We reviewed retrospectively all power-injectable PICCs inserted in acutely ill patients admitted to the shock/trauma ICU and the pediatric ICU of our institution (a 1,100-bed university hospital), during 12 months.
According to our hospital policies, indications for PICC insertion were (a) need for a central line for parenteral nutrition, and/or infusion of drugs that require a central line (pH < 5 or > 9, osmolarity > 500 mOsm/l, drugs associated with endothelial damage), and/or (b) central venous pressure monitoring, and/or (c) need for frequent blood sampling. Need for a central line with more than three lumens was considered a clear indication for a standard multiple-lumen CVC. Also, all PICCs were inserted as an elective procedure; all central lines inserted in emergency were standard CVCs. Overt sepsis was also considered a contraindication to PICC insertion. Other standard contraindications to PICC insertion, according to our hospital policies, were small deep veins of the arm (brachial/basilic vein < 4 mm), local contraindications due to specific arm conditions (skin infection, burns, orthopedic devices blocking the arm, previous axillary node resection due to breast cancer surgery, and so forth) as well as actual or impending chronic renal failure requiring an arteriovenous fistula. Severe arm edema and/or obesity are not considered contraindications to PICC insertion, although in these situations the brachial and basilic vein might be too deep ( > 3 cm) so the cephalic vein is preferentially cannulated.
We considered both multiple-lumen and single-lumen catheters, of different sizes (from 4 to 6 Fr) and different brands, as long as they were power injectable and were inserted during the ICU stay (Figures 1 and 2). All PICCs were inserted according to the specific protocol defined by our hospital PICC team [9]. All of the catheters were inserted by ultrasound-guided puncture of the deep veins in the upper mid-arm (Figure 3), as recommended by current guidelines [3, 10], using the micro-introducer technique. A standard 5 to 10 MHz linear ultrasound probe (adult patients) or a small 10 to 14 MHz hockey-stick ultrasound probe (children) was used. Veins with diameter = or > 4 mm were considered suitable for 4 Fr catheters, veins = or > 5 mm suitable for 5 Fr catheters and veins = or > 6 mm suitable for 6 Fr catheters. Maximal barrier precautions were consistently used during the procedure (cap, mask, sterile gown, sterile gloves, vast sterile field). The correct position of the tip of the catheter (that is, in proximity of the junction between the superior vena cava and the right atrium) was verified during the procedure using the intracavitary electrocardiography (EKG) method [11]; a post-procedural chest X-ray for checking the tip position was required only when the EKG method was not applicable (atrial fibrillation and/or no evident P-wave at the basal EKG). All PICCs were secured to the skin using sutureless devices, as currently recommended [12–14]. All procedures were performed by nurses or physicians specifically trained for PICC insertion. Maintenance of the line and dressing policies were carried out according to the intervention bundle for preventing line infections developed by the GAVeCeLT - Gruppo Accessi Venosi Centrali a Lungo Termine - and adopted by our hospital PICC team (preferential use of 2% chlorhexidine for antisepsis of the exit site, preferential use of transparent dressing, and so forth) [15]. Occlusion of the line was prevented by a specified policy of periodic flushing and locking with saline.
Acutely ill pediatric patients were also included in the study. Since 3 Fr power-injectable PICCs were not yet available in Italy at that time, power-injectable PICCs could be inserted in children only when an arm vein > 4 mm was available. In many acutely ill children, power-injectable PICCs had been inserted as direct central lines, by ultrasound-guided puncture of the internal jugular vein or of the brachio-cephalic vein, or as access to the inferior vena cava, by ultrasound-guided puncture of the femoral vein: all of these off-label uses of power-injectable PICCs were excluded from this analysis (only PICCs inserted into the upper mid-arm were considered).
According to our hospital policies, diagnosis of CRBSI was established by the differential time to positivity method (blood culture from the catheter becoming positive at least 120 minutes before the peripheral blood culture) or by direct culture of the tip of the catheter, should the catheter be removed or replaced over guidewire (culture of the same microorganism from the blood and from the tip of the catheter).
Diagnosis of catheter-related thrombosis was established by ultrasound examination (compression ultrasonography and duplex Doppler), performed only when clinically indicated by signs and symptoms suggesting venous occlusion (edema of the arm, PICC malfunction, unexplained local pain, and so forth). Catheter-related peripheral venous thrombosis was defined as the presence of occlusive thrombosis of the deep veins of the arm containing the PICC, extending or not to the axillary vein. Catheter-related central venous thrombosis was defined as the presence of any extent of thrombosis in the subclavian, internal jugular or brachio-cephalic vein or in the superior vena cava on the side of PICC insertion.
We collected all relevant data and information, including patient's age and disease, indication for PICC insertion, duration of the dwell time for the device, incidence of complications at insertion or during maintenance, and cause of removal. All data were included in a software-operated database and analyzed by standard descriptive statistics. Values are reported as the mean ± standard deviation.
According to the policy of our hospital, retrospective studies do not require approval from the Ethics Committee and do not require informed consent from the patient. Informed consent was obtained, however, from the patients represented in Figures 1 and 2 for publications of their images.