Hemoglobina Denver, una causa de desaturación en oximetría de pulso. Reporte de caso en un paciente pediátrico / Hemoglobin Denver, a cause of desaturated pulse oximetry. A pediatric case report

Las hemoglobinopatías son trastornos genéticos que afectan a la molécula de hemoglobina (Hb). Las mutaciones en las cadenas a o b que alteran el tetrámero de Hb pueden modificar la capacidad de la molécula para unirse al oxígeno. Las hemoglobinopatías con baja afinidad al oxígeno pueden presentarse con cianosis y una lectura alterada de la oximetría de pulso, lo que lleva a pruebas innecesarias y, a veces, invasivas para descartar afecciones cardiovasculares y respiratorias. En el siguiente reporte de caso, presentamos a una paciente pediátrica, asintomática, que se presentó a la consulta por detección de desaturación en oximetría de pulso. Las pruebas de laboratorio iniciales mostraron una anemia normocítica, normocrómica. Las muestras de gas venoso demostraron una p50 elevada. Después de extensas herramientas de diagnóstico, se diagnosticó una variante de Hb con baja afinidad al oxígeno, Hb Denver.

Hemoglobinopathies are genetic disorders that affect the hemoglobin (Hb) molecule. Mutations in the alpha or beta chains altering the Hb tetramer may modify the molecule's oxygen-binding capacity. Hemoglobinopathies with low oxygen affinity may occur with cyanosis and an altered pulse oximetry reading, leading to unnecessary and sometimes invasive tests to rule out cardiovascular and respiratory conditions. In the case report described here, we present an asymptomatic pediatric patient who consulted for desaturated pulse oximetry. Her initial laboratory tests showed normocytic, normochromic anemia. Venous blood gas samples showed an elevated p50. After using extensive diagnostic tools, a variant of Hb with low oxygen affinity was diagnosed: Hb Denver.

Carbon Monoxide Poisoning from Heavy Cigarette Smoking Presenting as Delusion in a Patient with a History of Chronic Schizophrenia (Methamphetamine Induced)

We describe a case of carbon monoxide poisoning in a 54-year-old male from heavy cigarette smoking presenting as delusions. The patient has a history of methamphetamine-induced schizophrenia now in remission for 2 years, and not on any psychotropics and is drug-free.

Research progress on mechanism of biotrauma caused by ventilation-induced lung injury / 中华危重病急救医学

Mechanical ventilation is an advanced life support treatment for patients with acute respiratory failure. While stabilizing respiratory function, it also acts as an injury factor to exacerbate or lead to lung injury, that is, ventilation-induced lung injury (VILI). There may be a more subtle form of damage to VILI known as "biotrauma". However, the mechanism of biotrauma in VILI is still unclear. This article intends to review the mechanism of biotrauma of VILI from the aspects of inflammatory response, oxidative stress and complement activation, in order to provide a new strategy for clinical prevention and treatment of biotrauma caused by VILI.

Clinical efficacy of acupoint application therapy combined with pressing needle in the treatment of acute exacerbation of chronic obstructive pulmonary disease / 中国基层医药

Objective:To investigate the clinical efficacy of acupoint application therapy combined with pressing needle therapy in the treatment of acute exacerbation of chronic obstructive pulmonary disease.Methods:Eighty-six patients with acute exacerbation of chronic obstructive pulmonary disease who received treatment at Lishui Hospital of Traditional Chinese Medicine from February 2022 to August 2022 were retrospectively included in this study. They were randomly divided into Group A ( n = 29), group B ( n = 29), and the combined treatment group ( n = 28) according to different treatment methods. All three groups were treated with conventional Western medicine. Based on this, group A was treated with acupoint application therapy, group B was treated with pressing needle therapy and the combined treatment group with treated with acupoint application therapy and pressing needle therapy. Clinical efficacy was compared among the three groups. Traditional Chinese medicine symptom score, pulmonary function index, blood gas index, and quality of life score pre- and post-treatment were compared among the three groups. Results:There was a significant difference in total response rate among group A [75.86% (22/29)], group B [79.31% (23/29)], and the combined treatment group [96.43% (27/28), H = 6.15, P < 0.05]. After treatment, the scores of cough, expectoration, and dyspnea in the three groups were significantly decreased compared with those before treatment (all P < 0.05). After treatment, the scores of cough, expectoration, and dyspnea in the combined treatment group were (1.79 ± 0.48) points, (2.30 ± 0.32) points, and (1.96 ± 0.43) points, respectively, which were significantly lower than those in (2.32 ± 0.41) points, (2.68 ± 0.42) points, and (2.27 ± 0.36) points in group A and (2.17 ± 0.50) points, (2.91 ± 0.43) points, and (2.33 ± 0.43) points in group B ( F = 9.81, 17.38, 6.72, all P < 0.05). After treatment, forced vital capacity (FVC), forced expiratory volume in the first second (FEV 1), and FEV 1/FVC were increased in each group compared with those before treatment (all P < 0.05). After treatment, FVC, FEV 1, and FEV 1/FVC in the combined treatment group were (3.95 ± 0.47) L, (2.01 ± 0.36) L, and (82.91 ± 13.35)%, respectively, which were significantly higher than (3.63 ± 0.59) L, (1.76 ± 0.21) L, and (73.23 ± 10.85)% in group A and (3.89 ± 0.38) L, (1.64 ± 0.37) L and (73.91 ± 7.62)% in group B ( F = 3.49, 9.80, 7.05, all P < 0.05). After treatment, blood gas indicators in each group were significantly increased compared with those before treatment (all P < 0.05). After treatment, blood oxygen partial pressure in the combined treatment group, group A and group B was (85.76 ± 3.21) mmHg, (81.05 ± 4.23) mmHg, and (80.62 ± 4.03) mmHg, respectively. The partial pressure of carbon dioxide in the three groups was (37.74 ± 5.88) mmHg, (44.32 ± 5.59) mmHg, and (43.22 ± 6.41) mmHg, respectively. There were significant differences in blood oxygen partial pressure and partial pressure of carbon dioxide among the three groups ( F = 15.50, 9.88, all P < 0.05). After treatment, the quality of life score in each group was significantly increased compared with that before treatment (all P < 0.05). After treatment, the quality of life score in the combined treatment group, group B, and group A was (43.97 ± 6.34) points, (39.16 ± 4.45) points, and (40.19 ± 4.67) points, respectively, and there was significant difference among the three groups ( F = 4.12, P < 0.001). Conclusion:In the treatment of acute exacerbation of chronic obstructive pulmonary disease, acupoint application therapy combined with pressing needle therapy is highly effective than monotherapy. The combined therapy can better improve traditional Chinese medicine symptoms and blood gas indicators, effectively enhance pulmonary function, and improve quality of life than monotherapy.

Relationship between arterial blood partial pressure of carbon dioxide and prognosis of neurological function after cardiopulmonary resuscitation / 中国基层医药

Objective:To investigate the relationship between arterial blood partial pressure of carbon dioxide and neurological outcome after cardiopulmonary resuscitation.Methods:The clinical data of 116 patients who underwent cardiopulmonary resuscitation admitted to the Intensive Care Unit and Emergency Department of the Second People's Hospital of Hefei from January 2018 to January 2020 were retrospectively analyzed. According to the average arterial blood partial pressure of carbon dioxide within 24 hours after admission, patients were divided into normal (35 mmHg ≤ PaCO 2 ≤ 55 mmHg, 1 mmHg = 0.133 kPa, n = 44), hypercapnia (PaCO 2 > 55 mmHg, n = 51), and hypocapnia (PaCO 2 < 35 mmHg, n = 21) groups. ICU stay, in-hospital mortality, and neurological outcome at discharge were compared among groups. A logistic regression analysis model was established. The relationship between PaCO 2 and neurological outcome was determined. Results:There were no significant differences in age, sex, cardiac arrest time, acute physiological and chronic health evaluation II score at admission, 1-hour mean arterial pressure, location of cardiac arrest, and initial heart rhythm among the three groups (all P > 0.05). ICU stay in the normal group [(7.23 ± 2.55) days] was significantly higher than that in the hypercapnia [(12.21 ± 4.12) days] and hypocapnia [(11.78 ± 4.72) days] groups ( t = 6.48, 4.59, both P < 0.01). In-hospital mortality in the normal group was 38.6% (17/44), which was significantly lower than 60.8% (31/51) in the hypercapnia group and 66.7% (14/21) in the hypocapnia group ( χ2 = 4.63, 4.47, both P < 0.05). The good neurological outcome rate in the normal group was 55.6% (15/44), which was significantly higher than 25.0% (5/51) in the hypercapnia group and 28.6% (2/21) in the hypocapnia group ( χ2 = 8.38, 5.14, both P < 0.05). Multivariate logistic regression analysis showed that cardiac arrest time, 1-hour mean arterial pressure, acute physiological and chronic health evaluation II score, and PaCO 2 are important factors for neurological outcomes of resuscitated patients at discharge (all P < 0.01). Conclusion:Within 24 hours after cardiopulmonary resuscitation, maintaining a normal PaCO 2 level can help improve the neurological outcome of patients at discharge.

Clinical efficacy of ateplase combined with heparin in the treatment of acute moderate- and high-risk pulmonary thromboembolism and its effects on arterial blood gas analysis and myocardial enzyme level / 中国基层医药

Objective:To investigate the clinical efficacy of alteplase combined with heparin in the treatment of acute moderate- and high-risk pulmonary thromboembolism and its effects on arterial blood gas analysis and myocardial enzyme level.Methods:Seventy-eight patients with acute moderate- and high-risk pulmonary thromboembolism who received treatment in Dongyang People's Hospital from January 2015 to January 2022 were retrospectively included in this study. They were divided into observation ( n = 39) and control ( n = 39) groups according to different treatment methods. The control group was treated with heparin, while the observation group was treated with alteplase based on heparin. All patients were treated for 7 days. Clinical efficacy as well as arterial blood gas analysis, myocardial enzymes, pulmonary artery pressure, and tricuspid annular plane systolic excursion pre- and post-treatment were compared between the two groups. Results:The total response rate in the observation group was significantly higher than that in the control group (94.87% vs. 76.92%, χ2 = 5.18, P < 0.05). After treatment, the partial pressure of carbon dioxide in the observation group was significantly lower than that in the control group [(36.24 ± 5.12) mmHg vs. (44.25 ± 3.78) mmHg, 1 mmHg = 0.133 kPa, t = 7.86, P < 0.05]. After treatment, the partial pressure of oxygen in the observation group was significantly higher than that in the control group [(78.82 ± 5.1) mmHg vs. (71.23 ± 4.89) mmHg, t = 6.66, P < 0.05]. After treatment, lactate dehydrogenase, creatine kinase, and creatine kinase isoenzyme in the observation group were (107.42 ± 15.45) U/L, (37.21 ± 10.84) U/L, and (12.28 ± 3.54) U/L, respectively, which were significantly lower than (189.94 ± 21.20) U/L, (65.42 ± 6.57) U/L, and (19.29 ± 3.08) U/L in the control group ( t = 19.64, 13.89, 9.33, all P < 0.001). After treatment, the pulmonary arterial pressure in the observation group was significantly lower than that in the control group [(32.24 ± 3.86) mmHg vs. (37.79 ± 5.17) mmHg, t = 5.37, P < 0.001]. Tricuspid annular plane systolic excursion in the observation group was significantly higher than that in the control group [(14.07 ± 1.27) mm vs. (12.63 ± 1.16) mm, t = 5.22, P < 0.001]. Conclusion:Ateplase combined with heparin has an obvious effect on acute moderate- and high-risk pulmonary thromboembolism. It can improve arterial blood gas analysis and reduce myocardial enzyme levels.

Prediction of short term clinical outcomes in low Apgar score neonates using umbilical artery blood gas analysis plus amplitude integrated electroencephalography / 中国新生儿科杂志

Objective:To study the predictive values of umbilical artery blood gas analysis(UABG) plus amplitude-integrated electroencephalography(aEEG) monitoring within 6 h after birth for early complications and short term neurological outcomes in low Apgar score neonates.Methods:From January 2020 to February 2022, neonates with gestational age (GA) ≥35 weeks and 1 min or 5 min Apgar score ≤7 admitted to NICU of our hospital were retrospectively reviewed. According to UABG pH values, the neonates were assigned into pH<7.2 group and pH ≥7.2 group, and further grouped into abnormal aEEG group and normal aEEG group. The ttest, rank sum test and χ2 test were used to compare laboratory results, incidences of diseases, physical growth and neurological prognosis at 6 month of age. Results:A total of 105 neonates with low Apgar scores were enrolled, including 73 cases in the pH<7.2 group and 32 cases in the pH≥7.2 group. In the pH<7.2 group, 52(71.2%) had abnormal aEEG and 21 had normal aEEG. In the pH≥7.2 group, 6(18.8%) had abnormal aEEG and 26 had normal aEEG. The incidence of abnormal aEEG in the pH<7.2 group was higher than the pH≥7.2 group ( P<0.001). The degree of aEEG abnormality was negatively correlated with UABG pH ( r=-0.463, P<0.001). In the pH<7.2 group, the levels of creatine kinase isozymes (CK-MB), activated partial thromboplastin time and the incidence of hypoxic-ischemic encephalopathy (HIE) in neonates with abnormal aEEG were significantly higher than those with normal aEEG, and the head circumference (HC) at 6 month was significantly smaller in neonates with abnormal aEEG (all P<0.05). In the pH≥7.2 group, the level of CK-MB, incidences of HIE and respiratory failure in neonates with abnormal aEEG were higher than those with normal aEEG, HC at 6 month was smaller and the incidence of adverse neurological prognosis was higher in neonates with abnormal aEEG (all P<0.05). Conclusions:UABG plus aEEG monitoring within 6 h after birth shows predictive values for early complications and short term neurological outcomes in low Apgar scores neonates.

Effect of repeated episodes of ventricular fibrillation and defibrillation on arterial acid-base and electrolytes changes in a swine model / 中华急诊医学杂志

Objective:To investigate changes in arterial acid-base and electrolytes after repeated episodes of ventricular fibrillation (VF) and defibrillation in a swine model.Methods:Sixteen Peking white swine, weighting (32±2.5) kg, were placed with temporary pacemaker electrodes via the left femoral vein into the right ventricle after anesthesia. Then VF was electrically induced by using a programmed electrical stimulation instrument. An arterial cannula was inserted into the left femoral artery to measure mean arterial blood pressure and cardiac output using a PiCCO monitor, with blood samples collected. The pigs were randomly divided into two group: the manual defibrillation group (MD, n=8) and the automated external defibrillation group (AED, n=8). The first defibrillation was attempted with the manufacturer’s dose (150 J) for 15 s after the successful induction of VF in the MD group. If spontaneous circulation was not recovered, 2-min chest compression and subsequent defibrillation (200 J) were attempted. For the AED group, the defibrillation was delivered following voice prompts of the AED. After the return of spontaneous circulation, the pig was allowed to stabilize for 30 min, followed by the induction of the next episode of VF. The above process was repeated five times. Arterial blood gas, cardiac biomarkers, and hemodynamic variables were measured at 30 min after the return of spontaneous circulation. Results:All pigs were successfully induced VF five times and defibrillated successfully. There were no significant changes in heart rate and mean arterial blood pressure between the two groups after repeated episodes of VF and defibrillation. Compared with baseline measurements, cardiac output tended to decrease after repeated episodes of VF and defibrillation but was not statistically significant (all P>0.05). There were no significant differences in arterial pH, HCO 3-, sodium, and lactic acid in the two groups between each measurement time point and baseline values after repeated VF (all P>0.05), but potassium levels in the two groups decreased with time, and the difference was statistically significant compared with the baseline measurement (all P<0.05). There were no significant differences in myoglobin, creatine kinase isoenzyme-MB, and cardiac troponin I for the two groups compared with baseline values after repeated episodes of VF and defibrillation or various episodes of VF between the two groups (all P > 0.05). Conclusions:Repeated episodes of VF and defibrillation have no significant effect on pH balance, but significantly decrease blood potassium. Clinical approaches (MD vs. AED) do not affect defibrillation effect, with no significant differences in hemodynamic variables and myocardial injuries.

Accuracy of intrapartum cardiotocography in identifying acidemia at birth by umbilical cord blood gasometry in high-risk pregnancies

SUMMARY OBJECTIVE: The aim of this study was to evaluate the accuracy of intrapartum cardiotocography in identifying acidemia at birth by umbilical cord blood gasometry in high-risk pregnancies. METHODS: This was a retrospective cohort study of singleton high-risk parturients using intrapartum cardiotocography categories I, II, and III. The presence of fetal acidemia at birth was identified by the analysis of umbilical cord arterial blood pH (<7.1). Associations between variables were determined using the chi-square test and Kruskal-Wallis tests. RESULTS: We included 105 cases of cardiotocography category I, 20 cases of cardiotocography category II, and 10 cases of cardiotocography category III. cardiotocography category III had a higher prevalence of cesarean sections compared to cardiotocography category I (90.0 vs. 42.9%, p<0.006). Venous pH was higher in patients with cardiotocography category I compared to cardiotocography category III (7.32 vs. 7.23, p=0.036). Prevalence of neonatal intensive care unit (NICU) admission was lower in neonates of patients with cardiotocography category I compared to cardiotocography category III (3.8 vs. 30.0%, p=0.014). Prevalence of composite adverse outcomes was lower in neonates of patients with cardiotocography category I compared to cardiotocography category II (9.5 vs. 30.0%, p=0.022) and cardiotocography category III (9.5 vs. 60.0%, p=0.0004). cardiotocography categories II and III had low sensitivity (0.05 and 0.00, respectively) and high negative predictive value (NPV) (0.84 and 0.91, respectively) for identifying fetal acidemia at birth. The three categories of intrapartum cardiotocography showed high specificities (96.0, 99.0, and 99.0%, respectively). CONCLUSION: All three categories of intrapartum cardiotocography showed low sensitivity and high specificity for identifying acidemia at birth.

Accuracy of intrapartum cardiotocography in identifying fetal acidemia by umbilical cord blood analysis in low-risk pregnancies

SUMMARY OBJECTIVE: The aim of this study was to evaluate the accuracy of intrapartum cardiotocography in identifying fetal acidemia by umbilical cord blood analysis in low-risk pregnancies. METHODS: This is a retrospective cohort study of low-risk singleton pregnancies in labor after performing intrapartum cardiotocography categories I, II, and III. The presence of fetal acidemia at birth was identified by analyzing the pH of umbilical cord arterial blood (pH<7.1). RESULTS: No significant effect of the cardiotocography category on the arterial (p=0.543) and venous (p=0.770) pH of umbilical cord blood was observed. No significant association was observed between the cardiotocography category and the presence of fetal acidemia (p=0.706), 1-min Apgar score <7 (p=0.260), hospitalization in the neonatal intensive care unit (p=0.605), newborn death within the first 48 h, need for neonatal resuscitation (p=0.637), and adverse perinatal outcomes (p=0.373). Sensitivities of 62, 31, and 6.0%; positive predictive values of 11.0, 16.0, and 10.0%; and negative predictive values of 85, 89.0, and 87.0% were observed for cardiotocography categories I, II, and III, respectively. CONCLUSION: The three categories of intrapartum cardiotocography presented low sensitivities and high negative predictive values to identify fetal acidemia at birth in low-risk pregnancies.

Value of short-time transcutaneous carbon dioxide and oxygen pressure monitoring in critically ill preterm infants / 中华围产医学杂志

Objective:To investigate the value of short-time transcutaneous carbon dioxide pressure (TcPCO 2) and transcutaneous oxygen pressure (TcPO 2) monitoring in critically ill preterm infants. Methods:From January to December 2018, 62 critically ill neonates receiving respiratory support at Guangzhou Women and Children's Medical Center were retrospectively enrolled. A total of 348 sets of paired data including TcPCO 2/TcPO 2 and arterial carbon dioxide pressure (PaCO 2)/arterial oxygen partial pressure (PaO 2) were analyzed. The patients were divided into different groups based upon birth weight (23 cases>1 000 g-≤1 500 g, 129 sets of paired data; 18 cases≤1 000 g, 130 sets of paired data) and gestational age (16 cases born at ≤28 gestational weeks, 127 sets of paired data; 29 cases born at 28-34 gestational weeks, 159 sets of paired data) and the differences between groups were compared. The correlation and consistency of TcPCO 2/TcPO 2 and PaCO 2/PaO 2 were evaluated using Pearson's correlation and Blan-Altman scatter plots. Receiver operating characteristic (ROC) curve was drawn to analyze the diagnostic efficacy of TcPCO 2 in neonates with hypercapnia. Results:There was a positive correlation between TcPCO 2 and PaCO 2 in all patients ( r=0.913, 95% CI:0.894-0.929, P<0.05). In patients whose birth weight was>1 000 g-≤1 500 g or≤1 000 g, TcPCO 2 and PaCO 2 were positively correlated and the consistency were good ( r=0.909, 95% CI:0.874-0.935; r=0.934, 95% CI:0.908-0.953; both P<0.05), and the same finding was also observed in patients born at≤28 gestational weeks or 28-34 weeks of gestation ( r=0.938, 95% CI:0.913-0.956; r=0.871, 95% CI: 0.827-0.904; both P<0.05). The sensitivity, specificity and area under curve of TcPCO 2 in the diagnosis of hypercapnia were 90.91%, 85.85%, and 0.942, respectively. There was a poor correlation between TcPO 2 and PaO 2 in all patients and those with birth weight >1 000 g-≤1 500 g or gestational age 28-34 weeks (all r<0.75, all P<0.05). There was no correlation between TcPO 2 and PaO 2 in the birth weight ≤1 000 g and gestational age ≤28 weeks groups (both P>0.05). Conclusions:Short-time TcPCO 2 monitoring can accurately assess PaCO 2 in critically ill neonates requiring respiratory support and is of high diagnostic value for hypercapnia. However, TcPO 2 has limitation in evaluating PaO 2 and other indicators may need to be involved.

Primary assessment of patients admitted to the emergency ward using arterial blood gas

Background: Arterial blood gas study (ABG) is a point-of-care testing (POCT) diagnostic tool that can furnish metabolic and respiratory aberrations. This study was conducted systematically, to assess the metabolic and respiratory aberrations quickly and the scope for corrective treatment so that metabolic and respiratory abnormalities get corrected. Materials and Methods: A prospective cross-sectional study was done among 150 cases admitted to the Department of Emergency Medicine during a three-month period where the study on ABG was done. Data was collected in the prescribed format and a stepwise interpretation of the ABG was done. The four primary disorders taken into consideration are metabolic acidosis, metabolic alkalosis, respiratory alkalosis, and respiratory acidosis Results: Out of 150 cases 82 had respiratory alkalosis, 51 had metabolic acidosis, ten had respiratory acidosis, and seven had metabolic alkalosis as a primary disorder. Conclusion: ABG analysis is a POCT diagnostic tool for analyzing various metabolic and respiratory aberrations and can also guide us in the scope for correction of the disorder.

Application value of monitoring of percutaneous partial pressure of carbon dioxide/oxygen for patients in ICU after general anesthesia

For patients in ICU under mechanical ventilation, monitoring of percutaneous partial pressure of CO2 and O2 after general anesthesia is crucial as excessive or insufficient ventilation may prove to be fatal. However, the correlation between percutaneous monitoring and arterial blood gas analysis still remains unclear. Here, we studied the application value of monitoring of PtcCO2/PtcO2 for patients in ICU after general anesthesia for better management of patients in ICU on ventilation. A total of 195 eligible patients were selected. After transfer, when PtcCO2 and PtcO2 were stable (10-15 min), they were recorded as transfer-in values. Partial pressure of carbon dioxide (PaCO2), partial pressure of oxygen (PaO2), lactate, PtcO2 and PtcCO2 were recorded. Vital signs and hemodynamics data were also recorded. There were significant positive correlations between PtcCO2 and PtcO2 (r = 0.876), and between PtcO2 and PaCO2 (r = 0.817) (P <0.01). PaO2 was higher than PtcO2 (P <0.01). There were significant positive correlations between PtcCO2/PtcO2 and PaCO2/PaO2 at different time points (T0: upon transfer-in; T1: before extubation; T2: upon transfer-out, P <0.01). At different oxygen inhalation concentrations (21, 40 and 50%), PtcCO2 and PtcO2 were all well linearly correlated. The overall PtcO2/PaO2 was (0.75±0.12). When FIO2 values were 21, 40 and 50%, PtcO2/PaO2 values were similar (P >0.05). PtcCO2 and PtcO2 or PtcO2 and PaCO2 are significantly positively correlated, without significant differences between different time periods or oxygen concentrations. PtcCO2 and PtcO2 can predict the changes of PtcO2 and PaCO2, which is of great significance to the early observation of oxygenation changes, adjustment of ventilator parameters and improvement of prognosis. PtcCO2/PaO2 values are similar at different oxygen concentrations, as an eligible index for the postoperative evaluation of tissue perfusion status and hemodynamic level.

Justificativa e limitações da SpO2/FiO2 como possível substituta da PaO2/FiO2 em diferentes cenários pré-clínicos e clínicos / Rationale and limitations of the SpO2/FiO2 as a possible substitute for PaO2/FiO2 in different preclinical and clinical scenarios

RESUMO Embora a PaO2/FiO2 derivada da gasometria arterial continue sendo o padrão-ouro do diagnóstico de insuficiência respiratória aguda, a SpO2/FiO2 tem sido investigada como potencial substituta. Esta revisão narrativa apresenta o estado da literatura pré-clínica e clínica sobre a SpO2/FiO2 como possível substituta da PaO2/FiO2 e para uso como marcador diagnóstico e prognóstico; ainda, é fornecida uma visão geral da oximetria de pulso e suas limitações, além da avaliação da utilidade da SpO2/ FiO2 como substituta da PaO2/FiO2 em pacientes com COVID-19. Ao todo, foram encontrados 49 estudos comparando SpO2/FiO2 e PaO2/ FiO2 com base em uma estratégia de pesquisa mínima. A maioria dos estudos foi realizada em recémnascidos, alguns foram realizados em adultos com síndrome do desconforto respiratório agudo, e outros foram realizados em outros cenários clínicos (incluindo poucos em pacientes com COVID-19). Há certa evidência de que os critérios de SpO2/FiO2 podem substituir a PaO2/FiO2 em diferentes cenários clínicos. Isso é reforçado pelo fato de que devem ser evitados procedimentos invasivos desnecessários em pacientes com insuficiência respiratória aguda. É inegável que os oxímetros de pulso estão cada vez mais difundidos e podem proporcionar um monitoramento sem custos. Portanto, substituir a PaO2/FiO2 pela SpO2/FiO2 pode permitir que instalações com recursos limitados diagnostiquem a insuficiência respiratória aguda de maneira objetiva.

ABSTRACT Although the PaO 2/FiO 2 derived from arterial blood gas analysis remains the gold standard for the diagnosis of acute respiratory failure, the SpO2/FiO2 has been investigated as a potential substitute. The current narrative review presents the state of the preclinical and clinical literature on the SpO2/FiO2 as a possible substitute for PaO2/FiO2 and for use as a diagnostic and prognostic marker; provides an overview of pulse oximetry and its limitations, and assesses the utility of SpO2/ FiO2 as a surrogate for PaO2/FiO2 in COVID-19 patients. Overall, 49 studies comparing SpO2/FiO2 and PaO2/FiO2 were found according to a minimal search strategy. Most were conducted on neonates, some were conducted on adults with acute respiratory distress syndrome, and a few were conducted in other clinical scenarios (including a very few on COVID-19 patients). There is some evidence that the SpO2/ FiO2 criteria can be a surrogate for PaO2/FiO2 in different clinical scenarios. This is reinforced by the fact that unnecessary invasive procedures should be avoided in patients with acute respiratory failure. It is undeniable that pulse oximeters are becoming increasingly widespread and can provide costless monitoring. Hence, replacing PaO2/FiO2 with SpO2/FiO2may allow resourcelimited facilities to objectively diagnose acute respiratory failure.

Clinical efficacy of Qianjin Weijing Decoction in the treatment of severe pneumonia with accumulation of phlegm and heat in the lung / 中国基层医药

Objective:To investigate the clinical efficacy of Qianjin Weijing Decoction in the treatment of severe pneumonia with the accumulation of phlegm and heat in the lung. Methods:Eighty patients with severe pneumonia with the accumulation of phlegm and heat in the lung received treatment in Wenzhou Hospital of Traditional Chinese Medicine from December 2018 to December 2020. They were randomly allocated to undergo routine treatments (control group, n = 40) or routine treatments combined with Qianjin Weijing Decoction (observation group, n = 40) for 7 days. Clinical efficacy, blood gas analysis, oxygenation index, inflammatory factors (C-reactive protein and procalcitonin), and sequential organ failure score were compared between the two groups. Results:Total response rate in the observation group was significantly higher than that in the control group [87.50% (35/40) vs. 65.00% (26/40), χ2 = 5.59, P < 0.05]. Partial pressure of carbon dioxide (PaCO 2) post-treatment was significantly lower in the observation group than that in the control group [(30.24 ± 2.68) mmHg vs. (39.95 ± 3.27) mmHg, t = 14.52, P < 0.05]. The partial pressure of blood oxygen (PaO 2) and oxygenation index (PaO 2/FiO 2) in the observation group were (76.85 ± 4.56) mmHg and (326.84 ± 8.49) mmHg, respectively, which were significantly higher than those in the control group [(68.39 ± 4.12) mmHg, (284.16 ± 15.56) mmHg, t = -8.70, -15.22, both P < 0.05). Serum levels of C-reactive protein and procalcitonin post-treatment in the observation group were (23.12 ± 6.56) mg/L and (0.31 ± 0.08) μg/L, respectively, which were significantly lower than those in the control group [(38.92 ± 5.62) mg/L, (0.78 ± 0.20) μg/L, t = 11.56, 13.80, both P < 0.05]. Sequential organ failure score was significantly lower in the observation group than in the control group [(2.31 ± 0.46) points vs. (5.12 ± 1.25) points, t = 13.34, P < 0.05)]. Conclusion:Qianjin Weijing Decoction has a good therapeutic effect on severe pneumonia with the accumulation of phlegm and heat in the lung. The treatment can improve blood gas analysis and decrease inflammatory factor levels with a good prognosis.

Effect of excessive umbilical cord torsion on fetal and neonatal outcomes / 中国新生儿科杂志

Objective:To study the effect of excessive torsion of the umbilical cord on fetal or neonatal outcomes.Methods:The observation group was selected from the puerperae who delivered in Beijing Obstetrics and Gynecology Hospital from July 2016 to June 2020 with excessive torsion of the umbilical cord. In the same period, the puerperae without excessive torsion of the umbilical cord were selected as the control group with a ratio of 1∶1. The general condition, mode of delivery, perinatal outcomes, and the effect of different umbilical coiling index (UCI) [twisted umbilical cord weeks/umbilical cord length (cm)] on fetal and neonatal outcomes were retrospectively analyzed between two groups.Results:Compared with the control group, the observation group (1 780 cases) had smaller neonatal gestational age [(37.9±3.2) weeks vs. (38.4±2.9) weeks], birth weight [(3 007±726) g vs. (3 354±616) g] and length [(48.5±4.3) cm vs. (49.6±4.1) cm], but higher incidence of fetal distress [34.9% (622/1 780) vs. 12.9% (230/1 780)], neonatal asphyxia [1.5% (26/1 780) vs. 0.7% (13/1 780)], and cord blood pH<7.20 [4.2% (75/1 780) vs. 2.8% (49/1 780)], the difference was statistically significant ( P<0.05). The UCI≥0.73 group had lower neonatal gestational age, birth weight and length, but higher incidence of cord blood pH<7.20 and neonatal asphyxia than the UCI<0.73 group, with statistically significant differences ( P<0.05). Conclusions:Excessive torsion of the umbilical cord increases the incidence of fetal hypoxia and neonatal asphyxia and has a significant effect on neonatal gestational age, birth weight and length. The higher the UCI, the greater the impact on fetus and neonate.

Correlation analysis of umbilical artery blood gas and Apgar score in neonates / 中国新生儿科杂志

Objective:To study the correlation between umbilical artery blood gas (UABG) and Apgar score of neonates and the risk factors of low base excess (BE) in UABG.Methods:From March 2017 to September 2020, newborns without congenital malformation born in three hospitals were prospectively enrolled and received UABG analysis. According to their Apgar score, the infants were assigned into low Apgar score group and normal Apgar score group. According to BE of UABG, they were assigned into BE<-12 mmol/L group and BE≥-12 mmol/L group. The UABG indexes including abnormal pH and BE between the low Apgar score group and the normal Apgar score group were compared. The risk factors of low BE in UABG were analyzed.Results:A total of 1 351 qualified samples were included including 208 cases in low Apgar score group and 1 143 cases in normal Apgar score group. 115 cases were in BE <-12 mmol/L group and 1 236 cases in BE ≥-12 mmol/L group. The incidences of abnormal pH and BE values in the low Apgar score group were higher than the normal Apgar score group [50.0% (104/208) vs. 13.8% (158/1 143), 34.6% (72/208) vs. 3.8% (43/1 143)]. The pH and BE values of UABG were positively correlated with 1 min Apgar score ( r=0.402, 0.398, P<0.001). Multivariate logistic regression analysis indicated that the risk factors for BE<-12 mmol/L were Ⅲ° contaminated amniotic fluid ( OR= 3.155, 95% CI 1.972~5.025, P<0.001) and placental abruption ( OR = 3.968, 95% CI 1.992~7.874, P <0.001). Conclusions:The pH and BE values of neonatal UABG are positively correlated with 1 min Apgar score. Ⅲ° contaminated amniotic fluid and placental abruption are risk factors of low BE in UABG.

Factors influencing pH value of umbilical arterial blood gas analysis in preterm infants / 中华围产医学杂志

Objective:To analyze the factors influencing pH value in umbilical arterial blood gas (UABG) analysis in preterm infants.Methods:A retrospective study was conducted on live singleton preterm infants ( n=573) who received UABG analysis in Peking University Third Hospital from January 2017 to February 2019. Analysis of variance, independent sample t-test, Spearman's or Pearson's correlation analysis, or linear regression analysis was used to analyze the influencing factors. Results:There was no significant difference in UABG pH value between preterm infants of different gestational ages (F=1.74, P=0.077). Spearman's correlation analysis found no correlation between gestational age and UABG pH value in premature infants ( r=0.003, P=0.940), and neither did Pearson's correlation between birth weight and pH value ( r=0.025, P=0.548). UABG pH value in preterm infants was linearly correlated with vaginal delivery ( t=－5.72, P<0.001), gestational hypertension ( t=－3.99, P<0.001) and placental abruption ( t=－4.52, P<0.001). Conclusions:Preterm infants at different gestational ages show a similar pH value in UABG. For those born to mothers with gestational hypertension or placental abruption, when vaginal delivery is pending, close monitoring and full preparation for resuscitation are necessary.

Clinical efficacy of sequential invasive-noninvasive mechanical ventilation for chronic obstructive pulmonary disease complicated by type II respiratory failure / 中国基层医药

Objective:To investigate the clinical efficacy of sequential invasive-noninvasive mechanical ventilation for chronic obstructive pulmonary disease complicated by type II respiratory failure.Methods:Eighty-four patients with chronic obstructive pulmonary disease complicated by type II respiratory failure who received treatment in The First Affiliated Hospital of University of Science and Technology of China from January 2017 to December 2019 were included in this study. Patients were selected to withdraw the ventilator for performing a spontaneous breathing test according to recovery status. Patients who underwent invasive mechanical ventilation were included in the control group ( n = 42). Patients who underwent sequential invasive-noninvasive mechanical ventilation based on the pulmonary infection control window were included in the observation group. Mortality rate, reintubation rate, total ventilation time, length of hospital stay, heart rate, and blood gas analysis were compared between the two groups. Results:The length of hospital stay and total ventilation time in the observation group were (9.69 ± 1.94) days and (7.49 ± 1.53) days, respectively, which were significantly shorter than those in the control group ( t = 8.87, 5.10, both P < 0.05). Reintubation rate and mortality rate in the observation group were 4.76% (2/42) and 2.38% (1/42), respectively, which were significantly lower than those in the control group ( χ2 = 5.13, 3.90, both P < 0.05). In each group, heart rate, partial pressure of carbon dioxide and partial pressure of oxygen measured after treatment were superior to those measured before treatment (all P < 0.05). Conclusion:Based on pulmonary infection control window, invasive-noninvasive sequential ventilation for chronic obstructive pulmonary disease complicated by type II respiratory failure can not only reduce total ventilation time and length of hospital stay, remarkably improve clinical manifestations, but also effectively reduce reintubation rate and mortality rate.