Effect of sequential high-flow nasal cannula oxygen therapy and non-invasive positive-pressure ventilation in patients with difficult weaning from mechanical ventilation after extubation on respiratory mechanics.

BACKGROUND: Patients with difficult weaning who undergo mechanical ventilation are more likely to be at risk of reintubation and the sequential use of oxygen therapy after extubation is a concern for clinicians. Therefore, the aim of the present study was to compare the effects of transnasal high-flow nasal cannula (HFNC) oxygen therapy and non-invasive positive-pressure ventilation (NIV) on respiratory mechanics in patients with difficult weaning. METHODS: The present study was a single-center, retrospective, observational study. Twenty-nine patients with difficult weaning off invasive mechanical ventilation from the Department of Critical Care Medicine, The First Affiliated Hospital of Guangzhou Medical University, from December 2018 to April 2021, were included. Within 48 h after extubation, alternate respiratory support with HFNC and NIV was provided. Relevant indicators were recorded after each support mode had been maintained for at least 60 min. These included esophageal pressure (Pes), gastric pressure (Pga), transdiaphragmatic pressure (Pdi), pressure-time product of Pes (PTPes), pressure-time product of Pga (PTPga), pressure-time product of Pdi (PTPdi), ratio of the PTPdi to the PTPes (PTPdi/PTPes), and ratio of the Pes to the Pdi (Pes/Pdi), diaphragmatic electromyogram (EMGdi), percentage of esophageal pressure coefficient of variation (CVes%),diaphragmatic electromyogram coefficient of variation (CVEMG),inspiratory time (Ti), expiratory time (Te) and respiratory cycle time (Ttot). RESULTS: Of the 29 patients included, 22 were males and 7 were females [age: 63.97±15.34 years, Acute Physiological and Chronic Health Estimation II (APACHE II) score: 18.00±5.63]. The CVes% and the Pes/Pdi were significantly higher in patients with NIV than HFNC using 40 L/min, CVes%: 9 (-6, 20) vs. -7 (-23, 6) and Pes/Pdi: 0.17 (-0.1, 0.53), vs. -0.12 (-0.43, 0.08) (P<0.05). The remaining indicators were not statistically different. CONCLUSIONS: The sequential NIV and HFNC can be tolerated in patients with such difficult weaning off mechanical ventilation after extubation, and more patients tend to choose HFNC subjectively. Compared with HFNC, NIV reduces the work of adjunctive respiratory muscle, but the patient's Pes dispersion is high when NIV is used, and it is necessary to pay attention to patient-ventilator coordination in clinical practice. We recommend alternating HFNC and NIV during the sequential respiratory therapy after extubation.

Compliance with severe sepsis bundles and its effect on patient outcomes of severe community-acquired pneumonia in a limited resources country.

INTRODUCTION: Validation of compliance with severe sepsis bundles is still needed. The purpose of this study was to determine compliance and its outcomes in severe community-acquired pneumonia (CAP) patients in a limited resources country. MATERIAL AND METHODS: A prospective cohort study of 212 severe CAP patients was carried out. The implementation programme was organized into two continuous phases. The primary outcomes were compliance and hospital mortality. RESULTS: Compliance with administration of antibiotics and vasopressors as well as plateau pressure on average < 30 cm H2O was high in both groups. In the bundles group, patients received more serum lactate monitoring (62.3% vs. 11.3%), more blood cultures (47.1% vs. 24.5%), more fluid resuscitation (63.2% vs. 26.4%) and volumes infused (1319.8 ±1107.4 ml vs. 461.9 ±799.3 ml), more inotropic dobutamine and/or packed red blood cells (21.7% vs. 10.0%), more low-dose steroids (56.5% vs. 15.0%), and more glucose control (51.9% vs. 6.6%) compared with such patients in the control group. The rates of total compliance with 6-hour, 24-hour, and 6/24-hour bundles in the prospective period were 47.1%, 51.9%, and 42.5%, respectively. Hospital mortality was reduced from 44.3% to 29.2% (p = 0.023) in the bundles group, and the compliant subgroup had a more than twofold decrease in mortality (17.8% vs. 37.7%, p = 0.003). Serum lactate measured, blood cultures, and fluid resuscitation showed independent relationships with decreased mortality. CONCLUSIONS: Total compliance was relatively low, but the implementation of severe sepsis bundles could clearly reduce mortality from severe CAP.

[Intrathoracic blood volume index as an indicator of fluid management in septic shock].

OBJECTIVE: To investigate the value of intrathoracic blood volume index (ITBVI) monitoring in fluid management strategy in septic shock patients. METHODS: In a prospective study, 33 patients who were diagnosed to be suffering from septic shock in the intensive care unit (ICU) were enrolled . Seventeen patients who received pulse indicator continuous cardiac output (PiCCO) monitoring, and ITBVI was used as indicator of fluid management, were enrolled into ITBVI group; 16 patients who received traditional fluid management strategy [directed by central venous pressure (CVP)] were enrolled into control group. Acute physiology and chronic health evaluation II (APACHEII) score, sepsis related organ failure assessment (SOFA) score and vasopressor score were compared between 1 day and 3 days of treatment. The characteristics of fluid management were recorded and compared within 72 hours. RESULTS: (1)In 3 days of treatment, APACHEII, SOFA and vasopressor score were significantly lower in ITBVI group compared with that of in 1 day of treatment[21.3±6.2 vs. 25.4±7.2, 6.1±3.4 vs. 9.0±3.5, 5 (0, 8.0) vs. 20.0 (8.0, 35.0), respectively, all P<0.01], whereas there were no changes in control group. (2)Although fluid output (ml) was higher in ITBVI group during 48-72 hours period (2 421± 868 vs. 1 721±934, P=0.039), there was no difference in fluid intake, fluid output or fluid balance (ml) within 0-72 hours between two groups (fluid intake: 9 918±137 vs. 10 529±1 331, fluid output : 6 035±1 739 vs. 5 827±2 897, fluid balance: 3 882±1 889 vs. 4 703±2 813, allP>0.05). (3)Comparing the fluid volume (ml) used for fluid replacement period, except that there was no significance in fluid challenge with colloid during 0-6 hours between two groups [ml: 250 (125, 500) vs. 250 (69,250), P>0.05], more fluid intake (ml) was found in ITBVI group [0-6 hours crystalloid: 250(150,250) vs. 125 (105,125), 6-72 hours crystalloid: 125 (125, 250) vs. 100 (56, 125), 0-72 hours crystalloid: 250(125, 250) vs. 125 (75, 125), 6-72 hours colloid: 125 (106, 250) vs. 75 (50, 125), 0-72 hours colloid: 200 (125, 250) vs. 100 (50, 125),all P<0.01]. CONCLUSION: Clinical picture in patients with septic shock is improved after 3 days of treatment than 1 day of treatment under fluid management directed by ITBVI, compared with by CVP. This improvement may be attributable to accurate assessment of preload and appropriate infusion rate in fluid challenge.

[Evaluation of compliance with bundle treatment in the management of severe infection].

OBJECTIVE: To evaluate compliance with bundle treatment in the management of severe infection in a tertiary hospital, aiming at analyzing clinical data in order to popularize guidelines for management of severe sepsis and septic shock. METHODS: A 14-month (from November 1, 2006 to December 31, 2007) prospective observational study of a group of 43 patients admitted to the respiratory intensive care unit in First Affiliated Hospital (tertiary hospital) of Guangzhou Medical College meeting the criteria for severe pneumonia and septic shock was carried out. Implementation of 6-hour and 24-hour bundle treatment for severe infection was divided into three phases consisting of education, trial, and application. A cohort of 43 patients with matched disease history admitted during January 1, 2004 to October 31, 2006 were enrolled as control group. RESULTS: (1) In 6-hour bundle treatment for severe infection, 20.9% (9/43) had serum lactate measured, blood culture was obtained prior to antibiotic administration in 7.0% (3/43) of patients, 100% (43/43) had empirical antibiotics administration within 1 hour, an infusion of an initial minimum of 20 ml/kg of crystalloid or colloid equivalent (1.1 ml/kg of 20% albumin or 4.8 ml/kg of 6% hydroxyethyl starch) was given in 44.2% (19/43), with infused fluid (converted into 6% hydroxyethyl starch) reaching (503.95+/-176.19) ml within 6 hours, in 94.7% (18/19) of patients had received vasopressors , and inotropic dobutamine and/or transfusion of packed red blood cells were administered in 7.0% (3/43). (2) In 24-hour bundle treatment for severe infection group, 31.6% (6/19) had received low-dose steroids, 34.9% (15/43) had their blood glucose controlled<8.3 mmol/L, mechanical ventilation with inspiratory plateau pressures maintained<30 cm H(2)O (1 cm H(2)O=0.098 kPa, 6 ml/kg tidal volume) was instituted in 97.6% (40/41) of patients. (3) The percentage of compliance with 6-hour and 24-hour bundle treatment for severe infection were 0 and 21.4% respectively, total compliance was also 0. (4) As compared with control group, a 23.30% absolute mortality reduction was found in bundle group (18.6% vs. 41.9%, P=0.019). CONCLUSION: Bundle treatment for severe infection is complied with partially in our hospital, suggesting that it is still quite arduous to popularize guidelines for management of severe sepsis and septic shock in our country.

[Evaluation of the efficacy and safety of corticosteroid in the treatment of severe SARS in Guangdong province with multi-factor regression analysis].

OBJECTIVE: To investigate the clinical database of severe acute respiratory syndrome (SARS) in Guangdong province and evaluate the efficacy and safety of corticosteroid in the treatment of severe SARS from December 2002 to December 2003. METHODS: The detail data of 1 278 SARS patients and borderline cases were collected. Four hundred and two confirmed SARS cases were recruited in our study. Out of them, 358 cases were assigned to the severe SARS group based on the criteria issued by Ministry of Health. Subjects who received steroid (which was converted into methylprednisolone) treatment were further divided into three groups: small dose group (<80 mg/day); moderate dose group (80-320 mg/day); high dose group (>or=320 mg/day). A Logistic regression model was applied to investigate the outcome variables:death, complications, subsequent lung infection and other infections and COX regression was made. RESULTS: (1) Small dose of steroid seemed to have protective effect, but it did not reach significant level. (2) COX regression revealed that steroid was not related to instant mortality rate. (3) Length of stay in hospital of patients steroid usage in medium dosage seemed to be 0.619 time less risky than in patients without steroid usage (chi (2)=7.262, P=0.007), and that in patients with immunomodulator (including gamma globulin, thymic peptide and interferon) was 0.671 time less risky than in patients without immunomodulator (chi (2)=10.252, P=0.001). (4)Incidence of infections in patients with steroid was 3.095 times higher than in patients without steroid (chi (2)=4.289, P=0.038). CONCLUSION: There is no significant difference in mortality, instant death incidence between steroid treatment and non-steroid treatment group of SARS patients diagnosed with the diagnostic criteria issued by Ministry of Health. However, steroid seem to shorten the length of hospital stay. But attention should be paid that infection rate could be increased in such cases.

[A survey of present situation of general intensive care unit in second grade hospitals and construction of intensive care network in Guangdong province].

OBJECTIVE: To investigate the present situation of general intensive care unit (ICU) in second grade hospitals, and to establish intensive care network for the Department of Public Health of Guangdong province in Guangdong province. METHODS: Data from ICU of 26 hospitals in Guangdong were collected through questionnaire concerning different aspects of critical care medicine. RESULTS: (1) ICU size was (10.12+/-3.82) beds per unit, ratios of doctors to beds and nurses to beds were 0.73+/-0.25 and 1.80+/-0.57 respectively, and proportions of closed model or semi-closed model of ICU management were 69.2% and 26.9% respectively. (2) Area occupied by per bed was (17.57+/-7.58) m2, ratio of basins with infrared control facet to beds was 0.47+/-0.33, proportions of ICU equipped with room equipped with positive or negative air pressure, laminar flow, or with room for preparing nutrition support were 15.4%, 30.8%, and 23.1% respectively. (3) All the ICU were capable of institution and management of artificial airway, mechanical ventilation, placement of deep vein line, cardioversion and defibrillation, parenteral nutrition, and sedation. Ninety-six point two percent of the ICU could accomplish trachea intubation independently. Fifty-three point eight percent of the ICU could perform hemodynamic monitoring. Continuous blood purification could be done in 73.1 % of the ICU. (4) Ninety-six point two percent of the ICU were equipped with continuous bedside multifunctional electrocardiogram monitor and ratio of the monitors to beds was 0.89+/-0.29. Ratios of resuscitation air bags to beds and ventilators to beds were 0.71+/-0.34 and 0.71+/-0.24 respectively. Portable ventilator was equipped in 34.6 % of the ICU. Forty percent of the ICU could not perform non-invasive ventilation, 65.4 % of the ICU were equipped with fiberoptic bronchoscope, blood gas analysis could be done during 24 hours round in 92.3 % of the ICU. (5) Twenty-six ICU investigated were found to be distributed over the district of Zhujiang delta, and east, north and west regions of Guangdong, forming the base of intensive care network in Guangdong province. CONCLUSION: Most of the general ICU in second grade hospitals in Guangdong province have fulfilled the main requirement for ICU in accordance with the guidelines for construction of ICU in Guangdong province and of guidelines for construction and management of ICU in China. The average level of the ICU is close to level II. It is possible for the intensive care network to integrate, the present resources effectively and then enhance the level of treatment of critical illness in the said district.

[Retrospective discriminant analysis of the clinical diagnostic criteria for serious contagious severe acute respiratory syndrome].

OBJECTIVE: To analyze the clinical diagnostic criteria for serious severe acute respiratory syndrome (SARS) in Guangdong retrospectively discriminant with SARS database, and to screen out the sensitive warning factors in predicting the outcome. METHODS: Four hundred and two SARS patients were selected based on the diagnostic criteria for SARS from Ministry of Health, China. Of them, 358 SARS patients were selected as their clinical manifestations conformed to the diagnostic criteria of serious SARS. The study subjects were divided into two groups. One group consisted of the patients with serious SARS (358 patients), and they either underwent invasive or non-invasive mechanical ventilation or died of the disease. The remaining 44 SARS patients constituted the non-serious SARS group. Taking the lowest value of oxygen index (OI) as the main index, the OI was categorized into 3 classes, namely< or =200 mm Hg (1 mm Hg=0.133 kPa) as 1,200-300 mm Hg as 2, and >300 mm Hg as 3. According to this index, the seriousness and the prognosis were analyzed. RESULTS: OI less than 300 mm Hg were identified as the unequivocal serious SARS patients, and the mistake judgement rate was 6.800%. Furthermore mortality and complications were compared with Logistic regression, and questionable SARS patients were excluded. The results showed that the patients identified with OI less than 300 mm Hg had worse outcome than the original ones diagnosed with criteria of Ministry of Health. CONCLUSION: OI less than 300 mm Hg in patients with ALI meet the diagnostic criteria of serious SARS better, and it can be taken as a prognostic criterion in clinic.

[Changes in pulmonary function in severe acute respiratory syndrome patients during convalescent period].

OBJECTIVE: To investigate the changes and pattern of pulmonary function in severe acute respiratory syndrome (SARS) patients during convalescent period. METHODS: Pulmonary function tests were performed in 26 SARS convalescent patients regularly every 3 months after their discharge from hospital. The significance of changes in pulmonary function indexes was analyzed. RESULTS: Restrictive pulmonary ventilation function and diffusing dysfunction of the lung were found in one third of the patients during third to sixth month from onset. There was a little improvement in forced vital capacity (FVC), one second forced expiratory volume (FEV(1.0)), functional residual capacity (FRC) and residual volume (RV) as convalescent period was prolonged, but no difference was found between different stages (3-6 months, 6-9 months, 9-12 months, 12-15 months and 15-17 months). Meanwhile, the FEV(1.0)/FVC showed no significant change. However, there was an obvious improvement in total lung capacity (TLC) and diffusing capacity of the lung for carbon monoxide (DLCO) with the elapse of time, and also a significant difference was found between the later stage and the earlier stage. CONCLUSION: Pulmonary dysfunction is found among some SARS patients after convalescence presenting mainly as restrictive ventilatory function and diffusing capacity abnormality. These dysfunctions would improve gradually with the elapse of time.

[Study of continuous blood purification in severe pneumonia patients with multiple organ failure].

OBJECTIVE: To review retrospectively the effect of continuous blood purification (CBP) on septic shock with acute renal failure and respiratory failure as a result of severe pneumonia, and to analyze its relationship with prognosis. METHODS: Twenty-five patients diagnosed as severe pneumonia with varying degrees of multiple organ failure (MOF), septic shock and anuria, were allocated into three groups based on outcome of the patients A (7 patients), died of progressive worsening of septic shock, (9 patients, yet died of severe pneumonia afterwards). Laboratory data and critical scored of the patients 1 day before and 24, 48, and 72 hours after the initiation of CBP were compared among the three groups. RESULTS: (1) The survival rate in group A was 28%, while the combined fatality in groups B and C was 72%. (2) CBP was forced to be stopped in group B patients within less than 48 hours from the start of treatment. Single-factor analysis suggested: group B exhibited higher level of blood sugar compared with group A [(13.17+/-5.84) mmol/L vs. (8.07+/-2.28) mmol/L, P<0.05], and higher fibrinogen levels compared with group C[(5.75+/-3.08) g/L vs. (3.10+/-1.06) g/L, P<0.05] before the treatment. Forty-eight hours after the initiation of CBP, patients in group B exhibited higher fibrinogen and dopamine levels compared with those of groups A and C [(8.24+/-3.57) g/L vs. (5.13+/-0.94) g/L, (3.01+/-1.22) g/L, P<0.05 and (12.00+/-6.93) microgxkg(-1)xmin(-1) vs. (1.00+/-2.45) microgxkg(-1)xmin(-1), (2.89+/-4.37) microgxkg(-1)xmin(-1), P<0.05, respectively]. (3) Acute physiology and chronic health evaluation III (APACHE III) score of group A before treatment was significantly lower than those in groups B and C (89.43+/-11.28 vs. 108.00+/-15.10 and 104.67+/-13.77, both P<0.05). After 72 hours of CBP treatment, patients in groups A and C showed significantly different changed in APACHE II scores compared with group B (-10.43+/-4.89, -9.11+/-3.76 vs. -2.33+/-4.39, P<0.05) and APACHE III scores (-2.14+/-2.19, -1.00+/-1.87 vs. 0.56+/-1.88, P<0.05). CONCLUSION: (1) CBP is curative for some patients in septic shock with acute renal failure and respiratory failure as a result of severe pneumonia, with and overall survival rate of 28%. (2) APACHE III score is a sensitive index before and after CBP treatment, and scores of 90-100 may be taken as an indication for CBP. (3) High blood sugar and fibrinogen levels may be potential risk factors, in particular, a high fibrinogen level implies a poor prognosis.

[Clinical therapy of severe acute respiratory syndrome: 38 cases retrospective analysis].

OBJECTIVE: To analyze the clinical features and therapy experience of severe acute respiratory syndrome (SARS). METHODS: From December 2002 to April 2003 in Guangzhou Institute of Respiratory Disease, 38 patients with severe SARS were retrospectively studied to evaluate the relationship between treatment strategy and prognosis. RESULTS: Thirty-eight cases of severe SARS were diagnosed. Comprehensive measures most commonly included corticosteroids, antibiotics, antivirotics, nutritional support and mechanical ventilation. Thirty cases were cured (78.9%), of them 11 cases had pulmonary fibrosis (36.7%), 8 patients died (21.1%) in all cases. CONCLUSION: Severe SARS might develop rapidly. In addition to early diagnosis, prompt isolation, and emergency therapy, appropriate use of corticosteroid and noninvasive ventilation should be recommended.