The prognostic value of continuous dynamic monitoring of intrapulmonary shunt in patients with acute respiratory distress syndrome / 中华危重病急救医学

Objective To investigate the predictive value of continuous dynamic monitoring of intrapulmonary shunt (Qs/Qt) in patients with acute respiratory distress syndrome (ARDS).Methods A prospective observational study was conducted.The adult patients with ARDS undergoing mechanical ventilation admitted to intensive care unit (ICU) of Tianjin Third Central Hospital from June 2014 to December 2015 were enrolled.Baseline characteristics,demographic data and relevant physiologic data were recorded.All patients were divided into survivors and non-survivors according to the outcome of patients within 28 days.Artery and mixed venous blood was collected immediately after admission for blood gas analysis,and daily Qs/Qt within 7 days was continuously monitored in ARDS patients.The receiver operating characteristic curve (ROC) was used to evaluate the prognosis accuracy of Qs/Qt.Results In 46 enrolled ARDS patients,20 died,and 26 survived.During the first 7 days of ARDS,the mean Qs/Qt in survivors showed an increasing tendency [(23 ± 6)％,(27 ± 6)％,(28 ± 9)％,respectively,at 1-3 days] and a downtrend tendency from 4 days [(27 ± 5)％,(25 ± 4)％,(19 ± 4)％,(16 ± 2)％,respectively,at 4-7 days].However,a rising tendency of Qs/Qt in non-survivors was found at 1-7 days [(28 ± 7)％,(30 ± 3)％,(33 ± 6)％,(33 ± 11)％,(34 ± 5)％,(33 ± 6)％,(35 ± 6)％,respectively],and Qs/Qt from the 5th day in non-survivors was significantly higher than that in survivors (all P ＜ 0.05).The fluctuation of oxygenation index (PaO2/FiO2) within 1 week in both groups was small,and PaO2/FiO2 (mmHg,1 mmHg =0.133 kPa) at 1-7 days in survivors was 167.37±43.98,180.55±39.90,174.27±35.47,188.64±39.74,252.54±49.22,239.35±25.63,248.93±45.64,respectively,and it was 168.65±35.54,182.31 ± 32.36,159.80 ± 34.39,176.97 ± 31.75,200.69 ± 45.33,185.98 ± 36.47,and 175.43 ± 30.98 in non-survivors respectively.PaO2/FiO2 was significantly lower in non-survivors than survivors from 5 days (all P ＜ 0.05).It was shown by ROC curve that area under ROC curve (AUC) for Qs/Qt evaluating the prognosis on the 5th day was 0.958,and 95％ confidence interval (95％CI) was 0.777-0.999 (P ＜ 0.000 1,Z =13.13).When the cut-off value of Qs/Qt was 28％,sensitivity and specificity were 83.3％ and 90.0％,respectively.AUC for PaO2/FiO2 evaluating the prognosis on the 5th day was 0.790,and 95％CI was 0.577-0.928 (P =0.002 1,Z =3.08).When the cut-off value of PaO2/FiO2 was 223 mmHg,sensitivity and specificity were 69.2％ and 81.8％,respectively.Conclusion Dynamic Qs/Qt surveillance can help physician to analyze the changes of the patient's condition,and it was better than PaO2/FiO2,and can be an important evaluation indicator of prognosis for ARDS patients.

Exercise-Induced Intrapulmonary Arteriovenous Shunt in a Patient Complaining of Dyspnea during Strenuous Exercise

A 51-year-old highly fit man presented for dyspnea with strenuous aerobic exercise. The patient was asymptomatic and all tests were normal at rest. With increasing exercise intensity, he suddenly complained of dyspnea and showed a severe exercise-induced hypoxemia with an excessive alveolar-arterial oxygen tension difference. In agitated saline contrast echocardiography at peak exercise, a large amount of left to right shunt was identified after > 5 cardiac cycles, which suggests the presence of exercise-induced intrapulmonary arteriovenous shunt in this patient.

The effect of sevoflurane pretreatment or aftertreatment on intrapulmonary shunt for patients with one lung ventilation during thoracic surgical procedures / 重庆医学

Objective To study the effect of sevoflurane pretreatment or aftertreatment on intrapulmonary shunt for patients with one lung ventilation(OLV)during thoracic surgical procedures .Methods 80 ASA I or II patients underwent thoracic surgery with OLV were randomly divided into four groups(n= 20 for each):(1)Propofol group(group P);(2)Sevoflurane pretreatment group(group S1);(3)Sevoflurane aftertreatment group(group S2);(3)Sevoflurane whole-treatment group(group S3) .Blood sam-ples were taken from radial artery and right atrial blood before induction of anesthesia(baseline T .0) ,before OLV(sevoflurane pre-treatment 30 min ,T1) ,after OLV 30 ,60 min and before the end of OLV(T2-T4)and after the end of OLV(T5)for measurement of blood gases and calculation of Qs/Qt .The indexs of hemodynamics and relative clinical data were recorded .Results Arterial oxy-gen pressure of the four groups for OLV significantly reduced ,when compared with double lung ventilation(P0 .05) .Intrapulmonary shunt of the four groups for OLV significantly in-creased ,when compared with double lung ventilation(P 0 .05) .Conclusion Sevoflurane can decrease intrapulmonary shunt for patients during OLV ,but there is no significant difference for pretreatment or af-tertreatment or whole treatment and do not increase arterial oxygen pressure .

Effects of dexmedetomidine on intrapulmonary shunt and inflammatory response in patients with one lung ventilation / 中国医师进修杂志

[Objective]To explore the effects of dexmedetomidine on intrapulmonary shunt and inflammatory response in patients with one lung ventilation(OLV).[Methods] Fifty-six patients scheduled for radical resection of esophageal cancer were divided by random digits table method into dexmedetomidine group and control group with 28 cases each.Serum levels of interleukin(IL)-6,IL-8,tumor necrosis factor alpha(TNF- α)before openiαg the chest(To),at 30 min(T1)and 90 min(T2)after OLV,at 6 h(T3)and 24h(T4)after operation were detected and the intrapulmonary shunt fraction(Qs/Qt)was calculated.[Results]Compared with T0,serum levels ofTNF- α,IL-6 and IL-8 increased in both groups at T1-T4[dexmedetomidine group:(30.4 ± 4.7),(51.6 ± 7.8),(81.6 ± 7.6),(127.2 ± 16.8)ng/L vs.(19.7 ± 3.8)ng/L;(17.9 ± 4.4),(37.1 ± 9.6),(89.6 ± 12.9),(78.9 ± 13.1)ng/L vs.(15.0 ± 2.9)ng/L;(14.9 ± 2.2),(19.8 ± 3.3),(36.2 ±4.0),(35.8 ± 6.5)ng/L vs.(7.6 ± 1.4)ng/L;control group:(33.6 ±3.9),(79.8 ± 6.3),(101.5 ± 10.2),(145.3 ± 17.3)ng/L vs.(18.2 ±3.4)ng/L;(21.6 ±5.3),(46.9 ± 10.2),(112.5 ± 13.6),(106.2 ± 15.6)ng/L vs.(15.3 ±2.8)ng/L;(16.1 ±2.8),(26.3 ±4.7),(47.6 ±5.1),(40.2 ±6.2)ng/L vs.(8.3 ±2.0)ng/L],which had significant differences(P ＜ 0.01).There were statistical significance in the levels of TNF- α,IL-6 and IL-8 at T2-T4 between two groups(P ＜ 0.05).However,there was no statistical difference in Qs/Qt between two groups(P ＞ 0.05).[Conclusions] Perioperative continuous infusion of dexmedetomidine can reduce the inflammatory responses to a certain extent during OLV.But it has no obvious effects on intrapulmonary shunt.

Pathogenisis of hepatopulmonary syndrome / 国际外科学杂志

Hepatopulmonary syndrome is the triad of arterial hypoxemia due to pulmonary vascular dilatation induced by liver diseases.The pathogenis' s is complicated.This article reviews the advances of pathogenisis of the disease.

Effects of tidal volume on arterial oxygenation and intrapulmonary shunt during one lung ventilation / 临床麻醉学杂志

Objective To investigate the effects of different tidal volume (V_T) on arterial oxygenation and intrapulmonary shunt(Q_S/Q_T) during one lung ventilation(OLV).Methods Sixty patients scheduled for selective lobectomy under left lateral decubitus position were randomly divided into groups of A,B and C with 20 cases each.After bronchial induction,two lung ventilation(TLV) was performed with V_T 10 ml/kg,frequency(f) 12 breaths per minute(BPM),ratio of inspiration to expiration(I: E) was 1:2 at first.During OLV,I: E was kept steady,V_T 6 ml/kg and f 20 BPM were chosed in group A,V_T8 ml/kg and f 15 BPM in group B,V_T 10ml/kg,f 12 BPM in group C.Blood gas analysis was determined before OLV (T_1) and at 10 min(T_2) ,20 min(T_3) ,and 30 min after OLV (T_4).Q_S/Q_T and lung complience(Cdyn) was calculated.Results OLV Compaired to T_1,PaO_2 and Cdyn were lower (P<0.05) and Q_S,Q_T and peak airway pression were increased (P<0.05).The decrease of PaO_2 was more in groups of A and C than that in group B(P<0.05).Conclusion During OLV,a better PaO_2.may be maintained with the ventilation parameters of V_T8 ml/kg and f 15 BPM with less increase in Q_S/Q_T and higher Cdyn.

Anesthetic Care for a Patient with a Pulmonary Arteriovenous Malformation Undergoing Brain Abscess Removal and Pulmonary Lobectomy: A case report / 대한마취과학회지

The serious complications of pulmonary arteriovenous malformation (PAVM) are hypoxia, dyspnea, hemothorax, cerebrovascular accident, and brain abscess due to an intrapulmonary right to left shunt. We report no anesthetic complications intraoperatively or postoperatively in a 40-year-old male with PAVM who underwent brain abscess removal and pulmonary lobectomy without specific invasive monitoring.

Change of Intrapulmonary Shunt after Liver Transplantation in Irreversible Acute or Chronic Liver Diseases

BACKGROUND AND OBJECTIVES: The intrapulmonary shunt, after a liver transplantation, is expected to improve, but the frequency, and predictors, of improvement are not well known. We studied the frequency of the improvement in the intrapulmonary shunt, and the relation between this improvement and the clinical parameters, using contrast echocardiography in liver transplant candidates. SUBJECTS AND METHODS: Preoperative and postoperative contrast echocardiography, with intravenous agitated saline, was performed in 25 liver transplant candidates(M:F=9:6, mean age=6+/-10). The extent of the intrapulmonary shunt was semi-quantitatively assessed on a grade scale from 0 to 4+, according to the degree of appearance of the contrast in the left heart chambers. The etiology of the underlying chronic liver disease, Child-Pugh classification scores, pulmonary function tests and arterial blood gas analyses were all evaluated. The change in the shunt grade after the liver transplantation, and the association of these changes, with clinical parameters, were also evaluated. RESULTS: Twenty-four(6%) f the 25 patients showed positive results for the intrapulmonary shunt on preoperative contrast echocardiography. At follow up, the shunt was visible in only 5(1%) atients. All 24 patients whose preoperative echocardiography revealed a positive intrapulmonary shunt showed an improvement in the intrapulmonary shunt after the liver transplantation. There was a significant correlation between the improvements in the shunt and the Child-Pugh classification scores(r=0.59, p=0.02). CONCLUSION: Contrast echocardiography is a feasible, noninvasive, method for the detection of changes in the intrapulmonary shunt before and after a liver transplantation, and the intrapulmonary shunt is improved after a liver transplantation in most patients.

Alterations of the Ventilation-Perfusion Ratio Measured by Using a Multiple Inert Gas Elimination Technique (MIGET) in One Lung Ventilated Rabbit / 대한마취과학회지

BACKGROUND: In this study, we performed one-lung ventilation (OLV) in rabbits to assess the effects of OLV on the VA/Q ratio and the respiratory physiological changes using MIGET. METHODS: Ten male New Zealand white rabbits, weighing 3-4 kg were selected. To perform MIGET, six inactive gases (SF6, krypton, desflurane, enflurane, diethyl ether, acetone) in 500 ml normal saline were injected intravenously. During two-lung ventilation (TLV), and after OLV for 30 minutes, blood was sampled for blood gas analysis and MIGET, hemodynamic variables were measured. For MIGET, the concentrations of the injected inert gases were measured and converted to retention/excretion data; the VA/Q distribution curve was obtained using a computer. RESULTS: Systolic, mean, and diastolic pulmonary pressures were elevated significantly and pulmonary resistance was doubled (P<0.05) in OLV compared to TLV. Blood pH decreased in OLV. The calculated intrapulmonary shunt was 19% and 52%, TLV and OLV, respectively. The analysis of VA/Q using MIGET showed that the VA/Q distribution curve was wider and that the VA/Q area was larger in normal rabbits. And, that intrapulmonary shunt approximated to 11%. In the case of OLV, a significant increase in shunt was observed but no change in the amount of dead space at distribution area, (log SDQ, log SDV) remained the same, whereas the VA/Q distribution curve shifted toward the right. CONCLUSIONS: OLV in rabbits showed severe hypercapnia and hypoxemia leading to a considerable increase in shunt. Because of the wide range of VA/Q distribution in TLV, no significant changes in respiratory variables were observed during OLV.

Prevalence and Risk Factors of Significant Intrapulmonary Shunt in Cirrhotic patients awaiting liver transplantation / 대한간학회지

BACKGROUNDS/AIMS: Hepatopulmonary syndrome is a condition of severe hypoxia with intrapulmonary shunt (IPS) in the setting of hepatic dysfunction. Liver transplantation has been suggested as a definite treatment for hepatopulmonary syndrome with reversal of IPS in some patients. Inconsistency of response and inability to predict reversibility, however, are significant problems. We performed this study to evaluate the prevalence of significant IPS in pretransplantation cirrhotic patients and to find any risk factors of IPS. METHODS: Fifty-seven patients (M:F = 38:19, median age 49 years (range 18 - 71)) with liver cirrhosis awaiting liver transplantation were serially included. Their IPS status was evaluated using contrast- enhanced echocardiography. Significant shunt was defined as a shunt of grade >or= 2. RESULTS: Significant IPS was detected in 30 (52.6%) among 57 patients. Significant shunt was found in 24 (63.2%) of 38 Child-Pugh class C patients and in 6 (31.6%) of 19 Child-Pugh class A or B patients (p < 0.05). No significant difference in prevalence of significant shunt was seen according to age, sex, presence or absence of hepatocellular carcinoma, ascites, hepatic encephalopathy, and gastroesophageal varix. CONCLUSION: Significant intrapulmonary shunt is a common finding in cirrhotic patients awaiting liver transplantation. Child-Pugh class C is the risk factor associated with high prevalence of significant shunt.

Frequency and Clinical Significance of Intrapulmonary Shunt in Liver Cirrhosis; Detection by Contrast Echocardiography / 대한내과학회지

OBJECTIVES: Intrapulmonary vascular abnormalities resulting in right-to-left shunt have been described in patients with severe liver disease, especially advanced hepatic cirrhosis. They result in hypoxemia which is associated with liver cirrhosis without preexisting cardiac or pulmonary diseases. Since Rydell and Hoffbauer first described intrapulmonary shunt in a cirrhotic patient in 1956, it has been reported recently that 13 to 47 percent of the end-stage hepatic disease patients have these intrapulmonary vascular abnormalities. Contrast echocardiography(CE) has been proved useful in detecting intrapulmonary shunt. The aim of the study is to determine the prevalence of intrapulmonary shunt by CE in patients with hepatic cirrhosis, and to compare the clinical characteristics of those with and without evidence of intrapulmonary shunt. METHODS: We performed CE studies in 24 stable cirrhotic patients without the evidence of severe complications such as massive ascites, upper GI bleeding, and hepatic coma. Clinical information including symptom and sign, results of liver and pulmonary function tests, and arterial blood gas values measured both at the supine and erect position, were analyzed in each group of patients with or without intrapulmonary shunt. RESULTS: Positive CE suggesting intrapulmonary shunt was found in 8 of 24 patients(33.3%). However the degree of relative opacifications were one positive(1+) in all 8 patients, and hypoxemia and its related symptom and sign appeared to be rare. Any of the parameters of liver and pulmonary function test did not show the significant difference between CE-positive and CE-negative group. CONCLUSION: Only the presence of spider angioma was associated with intrapulmonary shunt among the several clinical signs, which suggests common pathogenesis of both vascular abnormalities.

Influence of sitting position on pulmonary hemodynamics and intrapulmonary shunt in neurosurgery / 中华麻醉学杂志

Objective To study the effects of sitting position on pulmonary hemodynamics and intrapulmonary shunt (Qs/Qt) during neurosurgery. Methods Twenty eight patients scheduled for posterior fossa and posterior cervical spinal surgery, were anesthetized with sevoflurane fentanyl pancuronium or enflurane fentanyl pancuronium after intravenous induction. Pulmonary hemodynamics were monitored with Swan Ganz catheter technique and Qs/Qt was calculated from the data of arterial and mixture venous blood gas analysis, including the following parameters: CI, RAP, MPAP, PCWP, PVRI, pHa, PaCO 2, PaO 2, PaO 2/FiO 2 and Qs/Qt. The detection time points were as the follow: before anesthesia induction, before sitting position, immediately ,60 min and 120min after sitting position, and at the supine position after termination of surgery.Results After induction of anesthesia and during operation at sitting position, CI decreased significantly (P0.05).Conclusions During neurosurgical procedure under general anesthesia and sitting position, pulmonary vascular auto regulation can be preserved and pulmonary oxygenation can be kept in normal.

Effects of Sodium Nitroprusside and Nitroglycerin on the Arterial Blood Oxygenation during Cross - Clamping of Descending Aorta in Dogs / 대한마취과학회지

Sodium nitroprusside(SNP) and nitroglycerin(NTG) have been used as one of the adjuvants that can modify the hemodynamie changes during cross-clamping of thoraco-abdominal aortic surgery. Cardiovascular changes after cross-clamping of aorta were well studied, but the respiratory effects of cross-clamping of aorta were not well defined. And both vasodilators are known to increase the intrapulmonary shunt when administered during anesthesia. So we have evaluated the effects on the arterial oxygenation of combination therapy of SNP and NTG over single use of SNP during cross-clamping of aorta in 12 dogs which anesthetized by halothane. After completion of anesthesia and preparation for cross-clamping of aorta was done at 10 cm distal to left subclavian artery through thoracotomy at 6th intercostal space. In control group, no drug was administered. In SNP group(2.5ug/kg/min) and SNP+NTG group(8 pg/kg/min), the drugs were administered before and after cross-clamping of descending thoracic aorta in each group for 45 minutes. The hemodynamic parameters were measured before aortic eross-clamping and at 1, 15, 30, 45 minutes after aortic cross-clamping. Results were follows, 1) Arterial oxygen tensions were decreased significantly only at 45 minutes after cross-clamping of aorta in SNP+NTG group(P<0.05) and no significant difference between SNP group and SNP+NTG group. 2) Intrapulmonary shunt was increased significantly at l5 minutes after cross clamping in SNP+NTG group(P<0.05), but not significant difference between NTG group and SNP+NTG group. 3) PCWP was significantly decreased at 15, 30, 45 minutes after cross-clamping in SNP and SNP+NTG group compared to control group(P<0.05), but not significant difference between SNP group and SNP+NTG group. 4) PVR were decreased significantly at 15, 30 minutes after cross-clamping of aorta in SNP+ NTG group compared to control group(P<0.05). But there was no significant diffrence between SNP group and SNP+ NTG group. 5) CI were increased at 45 minutes after aortic cross-clamping in SNP group and at 15, 30, 45 minutes after aortic cross-clamping in SNP+NTG groupg<0.05). But there was no significant difference between SNP and SNP+NTG group. These results showed that sodium nitroprusside did not affect the arterial oxygenation during cross-clamping of thoracic aorta and combination use of sodium nitroprusside and nitroglycerin had no additional risk of increasing arterial hypoxemia.

The Effets of Independent Lung Ventilation with Unilateral HFJV and CPAP / 대한마취과학회지

The effects of oxygenation of differential independent lung ventilation using HFJV (High Frequency Jet Ventilation) and CPAP (Continuous Positive Airway Pressure) on PaO2 and Qs/Qt were studied during one lung anesthesia in 11 mongrel dogs in left semilateral position with pentobarbital anesthesia. The dogs were divided into two groups. In group A(N = 7), following the conventional two lung ventilation, one lung ventilation, HFJV, one lung ventilation, cpap 5 cmH2O, and CPAP 10 cmH20 were applied sequentially. In group B(N =4), following the conventional two lung ventilation the above applications were reversed. In group A PaO2 revealed a similar increase among a two lung ventilation, CPAP 5 cmH2O, CPAP 10 cmH2O and HFJV. Intrapulmonary shunt showed the similar decrease among two lung ventilation, HFJV and CPAP 10cmH2O, but CPAP 5 cmH2O was higher than CPAP 10cmH2O. Although there were no statistically significant differences in PaO2 and shunt among each step in group B, HFJV showed a greate increase in PaO2, and shunt than one lung ventilation, CPAP 5 cmH 20) 20, and CPAP 10 cmH2O. In conclusion, HFJV proved to be more effective than CPAP 5 cmH2O in increasing PaO2 and decreasing shunt in differential independent lung ventilation. Both CPAP and JFJV should be applied in the deflation phase of the nondependent lung to cause an effective increase in PaO2. HFFV proved to be more effective than CPAP in recruiting the small airway closure.

The Effects of Clonidine on the Hemodynamics and Intrapulmonary Shunting during Sodium Nitroprusside Hypotension under Halothane-N2O-O2 Anesthesia / 대한마취과학회지

Supplementation of antihypertensive action of sodium nitroprusside (SNP) is almost standard practice and should obviate the need for potentially toxic doses to control blood pressure. Clonidine, an antihypertensive agent known to reduce sympathetic outfiow via alpha2-adrenergic receptor stimulation, has been shown to decrease MAC of halogenated agent, and to reduce the amount of SNP required to reduce the desired hypotension. To determine the effects of clonidine on the hemodynamics and intrapulmonary shunting during SNP infusion, clonidine and/or SNP were administered to 22 patients anesthetized with halothane-N2, O-O2 (FIO2:0.5) In one group of 11 patients, clonidine 1.5ug/kg was injected intravenously. In another group of 11 patients, clonidine 1.5 ug/kg was injected intravenously 30 minutes after starting the SNP infusion (3 ug/kg/min). The results were as follows. 1) Clonidine alone produced a small decrease in MAP (10%) and CI (8%) but other hemodynamic values remained unaltered. 2) Arterial oxygen tension and intrapulmonary shunting was not changed by clonidine. 3) Heart rate (15%) was increased , but MAP (29%), MPAP (24%), PCWP (25%), CVP (32% ), SVR (29%)and PVR(24%) were decreased significantly, and CI, SVI remained unchanged during SNP hypotension. 4) SNP caused a significant increase in intrapulmonary shunt fraction from 8.62% to 10.58% and a decrease in PaO2. 5) In group of clonidine under SNP infusion, conidine did not significantly affect the hemodynamic response to SNP except for 15% decrease in BP. 6) Clonidine caused no significant change on gas exchange effect of SNP. These results indicate that clonidine did not significantly affect the hemodynamics and intrapul-monary shunting during SNP hypotension. Therefore, clonidine could be used as a valuable adjuvant for reducing the amount of SNP and decreasing MAC of halothane.