Letters to the Editor: Letters & Announcements
To the Editor:
The recently published letter “How to Enter a Medication Vial Without Coring”1 called for caution when drawing medication from a vial through a stopper because of the danger of coring and injecting a foreign body into the patient. Although we would like to commend Dr. Roth on reemphasizing this important issue,2–4 we disagree with his comment that blunt needles may reduce the risk of coring.
Despite the use of a blunt cannula, a technique routinely used in our institution to prevent needle injuries, we recently encountered a near-embolization of a cored rubber piece from a Diprivan® vial (Astra Zeneca Pharmaceuticals, Wilmington, DE) in a 16-mo old girl requiring total IV anesthesia during a rigid bronchoscopy. In our case, propofol had been drawn through a blunt plastic cannula (Becton Dickinson & CO, Franklin Lakes, NJ) from a 20-mL vial sealed with a rubber stopper. IV induction and anesthesia maintenance with propofol for about 15 min through a previously placed 24-gauge angiocath in the patient's hand had been uneventful until an additional bolus was necessary to deepen anesthesia. After injection of about 1 mL the infusion pump's high-pressure alarm sounded, and no additional propofol could be given manually. We rapidly inserted an additional catheter into a vein on the patient's foot, and continued and finished the procedure without problems. After emergence, we found a gray rubber core (approximately 0.4 × 1.5 mm) blocking the 24-gauge angiocath completely at its distal end. Subsequent tests showed reproducible coring of rubber pieces into Diprivan vials with the blunt cannula (Fig. 1A), but not with 20- or 18-gauge sharp needles. Since the rubber pieces are heavier than propofol, they are only clearly visible when the bottom of the bottle is inspected from below (Fig. 1B). Although the incidence of injecting a cylinder shaped rubber core through the narrow lumen of a syringe opening may be low, in our case embolization was only prevented by the smaller inner diameter of the 24-gauge angiocath (Fig. 1C). We therefore speculate that this may be an often undetected and thus underreported problem that health care providers need to be aware of. Following this near-incident, we are changing our technique and refrain from using blunt cannulae to withdraw liquid medications from rubber sealed vials.
We thank the Medical Media Services of the VA Medical Center, Milwaukee, WI, for the excellent photographic service.
Matthias L. Riess, MD, PhD
Tatyana Strong, MD
Department of Anesthesiology
Medical College of Wisconsin
1. Roth JV. How to enter a medication vial without coring. Anesth Analg 2007;104: 1615
2. Sakai T, Koh H, Matsuki A. A case of the foreign body due to “coring”. Masui 1996;45:1533–5
3. Adachi Y, Takigami J, Watanabe K, Satoh T. A case of coring on using a 1% Diprivan vial. Masui 2001;50:635–6
4. Shiroyama K. The incidence of “coring” during aspiration of propofol from a 50-ml vial. J Anesth 2001;15:120