Initial Infusions Research Articles

Endocrine complications in intensive care unit patients

Summary This review addressed end organ endocrine dysfunction or failure associated with diabetes, thyrid abnormalities, adrenal insufficiency, pheochromocytoma, and pituitary dysfunction, as well as the issue of corticosteroid replacement or pharmacologic application in the critically ill. Diabetes is a common cause that precipitates ICU admission or is a secondary factor in the routine care of the stressed and critically ill medical or surgical patient. Early identification of hypoglycemia is crucial to avoid potentially devastating neurologic sequale. Increasing data on the deleterious effects on immune function, wound healing, and recovery from ischemia has prompted the use of regular insulin infusions in acute and critically ill patients in an attempt to maintain euglycemia. 58 The large Diabetes Mellitus Insulin Glucose Infusion in Acute Myocardial Infarction trial reported the acute and long-term benefits of initial infusions of glucose, insulin, and potassium combined with tighter glycemic control in diabetics with acute myocardial infaretion. 15 DKA and NKHC share several common features and represent severe endpoints of abnormal glucose and fat metabolism. These entities require timely diagnosis and therapy and rapid identification of the inciting cause to limit morbidity and mortality. Cerebral edema is a relatively uncommon development in DKA, occurring most often in children and resulting in severe neurologic sequalae in many patients. Asymptomatic thyroid disease is fairly prevalant in the United States. Extremes of dysfunction may result in thyroid storm or myxedema coma, both requiring rapid identification and therapy. Thyroid hormone synthesis and peripheral metabllism and function are markedly altered in acute illness. The differentiation of thyroid activity has been markedly improved over the past several decades with the wide application of increasingly sensitive tests, such as the TSH, free T4, and free T3. The euthyroid sick syndrome is recognized as a “normal” physiologic response to critical illness. Supplementation with exogenous thyroid hormone in patients with euthyroid sick syndrome is not indicated and may be deleterious. Adrenal homeostasis is crucial for adequate response to life-threatening trauma or critical illness. The body is normally able to increase glucocorticoid release by a factor of roughly 10-fold. As the population ages and the use of corticosteroids increases, AI should be considered in any hemodynamically unstable patient. Relative AI is being recognized more commonly, particularly as a process in sepsis and septic shock. Recent preliminary data from an ongoing multicenter trial supports the short-term administration of physiologic, stress doses of glucocorticoids in such patients. Patients with pheochromocytoma, and uncommon chromaffin cell tumor, present to the ICU on occasion for acute diagnosis and initiation of therapy or for postoperative management. These tumors are most commonly adrenal in origin, secrete excessive norepinephrine, and may be associated with familial endocrinopathies. Alpha blockade is the mainstay of initial therapy followed by intravascular fluid expansion and judicious use of β blockade and calcium channel blockade in select patients. Pituitary pathology should be considered in patients with a period of significant shock; those who have undergone frontal craniotomy or pituitary resection; those who sustained head injury; or those with cerebral thrombosis who develop polyuria, hypothermia, electrolyte abnormalities, or hyperosmolarity. On occasion, nephrogenic DI develops in patients with renal pathology or secondary to medications, such as lithium or amphotericin B. Patients with central DI should be treated with fluids, have their serum sodium corrected, and receive DDAVP. Patients with suspected or known panhypopituitarism should be treated with appropriate doses of adrenal and thyroid hormone replacement.

Rituximab: An innovative therapy for non-Hodgkin's lymphoma

The epidemiology, etiology, classification, and treatment of non-Hodgkin's lymphoma (NHL) are reviewed, and rituximab, a newly available therapy, is discussed. NHL comprises a group of lymphoproliferative disorders the frequency of which continues to rise. Although many classification systems exist for identifying specific histological subtypes, NHL is generally divided into indolent (low-grade) and aggressive (intermediate- and high-grade) forms. Low-grade NHL is characterized by a slowly progressive, continually relapsing course, with eventual transformation to a more rapidly progressive form that is usually fatal. Several options are available for the management of indolent NHL; none is curative. Rituximab, a human-mouse monoclonal antibody that targets the CD20 antigen expressed in over 90% of B-cell NHLs, provides an alternative to conventional chemotherapy that is relatively safe and effective. In a Phase III trial involving 166 patients with relapsed or refractory low-grade B-cell NHL, rituximab produced an overall response of 48%, with 20 of 80 responders still in remission more than 36 months after treatment. Study results in patients with bulky disease and those requiring retreatment have also been encouraging. Most adverse effects associated with rituximab are mild to moderate. Infusion-related reactions occur more commonly during initial infusions and in patients with evidence of increased tumor burden but can be effectively managed with premedication, supportive care, and adjusted infusion rates. Hematologic effects are generally mild and transient, and adverse immune responses are rare. Rituximab is an alternative to conventional chemotherapy for the treatment of relapsed or refractory low-grade or follicular CD20-positive B-cell NHL.

A Phase II Multicenter Study of CAMPATH-1H Antibody in Previously Treated Patients with Nonbulky Non-Hodgkin's Lymphoma

CAMPATH-1H is a humanized antilymphocyte monoclonal antibody (mAb) directed against the CD52 antigen expressed on normal and malignant lymphocytes. We report the results of a multicenter phase II trial using intravenous CAMPATH-1H in previously treated patients with nonbulky non-Hodgkin's lymphoma (NHL) or minimal residual NHL. Sixteen previously treated patients with nonbulky NHL and two patients with minimal residual NHL, were treated with CAMPATH-1H. Changes in peripheral blood lymphocyte subsets were analyzed by multiparameter flow cytometric techniques in eleven patients. The 18 patients enrolled in the studies received CAMPATH-1H for a median duration of 6 weeks (range, 3 to 14 weeks), and a median cumulative dose of 470 mg (range, 180 to 1185 mg). Two of the sixteen patients with nonbulky NHL achieved a complete response (CR) and one patient achieved a partial response (PR). One of the two patients with minimal residual NHL achieved a molecular CR. Infusional complications were seen with the majority of patients but were more common with initial infusions. Significant hematologic toxicity was also observed with grade 3/4 thrombocytopenia (n = 10), grade 3/4 neutropenia (n = 4) and grade 3 anemia (n = 3). Due to excessive infectious complications observed with the patients enrolled, the trials were terminated early. Anti-tumor activity was demonstrated in a small subset of previously treated low-grade lymphoma patients with nonbulky or minimal residual disease. Future studies evaluating the effect of different drug schedules, modes of mAb administration, and concurrent use of prophylactic antibiotics/antiviral/antifungal agents to optimize anti-tumor activity and limit infectious toxicities are planned.

Maintenance therapy in Crohn's disease.

Symptoms of active Crohn's disease may respond to one or more of a number of classes of drug therapies. These include systemic glucocorticoids, budesonide, sulphasalazine, mesalazine (5-aminosalicylates), immunosuppressive agents and antibiotics. More recently, a chimeric mouse-human antibody to tumour necrosis factor (infliximab) has been shown to induce clinical remission and endoscopic improvement in patients with moderately active Crohn's disease refractory to other therapies. Despite this wide range of existing therapies and the potential of emerging biological therapies, recurrent Crohn's disease continues to be a major impediment to the fulfilment of a normal lifestyle and optimal quality of life for patients with Crohn's disease. Many drugs known to be effective for the treatment of active disease have been tried as maintenance therapy to prevent disease relapse or recurrence following medical or surgical therapy. The available evidence suggests that most of these drugs are not as useful in maintaining remission as they are in inducing it. Systemic glucocorticoids, budesonide, mesalazine (5-aminosalicylates), sulphasalazine and antibiotics are all associated with either marginal therapeutic gain in the setting of maintenance therapy or unacceptable long term toxicity. The immunosuppressive agents azathioprine, 6-mercaptopurine and methotrexate have been shown to have a beneficial effect in maintaining remission and may be helpful as steroid-sparing agents. Repeated infusions of antitumour necrosis factor antibody maintain the improvements observed after one or two initial infusions. The relative long term safety, efficacy and cost effectiveness of the various choices of maintenance therapy remain to be determined.

Advantages of continuous hyperpolarized arrest with pinacidil over St. Thomas' hospital solution during prolonged ischemia

Objective: The potassium channel opener, pinacidil, has been shown to be an effective cardioplegic agent over short periods of ischemia. However, clinical settings typically involve longer ischemic periods. This study tested the hypothesis that myocardial protection with a potassium channel opener is feasible during prolonged periods of arrest and is comparable with the traditional St. Thomas' Hospital solution. Methods: With a blood-perfused, isolated rabbit heart model, hearts underwent 1 hour of global normothermic ischemia followed by 30 minutes of reperfusion. During ischemia, three different cardioplegic solutions were administered either intermittently by infusion every 20 minutes or as continuous low-flow cardioplegia (150 ml total volume in all groups): (1) Krebs-Henseleit solution alone (control), (2) Krebs-Henseleit solution + pinacidil (50 μmol/L), or (3) St. Thomas' Hospital solution. Initial potassium channel opener infusions contained 5 mmol/L procaine. Postreperfusion systolic function (percent of developed pressure) was measured. Compliance changes were integrated from the end-diastolic pressure/volume relationships. Results: For intermittent cardioplegia, only St. Thomas' Hospital solution improved function (62.5% ± 4.0%) versus control (43.6% ± 3.3%, p < 0.001). However, with continuous cardioplegia, only pinacidil (75.6% ± 4.8%) exceeded control (62.7% ± 2.2%, p < 0.001) and was significantly better than St. Thomas' Hospital solution. Compared with the intermittent control group, all other groups showed significant preservation of preischemic diastolic properties. Conclusions: Myocardial protection during a longer, more clinically relevant ischemic period is feasible with a potassium channel opener only when it is given continuously. Continuous low-flow pinacidil cardioplegia was superior to St. Thomas' Hospital solution given either as an intermittent or continuous infusion. (J Thorac Cardiovasc Surg 1998;116:131-8)

Repeat intra-arterial papaverine for recurrent cerebral vasospasm after subarachnoid haemorrhage.

We assessed the prevalence of recurrent vasospasm following failure of intra-arterial papaverine and the efficacy of repeat intra-arterial infusions of papaverine for control of recurrent vasospasm. Of 24 patients treated with intra-arterial papaverine for vasospasm following aneurysm surgery, 12 did not improve clinically after the initial treatment; 9 received second or third infusions on consecutive days; 6 received only a second infusion; and 3 received a third. Superselective infusion into the intracranial arteries was performed in all nine cases. Despite angiographic improvement after the initial or second infusions, all nine patients showed varying degrees of recurrent vasospasm at the time of the second or third treatment. Within 24 h of a second infusion, three of the six patients had significant clinical improvement, and one of these showed marked improvement soon after a third infusion. Our preliminary results suggest that repeat papaverine infusion may be a way of controlling recurrent or recalcitrant vasospasm.

Physician-Guided Treatment Compared With a Heparin Protocol for Deep Vein Thrombosis

Effective heparin therapy, defined by therapeutic prolongation of the activated partial thromboplastin time (APTT), decreases the risk of recurrent venous thromboembolism. Achieving therapeutic prolongation of the APTT within 24 hours of the start of heparin therapy has proved difficult. We hypothesized that a protocol that delivered high initial heparin infusions to patients without identifiable risk for bleeding complications would decrease the time to achieve a therapeutic anticoagulant effect without increasing the incidence of major bleeding complications. To test this hypothesis, we studied concurrent patient cohorts. We defined a therapeutic anticoagulant effect (APTT > 55 seconds) to be an APTT more than 1.5 times the upper limit of normal. Twenty patients with acute symptomatic deep vein thrombosis received a 5000-U heparin bolus, followed by 1680 U/h (low risk to bleed) or 1240 U/h (high risk to bleed), adjusted by protocol-directed response to APTT results. Forty-eight patients with deep vein thrombosis were treated by their physicians. The Kaplan-Meier method was used to examine the proportion of patients who achieved an APTT greater than 55 seconds as a function of time. The two study cohorts did not differ with respect to age, weight, or risk factors for venous thromboembolism. Analysis of Kaplan-Meier curves showed that the heparin protocol decreased the time to achieve a therapeutic anticoagulant effect (P = .025). Ten (91%) of 11 patients (95% confidence interval, 59% to 100%) without risks to bleed who were treated by the heparin protocol and 29 (60%) of 48 patients (95% confidence interval, 45% to 74%) not treated by the protocol had an initial therapeutic APTT (P = .006). A protocol that delivers higher initial heparin infusions to patients without identifiable risks for bleeding decreases the time needed to achieve therapeutic prolongation of APTT, when compared with nonprotocol physician management.

Sufentanil Citrate and Morphine/ Bupivacaine as Alternative Agents in Chronic Epidural Infusions for Intractable Non-Cancer Pain

Intraspinal narcotic (usually intrathecal morphine) infusions with implanted pumps are increasingly used in patients with intractable chronic pain not caused by cancer. In some patients, pain control is difficult with infusions of morphine. Seven patients with diagnoses of arachnoiditis, epidural scarring, and/or vertebral body compression fracture were treated with alternative solutions in an epidural route. For maximal flexibility, Medtronic implanted programmable infusion pumps with catheters to T6-T10 were used, and pain was monitored by verbal pain scales. In three patients, epidural infusions of morphine in 0.5% bupivacaine (MS-MARC) resulted in little or no pain relief without significant side effects (e.g., headache, nausea, or vomiting). In these same patients, epidural infusions of sufentanil citrate resulted in pain scale reductions of 92%, 82%, and 40%, respectively, with no side effects. Four other patients found more effective pain relief when switched from initial sufentanil citrate infusions to MS-MARC. Pain scale reductions (with no side effects) were 92%, 76%, 59%, and 47% in these patients. Pain relief and minimal side effects with sufentanil citrate is theorized to result from its higher lipophilicity promoting local transdural diffusion to spinal cord and limiting upward diffusion to the brain stem. Sufentanil citrate is also advantageous for programmable pumps because it is 100 times more potent than morphine and therefore allows longer pump refill times and higher infusion doses. Although this study was done on a limited number of patients, sufentanil citrate and MS-MARC in epidural infusions using programmable infusion pumps for non-cancer patients provide significant alternative drug combinations and routes.

Controlled investigation of the amobarbital interview for catatonic mutism [published erratum appears in Am J Psychiatry 1992 May;149(5):720

Clinical reports over the last 60 years suggest that the amobarbital interview is effective in relieving catatonic symptoms. This has never been substantiated with methodologically sound trials. The authors postulated that a randomized blind comparison of intravenous amobarbital and saline would demonstrate the superiority of amobarbital in relieving catatonic mutism. The subjects were 20 inpatients with catatonic mutism. They were randomly assigned to either saline (N = 10) or a 5% amobarbital solution (N = 10), and the infusions were administered intravenously at a rate of 1 cc/min or less over 10 minutes by a blinded physician. A second blinded physician administered a semistructured interview during the infusion to control for the effect of suggestion. A third blinded physician rated patient responsiveness, reactivity, and arousal. Any patient who was unresponsive to the initial infusion was crossed over to the other infusion. Interviews were videotaped for determination of interrater reliability. In the initial infusions, six of 10 patients responded to amobarbital and zero of 10 responded to saline. Four of the saline nonresponders responded when given amobarbital. Response was evident by the 4th minute of the amobarbital infusion. Interrater reliability was high. The responders and nonresponders differed significantly in the variance of the weight-adjusted amobarbital dose, and the responders tended to be older and female. Intravenous amobarbital is superior to saline in relieving catatonic mutism, although only 50% of these patients responded. The nonresponders were distinguished from the responders by a greater variance in the weight-adjusted dose of amobarbital.

Sufentanil Citrate and Morphine/Bupivacaine as Alternative Agents in Chronic Epidural Infusions for Intractable Non-Cancer Pain

Abstract Intraspinal narcotic (usually intrathecal morphine) infusions with implanted pumps are increasingly used in patients with intractable chronic pain not caused by cancer. In some patients, pain control is difficult with infusions of morphine. Seven patients with diagnoses of arachnoiditis, epidural scarring, and/or vertebral body compression fracture were treated with alternative solutions in an epidural route. For maximal flexibility, Medtronic implanted programmable infusion pumps with catheters to T6-T10 were used, and pain was monitored by verbal pain scales. In three patients, epidural infusions of morphine in 0.5% bupivacaine (MS-MARC) resulted in little or no pain relief without significant side effects (e.g., headache, nausea, or vomiting). In these same patients, epidural infusions of sufentanil citrate resulted in pain scale reductions of 92%, 82%, and 40%, respectively, with no side effects. Four other patients found more effective pain relief when switched from initial sufentanil citrate infusions to MS-MARC. Pain scale reductions (with no side effects) were 92%, 76%, 59%, and 47% in these patients. Pain relief and minimal side effects with sufentanil citrate is theorized to result from its higher lipophilicity promoting local transdural diffusion to spinal cord and limiting upward diffusion to the brain stem. Sufentanil citrate is also advantageous for programmable pumps because it is 100 times more potent than morphine and therefore allows longer pump refill times and higher infusion doses. Although this study was done on a limited number of patients, sufentanil citrate and MS-MARC in epidural infusions using programmable infusion pumps for non-cancer patients provide significant alternative drug combinations and routes. (Neurosurgery 29:76-82, 1991)

Sufentanil citrate and morphine/bupivacaine as alternative agents in chronic epidural infusions for intractable non-cancer pain

Intraspinal narcotic (usually intrathecal morphine) infusions with implanted pumps are increasingly used in patients with intractable chronic pain not caused by cancer. In some patients, pain control is difficult with infusions of morphine. Seven patients with diagnoses of arachnoiditis, epidural scarring, and/or vertebral body compression fracture were treated with alternative solutions in an epidural route. For maximal flexibility, Medtronic implanted programmable infusion pumps with catheters to T6-T10 were used, and pain was monitored by verbal pain scales. In three patients, epidural infusions of morphine in 0.5% bupivacaine (MS-MARC) resulted in little or no pain relief without significant side effects (e.g., headache, nausea, or vomiting). In these same patients, epidural infusions of sufentanil citrate resulted in pain scale reductions of 92%, 82%, and 40%, respectively, with no side effects. Four other patients found more effective pain relief when switched from initial sufentanil citrate infusions to MS-MARC. Pain scale reductions (with no side effects) were 92%, 76%, 59%, and 47% in these patients. Pain relief and minimal side effects with sufentanil citrate is theorized to result from its higher lipophilicity promoting local transdural diffusion to spinal cord and limiting upward diffusion to the brain stem. Sufentanil citrate is also advantageous for programmable pumps because it is 100 times more potent than morphine and therefore allows longer pump refill times and higher infusion doses. Although this study was done on a limited number of patients, sufentanil citrate and MS-MARC in epidural infusions using programmable infusion pumps for non-cancer patients provide significant alternative drug combinations and routes.

Failure of intravenous infusions in neonates

The median life expectancy (survival) of 286 peripheral intravenous infusion sites in 105 babies in a children's intensive care unit was 36 h. Unadjusted univariate survival analysis revealed that dextrose infusions and the initial infusions received by a baby had longer survival than total parenteral nutrition (TPN) infusions and later infusions respectively. Also infusions with cloxacillin and penicillin survived for longer than average while infusions with phenytoin had reduced survival. Gestational age, weight, infusion site, other drugs, co-infusion of Intralipid with TPN solutions and neutralization of TPN did not influence survival of infusions. Multivariate survival analysis confirmed the findings for TPN and penicillin but not for cloxacillin, phenytoin or later infusions. Multivariate analysis also suggested that survival was improved with ampicillin and aminophylline and worse for leg sites, for older babies and for infusions in which the fluids were given at greater rates. It also indicated that neutralization of TPN improved survival.

Effects of short-term pulsatile and continuous insulin delivery on glucagon secretion and insulin secretion and action

In six normal nonobese subjects, hyperinsulinemic euglycemic clamps were performed during paired sequential two-hour intravenous (IV) insulin infusions separated by an hour washout period. Each infusion was either 32 mU/kg/h of continuous insulin (CI) or 75% of this dose as 40-second pulses delivered every 13 minutes (PI). Six studies were performed with each of the following sequences in random order: PI-CI, CI-PI, and CI-CI. Based on the initial infusions, the insulin-dependent fractional glucose disappearance rate (X) during pulsatile insulin delivery (3.0 ± 0.4 min −1 × 10 2, n = 6) was 73% of that of the continuous infusions (4.1 ± 0.3 min −1 × 10 2, n = 12). This ratio was similar to that of the measured time-averaged plasma insulin areas (PI = 24.7 ± 3.8 v CI = 31.4 ± 3.5 mU/L). There was an average 23% enhancement of insulin's hypoglycemic effect during the second 12 CI infusions compared with the 12 initial CI infusions (X = 5.1 ± 0.5 v 4.1 ± 0.3 min −1 × 10 2, P < .05). There was no significant difference between the enhancing effects of PI and CI infusions on insulin action in the subsequent CI's (X = 4.9 ± 0.9 for PI-CI v X = 5.3 ± 0.2 min −1 × 10 2 for CI-CI). First infusion PI significantly ( P < .05) decreased plasma C-peptide levels (0.34 ± 0.05 to 0.20 ± 0.06 μmol/L), whereas CI did not (0.33 ± 0.02 to 0.32 ± 0.07). Plasma glucagon remained suppressed (14 ± 4 ng/L) one hour after the first infusion of PI, but returned to baseline one hour after the first infusion of CI (29 ± 4). In conclusion, although PI administration over two hours did not produce greater hypoglycemic effect or greater enhancement of subsequent insulin action, pulsatile hyperinsulinemia over two hours in normal subjects produces greater suppression of insulin secretion and longer-lasting suppression of glucagon secretion than CI infusion. The latter may be of importance of the evolution of the greater hypoglycaemic potency of longer-term PI delivery.

The multi-dose clinical tolerance and pharmacokinetics of the combined radiosensitizers, Ro 03-8799 (pimonidazole) and SR 2508 (etanidazole)

The hypoxic cell radiosensitizers Ro 03-8799 (pimonidazole) and SR 2508 (etanidazole) have differing physicochemical properties and clinical toxicities. The former is basic, lipophilic and produces an acute but transient central nervous system syndrome; the latter is neutral, hydrophilic and causes cumulative peripheral neuropathy. We therefore investigated the possibility of combining these agents to achieve additive radiosensitization with no enhancement of toxicity, as demonstrated in a rodent tumor model. Following a single dose study which showed a lack of interaction with respect to both toxicity and pharmacokinetics, twenty-one patients have now completed simultaneous drug administration on an escalating, multiple dose schedule. There has been no adverse acute interaction up to 0.75 g/m 2 Ro 03-8799 with 2 g/m 2 SR 2508 for 15 doses. At this dose-level, however, all patients experienced peripheral neuropathy. There was no adverse pharmacokinetic interaction, or perturbation of plasma pharmacokinetics between initial and final infusions. Tumor concentrations were determined in 48 biopsy samples 0–60 min after administration. Mean values normalized to a dose of 0.75 g/m 2 Ro 03-8799 plus 2 g/m 2 SR 2508 were 33 μg/g Ro 03-8799 and 74 μg/g SR 2508. These would be expected to produce a single-dose sensitizer enhancement ratio of around 1.5. The combination is predicted to be around 6.8 times more active than misonidazole, and superior to any single agent tested to date. The current schedules are reaching the limits of clinical tolerance, and an attempt is now being made to define the optimal regimen for use in a randomized clinical trial of the combination.

GIVING AMPHOTERICIN B IN THE HOME

Carolyn Sipes, RN, MSN, formerly director, patient care services, Harmony Home Health of Mercy Center, Aurora, IL, currently works at RushPresbyterian-St. Luke's Medical Center in Chicago. daily, the patient must be able to hook up his own infusion before discharge from the hospital. If he is unable, a competent caregiver must be available to assume responsibility for the infusion. O The patient and/or his caregivers must show a basic understanding of how to manage the expected side effects. O Physician prescriptions and plans must be obtained for drug dosages, for how often blood specimens need to be drawn, and for specific parameters for withholding treatment based on lab results (such as BUN >40 or creatinine >3.5). D The patient must have had initial infusions of all drugs-meperidine, hydrocortisone, and heparin, as well as amphotericin Bbefore hospital discharge. This reduces the risk of serious adverse effects in the home. Generally, patients will have received at least three doses of amphotericin B before discharge. If you need to draw blood, do so before starting the infusion. After a baseline vital sign check, we monitor vital signs every 15 minutes for the first hour and every 30 minutes thereafter. Our agency policy requires that the nurse stay with the patient throughout the infusion-about six hours for the entire procedure. Our agency does not recommend unsupervised infusions due to the severity of the side effects. Other agencies, however, instruct the patient to premedicate himself onehalf hour before the nurse is scheduled to arrive. The nurse then checks vital signs, examines the patient, starts the infusion, and leaves while the drug is still running. When the infusion is finished, the patient or caregiver stops it and then flushes the central line. l

Giving Amphotericin B in the Home

Carolyn Sipes, RN, MSN, formerly director, patient care services, Harmony Home Health of Mercy Center, Aurora, IL, currently works at RushPresbyterian-St. Luke's Medical Center in Chicago. daily, the patient must be able to hook up his own infusion before discharge from the hospital. If he is unable, a competent caregiver must be available to assume responsibility for the infusion. O The patient and/or his caregivers must show a basic understanding of how to manage the expected side effects. O Physician prescriptions and plans must be obtained for drug dosages, for how often blood specimens need to be drawn, and for specific parameters for withholding treatment based on lab results (such as BUN >40 or creatinine >3.5). D The patient must have had initial infusions of all drugs-meperidine, hydrocortisone, and heparin, as well as amphotericin Bbefore hospital discharge. This reduces the risk of serious adverse effects in the home. Generally, patients will have received at least three doses of amphotericin B before discharge. If you need to draw blood, do so before starting the infusion. After a baseline vital sign check, we monitor vital signs every 15 minutes for the first hour and every 30 minutes thereafter. Our agency policy requires that the nurse stay with the patient throughout the infusion-about six hours for the entire procedure. Our agency does not recommend unsupervised infusions due to the severity of the side effects. Other agencies, however, instruct the patient to premedicate himself onehalf hour before the nurse is scheduled to arrive. The nurse then checks vital signs, examines the patient, starts the infusion, and leaves while the drug is still running. When the infusion is finished, the patient or caregiver stops it and then flushes the central line. l

Isolated thrombocytopenia in patients infected with HIV: Treatment with intravenous gammaglobulin

Isolated thrombocytopenia occurs frequently in patients infected with HIV. Studies of mechanisms of thrombocytopenia and clinical response to therapy suggest that the thrombocytopenia is often antibody mediated (ITP). The best approach to treatment of these patients is uncertain in that the routine modalities (steroids, splenectomy, vinca alkaloids) that are used to increase the platelet count in patients with classic ITP are known to be immunosuppressive. We report here the results of intravenous gammaglobulin (IVGG) treatment of 22 patients with HIV-related acute and chronic ITP who had severe thrombocytopenia and bleeding symptoms. Only one patient had an opportunistic infection at the time of treatment. Eight patients were homosexual, eight had hemophilia, three were i.v. drug abusers, two children had congenital acquisition of HIV, and one was the wife of an HIV + i.v. drug abuser. The average pretreatment platelet count was 22,000/microliter (hemophiliacs were treated at higher platelet counts than were the other patients), and the mean peak platelet count measured on days 5 to 8 was 182,000/microliter. Nineteen of 22 patients had peak platelet counts greater than 50,000/microliter following IVGG and 17/22 had peak counts greater than 100,000/microliter. After the initial infusions, all but three refractory patients could maintain adequate platelet counts with IVGG alone infused no more often than once every 2 weeks. The outcomes for the 22 patients after multiple maintenance IVGG infusions were remission, 5; stable without therapy, 1; maintenance, 13; and refractory, 3. The eight hemophiliacs with ITP responded better than did the eight homosexual ITP patients; their mean peak platelet count was 227,000/microliter versus 142,000/microliter in the homosexuals. In summary, patients with HIV-related ITP without opportunistic infections responded well to IVGG, with peak platelet counts comparable to those of ITP patients not infected with HIV. IVGG may be a useful therapy of ITP in HIV+ patients, since it appears to be less immunosuppressive than are conventional therapies, and none of the 22 HIV+ patients developed an opportunistic infection while receiving IVGG alone.

Is High Potassium Solution Necessary for Reinfusions in “Multidose” Cold Cardioplegia? A Randomized Prospective Study Using Computerized Holter System

Multidose potassium cardioplegia is a common method of myocardial preservation. Although initial potassium arrest conserves high-energy phosphates, there is conflicting evidence that repeat high potassium boluses augment this protection. Fifty-six patients were prospectively randomized to receive multidose cold high potassium cardioplegia (27 mEq of KCl/L) both in the initial and subsequent infusions (Group 1) or an initial cold high potassium (27 mEq/L) cardioplegia followed by boluses of cold low potassium (7 mEq, of KCl/L) solution (Group 2). The two groups were compared in terms of postoperative myocardial electrical stability and hemodynamic performance. Electrocardiograms were recorded by continuous Holter monitor, and the data were analyzed by computer. The duration of aortic cross-clamping and cardiopulmonary bypass did not differ between groups. Group 1, who received more total KCl than Group 2 ( p < .005), experienced more high-grade ventricular ectopia during both reperfusion ( p < .001) and the immediate postoperative period ( p < .001), and required more lidocaine hydrochloride ( p < .001) for arrhythmias. There was no significant difference in hemodynamic performance between the two groups. This study fails to show an advantage to multidose “high potassium” cardioplegia and found a significant increase in ventricular ectopia associated with its use. We advocate using low potassium solutions after initial cold high potassium arrest.

Intravenous immune globulin: dosage and administration.

Intravenous immune globulin (IV-IgG) is approved for use in substitution therapy of immunodeficiency syndromes and treatment of idiopathic thrombocytopenic purpura (ITP). The initial dose for substitution therapy is 0.2 g/kg body weight repeated monthly. If necessary, the dose may be increased to 0.3 g/kg and the frequency to every 2-3 weeks. The approved dosage for ITP is 0.4 g/kg daily for 2 to 5 consecutive days. Repeat doses of 0.4 g/kg have been used as maintenance therapy. The initial infusions of IgG to immunodeficient patients who have not been treated during the previous 8 weeks or never treated at all should proceed with caution. These patients are at risk of potentially serious complement-mediated adverse reactions. Adverse reactions due to IgG administration are less frequent and less severe for patients with ITP. Currently available preparations are contraindicated in patients with a selective IgA deficiency and detectable IgA antibodies.

Increase of serum immunoglobulin level into the normal range in primary hypogammaglobulinaemia by dosage individualization of intravenous immunoglobulin.

The effect of varying the dose or the frequency or of both dose and frequency of immunoglobulin administration was evaluated in 17 patients with primary hypogammaglobulinaemia treated with Scottish National Blood Transfusion Service intravenous immunoglobulin (SNBTS IV IgG), an intravenous immunoglobulin preparation manufactured by the pH 4/mild pepsin method. Individualised dosage of SNBTS IV IgG resulted in trough serum IgG levels of greater than 4.0 g/l in 13 of the 17 patients studied. 6 of the 17 patients had trough serum IgG levels in the normal range (5.0 g/l). In 2 patients, more frequent infusions were required to achieve normal trough serum IgG levels because of their clinical conditions. In 1 of these 2 patients, the frequency could be reduced to three weekly when the gastrointestinal loss of IgG was reduced. There was a low incidence of adverse reactions (6.4%) which occurred mainly during the initial infusions. Most patients benefited from an increased serum IgG level, but the frequency of diarrhoea was unaffected. One patient with severe bronchiectasis continued to suffer from respiratory infections despite normal serum IgG levels.