Tools, Clinical Prediction Rules, and Algorithms for the Insertion of Peripheral Intravenous Catheters in Adult Hospitalized Patients: A Systematic Scoping Review of Literature

Patient Variables

Vein characteristics were significant independent factors associated with insertion success in a number of studies.^{3,19,23,24,27,28} These included the number of veins, descriptive quality (eg, small, medium, large), size, location, visible veins, and palpable veins. Other factors appear to be patient specific (such as chronic conditions), including diabetes (OR, 2.1 [adjusted to identify demographic risk factors]; 95% CI, 1.3-3.4), sickle cell disease (OR, 3.5; 95% CI, 1.4-4.8), and intravenous drug abuse (OR, 2.4; 95% CI, 1.1-5.3).²⁶ It is unclear if a consistent relationship between weight classification and insertion outcomes exists. Despite a finding that BMI was not independently associated with insertion difficulty,²⁶ one study reports that BMI was independently associated with insertion failure (BMI <18.5 [OR, 2.24; 95% CI, 1.07-4.67], BMI >30 [OR, 1.98; 95% CI, 1.9-3.60])³ and another reports emaciated patients were associated with greater failure when compared to normal weight patients (OR, 0.07; 95% CI, 0.02-0.34).²³ Consequently, extremes of BMI appear to be associated with insertion outcomes despite 1 study reporting no significant association with BMI as an independent factor of insertion failure.²⁶ A history of difficult intravenous access (DIVA) was reported in 1 study and independently associated with insertion failure (OR, 3.86; 95% CI, 2.39-6.25; see Table 2). DIVA appears to be the motivating factor in the title of 7 studies. When defined, the definitions of DIVA are heterogeneous and varied and include the following: >1 minute to insert a PIVC and requiring >1 attempt²⁷; 2 failed attempts³⁰; 3 or more PIVC attempts.²⁶ In the remaining 4 studies, variables associated with difficulty are identified and, therefore, TRAs to target those in future with predicted difficulty prior to any attempts are proposed.^3,19,24,25

Clinician Variables

Specialist nurse certification, years of experience, and self-report skill level (P < 0.001) appear to be significantly associated with successful insertions.²⁵ This is in part validated in another study reporting greater procedural inserting PIVCs as an independent predictor of success (OR, 4.404; 95% CI, 1.61-12-06; see Table 2).²³ Two studies involved simple pragmatic percentage cut offs for PIVCs: likelihood of use²⁹ and likelihood of insertion success.²³ One paper using a cross-sectional design that surveyed ED clinicians suggested if the clinician’s predicted likelihood of the patient needing a PIVC was >80%, this was a reasonable trigger for PIVC insertion.²⁹ The other, in a self-report cohort study, reported that a clinician’s likelihood estimation of PIVC FTIS prior to insertion is independently associated with FTIS (OR, 1.06; 95% CI, 1.04-1.07).²³

Product Variables

In this review, higher failure rates were identified in smaller sizes (22-24 g).²⁶ One study revealed gauge size was significantly associated with a failed first attempt in a univariate analysis (OR, 0.44; 95% CI, 0.34-0.58), but this was not retained in a multivariate model.²⁴ Matching the PIVC size with vein assessment is considered in the VIA tool.²⁸ It suggests a large PIVC (18 g) can be considered in patients with at least 6 vein options; smaller PIVCs of 22 to 24 g are recommended when 3 or fewer veins are found.²⁸ One paper describes a greater proportion of success between PIVC brands.²⁵

The published evidence for TRAs for PIVCs is limited, with few studies using 2 or more reliability, validity, responsiveness, clinical feasibility, or utility measurements in their development. There is a clear need to assess the clinical utility and clinical feasibility of these approaches so they can be externally validated prior to clinical adoption.¹⁶ For this reason, a validated TRA is likely required but must be appropriate for the capability of the healthcare services to use it. We suggest the consistent absence of all of these phases is owing to the variety of healthcare practitioners who are responsible for the insertion, the care and surveillance of peripheral cannulae, and the fragmentation of clinical approaches that exist.³²

Previously, a comprehensive systematic review on the subject of PIVCs found that the presence of a visible and/or palpable vein is usually associated with FTIS.³³ This current review found evidence of simple scores or cutoff percentage estimates in 2 TRA reports to predict either appropriate PIVC insertion or FTIS.^23,29 If such methods are supported by future experimental trials, then such simple approaches could initiate huge clinical return, particularly given that idle or unused PIVCs are of substantial clinical concern.^34-36 PIVCs transcend a variety of clinical environments with excessive use identified in the ED, where it may be performed for blood sampling alone and, hence, are labeled as “just in case” PIVCs and contribute to the term “idle PIVC.”^23,34 Therefore, a clinical indication to perform PIVC insertion in the first instance must be embedded into any TRA; for example, clinical deterioration is likely and the risks are outweighed by benefit, intravenous fluids and/or medicines are required, and/or diagnostic or clinical procedures are requested (such as contrast scans or procedural sedation).

In the majority of papers reviewed, researchers described how to categorize patients into levels of anticipated and predicted difficulty, but none offered corresponding detailed recommendations for strategies to increase insertion success, such as insertion with ultrasound or vascular access expert. Hypothetically, adopting a TRA may assist with the early identification of difficult to cannulate patients who may require a more expert vascular access clinician. However, in this review, we identify that a uniform definition for DIVA is lacking. Both Webster et al.²¹ and Wells²² suggest that an expert inserter is required if difficult access is identified by their tools, but there is no clear description of the qualities of an expert inserter in the literature.³⁷ Recently, consensus recommendations for the definition of vascular access specialist add to discussions about defining vascular access as an interdisciplinary specialist role.³⁸ This is supported by other publications that highlight the association between PIVC procedural experience and increased insertion success.^6,23,39-41With regards to products, PIVC gauge size may or may not be significantly associated with insertion success. For identifying a relationship of PIVC gauge with vein quality, both the vein diameter and description will help with the clinical interpretation of results. For example, it may be the case that bigger veins are easier to insert a PIVC and, thus, larger PIVCs are inserted. The opposite can occur when the veins are small and poorly visualized; hence, one may select a small gauge catheter. This argument is supported by Prottengeier et al.⁴² in a prehospital study that excluded PIVC size in a multivariate analysis because of confounding. However, gauge size is very likely to influence postinsertion complications. Prospective studies are contradictory and suggest 16 to 18 g PIVCs are more likely to contribute to superficial thrombus,⁴³ phlebitis, and, thus, device failure, in contrast to others reporting more frequent dislodgement with smaller 22 g PIVCs.^6,44Finally, the studies included did not assess survival times of the inserted PIVCs, given postinsertion failure in the hospitalized patient is prevalent⁴⁵ and, importantly, modifiable.⁴⁶ A TRA may yield initial insertion success, but if postinsertion the PIVC fails because of a modifiable reason that the TRA has not acknowledged, then it may be of negligible overall benefit. Therefore, TRAs for PIVC insertion need calibration, further development, and ongoing refinement prior to external validation testing.²⁴ Future research should also examine the role of TRAs in settings where ultrasound or other insertion technology is routinely used.