You are resuscitating a hypotensive patient with severe sepsis and have just hung your 4th liter of crystalloid. On the fluid bags, you wrote the numbers 1 through 4 in permanent marker to help keep track of your resuscitation. As you finish placing your central line the charge nurse enters the room. He informs you that according to the Institute for Safe Medical Practices (ISMP), writing directly on IV bags with permanent marker is not recommended due to concerns that the ink will leach into the bag and potentially cause harm to your patient.1–4
This situation raises several questions:
- Should we write on IV bags in permanent marker?
- Is there a possibility of ink diffusing through polyvinylchloride (PVC) bags?
- If so, is there potential harm to the patient?
These are valid questions, but unfortunately the answers may be unclear, contradictory, or even non-existent. Are there theoretical concerns with writing on IV preparations? What do the manufacturers say?
According to IV bag manufacturers Baxter, Hospira, and B Braun the absence of ink leaching from permanent markers cannot be guaranteed and writing on bags with permanent marker is not recommended, especially since there are many different ink, marker, and pen manufacturers with varying types and styles of ink.5–9
If we cannot get a definitive answer from the manufacturers, let’s take a look at some literature that has attempted to identify possible ink contamination in IV bags. A PubMed search was done with search criteria including “PVC and ink”, “IV bag and ink”, “IV bag and marker”, “PVC and marker”, “ink and leaching”.
Gas chromatography was used to detect ink solvents from a Markette No. 590 felt-tip marker. A Baxter ViaflexTM IV bag completely covered with ink was compared to a control Baxter ViaflexTM IV bag without ink. The ink was in contact with the bag for 30 minutes before samples were drawn. The results from the gas chromatography showed no significant difference in the marked bag compared to the control bag. This study was designed to detect the volatile solvents in the marker and not all components of the ink. However, this study only looked at one type of PVC bag, fluid, and marker.
Story and colleagues had previously found biologically active contaminants in PVC bags containing 0.9% sodium chloride. In this study they wanted to determine if the contaminants varied by manufactured country of origin. They tested manufacture printed vs. non-printed bags for contaminants using high-resolution capillary gas chromatography-mass spectrometry. The authors concluded that printing ink on the bags was most likely the source of t-butyl cyclohexanol and t-butyl cyclohexanone contamination. The potential health concerns of these contaminants are unclear.
Multiple IV bag brands were studied including Baxter polyvinyl chloride laminate #146, Hospira VisIV® and Freeflex®, B. Braun Excel® system, Baxters’s VIAFLEX® and VIAFLEX.Plus® via visible and ultraviolet spectrophotometric scans. The solutions in the bags included 0.9% sodium chloride, Lactated Ringers, dobutamine in 5% dextrose, 6% hetastarch in 0.9% sodium chloride, and Plasma-Lyte A®. The manufacturer of Sharpie® provided the known wavelengths to detect black ink used in their products. Filter paper was inserted into empty Sharpie® marked bags and placed under approximately 20 pounds of pressure. The filter paper was visually inspected after a 24-hour time period to identify possible bag leaching from a fine-tip Sharpie®. The results of this study showed no visible or spectrophotometric evidence of leaching. Other components of Sharpie® ink, such as solvents, were not specifically tested. The authors also demonstrated that silk surgical tape is permeable to Sharpie® pens.
Eight Baxter PVC bags were divided into two groups — one group was marked with a 3×3 inch square using a soft-tip Sharpie® and the other group was used as a control. The bags were kept at room temperature for the duration of the study. They then employed gas chromatography/mass spectrophotometer with samples tested at 6, 12, and 24 hours. There were no ink molecules detected at any time. Additionally samples were cultured to evaluate possible microbial contaminates and all samples had no growth.
The methods used to test for potential contamination vary greatly. Mass spectroscopy is commonly used to detect ink whereas the volatile components, such as solvents, are best detected using gas chromatography. In addition, Story and colleagues point out that additional contaminants may be detected depending on the specific ink selected.
According to Sharpie® permanent fine point marker material safety data sheet (most commonly used marker at our institution) the ink can be an irritant and is the only side effect listed.12
With no definitive information from the manufacturers and limited literature on bag leaching, what are the answers to our earlier questions?
The ISMP recommends the use of labels that have appropriate information written on them. Implementing strategies such as standardized labels with required fields in all patient rooms for emergent situations could be beneficial. In the absence of labels, during emergent situations such as the resuscitation of a hypotensive patient, writing directly on the bags could be the best way to satisfy ISMP’s recommendation and preventing errors. Although there are many different manufacturers of both pens and bags which make extrapolation of data for all combinations difficult, there is limited evidence of ink leaching and no evidence to this date of patient harm from this practice. If the contents of the bags are infused within 30 minutes of writing, the possibility of leaching is not likely. One additional strategy would be to write near the top of the bag where there is less potential exposure to the contents of the bag.