The PACU is traditionally divided into phases 1 and 2. Phase 1 has monitoring and staffing ratios equivalent to the ICU. Phase 2 is a transitional period between intensive observation and either the surgical ward or home. The concept of bypassing or “fast-tracking” phase 1 is becoming more common as fast-offset anesthesia agents and practices are emerging. Bypass is typically appropriate for patients who have received either MAC or peripheral regional anesthesia, while phase 1 is typically required for general inhalational anesthesia or neuraxial regional techniques. Ultimately, however, patient co-morbidities, surgical techniques/complications and pharmacological choices also determine the appropriate level of post-operative care on an individual basis.
Additionally, the Aldrete scoring system is commonly used to determine when patients can be safely discharged from phase 1 to phase 2. The scoring basis includes the five parameters of activity, respiration, circulation, consciousness and oxygen saturation.