Letters Continued from page 600
vey hospitals to better understand current patterns of off-label rFVIIa use to determine the administrative safeguards implemented to reduce off-label use (if any) and how effective these safeguards are. These survey data should be combined with administrative data containing hospital-level characteristics to identify hospital- and provider-level factors associated with off-label rFVIIa use. By understanding what hospital and provider attributes are associated with the most off-label rFVIIa use, recommendations can be developed. Hospital-based pharmacists may have the strongest impetus to reduce off-label rFVIIa use, as the high price of rFVIIa significantly affects their department budget. Hospital-based pharmacists also often have access to accurate data, such as the number of patients who received rFVIIa, the number of doses administered, the department that placed the orders, and cost and purchasing data. As such, hospital-based pharmacists may be the ideal individuals to target for surveying. This sharp turn in research focus for off-label rFVIIa is necessary to acknowledge the patient safety issue raised by the
2012 Cochrane meta-analysis1 while promoting cost-effectiveness in healthcare. 1. Simpson E, Lin Y, Stanworth S et al. Recombinant factor VIIa for the prevention and treatment of bleeding in patients without haemophilia. Cochrane Database Syst Rev. 2012; 3:CD005011. 2. Hedner U. NovoSeven as a universal haemostatic agent. Blood Coagul Fibrinolysis. 2000; 11(suppl 1):S107-11. 3. Lin Y, Stanworth S, Birchall J et al. Recombinant factor VIIa for the prevention and treatment of bleeding in patients without haemophilia. Cochrane Database Syst Rev. 2011; 2:CD005011. 4. O’Connell KA, Wood JJ, Wise RP et al. Thromboembolic adverse events after use of recombinant human coagulation factor VIIa. JAMA. 2006; 295:293-8. 5. Johnson S, Blais D, Reichert E et al. Association between thromboembolic complications and recombinant factor VIIa when used in non-hemophiliacs. Pharmacotherapy. 2013; 33:e182. 6. Christenson S. Drug firm’s wooing made whistleblower suspicious (June 25, 2011). www.mysanantonio.com/news/ local/military/article/Drug-firm-s-wooingmade-whistleblower-suspicious-1440664. php#src=fb (accessed 2013 Oct 16). 7. Logan AC, Yank V, Stafford RS. Off-label use of recombinant factor VIIa in U.S. hospitals: analysis of hospital records. Ann Intern Med. 2011; 154:516-22. 8. Christenson S. Army again probing Fort Sam payments (June 14, 2011). www. mysanantonio.com/news/local/military/ article/Army-again-probing-Fort-Sampayments-1424304.php#src=fb (accessed 2013 Oct 16).
Unreliability of weighing elastomeric pumps for determining volume of fluid infused
E
lastomeric infusion pumps are used to deliver local anesthetic after surgery.1,2 Simplicity and portability are advantages over electronic pumps.3 Such infusions can be continued at home, but unlike electronic pumps, the precise flow rates may be difficult to monitor.4 Continuous brachial plexus block provides efficacious and safe analgesia after shoulder surgery; an accurate correlation between infusion rate and volume of delivered local anesthetic is important to maximize analgesia and decrease adverse effects, such as toxicity.5
602
The accuracy of elastomeric pump flow rates has been examined in vitro.6-8 Remerand et al.9 found that intermittent pump weighing was effective for monitoring local anesthetic delivery and recommended this method for flow monitoring. This raises the question: Can patients weigh their pumps at home and report variations from the expected local anesthetic delivery with accuracy? We conducted a study to examine whether weighing elastomeric pumps is an accurate indicator of the volume of local anesthetic delivered at the intersca-
Am J Health-Syst Pharm—Vol 72 Apr 15, 2015
9. Centers for Medicare and Medicaid Services. Medicare Part B drug average sales price. www.cms.gov/Medicare/MedicareFee-for-Service-Part-B-Drugs/McrPartBDrugAvgSalesPrice/index.html (accessed 2015 Jan 20). 10. Hébert PC, Fergusson D, Stanbrook MB. Off-label use of recombinant factor VIIa: why we need better drug monitoring. Can Med Assoc J. 2011; 183:26-7.
Agnes E. Aysola, M.D., Assistant Professor University of Florida College of Medicine Jacksonville Jacksonville, FL Monika M. Wahi, M.P.H., C.P.H., Lecturer Labouré College Milton, MA [email protected] Russell P. McKelvey, Pharm.D., Clinical Assistant Professor University of Florida College of Pharmacy Jacksonville Jacksonville, FL Cynthia Russell Gerdik, M.S.N., RN, Division Director Critical Care and Trauma Nursing UF Health Jacksonville Jacksonville, FL
The authors have declared no potential conflicts of interest. DOI 10.2146/ajhp140493
lene site after shoulder surgery. The potential adverse effects of catheter-related flow problems were also considered. Eighteen patients who had undergone shoulder surgery had their elastomeric pumps weighed for 24 hours postoperatively. After catheter insertion, 400 mL of ropivacaine 0.2% was used to fill an On-Q pump with Select-a-Flow (Kimberly-Clark, Roswell, GA). Flow rates were set between 6 and 10 mL/hr. Flow rate changes were made at weighing times. The pumps were weighed every 2 hours by trained nurses. The assumption was made that, at room temperature, 1 g of ropivacaine equated to 1 mL.9 An Continued on page 604
Letters Continued from page 602
assessment of the catheter was made at the end of the study period for physical problems. To validate the accuracy of the scales and weighing method, one additional pump was assessed in vitro using the same protocol where the delivered volume was recorded. The predicted local anesthetic volume for the time interval was compared to the weight and expressed as (weight change – predicted volume)/predicted volume, to give the percentage variation above or below the expected volume delivered. Of 174 measurements, 75 (43%) were within 20% of predicted values. Six of 18 pumps had weight variations greater than 100% from expected. For the in vitro pump, 8 of 12 readings were within 15% of the expected flow rate; 4 readings were within 25% of the expected flow rate. The variation between weight and volume never exceeded 15%; the median variation was 2.5% (–5% to 15%). Elastomeric pumps can deliver up to 15% above the predicted flow rates in the first few hours of delivery and as the pump nears completion.6 Other causes of increased flow include external compression on the pump or an increase in temperature, as when a pump is used for a febrile patient. More commonly, flow rates are lower than expected due to catheter occlusion.9 However, these physical factors are unlikely to explain the reading variations that we report; we hypothesize that much of the variance from predicted values was due to measurement problems. The lowest value (492% below that predicted) is not possible without the pump gaining weight, and the highest value (755% above predicted) implies leakage, which was not evident. Variations of weight exceeding 100% of the expected value were present in 6 of 18 patients; in 5 of these patients, there was an immediate correction within 2 subsequent readings. The single in vitro measurements showed less variation from expected measurements than the patient series. The natural assumption would be that this is because of the lack of physical causes of variation in vivo. However, a
604
lack of observable problems with the infusion and the absence of infusion failure strongly suggest measurement error. The mobile interscalene site and the physical limitations of the catheter may predict a high rate of occlusion and lower than predicted flow rates. However, we observed an even spread of lower-thanexpected and higher-than-expected readings, which supports measurement error. In light of our findings, we question the recommendation that weighing is a reliable means of tracking local anesthetic delivery with elastomeric pumps. We suggest the use of a pump with a proven correlation between the digital flow rate and the volume delivered. This would improve the accuracy of local anesthetic delivery and enhance analgesic efficacy and patient safety. 1. Ilfeld BM, Le LT, Ramjohn J et al. The effects of local anesthetic concentration and dose on continuous infraclavicular nerve blocks: a multicenter, randomized, observer-masked, controlled study. Anesth Analg. 2009; 108:345-50. 2. Ilfeld BM, Esener DE, Morey TE, Enneking FK. Ambulatory perineural infusion: the patients’ perspective. Reg Anesth Pain Med. 2003; 28:418-23. 3. Skryabina EA, Dunn TS. Disposable infusion pumps. Am J Health-Syst Pharm. 2006; 63:1260-8. 4. Ganapathy S, Amendola A, Lichfield R et al. Elastomeric pumps for ambulatory patient controlled regional analgesia. Can J Anaesth. 2000; 47:897-902.
5. Ilfeld BM, Morey TE, Wright TW et al. Interscalene perineural ropivacaine infusion: a comparison of two dosing regimens for postoperative analgesia. Reg Anesth Pain Med. 2004; 29:9-16. 6. Ilfeld BM, Morey TE, Enneking FK. Delivery rate accuracy of portable, boluscapable infusion pumps used for patientcontrolled continuous regional analgesia. Reg Anesth Pain Med. 2003; 28:17-23. 7. Ilfeld BM, Morey TE, Enneking FK. Portable infusion pumps used for continuous regional analgesia: delivery rate accuracy and consistency. Reg Anesth Pain Med. 2003; 28:424-32. 8. Ilfeld BM, Morey TE, Enneking FK. The delivery rate accuracy of portable infusion pumps used for continuous regional analgesia. Anesth Analg. 2002; 95:1331-6. 9. Remerand F, Vuitton AS, Palud M et al. Elastomeric pump reliability in postoperative regional anesthesia: a survey of 430 consecutive devices. Anesth Analg. 2008; 107:2079-84.
John R. Cormack, M.B.B.S., FANZCA, Consultant Anaesthetist [email protected] Andrew Iliov, M.B.B.S., Anaesthesia Registrar Roman Kluger, M.B.B.S., FANZCA, Consultant Anaesthetist Anaesthetic Department St. Vincent’s Hospital Melbourne, Australia
The authors have declared no potential conflicts of interest. DOI 10.2146/ajhp140556
Being an academic part-time pharmacist
R
ecently I participated in a symposium entitled “Practitioner’s Choices” at the 2014 Eastern States Conference for Pharmacy Residents and Preceptors. The planning committee invited pharmacists in three stages of their careers—new practitioners, midcareer practitioners (me), and senior practitioners—to reflect on life decisions they had made and how these decisions affected their pharmacy career. I was specifically asked to address the choices that led to my current position as a part-time clinical pharmacist in
Am J Health-Syst Pharm—Vol 72 Apr 15, 2015
a large academic tertiary health system. Initially I struggled with how to deliver a helpful yet evidence-based view on such a personal topic. After reading a blog post written by former ASHP president Sara White,1 I was inspired to tell my story. This blog highlighted a Harvard Business Review article that addressed work–life balance2; what was missing from this article were options for balancing work–life issues while being employed part-time. Five years ago, with the assistance of my pharmacy director, I was able to de-
Copyright of American Journal of Health-System Pharmacy is the property of American Society of Health System Pharmacists and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
vey hospitals to better understand current patterns of off-label rFVIIa use to determine the administrative safeguards implemented to reduce off-label use (if any) and how effective these safeguards are. These survey data should be combined with administrative data containing hospital-level characteristics to identify hospital- and provider-level factors associated with off-label rFVIIa use. By understanding what hospital and provider attributes are associated with the most off-label rFVIIa use, recommendations can be developed. Hospital-based pharmacists may have the strongest impetus to reduce off-label rFVIIa use, as the high price of rFVIIa significantly affects their department budget. Hospital-based pharmacists also often have access to accurate data, such as the number of patients who received rFVIIa, the number of doses administered, the department that placed the orders, and cost and purchasing data. As such, hospital-based pharmacists may be the ideal individuals to target for surveying. This sharp turn in research focus for off-label rFVIIa is necessary to acknowledge the patient safety issue raised by the
2012 Cochrane meta-analysis1 while promoting cost-effectiveness in healthcare. 1. Simpson E, Lin Y, Stanworth S et al. Recombinant factor VIIa for the prevention and treatment of bleeding in patients without haemophilia. Cochrane Database Syst Rev. 2012; 3:CD005011. 2. Hedner U. NovoSeven as a universal haemostatic agent. Blood Coagul Fibrinolysis. 2000; 11(suppl 1):S107-11. 3. Lin Y, Stanworth S, Birchall J et al. Recombinant factor VIIa for the prevention and treatment of bleeding in patients without haemophilia. Cochrane Database Syst Rev. 2011; 2:CD005011. 4. O’Connell KA, Wood JJ, Wise RP et al. Thromboembolic adverse events after use of recombinant human coagulation factor VIIa. JAMA. 2006; 295:293-8. 5. Johnson S, Blais D, Reichert E et al. Association between thromboembolic complications and recombinant factor VIIa when used in non-hemophiliacs. Pharmacotherapy. 2013; 33:e182. 6. Christenson S. Drug firm’s wooing made whistleblower suspicious (June 25, 2011). www.mysanantonio.com/news/ local/military/article/Drug-firm-s-wooingmade-whistleblower-suspicious-1440664. php#src=fb (accessed 2013 Oct 16). 7. Logan AC, Yank V, Stafford RS. Off-label use of recombinant factor VIIa in U.S. hospitals: analysis of hospital records. Ann Intern Med. 2011; 154:516-22. 8. Christenson S. Army again probing Fort Sam payments (June 14, 2011). www. mysanantonio.com/news/local/military/ article/Army-again-probing-Fort-Sampayments-1424304.php#src=fb (accessed 2013 Oct 16).
Unreliability of weighing elastomeric pumps for determining volume of fluid infused
E
lastomeric infusion pumps are used to deliver local anesthetic after surgery.1,2 Simplicity and portability are advantages over electronic pumps.3 Such infusions can be continued at home, but unlike electronic pumps, the precise flow rates may be difficult to monitor.4 Continuous brachial plexus block provides efficacious and safe analgesia after shoulder surgery; an accurate correlation between infusion rate and volume of delivered local anesthetic is important to maximize analgesia and decrease adverse effects, such as toxicity.5
602
The accuracy of elastomeric pump flow rates has been examined in vitro.6-8 Remerand et al.9 found that intermittent pump weighing was effective for monitoring local anesthetic delivery and recommended this method for flow monitoring. This raises the question: Can patients weigh their pumps at home and report variations from the expected local anesthetic delivery with accuracy? We conducted a study to examine whether weighing elastomeric pumps is an accurate indicator of the volume of local anesthetic delivered at the intersca-
Am J Health-Syst Pharm—Vol 72 Apr 15, 2015
9. Centers for Medicare and Medicaid Services. Medicare Part B drug average sales price. www.cms.gov/Medicare/MedicareFee-for-Service-Part-B-Drugs/McrPartBDrugAvgSalesPrice/index.html (accessed 2015 Jan 20). 10. Hébert PC, Fergusson D, Stanbrook MB. Off-label use of recombinant factor VIIa: why we need better drug monitoring. Can Med Assoc J. 2011; 183:26-7.
Agnes E. Aysola, M.D., Assistant Professor University of Florida College of Medicine Jacksonville Jacksonville, FL Monika M. Wahi, M.P.H., C.P.H., Lecturer Labouré College Milton, MA [email protected] Russell P. McKelvey, Pharm.D., Clinical Assistant Professor University of Florida College of Pharmacy Jacksonville Jacksonville, FL Cynthia Russell Gerdik, M.S.N., RN, Division Director Critical Care and Trauma Nursing UF Health Jacksonville Jacksonville, FL
The authors have declared no potential conflicts of interest. DOI 10.2146/ajhp140493
lene site after shoulder surgery. The potential adverse effects of catheter-related flow problems were also considered. Eighteen patients who had undergone shoulder surgery had their elastomeric pumps weighed for 24 hours postoperatively. After catheter insertion, 400 mL of ropivacaine 0.2% was used to fill an On-Q pump with Select-a-Flow (Kimberly-Clark, Roswell, GA). Flow rates were set between 6 and 10 mL/hr. Flow rate changes were made at weighing times. The pumps were weighed every 2 hours by trained nurses. The assumption was made that, at room temperature, 1 g of ropivacaine equated to 1 mL.9 An Continued on page 604
Letters Continued from page 602
assessment of the catheter was made at the end of the study period for physical problems. To validate the accuracy of the scales and weighing method, one additional pump was assessed in vitro using the same protocol where the delivered volume was recorded. The predicted local anesthetic volume for the time interval was compared to the weight and expressed as (weight change – predicted volume)/predicted volume, to give the percentage variation above or below the expected volume delivered. Of 174 measurements, 75 (43%) were within 20% of predicted values. Six of 18 pumps had weight variations greater than 100% from expected. For the in vitro pump, 8 of 12 readings were within 15% of the expected flow rate; 4 readings were within 25% of the expected flow rate. The variation between weight and volume never exceeded 15%; the median variation was 2.5% (–5% to 15%). Elastomeric pumps can deliver up to 15% above the predicted flow rates in the first few hours of delivery and as the pump nears completion.6 Other causes of increased flow include external compression on the pump or an increase in temperature, as when a pump is used for a febrile patient. More commonly, flow rates are lower than expected due to catheter occlusion.9 However, these physical factors are unlikely to explain the reading variations that we report; we hypothesize that much of the variance from predicted values was due to measurement problems. The lowest value (492% below that predicted) is not possible without the pump gaining weight, and the highest value (755% above predicted) implies leakage, which was not evident. Variations of weight exceeding 100% of the expected value were present in 6 of 18 patients; in 5 of these patients, there was an immediate correction within 2 subsequent readings. The single in vitro measurements showed less variation from expected measurements than the patient series. The natural assumption would be that this is because of the lack of physical causes of variation in vivo. However, a
604
lack of observable problems with the infusion and the absence of infusion failure strongly suggest measurement error. The mobile interscalene site and the physical limitations of the catheter may predict a high rate of occlusion and lower than predicted flow rates. However, we observed an even spread of lower-thanexpected and higher-than-expected readings, which supports measurement error. In light of our findings, we question the recommendation that weighing is a reliable means of tracking local anesthetic delivery with elastomeric pumps. We suggest the use of a pump with a proven correlation between the digital flow rate and the volume delivered. This would improve the accuracy of local anesthetic delivery and enhance analgesic efficacy and patient safety. 1. Ilfeld BM, Le LT, Ramjohn J et al. The effects of local anesthetic concentration and dose on continuous infraclavicular nerve blocks: a multicenter, randomized, observer-masked, controlled study. Anesth Analg. 2009; 108:345-50. 2. Ilfeld BM, Esener DE, Morey TE, Enneking FK. Ambulatory perineural infusion: the patients’ perspective. Reg Anesth Pain Med. 2003; 28:418-23. 3. Skryabina EA, Dunn TS. Disposable infusion pumps. Am J Health-Syst Pharm. 2006; 63:1260-8. 4. Ganapathy S, Amendola A, Lichfield R et al. Elastomeric pumps for ambulatory patient controlled regional analgesia. Can J Anaesth. 2000; 47:897-902.
5. Ilfeld BM, Morey TE, Wright TW et al. Interscalene perineural ropivacaine infusion: a comparison of two dosing regimens for postoperative analgesia. Reg Anesth Pain Med. 2004; 29:9-16. 6. Ilfeld BM, Morey TE, Enneking FK. Delivery rate accuracy of portable, boluscapable infusion pumps used for patientcontrolled continuous regional analgesia. Reg Anesth Pain Med. 2003; 28:17-23. 7. Ilfeld BM, Morey TE, Enneking FK. Portable infusion pumps used for continuous regional analgesia: delivery rate accuracy and consistency. Reg Anesth Pain Med. 2003; 28:424-32. 8. Ilfeld BM, Morey TE, Enneking FK. The delivery rate accuracy of portable infusion pumps used for continuous regional analgesia. Anesth Analg. 2002; 95:1331-6. 9. Remerand F, Vuitton AS, Palud M et al. Elastomeric pump reliability in postoperative regional anesthesia: a survey of 430 consecutive devices. Anesth Analg. 2008; 107:2079-84.
John R. Cormack, M.B.B.S., FANZCA, Consultant Anaesthetist [email protected] Andrew Iliov, M.B.B.S., Anaesthesia Registrar Roman Kluger, M.B.B.S., FANZCA, Consultant Anaesthetist Anaesthetic Department St. Vincent’s Hospital Melbourne, Australia
The authors have declared no potential conflicts of interest. DOI 10.2146/ajhp140556
Being an academic part-time pharmacist
R
ecently I participated in a symposium entitled “Practitioner’s Choices” at the 2014 Eastern States Conference for Pharmacy Residents and Preceptors. The planning committee invited pharmacists in three stages of their careers—new practitioners, midcareer practitioners (me), and senior practitioners—to reflect on life decisions they had made and how these decisions affected their pharmacy career. I was specifically asked to address the choices that led to my current position as a part-time clinical pharmacist in
Am J Health-Syst Pharm—Vol 72 Apr 15, 2015
a large academic tertiary health system. Initially I struggled with how to deliver a helpful yet evidence-based view on such a personal topic. After reading a blog post written by former ASHP president Sara White,1 I was inspired to tell my story. This blog highlighted a Harvard Business Review article that addressed work–life balance2; what was missing from this article were options for balancing work–life issues while being employed part-time. Five years ago, with the assistance of my pharmacy director, I was able to de-
Copyright of American Journal of Health-System Pharmacy is the property of American Society of Health System Pharmacists and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
