Vasoactive Drug Therapy Research Articles

The effects of vasoactive drugs on pulse pressure and stroke volume variation in postoperative ventilated patients

IntroductionAlthough pulse pressure variation (PPV) and stroke volume variation (SVV) during mechanical ventilation have been shown to predict preload responsiveness, the effect of vasoactive therapy on PPV and SVV is unknown. MethodsPulse pressure variation and SVV were measured continuously in 15 cardiac surgery patients for the first 4 postoperative hours. Pulse pressure variation was directly measured from the arterial pressure waveform, and both PPV and SVV were also calculated by LiDCO Plus (LiDCO Ltd, Cambridge, United Kingdom) before and after volume challenges or changes in vasoactive drug infusions done to sustain cardiovascular stability. ResultsSeventy-one paired events were studied (38 vasodilator, 10 vasoconstrictor, 14 inotropes, and 9 volume challenges). The difference between the measured and LiDCO-calculated PPV was 1% ± 7% (1.96 SD, 95% confidence interval, r2 = 0.8). Volume challenge decreased both PPV and SVV (15% to 10%, P < .05 and 13% to 9%, P = .09, respectively). Vasodilator therapy increased PPV and SVV (13% to 17% and 9% to 15%, respectively, P < .001), whereas increasing inotropes or vasoconstrictors did not alter PPV or SVV. The PPV/SVV ratio was unaffected by treatments. ConclusionVolume loading decreased PPV and SVV; and vasodilators increased both, consistent with their known cardiovascular effects. Thus, SVV and PPV can be used to drive fluid resuscitation algorithms in the setting of changing vasoactive drug therapy.

Early Transjugular Intrahepatic Portosystemic Shunt for Acute Variceal Bleeding Lowers Treatment Failure and Mortality

A study published in The New England Journal of Medicine finds that early rescue treatment with a transjugular intrahepatic portosystemic shunt (TIPS) for cirrhosis patients who are hospitalized for acute variceal bleeding could significantly lower treatment failure and mortality. If large varices develop in the esophagus or upper stomach, patients with cirrhosis are at risk for serious bleeding due to rupture of these varices. Once varices have bled, they tend to rebleed and the probability that a patient will die from each bleeding episode is high (30%–35%). Among current practice guidelines recommended for treating patients with acute variceal bleeding are fluid resuscitation, antibiotic prophylaxis, and vasoactive drugs such as octreotide, terlipressin, or somatostatin, followed by early endoscopy and either ligation or sclerosis of the varices. Despite these measures, failure to control index bleeding occurs in 10%–20% of patients. TIPS is indicated in patients who fail to respond to β-blockers, variceal sclerotherapy, or banding. TIPS can also be considered in treating patients with ascites that does not respond to salt and fluid restriction and diuretics. Researchers with the Early TIPS Cooperative Study Group randomized 63 patients with Child class B or C cirrhosis and acute variceal bleeding who had been treated with vasoactive drugs plus endoscopic therapy, either to treatment with a polytetrafluoroethylene (PFTE)-covered stent within 72 hours of randomization (early TIPS group, 32 patients) or to continuation of vasoactive drug therapy followed by propranolol or nadolol and long-term endoscopic band ligation (EBL), with insertion of a TIPS if needed as rescue therapy (31 patients). In this multicenter international study, patients who received early TIPS had a significantly better chance of remaining free of bleeding than did those who received the standard care (97% vs 50%). The rate of survival at 6 weeks was 97% in the TIPS group as compared with 67% in the medical therapy group, as a result of reductions in rebleeding, sepsis, and liver failure. In addition, “the number of days in the intensive care unit and percentage of time in the hospital during follow-up were significantly higher in the pharmacotherapy-EBL group,” the authors state. An editorial in the same issue of the journal notes that the study “should stimulate a reevaluation of how we approach variceal bleeding in patients with Child–Pugh class B or C disease. Instead of taking a wait-and-see approach, physicians should consider the early use of TIPS with a PFTE–covered stent as first-line therapy rather than as rescue treatment if rebleeding occurred. Additional clinical trials of adequate size should be performed to confirm these findings and to examine the effect of a rapid reduction in portal pressure on disease progression in patients with cirrhosis of various causes.” See NEJM 2010;362:2370–2379, 2421–2422. Also see Hepatology 2010:51, for AASLD TIPS practice guidelines and overview.

Early hemodynamics monitoring and nursing care after orthotopic heart transplantation

Objective To explore the experience of monitoring and the nursing care of early hemodynamics after orthotopic heart transplantation in order to improve the short-term outcome. Methods A total of 96 patients with end-stage cardiopathy underwent orthotopic heart transplantation. The hemodynamic were closely monitored and nursed care after operation in order to maintain the stability of hemodynamics of allografts. Results All recipients received vasoactive drug therapy and seven recipients died of acute allograft right ventricle dysfunction during the postoperative period. The rest survived well and had a rather good quality of life. Conclusions The hemodynamic changes often occur at the early term after orthotopic heart transplantation. The main change is the right ventrieular failure. It is important for the recovery and prognosis to monitor the hemodynamic changes and analyze the cauls in order to direct the therapy. Key words: Heart Transplantation; Hemodynamics ; Monitoring; Nursing

Urinary liver fatty acid-binding protein: another novel biomarker of acute kidney injury

Liver fatty acid-binding protein (L-FABP) binds selectively to intracellular free unsaturated fatty acids and lipid peroxidation products during hypoxic tissue injury. Urinary L-FABP is a potential biomarker for the detection and assessment of acute kidney injury (AKI). Ferguson et al. have demonstrated in a cross-sectional study that urinary L-FABP is an excellent biomarker of AKI and may be useful in predicting dialysis-free survival. This study did not assess utility for early diagnosis of AKI.

Sclerotherapy and esophageal variceal bleeding: time to forget it, or not?

With great interest, we have read the article of Triantos et al. on evaluation of emergency sclerotherapy of varices [1]. Recently, the role of endoscopic injection sclerotherapy (EIS) has been challenged by endoscopic variceal ligation (EVL) and vasoactive drug therapy [2] [3], the latter being considered by many physicians to be the treatment of choice for patients with bleeding esophageal varices. Triantos et al. have questioned this interpretation [4], and we agree with them. In our opinion, EIS has been censured because is a technique that requires competence in endoscopy. By contrast, EVL is a simple technique with comparable results that does not require an experienced endoscopist. For this reason, the efficacy and safety of EIS are tied to the endoscopist, so there are wide variations in reported efficacy rates - the main reason is technique. On the basis of our experience, we know that a properly performed EIS needs paravariceal and intravariceal injection.

Evolving Consensus in Portal Hypertension Report of the Baveno IV Consensus Workshop on methodology of diagnosis and therapy in portal hypertension

Portal hypertension is associated with the most severe complications of cirrhosis, including ascites, hepatic encephalopathy, and bleeding from gastro-esophageal varices. Despite the progress achieved over the last decades, the 6-week mortality associated with variceal bleeding is still in the order of 10–20%. Awareness of the difficulty inherent to the evaluation of diagnostic tools and the design and conduct of good clinical trials for the treatment of portalhypertensionhas led to theorganization, since1986,of a series of consensus meetings. The first one was organized by Andrew Burroughs in Groningen, The Netherlands [1]. After Groningen, other meetings followed, in Baveno in 1990 (Baveno I) [2] and in 1995 (Baveno II) [3,4], in Milan in 1992 [5], in Reston, USA, in 1996 [6], in Stresa in 2000 (Baveno III) [7,8], again in Baveno in 2005 (Baveno IV) [9,10], and in Atlanta in 2007 [11]. The aims of these meetings were to develop definitions of key events in portal hypertension and variceal bleeding, to review the existing evidence on the natural history, the diagnosis and the therapeutic modalities of portal hypertension, and to issue evidence-based recommendations for the conduct of clinical trials and the management of patients. All these meetings were successful and produced consensus statements on some important points, although some issues remained unsettled. To continue the work of the previous meetings, a Baveno V workshop was held on May 21–22, 2010. The workshop was attended by many of the experts responsible for most of the major achievements of the last years in this field. Many of them had attended the previous meetings as well. The main fields of discussion of the Baveno V workshop were the same as in Baveno I–IV, i.e. the definitions of key events concerning the bleeding episode and the therapeutic options in patients with portal hypertension. For each of these topics, a series of consensus statements were discussed and agreed upon. As in Baveno IV, whenever applicable, the level of existing evidence was evaluated and the recommendations were ranked according to the Oxford System [12] (i.e.: level of evidence from 1 = highest

Practical considerations in the administration of intravenous vasoactive drugs in the critical care setting: the double pumping or piggyback technique?part one

Part I of this review aims to identify the factors associated with safe administration of continuous intravenous vasoactive drug therapy, specifically epinephrine and norepinephrine. Intravenous vasoactive drugs are administered in the critical care setting to maintain patients’ cardiovascular function by continuous intravenous infusion. To ensure uninterrupted administration, one infusion is commenced when the other is almost empty. A technique often employed to achieve this is known as ‘double pumping’ or ‘piggybacking’. Due to the absence of a standardised protocol for administering continuous intravenous vasoactive medication and technological developments in infusion pumps, a review of current literature was undertaken. Despite a paucity of evidence regarding safe administration of these drugs, recommendations from the available literature included ensuring that critical care nurses are competent and formally trained in the use of equipment and the administration of continuous intravenous vasoactive medication. Furthermore, the infusion pump should feature minimal start up delay, a sensitive occlusion alarm system and the absence of a bolus in the event of infusion occlusion. This may reduce patients experiencing adverse haemodynamic responses due to alterations to the infusion. Indeed, a review of the ‘double pumping’ or ‘piggybacking’ technique in the clinical setting is required to establish current practice and develop evidence based guidelines.

Practical considerations in the administration of intravenous vasoactive drugs in the critical care setting: the double pumping or piggyback technique-part one.

Part I of this review aims to identify the factors associated with safe administration of continuous intravenous vasoactive drug therapy, specifically epinephrine and norepinephrine. Intravenous vasoactive drugs are administered in the critical care setting to maintain patients' cardiovascular function by continuous intravenous infusion. To ensure uninterrupted administration, one infusion is commenced when the other is almost empty. A technique often employed to achieve this is known as 'double pumping' or 'piggybacking'. Due to the absence of a standardised protocol for administering continuous intravenous vasoactive medication and technological developments in infusion pumps, a review of current literature was undertaken. Despite a paucity of evidence regarding safe administration of these drugs, recommendations from the available literature included ensuring that critical care nurses are competent and formally trained in the use of equipment and the administration of continuous intravenous vasoactive medication. Furthermore, the infusion pump should feature minimal start up delay, a sensitive occlusion alarm system and the absence of a bolus in the event of infusion occlusion. This may reduce patients experiencing adverse haemodynamic responses due to alterations to the infusion. Indeed, a review of the 'double pumping' or 'piggybacking' technique in the clinical setting is required to establish current practice and develop evidence based guidelines.

Cerebral blood flow in critically ill cardiac patients: effects of vasoactive drug therapy

The introduction of the thermodilution technique (TD) in measuring cardiac output (CO) and coronary sinus blood flow has suggested the application of the same technique into measuring CBF which has been validated by several methods using transcranial Doppler and Xenon inhalation clearance curves. The present work is intended to assess the effect of two vasoactive drugs on CBF in 20 critically ill patients (12 males, 8 females, mean age: 5.86 ± 9.46) all having CHF due to dilated cardiomyopathy. Following clinical examination all patients were subjected to haemodynamic evaluation including central venous line, arterial cannulation and jugular vein catheterization. The latter was performed using Baim coronary sinus catheter directed towards the right jugular vein under fluroscopic guidance up to the bulb of internal jugular vein. Jugular blood flow (JBF) was measured by constant infusion of ice cold (5%) dextrose solution and recorded digitally on a Baim coronary sinus computer. Haemodynamic measurements including CBF were made at rest and repeated following infusion of noradrenaline (NA) in incremental doses sufficient to raise BP by one third of the basal reading. An average of three readings were taken. NA was discontinued and after 20 min the same method was repeated after dobutamine infusion given in a dose of 10 μg/kg/min for 20 min. Compared to basic measurements, NA significantly reduced CBF by 22.4 ± 4.79% in 13 patients with simultaneous increase in CVR by 106.73 ± 29.0%, NA increased CBF by 40.46 ± 12.0% in seven patients with simultaneous decrease of CVR by 13.7 ± 6.2%. It also increased systemic vascular resistance by 24.9 ± 2.76%, P < 0.0001. On the other hand dobutamine has led to an increase in CBF by 56 ± 12% in 11 patients with simultaneous decrease in CVR by 22 ± 6.31%. It decreased the CBF by 38.1 ± 11.8% in four patients with simultaneous increase in CVR by 130.68 ± 70.01%, and a decrease SVR by 21 ± 5%, P < 0.0359. In conclusion, vasoactive drugs commonly used in critically ill cardiac patients have different effects on cerebral blood flow. Despite the beneficial effects obtained from using NA in increasing perfusion pressure and cardiac output, the adverse effects on CBF are an obvious limitation to its use as a monotherapy, compared to dobutamine which besides augmenting CO improves dramatically CBF.

Acute respiratory distress syndrome among trauma patients: trends in ICU mortality, risk factors, complications and resource utilization.

To evaluate trends in mortality and related factors among trauma patients who developed acute respiratory distress syndrome (ARDS). Observational study based on data prospectively gathered in computerized trauma registry. Trauma intensive care unit (ICU) of 48 beds in level I trauma center. All trauma patients with ARDS admitted during 1985-87 (486, group 1 [G1]) and 1993-95 (552, group 2[G2]). ARDS was defined by American-European Consensus Conference criteria and the need for 48 h or more on mechanical ventilation with FIO2 greater than 0.50 and PEEP of more than 5 cmH2O. Demographics, severity score, injury-admission delay time, first 24-h transfusion and septic and organ system failure complications were independent variables. ICU mortality was the dependent variable. ICU length of stay (LOS) and life support techniques were considered. Respiratory and renal support strategies were different in the two time periods. Mortality decreased over the period (G1: 29.2% vs G2: 21.4%, p < 0.04), in patients aged both over and under 65 years. Multivariate analysis showed mortality was related to age, severity and time period (G1 1.68-fold that in G2) and that the greater G1 mortality was related to more renal failure and hematologic failure/dysfunction. ICU LOS decreased from 31.7+/-26.7 days (G1) to 27.3+/-22 days (G2) (p < 0.003). Mortality among trauma patients with ARDS declined over the 8 years studied and was associated with less organ failure. This reduction was probably the result of new approaches to mechanical ventilation, renal failure replacement and vasoactive drug therapy.

Management of variceal haemorrhage in cirrhotic patients

Editor,—We have serious concerns about several of the recent UK guidelines for the management of variceal haemorrhage in cirrhotic patients ( Gut 2000; 46 (suppl 3 and 4):iiiI–iii115), particularly those that contradict current published evidence. We highlight below the ones we feel are the most important. In the management of acute variceal bleeding, variceal ligation is not the method of first choice which was given an AI recommendation. Meta-analysis of all trials of acute bleeding of banding versus injection sclerotherapy have shown no statistically significant difference between the two treatments for either control of bleeding or survival (data derived from 12 studies with 419 patients), with no statistical heterogeneity.1 The implication of recommending ligation for acute bleeding is that double intubation would be necessary in a patient who is actively bleeding so as to attach the ligation device after the initial diagnostic endoscopy. Although there is no evidence, this would create more risk to the patient; it is common sense that a single intubation would be preferable and would take less time. At best the recommendation should be that either endoscopic technique could be used as first choice, dependent on operator expertise and facilities. Secondly, there is evidence from randomised studies of vasoactive drug therapy combined with endoscopic techniques that combination therapy is superior in terms of control of bleeding. This is based on five randomised studies with 610 patients (pooled odds ratio 0.42, 95% confidence interval 0.29–0.6).1 Publication bias assessment has shown that 29 null or negative studies would be needed to render the results non-significant, and thus this effect is fairly robust. Moreover, in several of these studies vasoactive drugs were given before diagnostic endoscopy, demonstrating their utility during the period of resuscitation before endoscopy could be safely performed, which in practice may be several … Dr R Jalan, Institute of Hepatology, University College London Medical School, 69–75 Chenies Mews, London WC1E 6HX, UK. r.jalan{at}ucl.ac.uk

Drug treatment for bleeding oesophageal varices

At the time of diagnosis of cirrhosis, varices are present in about 60% of decompensated and 30% of compensated patients. The risk factors for the first episode of variceal bleeding in cirrhotic patients are the severity of liver dysfunction, a large size of the varices and the presence of endoscopic red colour signs, but only a third of patients who suffer variceal haemorrhage demonstrate the above risk factors. The only treatment that does not require sophisticated equipment or the skills of a specialist, and is immediately available, is vasoactive drug therapy. Hence, drug therapy should be considered to be the initial treatment of choice and can be administered while the patient is transferred to hospital, as has been done in one recent study. Moreover, drug therapy is no longer considered to be only a ‘stop-gap’ therapy until definitive endoscopic therapy is performed. Several recent trials have reported an efficacy similar to that of emergency sclerotherapy in the control of variceal bleeding. Furthermore, recent evidence suggests that those patients with high variceal or portal pressure are likely to continue to bleed or re-bleed early, implying that prolonged therapy lowering the portal pressure over several days may be the optimal treatment. Pharmacological treatment with beta-blockers is safe, effective and the standard long-term treatment for the prevention of recurrence of variceal bleeding. The combination of beta-blockers with isosorbide-5-mononitrate needs further testing in randomized controlled trials. The use of haemodynamic targets for the reduction of the HVPG response needs further study, and surrogate markers of the pressure response need evaluation. Ligation has recently been compared with beta-blockers for primary prophylaxis, but there is as yet no good evidence to recommend banding for primary prophylaxis if beta-blockers can be given.

LONG TERM ANGIOTENSIN CONVERTING ENZYME INHIBITOR TREATMENT INCREASES VASOCONSTRICTOR REQUIREMENT DURING NORMOTHERMIC CARDIOPULMONARY BYPASS

S74 Introduction: Cardiopulmonary bypass (CPB) results in sympathoadrenal and renin angiotensin system activation due to stress of haemodilution and nonpulsatile perfusion. Systemic vascular resistance (SVR) is lower during normothermic than in hypothermic CPB [1]. Long term use of angiotensin converting enzyme (ACE) inhibitors attenuates effects of catecholamines and thus should lower the SVR further during normothermic CPB, in the absence of hypothermic effects. Methods: After ethical committee approval and informed consent, 37 adult patients for elective cardiac surgery were studied prospectively. The study group of 14 patients were on chronic ACE inhibitor therapy and took the drug on the morning of surgery. The control group of 23 patients were not on any preoperative vasoactive drug therapy. All patients were premedicated with Morphine and Phenargan. GA was induced with Morphine/Diazepam/Thiopentone and maintained with Morphine/Vecuronium/Pancuronium/N (2) O/O2. Bubble oxygenator was used on CPB and perfusate was not cooled but temperature was allowed to drift. Haemodynamics and blood gas parameters were recorded at regular interval. MAP was maintained >50 mmHg with 1 mg increments of phenylepherine, if required, and its use recorded. Haemodynamic values at 10 min. after cross clamp were evaluated with pump flow of 3 L m-2 min-1. Results: The two groups had similar demography, preoperative haemodynamics, CPB haematocrit, oxygen delivery and consumption. Study group showed a significant decrease in MAP and SVR Index on CPB and a significant number required vasconstrictor use to maintain MAP > 50 mm Hg. (Table 1)Table 1Discussion: Long term ACE inhibitor therapy significantly altered haemodynamics during normothermic CPB with a significant number of patients requiring vasoconstrictor use to maintain acceptable perfusion pressures on CPB. In another study, haemodynamic control was not altered during hypothermic CPB despite attenuation of adrenergic response in this group of patients [2]. Extra care should be taken in cardiosurgical patients on ACE inhibitors and the safety of hypothermic CPB extended to this group of patients.

Regional blood flow and oxygen transport in patients with the low cardiac output syndrome after cardiac surgery

To assess systemic and regional oxygen transport after open heart surgery in patients with the low cardiac output syndrome who are receiving vasoactive drugs and in patients with normal hemodynamics during spontaneous rewarming. Prospective, nonrandomized controlled trial. Tertiary care center. Sixteen patients aged 53.1 +/- 8.4 yrs were studied after coronary artery bypass operations: ten patients with a cardiac index of < 1.75 L/min/m2 and six control patients with a cardiac index of > 1.75 L/min/m2. The patients with a cardiac index of < 1.75 L/min/m2 received either dobutamine alone (n = 5) or in combination with nitroprusside (n = 5). The control patients with a cardiac index of > 1.75 L/min/m2 did not receive vasoactive treatment. The systemic oxygen consumption was measured by indirect calorimetry and the regional blood flow was measured by primed continuous infusion of indocyanine green. Both splanchnic and femoral blood flows increased (p < .05) in parallel with cardiac output during vasoactive drug therapy. High splanchnic oxygen extraction in patients with low cardiac index and flow-dependent splanchnic oxygen consumption in some patients indicated marginal splanchnic oxygen delivery. In addition, femoral blood flow was low and oxygen consumption changed in parallel with oxygen delivery in patients with the low cardiac output syndrome. In low cardiac output syndrome after cardiac surgery, splanchnic oxygen delivery was marginal and was maintained at the expense of peripheral oxygen delivery. Dobutamine, both alone and in combination with sodium nitroprusside, improved splanchnic oxygen delivery.

Transition of diagnosis and treatment for impotence

Statistic study was made on 685 outpatients with erectile dysfunction during 13 years periods from 1979 to 1991 in the Department of Urology, Takamatsu Red Cross Hospital. The age distribution showed the highest frequency in the thirties decade (27.9%). 1. Diagnosis Nocturnal penile tumescence monitoring was the only method to distinguish organic impotence from functional impotence during the first 5 years. From 1984 we have been able to diagnose corporal veno-occlusive insufficiency (CVI) by papaverine test and dynamic infusion cavernosometry and cavernosography. Measurement of penile brachial index and pelvic angiography were performed to diagnose arterial insufficiency (AI). In neurological examination we have measured bulbo-cavernosus reflex latency and nerve conduction velocity of the dorsal penile nerve and performed microvibration measurement and sweat spots test. All diagnostic methods were established in 1987 and we have been able to classify about 80% patients. We classified 305 patients during the last 5 years from 1987 as follows: psychogenic; 31.1%, CVI; 20.0%, AI; 7.9%, neurogenic; 7.9%, others; 14.1%, drop-out and unknown; 19.0%. 2. Treatment In the beginning only counseling and drug therapy were performed. However we lately performed various suitable methods for individuals based on their diagnoses. We performed counseling, drug therapy and intracavernous injection of vasoactive drug therapy for recovery of spontaneous erection (vascular training) for psychogenic IMP. The efficacy rate of counseling was low (30.4%) but that of drug therapy was 41.6%, and that of vascular training, 64.2%. For CVI without other factors we performed venous surgeries. Only about 25% of them perform sexual intercourse with or without self injection of vasoactive drug (self injection).(ABSTRACT TRUNCATED AT 250 WORDS)

Continuous central venous oximetry and shock index in the emergency department: use in the evaluation of clinical shock.

Initial therapy of shock in the emergency department (ED) emphasizes the normalization of physiologic variables such as heart rate (HR), mean arterial pressure (MAP), and central venous pressure (CVP) rather than restoration of adequate tissue oxygenation. After hemodynamic stabilization of MAP, CVP, and HR, the authors examined tissue oxygenation as indicated by continuous central venous oximetry (SCVO2), lactic acid concentration, and shock index (SI). Sixteen consecutive nonrandomized patients presenting to the ED of a large urban hospital in shock (MAP < 60 mm Hg, HR > 120 beats/min, and altered sensorium) were initially resuscitated with fluid, blood, inotropes, and/or vasoactive drug therapy to normalize MAP, CVP, and HR. In addition, SCVO2, arterial lactate concentration, and SI were measured after completion of resuscitation in the ED. Eight patients (group no. 1) had inadequate tissue oxygenation reflected by low SCVO2 (less than 65%). Four patients in group no. 1 had elevated arterial lactic acid concentration. All group no. 1 patients had an elevated SI (> 0.7) suggesting persistent impairment of left ventricular stroke work. Eight patients (group no. 2) had normal or elevated SCVO2 (> 65%). In group no. 2, arterial lactic acid concentration was elevated in six and SI in seven patients. Normalization of hemodynamic variables does not adequately reflect the optimal endpoint of initial therapy in shock in the ED. Most (94%) of these patients continue to have significant global ischemia and cardiac dysfunction as indicated by reduced SCVO2 and elevated lactic acid concentration and SI. Systemic tissue oxygenation should be monitored and optimized in the ED in these critically ill patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Pharmacokinetics and clinical uses of vasoactive drugs

Pharmacokinetics and clinical uses of vasoactive drugs

An Improved Vasoactive Drug Combination for a Pharmacological Erection Program

Papaverine hydrochloride (smooth muscle relaxant), phentolamine mesylate (α-adenergic blocking agent) and prostaglandin E1 (vasodilator and smooth muscle relaxant) were combined to produce a potent vasoactive drug therapy for use in a pharmacological erection program. Doses of 2.5 cc papaverine (30mg./cc), 0.5 cc phentolamine (5mg./cc), 0.05 cc prostaglandin E1 (500μg./cc) and 1.2 cc 0.9% normal saline were combined to produce a vial of 4.25 cc for patient convenience. Twenty unit vials were made from the 1 cc vial of prostaglandin E1, the most expensive ingredient. The solution is physiologically active for at least 6 months and can be stored at room temperature although refrigeration is recommended. The pH of the solution is 4.This vasoactive drug combination has been used in 116 patients for diagnostic testing and subsequent treatment. A dose of 0.25 cc has been effective for diagnosis and treatment in the majority of patients with mild to moderate arteriogenic and/or venogenic and diabetic impotence. For patients with neurogenic dysfunction 0.1 to 0.125 cc was the usual dose. Two patients had a prolonged erection requiring irrigation, 1 on the day of initial testing and 1 on home therapy. Pain at the site of injection or during intercourse was noted in only 2 patients and to date no fibrosis or plaques have been found.

Postganglionic Hornerʼs syndrome after insertion of a pulmonary artery catheter through the internal jugular vein

Invasive hemodynamic monitoring by pulmonary arterial (PA) catheterization is commonly used to guide fluid and vasoactive drug therapy in the critically ill patient (1). However, multiple catheter-related complications have been described (1–3). It might be anticipated from the proximity of arterial and cervical sympathetic nerve structures to the internal jugular vein that local complications during insertion can lead to ipsilateral injury. Nevertheless, the spectrum of neurologic injury is incompletely defined. We report the first instance of a postganglionic Homer's syndrome, confirmed by pharmacologie localization (4–6), developing after otherwise uneventful percutaneous insertion of a PA catheter via the ipsilateral internal jugular vein.

Vasoactive Drug Therapy in Shock

The process of supporting the patient in shock with vasoactive infusions is never a static one. There are a variety of vasoactive infusions available; unfortunately, no one medication effectively corrects the numerous abnormalities in all forms of shock and no magic formula exists for combining medications to achieve optimum tissue perfusion. The nurse is challenged to utilize keen assessment skills and sophisticated monitoring techniques to follow the patient's response to changing vasoactive drug therapy. The nurse must collaborate with the physician and other health team members to integrate drug therapy with the other aspects of shock therapy, including fluid repletion, oxygenation and ventilation, metabolic support, and antibiotic therapy to facilitate the successful resuscitation of the patient in shock.