Evaluation of i-STAT CHEM8+ Point-of-Care Chemistry Analyzer

BACKGROUND: We evaluated the analytical performance of the Abbott i-STAT CHEM8+, a point-of-care testing system that measures 8 basic chemical analytes, namely, sodium, potassium, chloride, total carbon dioxide, BUN, creatinine, glucose, and ionized calcium. METHODS: The precision and linearity of 8 analytes were evaluated according to the CLSI guidelines EP15-A and EP6-A, respectively, using standard material provided by the manufacturer. i-STAT CHEM8+ and other primary methods (e.g. Hitachi Clinical Analyzer 7600 for 7 analytes, Nova CCX for ionized calcium) were also compared according to the CLSI guideline EP9-A2, using 113 patient samples. RESULTS: The standard deviation (SD) of within-run and total precision of 7 analytes except chloride was within the claimed SD or within the verification value. The coefficient of variation of total precision of 7 analytes except creatinine was within 2%. With regard to linearity, all 8 analytes showed first-order equation or at least no statistical difference with the first-order equation. We observed that the efficiency of i-STAT CHEM8+ was comparable to that of primary methods, and that this method has potential applications in the clinical laboratory. CONCLUSIONS: i-STAT CHEM8+ showed good precision and linearity, and an efficiency comparable to that shown by routine chemistry analyzers; thus, it has potential applications in the clinical laboratory. It can provide much faster results and relatively accurate value to clinicians in need of immediate results, such as in an emergency unit or in the intensive care unit.

Evaluation of i-STAT CHEM8+ Point-of-Care Chemistry Analyzer

BACKGROUND: We evaluated the analytical performance of the Abbott i-STAT CHEM8+, a point-of-care testing system that measures 8 basic chemical analytes, namely, sodium, potassium, chloride, total carbon dioxide, BUN, creatinine, glucose, and ionized calcium. METHODS: The precision and linearity of 8 analytes were evaluated according to the CLSI guidelines EP15-A and EP6-A, respectively, using standard material provided by the manufacturer. i-STAT CHEM8+ and other primary methods (e.g. Hitachi Clinical Analyzer 7600 for 7 analytes, Nova CCX for ionized calcium) were also compared according to the CLSI guideline EP9-A2, using 113 patient samples. RESULTS: The standard deviation (SD) of within-run and total precision of 7 analytes except chloride was within the claimed SD or within the verification value. The coefficient of variation of total precision of 7 analytes except creatinine was within 2%. With regard to linearity, all 8 analytes showed first-order equation or at least no statistical difference with the first-order equation. We observed that the efficiency of i-STAT CHEM8+ was comparable to that of primary methods, and that this method has potential applications in the clinical laboratory. CONCLUSIONS: i-STAT CHEM8+ showed good precision and linearity, and an efficiency comparable to that shown by routine chemistry analyzers; thus, it has potential applications in the clinical laboratory. It can provide much faster results and relatively accurate value to clinicians in need of immediate results, such as in an emergency unit or in the intensive care unit.

The Effects of Normocapnia and Hypercapnia on Venous Oxygen Saturation and Lactate Levels at the Jugular Bulb during Rewarming from Hypothermic Cardiopulmonary Bypass / 대한마취과학회지

BACKGROUND: Neurologic and neuropsychologic dysfunction after cardiopulmonary bypass is frequent and can be caused by inadequate cerebral perfusion and oxygenation. A decrease of SjvO2 suggests a situation in which the oxygen supply to the brain is insufficient to meet metabolic demands. This study investigated the effects of normocapnia and hypercapnia on changes in SjvO2 and lactate levels during rewarming from hypothermic cardiopulmonary bypass. METHODS: Anesthesia was induced and maintained with bolus and continuous infusion of fentanyl, midazolam and vecuronium. Patients were assigned to a normocapnic (PaCO2: 35 - 40 mmHg, n = 10) or hypercapnic (PaCO2: 45 50 mmHg, n = 10) group during rewarming. SjvO2 and lactate levels at the jugular bulb were measured at 30, 34 and 37degrees C nasopharyngeal temperature. RESULTS: There was not a reduction in SjvO2 to < 50% in normocapnic and hypercapnic group during the rewarming period, and there was no significant difference in lactate levels at the jugular bulb. However, the hypercapnic group had a higher SjvO2 than the normocapnic group at 30, 34 and 37degrees C nasopharyngeal temperature during rewarming (P<0.05). CONCLUSIONS: Hypercapnia is more effective increasing SjvO2 than normocapnia and may contribute to the prevention of postoperative neurologic dysfunction, especially in patients having a low SjvO2.

Comparison of Systolic Pressure Variation and Plethysmographic Pulse Wave Variation of a Pulse Oximeter / 대한마취과학회지

BACKGROUND: Maintenance of volume status and treatment of hypovolemia constitute an important component of anesthetic management. A Pulse oxymeter providing a continuous display of the pulse waveform offers a new method of estimating relative volume status during positive pressure ventilation. This study was undertaken to use the pulse wave variance of a plethysmographic signal measured from a pulse oximeter as a useful tool in the assessment of volume status. METHODS: Forty patients underwent general anesthesia with controlled positive pressure ventilation. After induction, the fluid infusion rate was 100 cc/hr until the dura was opened. During the operation, fluid losses were not replaced until hemodynamic variables were printed out. In addition to standard monitoring,the arterial pressure was monitored with a radial artery catheter. Systolic pressure variation (SPV) was defined as the maximum variation in peak systolic pressure during the respiratory cycle and measured in mmHg. Plethysmographic pulse wave variation (PWV) was defined as the maximum variation in the waveform peaks during the respiratory cycle and measured in millimeters from the printed output of the pulse oximeter. SPV and PWV were printed out right after induction and right before dura opening. In addition to SPV and PWV, other hemodynamic variables (HR, MAP, CVP) were obtained. RESULTS: Heart rate, SPV and PWV increased before the dura opening compared with those after induction. PWV correlated well with SPV after fluid losses CONCLUSIONS: A Pulse oximeter which is a standard monitor in anesthesia provides a useful, noninvasive and inexpensive adjunct to the more invasive estimators of volume status.

A Case of Severe Anemia Due to Anti Ce in Transfused Patient / 대한구급학회지

Intraoperative massive bleeding requires fluid therapy and blood transfusion. But transfusion may elicit infection, hemolytic reaction, hemostatic disorder and other complication. Individuals often produce antibodies to the alleles which lack in ABO and Rh system. Such antibodies are responsible for the most serious reaction to transfusions. Antibodies may occur "naturally" or in response to sensitization from a previous transfusion or pregnancy. We report a case of severe anemic patient who had Anti Ce due to previous transfusion and was not transfused for several hours because of incompatible cross-matching. His Rh phenotype is revealed cDE.

Anesthesia for Day Surgery in Pediatric Outpatients / 대한마취과학회지

BACKGROUND: Day surgery is increasing recently because of various benefits such as cost-saving, reduced emotional disturbance, and risk of infection. Children are ideal patients for day surgery. Developments in surgical, anesthetic technique, and pharmacology made day surgery to be increased without major complications. METHODS: This retrospective study includes our experience about outpatient anesthesia for pediatric general surgery in 219 children including both sexes up the age of 15 years over two years from jan. 1. 1994 to dec. 31. 1995. RESULTS: In 183 patients(83.5%), general anesthesia was done with mask inhalation. In 165 patients (75%), herniorrhaphy was done. Mean duration of operation, anesthesia and stay in recovery room were 25, 30 and 25 minutes respectively. There was no patient who needs admission and treatment due to complications. CONCLUSIONS: If we considered selection of patients, anesthetic techniques, and prevention and treatment of complications in day surgery, it is safe and desirable in modern anesthesia for us to do day surgery in pediatric outpatients.

Comparison of Oxygen Saturation of Pulmonary Artery and Superior Vena Cava during Mitral Valve Replacement / 대한마취과학회지

BACKGROUND: Mixed venous oxygen saturation (SO2) has been considered as an important parameter during therapy of critically ill patients. But pulmonary artery catheterization for monitoring of SO2 involves risks and sometimes may be contraindicated. The purpose of this study was to evaluate whether SO2 could be replaced by oxygen saturation of superior vena cava (SvcO2). METHODS: We inserted pulmonary artery catheter in 38 patients scheduled for undergoing mitral valve replacement. Blood samples for SO2 were drawn from PA ports of pulmonary artery catheter, blood samples for distal SvcO2 were drawn from CVP ports of pulmonary artery catheter and blood samples for proximal SvcO2 were drawn from distal ports of sheat introducer. RESULTS: There was no significant difference between SO2 and SvcO2 (79.6% and 79.9%, 78.0%), and also no significant difference between distal and proximal SvcO2 (79.9%, 78.0%). Correlation of SO2 and SvcO2 was good (r=0.69: PA and SVCD, r=0.62: PA and SVCP). CONCLUSION: We conclude that mixed venous oxygen saturation might be replaced by oxygen saturation of superior vena cava during mitral valve replacement.

Arterial Oxygen Tension Measurements during Nitrous Oxide - Oxygen Anesthesia / 대한마취과학회지

In 30 ASA class I patients aged 15-30 undergoing peripheral operations, PaO2 and SaO2 were determined while the mixture of nitrous oxide and oxygen was administered at the inspired oxygen concentration of 21%. Anesthesia was maintained with 75% or so nitrous oxide and small dose fentanyl, and ventilation was adjusted to maintain normoventilation with tidal volume increased to 15 ml/kg. PaO2 and SaO2 during anesthesia were increased significantly when compared to those which were measured immediately prior to anesthetic induction, that is to say, no one developed hypoxemia despite administration of the same inspired oxygen concentration as that of room air. These results indicate that, in case rapid emergence from anesthesia is required, balanced anesthesia with high concentration nitrous oxide and small dose fentanyl should be very useful and safe so long as we make good selections of patients and deliver large tidal volumes to them during artificial ventilation.