Background: Blood pH and bicarbonate estimations are basal acid-base laboratory tests that are performed in infants with infantile hypertrophic pyloric stenosis (IHPS). This study aimed to define the clinical value of...Background: Blood pH and bicarbonate estimations are basal acid-base laboratory tests that are performed in infants with infantile hypertrophic pyloric stenosis (IHPS). This study aimed to define the clinical value of pCO<sub>2</sub> and BE in infants suspected to have IHPS. Methods: We collected data from 80 “surgical” infants younger than 100 days with prolonged nonbilious vomiting who were suspected to have IHPS. In 65 infants, pyloric stenosis was confirmed, and 15 infants had nonsurgical conditions. Capillary blood was tested for standard acid-base parameters and lactate. The two groups were compared. Results: Eighty-eight percent of the IHPS infants had elevated standard bicarbonate levels (st bicarb) > 25 mmol/l, and 60% had BE > 3.5 mmol/l;12% of the infants showed hypercapnia (pCO<sub>2</sub> ≥ 50 mmHg) associated with markedly increased standard bicarbonate and BE. Infants with nonsurgical vomiting were older at admission (p = 0.002), had a longer duration of vomiting (p < 0.001), were older (p = 0.002) and weighted more at admission (p = 0.004), had lower pCO<sub>2</sub> (p = 0.021), lower st bicarb (p < 0.001) and lower BE (p = 0.001). In addition, nonsurgical infants showed a trend to anemia (p = 0.002). Conclusions: In infants with IHPS/nonbilious vomiting, acid-base analysis (ABA) is equivocal or inconclusive. These findings may be misleading and could result in a false clinical decision. Nonsurgical vomiting is associated with a lower degree of alkalosis, normocapnia to slight hypercapnia and a base deficit. However, even infants with IHPS may present with a negative BE. In infants with IHPS and severe alkalosis, hypercapnia carries a risk for respiratory depression. Monitoring the infant’s respiration allows for the early detection of respiratory deterioration.展开更多
The Stewart approach-the application of basic physicalchemical principles of aqueous solutions to blood-is an appealing method for analyzing acid-base disorders. These principles mainly dictate that p H is determined ...The Stewart approach-the application of basic physicalchemical principles of aqueous solutions to blood-is an appealing method for analyzing acid-base disorders. These principles mainly dictate that p H is determined by three independent variables, which change primarily and independently of one other. In blood plasma in vivo these variables are:(1) the PCO2;(2) the strong ion difference(SID)-the difference between the sums of all the strong(i.e., fully dissociated, chemically nonreacting) cations and all the strong anions; and(3) the nonvolatile weak acids(Atot). Accordingly, the p H and the bicarbonate levels(dependent variables) are only altered when one or more of the independent variables change. Moreover, the source of H+ is the dissociation of water to maintain electroneutrality when the independent variables are modified. The basic principles of the Stewart approach in blood, however, have been challenged in different ways. First, the presumed independent variables are actually interdependent as occurs in situations such as:(1) the Hamburger effect(a chloride shift when CO2 is added to venous blood from the tissues);(2) the loss of Donnan equilibrium(a chloride shift from the interstitium to the intravascular compartment to balance the decrease of Atot secondary to capillary leak; and(3) the compensatory response to a primary disturbance in either independent variable. Second, the concept of water dissociation in response to changes in SID is controversial and lacks experimental evidence. In addition, the Stewart approach is not better than the conventional method for understanding acid-base disorders such as hyperchloremic metabolic acidosis secondary to a chloride-rich-fluid load. Finally, several attempts were performed to demonstrate the clinical superiority of the Stewart approach. These studies, however, have severe methodological drawbacks. In contrast, the largest study on this issue indicated the interchangeability of the Stewart and conventional methods. Although the introduction of the Stewart approach was a new insight into acid-base physiology, the method has not significantly improved our ability to understand, diagnose, and treat acid-base alterations in critically ill patients.展开更多
Objective: The traditional approach for acid base interpretation is based on Handerson-Hasselbalch formula and includes Base Excess (BE), bicarbonate (HCO3), albumin corrected anion gap. The Physicochemical approach i...Objective: The traditional approach for acid base interpretation is based on Handerson-Hasselbalch formula and includes Base Excess (BE), bicarbonate (HCO3), albumin corrected anion gap. The Physicochemical approach is centered on the Carbon Dioxide tension (PCO2), the strong ion difference (SID), strong ion gap (SIG) = SID apparent-SID effective and totally weak acids (Atot). The study aims to compare between the traditional approach and the physicochemical approach in acid base disorder interpretation. Design: Prospective observational study in an adult Intensive Care Unit (ICU) recruiting six hundred and sixty one patients. Methods: Arterial blood samples were analyzed to measure pH, PaCO2 sodium, potassium, chloride and lactate. Venous blood samples were analyzed to measure ionized calcium, magnesium, phosphorous and albumin. These samples were interpreted by both techniques. Results: Normal HCO3 and BE were detected by traditional approach in 49 cases of which SIG acidosis was detected in 22 cases (46%) and Hyperchloremic acidosis was detected in 29 cases (60%) by physicochemical method. SIG was elevated in 72 cases (58%) of 124 cases with high anion gap acidosis. SIDeff and BE were strongly correlated, r = 0.8, p 0.0001, while SIG and Albumin corrected Anion Gap (ALAG) were moderately correlated r = 0.56, p Conclusion: Both approaches are important for interpretation of the acid base status. Traditional approach identifies the diagnostic description without many calculations and detects body compensatory response to acid base disorders. Physicochemical approach is essential to identify the exact causation and the severity of the acid base disorders.展开更多
Introduction The formation of gelatin-containing mieroemulsionbased gels（MBGs） was first described in 1986 and the physical/structural characterization was carried out by a number of groups with a variety of techni...Introduction The formation of gelatin-containing mieroemulsionbased gels（MBGs） was first described in 1986 and the physical/structural characterization was carried out by a number of groups with a variety of techniques including tracer diffusion, electrical conductivity, NMR, X-ray and small angle neutron scattering. The MBGs were proposed to comprise an extensive, rigid, interconnected network of gelatin/water rods stabilized by a monolayer of surfactant, in coexistence with a po- pulation of conventional W/O microemulsion droplets.展开更多
文摘Background: Blood pH and bicarbonate estimations are basal acid-base laboratory tests that are performed in infants with infantile hypertrophic pyloric stenosis (IHPS). This study aimed to define the clinical value of pCO<sub>2</sub> and BE in infants suspected to have IHPS. Methods: We collected data from 80 “surgical” infants younger than 100 days with prolonged nonbilious vomiting who were suspected to have IHPS. In 65 infants, pyloric stenosis was confirmed, and 15 infants had nonsurgical conditions. Capillary blood was tested for standard acid-base parameters and lactate. The two groups were compared. Results: Eighty-eight percent of the IHPS infants had elevated standard bicarbonate levels (st bicarb) > 25 mmol/l, and 60% had BE > 3.5 mmol/l;12% of the infants showed hypercapnia (pCO<sub>2</sub> ≥ 50 mmHg) associated with markedly increased standard bicarbonate and BE. Infants with nonsurgical vomiting were older at admission (p = 0.002), had a longer duration of vomiting (p < 0.001), were older (p = 0.002) and weighted more at admission (p = 0.004), had lower pCO<sub>2</sub> (p = 0.021), lower st bicarb (p < 0.001) and lower BE (p = 0.001). In addition, nonsurgical infants showed a trend to anemia (p = 0.002). Conclusions: In infants with IHPS/nonbilious vomiting, acid-base analysis (ABA) is equivocal or inconclusive. These findings may be misleading and could result in a false clinical decision. Nonsurgical vomiting is associated with a lower degree of alkalosis, normocapnia to slight hypercapnia and a base deficit. However, even infants with IHPS may present with a negative BE. In infants with IHPS and severe alkalosis, hypercapnia carries a risk for respiratory depression. Monitoring the infant’s respiration allows for the early detection of respiratory deterioration.
文摘The Stewart approach-the application of basic physicalchemical principles of aqueous solutions to blood-is an appealing method for analyzing acid-base disorders. These principles mainly dictate that p H is determined by three independent variables, which change primarily and independently of one other. In blood plasma in vivo these variables are:(1) the PCO2;(2) the strong ion difference(SID)-the difference between the sums of all the strong(i.e., fully dissociated, chemically nonreacting) cations and all the strong anions; and(3) the nonvolatile weak acids(Atot). Accordingly, the p H and the bicarbonate levels(dependent variables) are only altered when one or more of the independent variables change. Moreover, the source of H+ is the dissociation of water to maintain electroneutrality when the independent variables are modified. The basic principles of the Stewart approach in blood, however, have been challenged in different ways. First, the presumed independent variables are actually interdependent as occurs in situations such as:(1) the Hamburger effect(a chloride shift when CO2 is added to venous blood from the tissues);(2) the loss of Donnan equilibrium(a chloride shift from the interstitium to the intravascular compartment to balance the decrease of Atot secondary to capillary leak; and(3) the compensatory response to a primary disturbance in either independent variable. Second, the concept of water dissociation in response to changes in SID is controversial and lacks experimental evidence. In addition, the Stewart approach is not better than the conventional method for understanding acid-base disorders such as hyperchloremic metabolic acidosis secondary to a chloride-rich-fluid load. Finally, several attempts were performed to demonstrate the clinical superiority of the Stewart approach. These studies, however, have severe methodological drawbacks. In contrast, the largest study on this issue indicated the interchangeability of the Stewart and conventional methods. Although the introduction of the Stewart approach was a new insight into acid-base physiology, the method has not significantly improved our ability to understand, diagnose, and treat acid-base alterations in critically ill patients.
文摘Objective: The traditional approach for acid base interpretation is based on Handerson-Hasselbalch formula and includes Base Excess (BE), bicarbonate (HCO3), albumin corrected anion gap. The Physicochemical approach is centered on the Carbon Dioxide tension (PCO2), the strong ion difference (SID), strong ion gap (SIG) = SID apparent-SID effective and totally weak acids (Atot). The study aims to compare between the traditional approach and the physicochemical approach in acid base disorder interpretation. Design: Prospective observational study in an adult Intensive Care Unit (ICU) recruiting six hundred and sixty one patients. Methods: Arterial blood samples were analyzed to measure pH, PaCO2 sodium, potassium, chloride and lactate. Venous blood samples were analyzed to measure ionized calcium, magnesium, phosphorous and albumin. These samples were interpreted by both techniques. Results: Normal HCO3 and BE were detected by traditional approach in 49 cases of which SIG acidosis was detected in 22 cases (46%) and Hyperchloremic acidosis was detected in 29 cases (60%) by physicochemical method. SIG was elevated in 72 cases (58%) of 124 cases with high anion gap acidosis. SIDeff and BE were strongly correlated, r = 0.8, p 0.0001, while SIG and Albumin corrected Anion Gap (ALAG) were moderately correlated r = 0.56, p Conclusion: Both approaches are important for interpretation of the acid base status. Traditional approach identifies the diagnostic description without many calculations and detects body compensatory response to acid base disorders. Physicochemical approach is essential to identify the exact causation and the severity of the acid base disorders.
基金Supported by the Natural Science Foundation of Shandong Province in China(No.Y2003B01).
文摘Introduction The formation of gelatin-containing mieroemulsionbased gels（MBGs） was first described in 1986 and the physical/structural characterization was carried out by a number of groups with a variety of techniques including tracer diffusion, electrical conductivity, NMR, X-ray and small angle neutron scattering. The MBGs were proposed to comprise an extensive, rigid, interconnected network of gelatin/water rods stabilized by a monolayer of surfactant, in coexistence with a po- pulation of conventional W/O microemulsion droplets.
文摘目的探讨乳酸清除率联合碱剩余对严重脓毒症目标性治疗效果及预后评估的价值。方法回顾性分析天津医科大学第二医院ICU2006年1月至2009年1月临床资料完整的60例严重脓毒症患者,根据28 d转归分为生存组38例,死亡组22例,比较目标性治疗6 h后生存组与死亡组患者乳酸、碱剩余、乳酸清除率、6 h和48 h急性生理学与慢性健康状况评分系统Ⅱ(APACHEⅡ)评分,将目标性治疗6 h后碱剩余及乳酸清除率与48 h APACHEⅡ评分进行相关分析。结果经目标性治疗6 h后生存组患者乳酸清除率明显高于死亡组(P<0.05),碱剩余亦明显高于死亡组(P<0.05),而血乳酸和入院6 h APACHEⅡ评分生存组与死亡组无统计学意义(P>0.05),6 h的碱剩余及乳酸清除率与48 h APACHEⅡ评分均具有相关性(P<0.05)。结论乳酸清除率联合碱剩余可以评估严重脓毒症目标性治疗的疗效和判断预后。
