Pharmacy-based special infant formula service

The preparation of infant formulas by a hospital pharmacy for a 280-bed department of pediatrics is discussed. A formulary of acceptable special therapeutic formulas was developed in conjunction with the pediatricians. Space and equipment originally intended for intravenous admixture and total parenteral nutrition services were supplemented to include special infant formula services. The personnel and equipment requirements, and quality control procedures, of the service are discussed.     

Clinical evaluation of a new programmable syringe infusion pump

A new programmable syringe infusion pump, Auto Syringe Model AS 40 A, was evaluated for infusion of muscle relaxants, vasodilators and opioids in 4 surgical patients. Every drug mentioned above was easily adjusted according to surgical requirement in these patients. Auto Syringe Model AS40A is light and compact. Its major advantages lie in the mechanisms for delivery of a bolus dose and automated delivery of intermittent doses, automatic rate calculation, and the applicability to various sizes of syringes. Auto Syringe Model AS40A was found to be very useful for intravenous infusion of drugs.     

Portable data acquisition and control apparatus for implanted drug infusion pump interrogation

Now that implantable drug infusion pumps are well established clinically, methods for diagnosing suspected pump failures are needed. The authors previously constructed a benchtop data acquisition and control apparatus to assist our work in developing new pump technology. Although this device is technically capable of in vivo pump monitoring, it is cumbersome. Thus, they recently created a portable interrogation unit with more limited features. This portable pump interrogation apparatus consists of a 32 bit MS-DOS labtop computer, data acquisition software, an analog/ASCII interface, a pressure transducer, and appropriate fluid conduits. Communication between the device and the implanted pump is via a percutaneous needle puncture of the drug reservoir refill septum. This procedure is identical to that employed in a standard pump refill. Pump performance is evaluated by incrementally filling the pump reservoir while simultaneously measuring reservoir pressure. The resulting data are presented on the computer screen as a plot of pressure versus volume that quickly and simply either eliminates or confirms the reservoir pressure source as a failure mode. Diagnostic runs are saved on file for archival purposes. Their benchtop apparatus has been a valuable and reliable tool over many years of use. The authors believe that their portable apparatus will be equally beneficial.     

In-111 DTPA to evaluate the patency of an implanted intrathecal infusion pump

In-111 DTPA cisternography confirmed placement and patency of a slow flow, implanted, programmable, intrathecal morphine infusion pump system. Other radiologic methods failed and were impractical.     

Continuous intrathecal meperidine via an implantable infusion pump for chronic, nonmalignant pain

OBJECTIVE: To report a continuous infusion of intrathecal meperidine via an implanted infusion pump for nonmalignant, chronic pain. CASE SUMMARY: A 69-year-old white woman had chronic, nonmalignant low-back pain and bilateral leg pain. Multiple drug therapies and other interventional techniques had failed. The patient achieved significant pain relief by a continuous infusion of intrathecal meperidine via an implanted infusion pump. DISCUSSION: To our knowledge, this is the first report of meperidine administered intrathecally by continuous infusion. Continuous infusion of intrathecal and epidural opiates by implanted infusion pumps is becoming more widely recognized as an alternative treatment for patients with chronic, benign pain. Epidural and intrathecal meperidine is an effective analgesic for short-term surgical procedures. Data reporting effective relief and safety with continuous intrathecal meperidine remain limited. CONCLUSIONS: Continuous intrathecal meperidine via an implantable infusion pump may be an effective alternative in the treatment of chronic pain.     

Decision matrix for selection of patients for a home infusion therapy program

Managed care and escalating healthcare costs have affected all aspects of clinical practice. Today's practitioners must evaluate each patient and clinical situation to select the appropriate intravenous delivery venue to improve the chances of producing a satisfactory outcome. The IV venue discussed in this article will focus on the key elements of identifying patients who will benefit from receiving pharmacomedical services in a home infusion therapy program.     

Continuous epidural analgesia in the obstetric patient: a feasibility study using a mechanical infusion pump

Eleven patients in uncomplicated labour received a continuous infusion of 0-125 or 0-25% bupivacaine solutions into the epidural space, using a simple rotary pump. Maternal and umbilical cord venous plasma bupivacaine levels were measured and were found to be within safe limits for mother and baby. Incidence of complications were noted.     

Platelet and neutrophil distributions in pump oxygenator circuits. III. Influence of nitric oxide gas infusion

The authors used quantitative gamma scintigraphy to evaluate the influence of nitric oxide gas on platelet and neutrophil deposition in Cobe Duo microporous oxygenators during cardiopulmonary bypass (CPB). The effects of nitric oxide gas on circulating platelet and neutrophil counts and platelet function also were assessed. Animals were prepared by standard methods. Cells were harvested, labeled (111 In platelet and 99mTc neutrophil), infused, and recirculated. Nitric oxide gas, a guanylate cyclase pathway promoter, was infused int he Duo gas port at 500 ppm (t = 0-60 min), increased to 1,000 (t = 60-80 min), and stopped (final, 10 min). Images were taken at 10-15 min intervals during CPB. Standard isotope image corrections were made. No differences between nitric oxide gas and control experiments were observed for flow, pressure, hematocrit, or replacement volume. Nitric oxide gas infusion significantly (p < 0.05) reduced both platelet adherence to the oxygenator and in vitro platelet aggregation. Neutrophil adhesion tended to be lower, and circulating platelet and neutrophil counts tended to be higher with nitric oxide gas infusion. Results of in vitro aggregometry studies using rabbit platelets indicate that the class V phosphodiesterase inhibitor zaprinast can strongly enhance the inhibitory effects of nitric oxide. The authors conclude nitric oxide gas is a promising platelet sparing agent in the setting of CPB.     

Misperfusion of the liver during hepatic artery infusion chemotherapy: value of preoperative angiography and postoperative pump scintigraphy

OBJECTIVE: One purpose of this study was to determine if patients who have anatomic variations in their hepatic arteries are at increased risk for complications associated with the use of intrahepatic arterial infusion pumps. We also tried to determine the value of perfusion studies obtained with 99mTc-microspheres or 99mTc-macroaggregated albumin in detecting postoperative hepatic or visceral misperfusion and in predicting complications in patients with anatomic variants despite pre- or intraoperative attempts to correct the arterial abnormality. SUBJECTS AND METHODS: We prospectively compared findings on scintigrams obtained after delivering the radionuclide through intrahepatic arterial infusion pumps with anatomic variations in hepatic arteries seen on celiac and superior mesenteric hepatic arteriograms obtained before placement of the pump in 49 consecutive patients with colon carcinoma metastatic to the liver. RESULTS: Despite pre- or intraoperative attempts to correct arterial abnormalities to ensure optimal perfusion of the liver in 24 patients with hepatic arterial anomalies seen on preoperative arteriograms, only two patients had normal findings on postoperative perfusion studies performed with 99mTc-microspheres and/or 99mTc-macroaggregated albumin. Abnormalities included perfusion of extrahepatic organs, including the spleen in 12 patients, stomach in seven, bowel in four, and pancreas in three. Eight patients had no perfusion of the left lobe of the liver, and three had no perfusion of the right lobe. Two patients had minimal or no perfusion of both lobes. In 23 of 25 patients with no demonstrable variations in vascular anatomy on preoperative celiac and superior mesenteric arteriograms, findings on hepatic pump scintigrams were normal. Of the 24 patients with abnormal scintigraphic findings, 20 had subsequent clinical complications. However, only two of the 25 patients with normal scintigraphic findings had clinical complications. CONCLUSION: Our results indicate that patients with anatomic variations in the hepatic arterial system are at high risk for misperfusion during chemotherapy despite pre- or intraoperative efforts to alter the perfusion for chemotherapeutic agents delivered by intrahepatic arterial infusion pumps. Misperfusion can be detected by using pump scintigraphy, and therefore patients should be closely monitored with 99mTc-macroaggregated albumin perfusion studies to ensure successful delivery of the chemotherapeutic agents and to avoid serious clinical complications caused by inadvertent perfusion of other organs.     

Evaluation of estimated blood concentration of propofol on wake-up using "ConGrase", a software to control the syringe pump for propofol infusion

We developed a software to control a Graseby 3500 syringe pump for propofol infusion through the serial port of Apple Macintosh/Power-Macintosh computer. This software, "ConGrase", was developed with Metrowerks CodeWarrior Professional (CWP 1) and PowerPlant framework using C++. ConGrase communicates with the syringe pump at least every three seconds, and calculates the estimated blood concentration (EBC) of propofol based on the amount of propofol actually infused by applying either the Euler or Runge-Kutta method using the three-compartment pharmacokinetic model. The parameter sets reported by Gepts et al. are used. ConGrase was released at the 44 th Annual Meeting of the Japan Society of Anesthesiology, and is distributed freely. The mean and S.D. of the emergence EBC calculated by ConGrase were 1.22 micrograms.ml-1 and 0.16 microgram.ml-1, respectively. These values are almost the same as values already reported outside Japan. The necessary wake-up time can be calculated with this estimated concentration. With this system, anesthetists can control the EBC at the required level and avoid long delays before the patients wake up after anesthesia.     

Noninvasive pump flow estimation of a centrifugal blood pump

A flow rate estimating method was investigated for a centrifugal blood pump developed in our institute. The estimated flow rate was determined by the power consumption, the rotating speed of the motor, and the hematocrit value. The power consumption and the rotating speed of the motor were measured with a wattmeter. The examinations were performed in a closed mock loop filled with goat blood with hematocrit values of 21.5%, 28%, 34%, and 42%. Measured values of blood viscosity were 2.47, 3.09, 3.71, and 5.07 mPa.s at a share rate of 37.5/s, respectively. A linear correlation between the power consumption and the pump flow rate was observed in all hematocrit values. But variations in hematocrit caused a difference in the flow rate up to 1.1 L/min at the same power consumption and rotating speed. Effects of blood viscosity on the flow estimation were corrected by the hematocrit value. The value of the coefficient of determination, R2, between the estimated flow rate and the measured flow rate was 0.988. These results may indicate that the flow estimating method calculated by the power consumption of the motor, the rotating speed, and the hematocrit value is useful in the clinical situation.     

Microporous infusion catheter

Subglottic laryngitis (croup) is a common disease in children. Its etiology is not quite clear. Thirty children (28 boys and 2 girls), aged between 4 months and up to 5 years (mean 3.6 years), have been hospitalized for the inflammatory swelling of the subglottic space. Laboratory and allergy tests, including: immunoglobulins A, G, M, total IgE, specific IgE blood levels, blood T cell level, and NBT test have been carried out in all children. An increased IgE blood level have been noted in 15 (50%) children, and significantly increased blood level of specific IgE in 10 (33%) children of this subgroup. Blood IgA, IgG, and IgM level have been normal in all children. An increase in NBT test have been seen in 10 (33) children, and a decrease in the number of T cells in 21 (70%) children.     

Saline infusion sonohysterography

Saline infusion sonography enhances endovaginal ultrasound examination of the uterine cavity. It is easily and rapidly performed at minimal cost. It is well tolerated by patients and virtually devoid of complications. It can prevent further invasive diagnostic procedures in some patients and optimize the preoperative triage process for those patients who will require therapeutic intervention.     

High-tech homecare infusion therapies

Dramatic changes in health care delivery have created an increased reliance on ambulatory care. Adults and children increasingly are receiving infusions of intravascular medication or fluid in the home for a wide array of conditions. Several therapies have been adapted to the home, including chemotherapy, BRMs, TPN, blood components, anti-infectives, analgesics, inotropic agents, and investigational drugs. High-technology therapy in the home mandates safe and reliable vascular access to maximize positive outcomes, independence, and self-care; minimize costs and disruption of daily activities and work schedules; and enhance client and family adjustments and satisfaction. Currently, the four main VADs for vascular access are central venous catheters (CVCs), peripherally inserted central catheters (PICCs, implantable infusion ports, and external or implantable ambulatory infusion pumps.     

Splenic arterial portal infusion

A significant number of gynecologic oncologic patients require intravenous chemotherapy. Peripheral venous access frequently becomes difficult, necessitating reliable central venous access. This study was done to retrospectively review our experience with completely implanted venous access ports (ports). There were 100 women from 1984 to 1992 who received 115 ports. These ports remained in situ on average 350 +/- 2.3 days for a total of 110 patient years; 38 ports were in place for more than one year. An average of six courses of chemotherapy were given through each port. There was no statistically significant difference demonstrated in the complication rate secondary to site or side of placement (p = 0.5). Catheter performance in 77 percent of the patients was impeccable. We conclude that implantable ports are a safe and reliable method of chronic venous access in gynecologic oncologic patients requiring intravenous chemotherapy. Although ports reduce the number of complications and manipulations associated with percutaneous catheters, they are not devoid of problems.