Ray R. Maddox

Continuous Oximetry/Capnometry Monitoring Reveals Frequent Desaturation and Bradypnea During Patient-Controlled Analgesia

BACKGROUND:The most serious complication of patient-controlled analgesia (PCA) is respiratory depression (RD). The incidence of RD in the literature is derived from intermittent sampling of pulse oximetry (Spo2) and respiratory rate and defined as a deviation below an arbitrary threshold. METHODS:We monitored postsurgical patients in a hospital ward receiving morphine or meperidine PCA with continuous oximetry and capnography. Nurses responding to audible monitor bedside alarms documented respiratory status and interventions. RESULTS:A total of 178 patients were included in the analysis, 12% and 41% of whom had episodes of desaturation (Spo2 <90%) and bradypnea (respiratory rate <10) lasting 3 min or more. One patient required “rescue” with positive pressure ventilation, and none required naloxone. Patients over 65 years of age and the morbidly obese were at greater risk for desaturation. Patients over 65 years of age were also more likely to have bradypnea, whereas the morbidly obese and patients receiving continuous infusions were less likely to have bradypnea. CONCLUSIONS:Our incidence of RD by bradypnea is significantly higher than the 1%–2% incidence in the literature, using the same threshold criteria but more stringent duration criteria, while our incidence of RD based on desaturation is consistent with previous estimates. We conclude that continuous respiratory monitoring is optimal for the safe administration of PCA, because any RD event can progress to respiratory arrest if undetected. Better alarm algorithms must be implemented to reduce the frequent alarms triggered by threshold criteria for RD.

Effect of barcode technology with electronic medication administration record on medication accuracy rates

PURPOSE The effect of barcode-assisted medication administration (BCMA) with electronic medication administration record (eMAR) technology on the occurrence of medication administration errors was evaluated. METHODS A pretest-posttest nonequivalent comparison group was used to investigate the effect of BCMA-eMAR on the medication administration accuracy rates at two community-based hospitals. Patient care units included three matched pairs in the two hospitals-two medical-surgical, two telemetry, and two rehabilitation units-plus a medical-surgical intensive care unit, an emergency department, and both an inpatient oncology unit and an outpatient oncology service at one of the hospitals. Medication administration accuracy rates were observed and recorded before (phase 1) and approximately 6 and 12 months after (phases 2 and 3, respectively) the implementation of BCMA-eMAR. RESULTS The overall accuracy rate at hospital 1 increased significantly from phase 1 (89%) to phase 3 (90%) (p = 0.0015); if wrong-time errors are excluded, the accuracy rate improved from 92% in phase 1 to 96% in phase 3 (p = 0.000008). The overall accuracy rate did not change significantly from phase 1 to phase 3 at hospital 2; when wrong-time errors were excluded from consideration, the accuracy rate improved from 93% in phase 1 to 96% in phase 3 (p = 0.015). CONCLUSION Implementation of BCMA-eMAR in two hospitals was associated with significant increases in total medication accuracy rates in most study units and did not introduce new types of error into the medication administration process. Accuracy rates further improved when wrong-time errors were excluded from analysis. The frequency of errors preventable by BCMA-eMAR decreased significantly in both hospitals after implementation of that technology. BCMA-eMAR and direct observation were more effective than voluntary reporting programs at intercepting and recording errors and preventing them from reaching patients.

New JCAHO pain standard bigger threat to patient safety than envisioned.

We are troubled by some of the methodology and analysis described in a recent article by Vila et al. (1) on the efficacy and safety implications of the Hospital Wide Pain Management Standards mandated by Joint Commission on Accreditation of Healthcare Organizations. We doubt using a single respiratory rate obtained from retrospective chart review of cases with opioid-related adverse drug reactions (ADRs) is useful in predicting a patient’s propensity for respiratory depression. The fact that 16/29 (55%) patients with opioid adverse drug reactions had respiratory rates more than or equal to 18 breaths/min (2 patients had a respiratory rate of 32 and 40 breaths/min) suggests that these events were mislabeled as opioid adverse drug reactions, involved an opioid side effect other than respiratory depression, or were measured after the patient was aroused or received naloxone. Not surprisingly, they did not observe a predictable decrease in respiratory rate before opioidinduced respiratory arrest. The difficulty of obtaining reliable “manual” respiratory rates is described by Vila in an earlier study where patients under monitored anesthesia care had prolonged periods of apnea, consistently missed by dedicated anesthesia providers using visual surveillance and oximetry (2). We are further alarmed at the suggestion that pulse oximetry alone may be “used effectively” for patients at high risk for ventilatory depression and respiratory arrest. “High risk” patients often receive supplemental oxygen, hindering the ability of oximetry to detect hypoventilation on a timely basis (3). More importantly, although oximetry may suffice as a monitor in procedural areas and recovery rooms, where these studies were performed, its delayed warning of hypoventilation may be tragically inadequate on a hospital ward where vital sign are monitored more infrequently and nurses have more patients. Finally, a recent, comprehensive, meta-analysis of 116 studies by Cashman and Dolin (4) found the incidence of respiratory depression during acute, opioid-containing, postoperative pain management (as measured by respiratory rate 10 breaths/min) in 29,607 patients to be 1.1% (95% confidence interval, 0.7%–1.7%). Although not strictly comparable, Vila et al.’s incidence of 29 cases of opioidrelated adverse drug reactions (respiratory rate 12 breaths/min) in 32,019 patients (0.091%), seems greatly at odds with the Cashman and Dolin findings. Although Vila et al. present valuable insight on patient satisfaction with pain therapy and consciousness changes with opioid adverse drug reactions, the respiratory rate data are unreliable, and hence their monitoring recommendation appears ill advised.

The essence of leadership

What a tremendous honor to have been selected the 2013 John W. Webb Lecture Honoree. I am truly humbled to have been included among the past recipients of this honor, who are men and women of great insight and leadership in our profession. I want to thank the ASHP Section of Pharmacy Practice

Automated pharmaceutical assistance systems. I. Clinical pharmacokinetics. II. Drug interference with laboratory tests results.

The function of the clinical pharmacokinetic service (CPS) in University Hospital is described. A methodological procedure was developed for routine interpretation of specified drug serum levels. Work lists that identify analytical procedures to be included for clinical pharmacokinetic evaluation are prepared daily. The results of all analyses of serum drug levels are evaluated by a pharmacist who is trained in clinical pharmacokinetics. Patient variables that influence serum levels of drugs are mathematically manipulated by program logic. Projections of expected drug levels as a result of dosing regimens are made and compared to measured laboratory results. Iterative programming that modifies projections on the basis of actual measurements is employed to determine individual drug dosing regimens the provide therapeutic/nontoxic serum levels of drugs. The drug/test interference system, which accesses the CPS data base, provides information concerning the potential physiologic, therapeutic, or toxic effect of drugs on biochemical substances. The system allows display of data concerning each drug before it is administered. Information concerning the date and time of initiation and termination of drug therapy allows for a warning comment to be attached automatically to the appropriate laboratory test result if interference is indicated.