2007 OPEN FORUM Abstracts
END-TIDAL CARBON DIOXIDE MONITORING IN PATIENT CONTROLLED ANALGESIA
T. McCarter1, Z. Shaik1, K. Scarfo1, T. Laura1
Background: Post operative patients require safe and effective pain management. Patient Controlled Analgesia (PCA) is used to deliver narcotic analgesics as it has considerable potential to improve pain management. Narcotics via PCA, create a possibility that self-administration will result in undetected respiratory depression with potential tragic consequences. If ventilation is adequately monitored via End-tidal Carbon Dioxide (EtCO2) monitoring, clinicians are able to provide safe and effective patient controlled pain management.
Method: PCA is delivered and monitored as per policies and procedures that include patient criteria for PCA and prescription order sets. Patient alerts for respiratory depression are set for low respiratory rate and increasing EtCO2 concentration during narcotic delivery. Additionally, the patients on PCA are monitored for general appearance, vital signs, nausea, sedation level, pain scale, PCA dosing, and pulse oximetry.
Results: During the five months period beginning from October 2006, there have been ten patients whose level of sedation while receiving narcotics led to low respiratory rates (RR). In each case, the capnography monitoring of respiratory rate and EtCO2 alerted caregivers before pulse oximetry and prevented serious health impact.
Conclusions: Relying on pulse oximetry alone is potentially dangerous as it reflects oxygenation status of the patient rather than effective ventilation. The risk of respiratory depression in the setting of PCA warrants a technology that can measure the RR, EtCO2 concentration and depict it in a wave form. Direct monitoring of respiratory rate and exhaled CO2 concentration with capnography is more effective in the detection of respiratory depression, than the monitoring of oxygenation alone. While pulse oximetry monitors oxygenation, capnography monitors respiratory rate and effectiveness of ventilation. Changes in pulse oximetry may lag behind changes in respiratory rates. The patients saved might have otherwise suffered negative respiratory events and/or depression requiring additional interventions and services were they not monitored by this technology.