Alternatives to subcutaneous injection of amino-amide or amino-ester anesthetics before arterial puncture for blood gas analysis: a systematic review

Background and objective. Arterial puncture for blood gas analysis is a painful procedure in the emergency department (ED). Local subcutaneous injection of anesthetics containing amino amides or esters is the usual pain relief technique applied before arterial puncture, but it is little used in some care settings, such as the ED. We aimed to analyze the literature on anesthetic approaches other than the traditional one of local injection of amino-amide or amino-ester compounds for pain relief during arterial puncture and to assess the efficacy of the alternatives. Methods. A systematic review of the literature was conducted in 6 bibliographic databases. We selected randomized clinical trials (RCTs) published in English or Spanish between 2000 and 2018. The trials compared self-reported pain immediately after arterial puncture for blood gas analysis. Some form of anesthesia other than local injection of an amino amide or ester compound was compared to another anesthetic technique, placebo, or no anesthetic. Results. We found 16 RCTs. Four compared the effect of topical anesthetic creams containing amino amides and/or amino esters, two assessed ultrasound-guided puncture, four used small-caliber needles or special syringes, one used a needle-free high-pressure anesthetic injection system, and five studied cryoanesthesia by application of ice or aerosols. Conclusion. The only effective alternative approaches to pain relief during arterial puncture for blood gas analysis were the use of very fine-caliber needles, the use of needle free pressure injectors for subcutaneous delivery of amino amides, and the application of ice for at least 3 minutes.