventilation with CPAP (10 cmH2O) in nonventilated lung and blocked broncho-gastric fistula with a bronchial blocker for prevention of both regurgitation of gastric fluid and leakage of anesthetic gases. One lung anesthesia was performed without any problem in this case.

Two Cases of Cataract Extraction in Eyes Filled with Silicone Oil by Infusion Cannula

Case Report The silicone oil is widely used as an intraocular tamponade after vitrectomy but its complications were frequently found in postoperative period. The cataract was one of the most common complications in the eyes filled with silicone oil. The cataract in the eyes filled with silicone oil can be removed with either the intracapsular or the extracapsular-extraction technique. But these surgical techniques have two major problems: posterior capsular fibrosis and intraoperative loss of silicone oil. We report two cases of complicated cataract in the eyes filled with silicone oil which those were successfully performed by lens aspiration or extracapsular cataract extraction with large posterior continuous circular capsulorhexis and basal iridectomy without any loss of silicone oil under the continuous positive pressure achieved with an anterior chamber maintainer such as healon and balaneed salt solution.