[Influence of the venous catheter site on data of pulse indicator continuous cardiac output monitoring].

OBJECTIVE: To compare the use of subclavian vein catheter and femoral vein catheter, in monitoring pulse indicator continuous cardiac output (PiCCO) monitoring data cardiac index (CI), extravascular lung water index (EVLWI), and global end-diastolic volume index (GEDVI) with central venous injection of the bolus cold saline injection, in order to determine whether the femoral vein access, which is not typically used, could be used to obtain reliable data. METHODS: Thirteen patients in Beijing Hospital intensive care unit (ICU) were involved, from January 2007 to March 2009. Each patient was monitored with PiCCOplus device, after an injection of cold saline bolus via both femoral and subclavian venous catheter. Paired t-test and Bland-Altman analysis were used to compare CI, EVLWI and GEDVI values. RESULTS: Data of 39 measurements were collected. The bias between femoral injection and subclavian injection were CI (0.28+/-0.46) L x min(-1) x m(-2), EVLWI (1.05+/-1.89) ml/kg, GEDVI (195.2+/-105.7) ml/m(2), and they were statistically significant (P values was 0.000 5, 0.001 3, <0.0001, respectively). The Bland-Altman analysis showed an clinically overestimation of GEDVI after femoral injection (limit of concordance was -11.9, 402.3), compared with that after subclavian injection. CONCLUSION: Measurements with a cold saline bolus via a femoral catheter, compared to those via a subclavian catheter, lead to overestimation of CI, EVLWI and GEDVI values, and a great bias of GEDVI should be taken into account in clinical work.

[Study on safety and efficacy of concentrated potassium chloride infusions in critically ill patients with hypokalemia].

OBJECTIVE: To explore the safety and clinical efficacy of intravenous infusion of concentrated potassium chloride using micro-pumps in critically ill patients with hypokalemia. METHODS: One hundred and twenty-eight critically ill patients with hypokalemia, the endogenous creatinine clearance rate over 0.5 ml/second and the urine output over 50 ml/hour were randomly divided into the therapy group (n=64) and the control group (n=64). Patients in therapy group received 1,208 mmol/L (9%) KCl, while those in the control group received 201 mmol/L (1.5%) potassium chloride, intravenously with the aid of a micro-pump, with hourly equal quantity of KCl in both groups. Patients in both groups were monitored strictly, and the potassium infusion was stopped whenever the serum potassium exceeded or equal to 3.5 mmol/L. RESULTS: It took (15.55+/-3.22) hours and (14.18+/-4.93) hours for the therapy group and the control group to correct the hypokalemia respectively, and there was no significant difference (P>0.05). Potassium infusion brought larger amount of fluid in the control group than the therapy group [(124.36+/-25.79) ml vs. (680.83+/-236.70) ml, P<0.01]. All patients tolerated the infusion without evidence of hemodynamic change, hyperkalemia or acute heart dysfunction. For all the patients, renal function did not throw significant influence on the potassium infusion time. An inverse correlation was observed between preinfusion potassium concentration and the quantity of potassium infused (r= -0.259, P<0.01). CONCLUSION: Under meticulous monitoring, it is safe and effective to infuse concentrated potassium for the critically ill patients with hypokalemia. This strategy can also be followed in patients with mild renal dysfunction but without oliguria or anuria under careful monitoring.