A Novel Technique to Maintain Radial Arterial Catheter Position: The Arterial Catheter Stabilizer

Despite widespread use of arterial catheters, there is remarkably little described about their stabilization in the literature. A brief review of arterial catheterization techniques is included. The fixation techniques described in the literature and in commercial product information are essentially to tape or suture the arterial catheter flat against the skin. Often the wrist is immobilized in the dorsiflexed position to prevent kinking or dislodging of the catheter. We describe a simple device made from a gauze pad and tape to elevate and protect the arterial line while minimizing its kinking during wrist flexion.

Neonatal necrotizing enterocolitis caused by umbilical arterial catheter-associated abdominal aortic embolism:A case report

BACKGROUND Reports of necrotizing enterocolitis(NEC)caused by umbilical arterial catheter(UAC)-associated abdominal aortic embolism in neonates are rare.Herein,we report the case of an extremely low birth weight(ELBW)infant with NEC caused by UAC-associated abdominal aortic embolism.CASE SUMMARY A female infant,aged 21 min and weighing 830 g at 28+6 wk of gestational age,was referred to our hospital because of premature birth and shallow breathing.The patient was diagnosed with ELBW,neonatal respiratory distress syndrome,neonatal intrauterine infection,and neonatal asphyxia.Umbilical arterial and venous catheters were inserted on the day after birth and were removed 9 d later,according to the doctor’s plan.Within 48 h after extubation,the patient’s manifestations included poor responsiveness,heart rate range of 175-185/min,and currant jelly stool.Therefore,we considered a diagnosis of NEC.To determine the cause,we used B-mode ultrasound,which revealed a partial abdominal aortic embolism(2 cm×0.3 cm)and abdominal effusion.The patient was treated with nil per os,gastrointestinal decompression,anti-infective therapy,blood transfusion,and low-molecular-weight heparin sodium q12h for anticoagulant therapy(from May 20 to June 1,the dosage of low-molecular-weight heparin sodium was adjusted according to the anti-Xa activity during treatment).On the 67th day after admission,the patient fully recovered and was discharged.CONCLUSION The abdominal aortic thrombosis in this patient was considered to be catheter related,which requires immediate treatment once diagnosed.The choice of treatment should be determined according to the location of the thrombus and the patient’s condition.

Pulmonary artery catheterization in acute myocardial infarction complicated by cardiogenic shock:A review of contemporary literature

Acute myocardial infarction(AMI)with left ventricular(LV)dysfunction patients,the most common cause of cardiogenic shock(CS),have acutely deteriorating hemodynamic status.The frequent use of vasopressor and inotropic pharmacologic interventions along with mechanical circulatory support(MCS)in these patients necessitates invasive hemodynamic monitoring.After the pivotal Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness trial failed to show a significant improvement in clinical outcomes in shock patients managed with a pulmonary artery catheter(PAC),the use of PAC has become less popular in clinical practice.In this review,we summarize currently available literature to summarize the indications,clinical relevance,and recommendations for use of PAC in the setting of AMI-CS.

Mathematical modelling of couple stresses on fluid flow in constricted tapered artery in presence of slip velocity-effects of catheter

This paper explores the mathematical model for couple stress fluid flow through an annular region. The above model is used for studying the blood flow be-tween the clogged （stenotic） artery and the catheter. The asymmetric nature of the stenosis is considered. The closed form expressions for the physiological parameters such as impedance and shear stress at the wall are obtained. The effects of various geomet-ric parameters and the parameters arising out of the fluid considered are discussed by considering the slip velocity and tapering angle. The study of the above model is very significant as it has direct applications in the treatment of cardiovascular diseases.

Application of intraoperative arterial pressure-based cardiac output monitoring for patients undergoing coronary artery bypass grafting surgery

Background For patients undergoing off-pump coronary artery bypass grafting （OPCABG）, it is important to establish a hemodynamic monitoring system to obtain powerful parameters for better intraoperative treatment. This study aimed to observe the clinical feasibility of arterial pressure-based cardiac output （APCO） for cardiac output （CO） monitoring and to evaluate the correlation between APCO and pulmonary artery catheter （PAC） for CO measurement for patients undergoing OPCABG intraoperatively. Methods Fifty patients of American Society of Anaesthesiologists （ASA） classification Ⅱ-Ⅲ, undergoing elective OPCABG at Beijing Anzhen Hospital were randomly enrolled into this study. All patients were assigned to CO monitoring by PAC and APCO simultaneously. Patients with pacemaker, severe valvular heart disease, left ventricular ejection fraction （EF） 〈40%, cardiac arrhythmias, peripheral vascular disease, application of intra-aortic balloon pump （IABP） and emergent diversion to cardiac pulmonary bypass were excluded. The radial artery waveform was analyzed to estimate the stroke volume （SV） and heart rate （HR） continuously. CO was calculated as SV × HR; other derived parameters were cardiac index （CI）, stroke volume index （SVI）, systemic vascular resistance （SVR）, and systemic vascular resistance index （SVRI）. PAC was placed via right internal jugular vein and the correct position was confirmed by PAC waveforms. Continuous cardiac output （CCO）, CI and other hemodynamic parameters were monitored at following 5 time points： immediate after anesthesia induction （baseline value）, anastomosis of left internal mammary artery to left anterior descending artery （LAD）, anastomosis of left circumflex （LCX）, anastomosis of posterior descending artery （PDA） and immediate after sternal closure. Results In the 50 patients, preoperative echocardiography measured left ventricular EF was （52.8±11.5）%, and 35 patients （70%） showed regional wall motion abnormalities. The correlation coefficient of CO monitored by APCO and PAC were 0.70, 0.59, 0.78, 0.74 and 0.85 at each time point. The bias range of CI monitored from both APCO and PAC were （0.39±0.06） L.minl.m2, （0.48±0.12） L.min^-1.m2, （0.26±0.06） L.min1.m-2, （0.27±0.06） L.min-l.m2, （0.30＋0.05） L.min-l.m2 at each time point. The results of SVR by two hemodynamic monitoring techniques had good correlation during OPCABG. The variation trends of SVR were opposite comparing with the results of CO. SVR collected from PAC obtained the highest value of （1220.0±254.0） dyn.s.cm5 at PDA anastomosis, but the highest value obtained from APCO was （1206.0±226.5） dyn.s.cm-5 in LCX anastomosis. Conclusions APCO is feasible in hemodynamic monitoring for patients undergoing OPCABG The results of hemodynamic monitoring derived from APCO and PAC are closely correlated. Its characterizations of timely, accurate and continuous display of hemodynamic parameters are also obviously demonstrated in the present study.

Hemodynamic monitoring in cardiogenic shock

Cardiogenic shock(CS)is a life-threatening condition characterized by acute end-organ hypoperfusion due to inadequate cardiac output that can result in multiorgan failure,which may lead to death.The diminished cardiac output in CS leads to systemic hypoperfusion and maladaptive cycles of ischemia,inflammation,vasoconstriction,and volume overload.Obviously,the optimal management of CS needs to be readjusted in view of the predominant dysfunction,which may be guided by hemodynamic monitoring.Hemodynamic monitoring enables(1)characterization of the type of cardiac dysfunction and the degree of its severity,(2)very early detection of associated vasoplegia,(3)detection and monitoring of organ dysfunction and tissue oxygenation,and(4)guidance of the introduction and optimization of inotropes and vasopressors as well as the timing of mechanical support.It is now well documented that early recognition,classification,and precise phenotyping via early hemodynamic monitoring(e.g.,echocardiography,invasive arterial pressure,and the evaluation of organ dysfunction and parameters derived from central venous catheterization)improve patient outcomes.In more severe disease,advanced hemodynamic monitoring with pulmonary artery catheterization and the use of transpulmonary thermodilution devices is useful to facilitate the right timing of the indication,weaning from mechanical cardiac support,and guidance on inotropic treatments,thus helping to reduce mortality.In this review,we detail the different parameters relevant to each monitoring approach and the way they can be used to support optimal management of these patients.

Assessment of right ventricular function by pressure-volume loops in off-pump coronary artery bypass surgery

Background Right ventricular function plays an important role in the hemodynamic derangement during off-pump coronary artery bypass （OPCAB） surgery. Pressure-volume loops have been shown to provide load-independent information of cardiac function. Therefore, the aim of this study was to investigate the feasibility of construction of right ventricular pressure-volume loops with pressure and volume data measured by a volumetric pulmonary artery catheter （PAC） and to evaluate right ventricular systolic and diastolic function by end-systolic elastance （EEs） and end-diastolic stiffness （EED） in OPCAB surgery. Methods Twenty-eight patients who underwent OPCAB surgery were included. After anesthesia induction, a volumetric PAC was placed via the right internal jugular vein. Data were recorded at： anesthesia steady-state before skin incision （T1）; 5 minutes after the stabilizer device was placed for anastomosis on the heart＇s anterior wall （T2）, lateral wall （T3）, posterior wall （T4）, respectively; after sternal closure （T5）. Three sets of data were collected at each time point： first, hemodynamic variables were measured; second, right ventricular EEs and EED were calculated; third, right ventricular pressure-volume loops were constructed with pressure and volume data measured from end-diastole point, end-isovolumic systole point, peak-ejection point, end-systole point and end-isovolumic diastole point. Results Right ventricular pressure-volume loops generally shifted to the left during OPCAB surgery. Especially, the end-diastolic point shifted upward and to the left at T2--T5 compared with that at T1. Decrease in right ventricular ejection fraction, stroke volume index and end-diastolic volume index occurred （P 〈0.05） at T4 compared with values at TI. Pulmonary vascular resistance index at T4 increased relatively compared with that at T2 and T3. The change of EEs was not statistically significant during operation. Right atrial pressure increased only during coronary anastomoses （T2-- T4, P 〈0.05）, whereas EED increased throughout OPCAB surgery （P 〈0.05）. Conclusions Right ventricular pressure-volume loops can be constructed using a volumetric PAC. Right ventricular systolic dysfunction occurred during anastomoses on the heart＇s posterior wall not due to impaired myocardial contractility but as a result of reduced preload and a relative increase in afterload. Right ventricular diastolic function was impaired throughout OPCAB surgery.

Bleeding from thermistor connector indicates entrapment of pulmonary artery catheter

Several complications of insertion and use of pulmonary artery catheter （PAC）, including catheter entrapment, are recognized during or after cardiac surgery. Early detection is very important. We report a case of PAC entrapment because the the catheter was accidentally su- tured to the superior vena cava. Bleeding from the thermistor connector was initially detected after surgery because the needle punctured the lumen of thermistor connector. The PAC was removed through re-exploration. Therefore, bleeding from the thermistor connector could early indicate the PAC entrapment. We suggest that abnormal bleeding from the non-injectate lumen ports of PAC should be checked before sternal closure.