Of rough starts and smooth finishes: correlations between post-anesthesia care unit and postoperative days 1-5 pain scores.

OBJECTIVE: The goal of this project was to explore the association between post-anesthesia care unit (PACU) pain scores recorded within the first and second hour of the end of surgery with maximum and median pain scores recorded on postoperative days (PODs) 1 through 5. DESIGN: This study was a retrospective cohort study of clinically documented pain scores in a mixed surgical population. SETTING: This study was set in a single tertiary-care teaching hospital over a 1-year time period. PATIENTS: All patients were adult patients undergoing a single, non-ambulatory, non-obstetric surgical procedure. MEASURES: Pain scores, measured using the numerical rating scale, from PODs 0 through 5 were obtained from an integrated data repository. Kendall's Tau-b correlations were then calculated between maximum pain scores occurring within each of the two PACU time periods and maximum and median pain scores in each of the five ensuing PODs. RESULTS: A total of 349,797 pain scores from 8,332 patients were reviewed. Correlations between maximum pain score by time period demonstrated a significant and high correlation at Tau-b = 0.86, between 1-hour PACU pain scores and 2-hour PACU pain scores. However, the correlation of maximum pain scores recorded in the PACU with those recorded on PODs 1 through 5 was significantly lower, ranging from 0.19 to 0.27. The correlation of maximum PACU pain score with median pain scores recorded on PODs 1 through 5 ranged from 0.22 to 0.29. The correlation structures of the PODs 1 through 5 median pain scores may be consistent with an autoregressive pattern. CONCLUSIONS: Maximum scores measured within the PACU likely reflect a set of circumstances distinct from those experienced on PODs 1 through 5.

Ultrasound: Basic understanding and learning the language.

Ultrasound (US) use has rapidly entered the field of acute pain medicine and regional anesthesia and interventional pain medicine over the last decade, and it may even become the standard of practice. The advantages of US guidance over conventional techniques include the ability to both view the targeted structure and visualize, in real time, the distribution of the injected medication, and the capacity to control its distribution by readjusting the needle position, if needed. US guidance should plausibly improve the success rate of the procedures, their safety and speed. This article provides basic information on musculoskeletal US techniques, with an emphasis on the principles and practical aspects. We stress that for the best use of US, one should venture beyond the "pattern recognition" mode to the more advanced systematic approach and use US as a tool to visualize structures beyond the skin (sonoanatomy mode). We discuss the sonographic appearance of different tissues, introduce the reader to commonly used US-related terminology, cover basic machine "knobology" and fundamentals of US probe selection and manipulation. At the end, we discuss US-guided needle advancement. We only briefly touch on topics dealing with physics, artifacts, or sonopathology, which are available elsewhere in the medical literature.