Adrenaline, terlipressin, and corticoids versus adrenaline in the treatment of experimental pediatric asphyxial cardiac arrest.

OBJECTIVE: To analyze if treatment with adrenaline (epinephrine) plus terlipressin plus corticoids achieves higher return of spontaneous circulation than adrenaline in an experimental infant animal model of asphyxial cardiac arrest. DESIGN: Prospective randomized animal study. SETTING: Experimental department in a University Hospital. SUBJECTS: Forty-nine piglets were studied. INTERVENTIONS: Cardiac arrest was induced by at least 10 minutes of removal of mechanical ventilation and was followed by manual external chest compressions and mechanical ventilation. After 3 minutes of resuscitation, piglets that did not achieve return of spontaneous circulation were randomized to two groups: adrenaline 0.02 mg kg every 3 minutes (20 animals) and adrenaline 0.02 mg kg every 3 minutes plus terlipressin 20 µg kg every 6 minutes plus hydrocortisone 30 mg kg one dose (22 animals). Resuscitation was discontinued when return of spontaneous circulation was achieved or after 24 minutes. MEASUREMENT AND MAIN RESULTS: Return of spontaneous circulation was achieved in 14 piglets (28.5%), 14.2% with only cardiac massage and ventilation. Return of spontaneous circulation was achieved in 25% of piglets treated with adrenaline and in 9.1% of those treated with adrenaline plus terlipressin plus hydrocortisone (p = 0.167). Return of spontaneous circulation was achieved in 45.4% of animals with pulseless electric activity, 20% with asystole, and 0% with ventricular fibrillation (p = 0.037). Shorter duration of cardiac arrest, higher mean blood pressure and EtCO2 and lower PaCO2 before resuscitation, and higher mean blood pressure during resuscitation were associated with higher return of spontaneous circulation. CONCLUSIONS: Treatment with adrenaline plus terlipressin plus corticoids does not achieve higher return of spontaneous circulation than that with adrenaline in an infant animal model of asphyxial cardiac arrest.

Effects of terlipressin on microcirculation of small bowel mesentery in rats with endotoxic shock.

BACKGROUND: Septic shock is still related to unacceptably high morbidity and mortality. Microcirculatory alteration has been demonstrated to be one important reason associated with this evolution. Vasoactive drugs are often used to restore adequate arterial pressure and tissue perfusion in septic shock. To define the roles of different drugs, the effects of terlipressin (TP) on the microcirculation of small bowel mesentery in rats with endotoxic shock were evaluated and compared with those of norepinephrine (NE). METHODS: Twenty-five adult male Wistar rats were randomized to the control (n = 5), TP (n = 10), and NE (n = 10) groups. After endotoxic shock was induced by intravenous lipopolysaccharide administration for 30 min, rats in the NE and TP groups were infused with saline 5 mL/kg/h and simultaneously given NE 4 µg/kg/min or TP 8 µg/kg/h. The mean arterial pressure, heart rate, blood gas analysis, and microvascular blood flow images of small bowel mesentery were recorded. RESULTS: After fluid resuscitation and vasopressor infusion, the mean arterial pressure was restored to the baseline values in the NE and TP groups. In the TP group, the heart rate was significantly lower compared with the NE group (P = 0.013). The proportion of perfused vessels and the microvascular flow index (MFI) were significantly increased; furthermore, the heterogeneity index of small vessels was markedly decreased in both the interventional groups with respect to the control group. Compared with the NE group, the MFI was significantly higher (P < 0.05) and the heterogeneity index was significantly lower (P < 0.05) in the TP group. CONCLUSIONS: Both TP and NE improved hemodynamic and microcirculatory alterations in rats with endotoxic shock. Compared with NE, TP was more effective in promoting MFI and improving the heterogeneity of small bowel mesentery in rats.

Controlled trial of ligation plus vasoconstrictor versus proton pump inhibitor in the control of acute esophageal variceal bleeding.

BACKGROUND: Endoscopic therapy combined with vasoconstrictor was generally recommended to treat acute variceal bleeding. However, up to 30% of patients may still encounter treatment failure. OBJECTIVES: This trial was to evaluate the efficacy of combination with endoscopic variceal ligation (EVL) and proton pump inhibitor (PPI) infusion in patients with acute variceal bleeding. METHODS: Cirrhotic patients presenting with acute esophageal variceal bleeding were rescued by emergency EVL. Soon after arresting of bleeding varices, eligible subjects were randomized to two groups. Vasoconstrictor group received either somatostatin or terlipressin infusion. PPI group received either omeprazole or pantoprazole. End points were initial hemostasis, very early rebleeding rate, and adverse events. RESULTS: Sixty patients were enrolled in vasoconstrictor group and 58 patients in PPI group. Both groups were comparable in baseline data. Initial hemostasis was achieved in 98% in vasoconstrictor group and 100% in PPI group (P = 1.0). Very early rebleeding within 48-120 h occurred in one patient (2%) in vasoconstrictor group and one patient (2%) in the PPI group (P = 1.0). Treatment failure was 4% in vasoconstrictor group and 2% in PPI group (P = 0.95). Adverse events occurred in 33 patients (55%) in vasoconstrictor group and three patients (6%) in PPI group (P < 0.001). Two patients in vasoconstrictor group and one patient in PPI group encountered esophageal ulcer bleeding. CONCLUSIONS: After successful control of acute variceal bleeding by EVL, adjuvant therapy with PPI infusion was similar to combination with vasoconstrictor infusion in terms of initial hemostasis, very early rebleeding rate, and associated with fewer adverse events.

[Septic shock. Update of treatment using hypertonic saline and antidiuretic hormone-vasopressin]. / Shock séptico. Actualización en tratamiento con suero salino hipertónico y hormona antidiurética-vasopresina.

Safety in the use of small volumes of hypertonic saline solution for hypovolaemic shock and in the treatment of intracranial hypertension has been demonstrated in studies in the field of resuscitation. There is little experience of this for septic shock in humans. Beneficial immunomodulatory effects have been detected in pre-clinical studies. Interactions with the pituitary-adrenal axis and with the secretion of anti-diuretic hormone are varied and suggestive, but are not sufficiently understood. On the other hand, vasopressin has cardiovascular, osmoregulatory, and coagulation effects, and also acts on the hypothalamic-pituitary-adrenal axis. There is a relative deficit of vasopressin in septic shock. Its use in these patients does not seem to have any advantages as regards mortality, but may be beneficial in patients at risk from acute renal failure, or those who receive corticosteroids. Terlipressin is a vasopressin analogue that has also been studied. The synergy between vasopressin and hypertonic saline is a hypothesis that is mainly supported in pre-clinical studies. The use of hypertonic saline solution in septic shock, although promising, is still experimental, and must be restricted to the field of controlled clinical trials.

Vasopressin in sepsis and septic shock.

Arginine vasopressin (AVP) and its synthetic, long-acting analog terlipressin (TP) are potent alternative vasoconstrictors in the treatment of septic patients with catecholamine-refractive vasodilatatory shock. The results from one large randomized clinical trial suggest that AVP plus norepinephrine (NE) infusion is as safe and effective as treatment with NE alone in patients with septic shock. Because the desired effects of vasopressin analogs are basically related to their vasopressinergic effects via the V1a receptor, more selective V1 agonists, such as TP, may be more potent in reversing sepsis-related arterial hypotension. In this regard, recent evidence from small-scale studies suggests that continuous low-dose infusion rather than intermittent bolus injection of TP is associated with fewer side effects, such as depression of cardiac output and rebound arterial hypotension. However, because clinical data on the administration of TP in patients with sepsis are limited, it should not currently be used beyond the scope of controlled trials. The optimal time point for the initiation of therapy with vasopressin analogs has yet to be determined. While AVP and TP are commonly used as last-resort therapies in severe septic shock, some evidence supports the initiation of treatment in a less severe state of the disease.

Recent advances in the management of hepato-renal syndrome (HRS).

Hepato-renal syndrome (HRS) is a functional renal failure complicating end-stage liver disease. HRS is characterized by marked arterial vasodilation (mainly of the splanchnic bed) and severe renal vasoconstriction. HRS is classified into 2 types: type I HRS shows a rapid and progressive decline in renal function with a very poor prognosis (median survival of about 2 weeks); HRS type 2 has a more stable renal failure, with a median survival of about 6 months. The management of HRS is still a big challenge. The definitive therapy for HRS is liver transplantation (LT); however, the survival rate of HRS patients is poor, and important organ shortage exists. Various approaches have been used for HRS treatment including vasoconstrictor therapy. Recent evidence has shown that vasoconstrictor agents are effective and serve as a bridge to LT; the rationale for vasoconstrictors is to counteract the splanchnic arterial vasodilation and increase the effective arterial blood volume. Thus, renal perfusion and glomerular filtration rates improve. Terlipressin, a V1 vasopressin agonist, has been used frequently. A recent meta-analysis of clinical trials showed that the pooled rate of patients who reversed HRS after terlipressin therapy was 0.52 (95% CI, 0.42; 0.61; P = 0.0001, /2 = 24.6%). The pooled Odds Ratio (OR) for mortality rate in HRS patients who were not responders to terlipressin versus responders was 5.746 (95% CI, 1.5; 21.9; P = 0.0005). Prospective, controlled clinical trials are in progress to address the impact of vasoconstrictor use on survival in HRS patients. Alternative therapies such as transjugular intrahepatic portosystemic shunts (TIPS) and extracorporeal albumin dialysis (ECAD) have given encouraging results but experience is extremely limited.

Rescue treatment with terlipressin in children with refractory septic shock: a clinical study.

INTRODUCTION: Refractory septic shock has dismal prognosis despite aggressive therapy. The purpose of the present study is to report the effects of terlipressin (TP) as a rescue treatment in children with catecholamine refractory hypotensive septic shock. METHODS: We prospectively registered the children with severe septic shock and hypotension resistant to standard intensive care, including a high dose of catecholamines, who received compassionate therapy with TP in nine pediatric intensive care units in Spain, over a 12-month period. The TP dose was 0.02 mg/kg every four hours. RESULTS: Sixteen children (age range, 1 month-13 years) were included. The cause of sepsis was meningococcal in eight cases, Staphylococcus aureus in two cases, and unknown in six cases. At inclusion the median (range) Pediatric Logistic Organ Dysfunction score was 23.5 (12-52) and the median (range) Pediatric Risk of Mortality score was 24.5 (16-43). All children had been treated with a combination of at least two catecholamines at high dose rates. TP treatment induced a rapid and sustained improvement in the mean arterial blood pressure that allowed reduction of the catecholamine infusion rate after one hour in 14 out of 16 patients. The mean (range) arterial blood pressure 30 minutes after TP administration increased from 50.5 (37-93) to 77 (42-100) mmHg (P < 0.05). The noradrenaline infusion rate 24 hours after TP treatment decreased from 2 (1-4) to 1 (0-2.5) microg/kg/min (P < 0.05). Seven patients survived to the sepsis episode. The causes of death were refractory shock in three cases, withdrawal of therapy in two cases, refractory arrhythmia in three cases, and multiorgan failure in one case. Four of the survivors had sequelae: major amputations (lower limbs and hands) in one case, minor amputations (finger) in two cases, and minor neurological deficit in one case. CONCLUSION: TP is an effective vasopressor agent that could be an alternative or complementary therapy in children with refractory vasodilatory septic shock. The addition of TP to high doses of catecholamines, however, can induce excessive vasoconstriction. Additional studies are needed to define the safety profile and the clinical effectiveness of TP in children with septic shock.

Switch therapy with ciprofloxacin vs. intravenous ceftazidime in the treatment of spontaneous bacterial peritonitis in patients with cirrhosis: similar efficacy at lower cost.

BACKGROUND: Intravenous administration of a third-generation cephalosporin is optimal antibiotic treatment for spontaneous bacterial peritonitis. AIMS: To compare an intravenous-oral step-down schedule with ciprofloxacin (switch therapy) to intravenous ceftazidime in the treatment of spontaneous bacterial peritonitis, and to evaluate the impact of terlipressin and albumin in the treatment of type 1 hepatorenal syndrome on mortality. METHODS: A total of 116 cirrhotic patients with spontaneous bacterial peritonitis, were randomly given switch therapy with ciprofloxacin (61 patients) or intravenous ceftazidime (55 patients). All patients who developed type 1 hepatorenal syndrome were treated with terlipressin (2-12 mg/day) and albumin (20-40 g/day). RESULTS: Resolution of infection was achieved in 46/55 patients treated with ceftazidime (84%) and in 49/61 patients treated with ciprofloxacin (80%, P = N.S.). An intravenous-oral step-down schedule was possible in 50/61 patients (82%) who received ciprofloxacin; 45/61 patients (74%) were discharged before the end of antibiotic treatment and completed it at home. The mean saving per patient due to the reduction of hospital stay in the ciprofloxacin group was 1150 . Type 1 hepatorenal syndrome was treated successfully in 12/19 patients (63%). As a consequence, the in-hospital mortality rate due to infection was 10%. CONCLUSIONS: Switch therapy with cephalosporin is more cost-effective than intravenous ceftazidime in the treatment of spontaneous bacterial peritonitis in cirrhotic patients who are not on prophylaxis with quinolones.

Resident-intruder trait aggression is associated with differences in lysine vasopressin and serotonin receptor 1A (5-HT1A) mRNA expression in the brain of pre-pubertal female domestic pigs (Sus scrofa).

Aggressive behaviour exhibited by domestic pigs following encounters with unfamiliar individuals is a serious welfare and economical problem. Aggression resulting in skin lesions is similarly prevalent in prepubertal pigs of either sex. Little is known about the neural circuits and neuropeptides that control aggression in the pig. Because there is evidence for the involvement of the vasopressin and serotonergic systems in the regulation of aggressive behaviour in male mammals, we sought differences using quantitative in situ hybridisation of vasopressin and serotonin 1A receptor (5-HT1A) mRNA expression within specific brain regions of aggressive and nonaggressive prepubertal female pigs. The number of cells expressing vasopressin mRNA was significantly higher in aggressive pigs in the medial amygdala, lateral septum (LS) and showed a similar trend in the bed nucleus of the stria terminalis (BnST) but not the paraventricular nucleus (PVN) or supraoptic nucleus. The 5-HT1A receptor was widely expressed through the porcine brain and a significantly lower intensity (silver grain density) of 5-HT1A mRNA expression was observed in the BnST. In the medial amygdala and LS fewer cells expressed 5-HT1A mRNA in aggressive pigs but no differences were found in the PVN. In the absence of inbred strains or selection lines, these findings have shown that prior identification of phenotypic behavioural extremes in a population in advance of neural studies is a useful technique. Moreover, these findings support a central role for vasopressin and serotonin in the mediation of high trait aggression in prepubertal female pigs.

Terlipressin in catecholamine-resistant septic shock patients.

To determine the effects on hemodynamics, laboratory parameters, and renal function of terlipressin used in septic-shock patients with hypotension not responsive to high-dose norepinephrine (>2.0 microg x kg(-1) x min(-1)) and dopamine (25 microg x kg(-1) x min(-1)), a prospective, open-label study was carried out in 17 patients. Patients received one or two boluses of 1 mg of terlipressin. In all patients terlipressin induced a significant increase in mean arterial pressure (MAP), systemic vascular resistance, pulmonary vascular resistance, and left and right ventricular stroke work. The increase in MAP was accompanied by a significant decrease in heart rate and cardiac index, but stroke volume remained unchanged. Oxygen delivery and consumption were significantly decreased. Blood lactate concentrations significantly decreased over the study period. Bilirubin, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were significantly increased. Thrombocytes were significantly decreased. No change in prothrombin time was observed. Renal function, assessed by urine flow and creatinine clearance, was significantly improved. Pulmonary function assessed by Pao2/Fio2 ratio was not affected. A significant reduction in norepinephrine and dopamine infusion rates was observed in all patients. Eight patients died during their ICU stay from late multiple organ failure. Within the limitations of the present study (open-label design, small group of patients), it can be concluded that in septic shock patients with hypotension nonresponsive to fluid resuscitation and high-dose vasopressors, terlipressin can be effective to restore MAP. Cardiac index should be closely monitored because it was significantly decreased by terlipressin. Renal function was significantly improved. Mesenteric circulation was not evaluated, but hepatic function was altered during the study period. Further studies are required to determine whether terlipressin is safe in terms of outcome in septic shock patients.

Terlipressin dose response in healthy and endotoxemic sheep: impact on cardiopulmonary performance and global oxygen transport.

OBJECTIVE: To determine whether a goal-directed terlipressin infusion increases mean arterial pressure without causing a pulmonary vasopressive effect and whether this response impacts on key parameters of oxygen transport in healthy and endotoxemic sheep. DESIGN AND SETTING: Prospective controlled trial in a university research laboratory. ANIMALS AND INTERVENTIONS: Six conscious adult ewes instrumented for chronic study received terlipressin as titrated infusion started with 10 microg x kg(-1) x h(-1) and increased by 5 microg x kg(-1) x h(-1) every 15 min, either until mean arterial pressure was increased by 15 mmHg from baseline, or a maximum of 40 microg x kg(-1) x h(-1) was given. Following 24 h of recovery sepsis was induced and maintained in the same ewes by a continuous infusion of endotoxin ( Salmonella typhosa, 10 ng x kg(-1) min(-1)). After 16 h of endotoxemia the sheep were again treated with terlipressin. MEASUREMENTS AND RESULTS: Systemic oxygen delivery and consumption were calculated before and after the titration period; hemodynamic parameters were measured every 15 min. The increase in mean arterial pressure was greater during endotoxemia than in healthy controls. In both states terlipressin administration decreased cardiac index and diminished oxygen delivery and consumption. While mean pulmonary arterial pressure remained constant, terlipressin increased the pulmonary vascular resistance index in endotoxemic sheep. CONCLUSIONS: During ovine endotoxemia titrated terlipressin reversed hypotension but impaired the pulmonary circulation. The observed decrease in oxygen delivery may carry the risk of tissue hypoxia especially in sepsis, where oxygen demand is typically increased.

Octreotide for acute esophageal variceal bleeding: a meta-analysis.

BACKGROUND & AIMS: Studies of octreotide have not demonstrated a consistent benefit in efficacy or safety compared with conventional therapies. This study statistically pooled existing trials to evaluate the safety and efficacy of octreotide for esophageal variceal hemorrhage. METHODS: We identified randomized trials of octreotide for variceal hemorrhage from computerized databases, scientific meeting abstracts, and the manufacturer of octreotide. Blinded reviewers abstracted the data, and a meta-analysis was performed. RESULTS: Octreotide improved control of esophageal variceal hemorrhage compared with all alternative therapies combined (relative risk [RR], 0.63; 95% confidence interval [CI], 0.51-0.77); vasopressin/terlipressin (RR, 0.58; 95% CI, 0.42-0.81); or no additional intervention/placebo (among patients that received initial sclerotherapy/banding before randomization) (RR, 0.46; 95% CI, 0.32-0.67). Octreotide had comparable efficacy to immediate sclerotherapy for control of bleeding (RR, 0.94; 95% CI, 0.55-1.62), fewer major complications than vasopressin/terlipessin (RR, 0.31; 95% CI, 0.11-0.87), and a complication profile comparable to no intervention/placebo (RR, 1.06; 95% CI, 0.72-1.55). No specific alternative therapy demonstrated a mortality benefit. CONCLUSIONS: These results favor octreotide over vasopressin/terlipressin in the control of esophageal variceal bleeding and suggest it is a safe and effective adjunctive therapy after variceal obliteration techniques. Trials are needed to determine the optimal dose, route, and duration of octreotide treatment.

Restricting maternal space during parturition in the pig. Effects on oxytocin, vasopressin and cortisol secretion following vagino-cervical stimulation and administration of naloxone.

This experiment studied the effects on endocrine and birth parameters of parturient pigs produced by restricting maternal freedom of movement without otherwise altering environment. Six primiparous pigs (gilts) were each given a jugular catheter under anaesthesia 7 days before parturition and commenced birth in a strawed pen, 2.0 m x 1.5 m in size. Continuous automated blood sampling (3 ml min-1) from unrestrained gilts began following the birth of the first piglet (stage 1) and continued for 2 h. After at least 30 min of blood collection, maternal space was reduced to 2.0 m x 0.55 m by placing rails across the pen (stage 2). The scope for movement in stage 2 was similar to that offered by a farrowing crate. After at least 25 min each gilt was given the opioid antagonist naloxone (1 mg kg-1 i.v.: stage 3). At each stage, vagino-cervical stimulation (VCS) was applied to mimic foetal ejection. Non-cervically stimulated oxytocin (OT) secretion between stages 1 and 2 was unchanged (P > 0.05) but increased significantly relative to both stages 1 and 2 following naloxone treatment for 15-20 min (P < 0.05, paired t-tests on log10 data). Following VCS in all stages plasma OT rose (P < 0.05) for 1-2 min in a similar way to that seen previously following foetal ejection, the increases being proportionally similar irrespective of stage or baseline secretion. Cortisol secretion did not increase as a consequence of space restriction (mean +/- SEM concentrations were 28.6 +/- 8.51 pmol l-1 and 32.3 +/- 11.8 pmol l-1 in stages 1 and 2, respectively). In addition, VCS did not significantly affect cortisol output. Lysine vasopressin concentrations were not affected as a consequence of either stage or VCS. Parturition was not interrupted following space restriction of gilts. These data suggest that reducing maternal space allowance during parturition is not stressful when the process does not involve the movement of animals to novel surroundings.

A case of adrenal insufficiency due to acquired hypothalamic CRH deficiency.

A 40-year-old woman with adrenal insufficiency was clinically diagnosed and examined with human corticotropin releasing hormone (CRH). This patient with secondary hypo-adrenalism has shown a normal serum cortisol response to exogenous ACTH administration and has been examined with CRH, lysine-vasopressin (LVP) and insulin tolerance test (ITT), respectively. Success in secreting ACTH in response to both CRH and LVP tests, but not ITT, suggests that this disorder was possibly due to a hypothalamic CRH deficiency rather than pituitary corticotroph dysfunction. A combination of the CRH test and ITT has come to play an increasingly significant role in the diagnosis and differential diagnosis of isolated ACTH deficiency syndrome.

Vasopressin-responsive adrenocortical tumor in a mild Cushing's syndrome: in vivo and in vitro studies.

We report a case of a Cushing's syndrome caused by an autonomously secreting unilateral adrenocortical tumor, characterized by a clinically and biologically mild hypercortisolemic state and an unusual response pattern to vasopressin. Laboratory tests showed normal early morning plasma cortisol and 24-h urinary cortisol excretion, but lack of nycthemeral variations and suppressed plasma ACTH. Urinary cortisol excretion was not suppressed by either the low dose or the high dose dexamethasone test. Injection of lysine vasopressin, (10 IU, im) induced a marked increase in plasma cortisol, without an elevation of plasma ACTH. Computed tomography scan revealed an adrenocortical mass of the left gland with a contralateral atrophic gland. Removal of the tumor led to complete remission of Cushing's symptoms. In vitro studies were then performed to investigate the effect of arginine vasopressin (AVP) on calcium mobilization in cultured tumor cells using a microfluorimetric technique. Application of AVP in the vicinity of the cells induced a rapid and marked increase in the intracellular calcium concentration. Preincubation of the cells with the V1 vasopressin receptor antagonist [d(CH2)5,Tyr(OMe)2]AVP totally suppressed the AVP-induced stimulation of intracellular calcium concentration. Reverse transcription followed by polymerase chain reaction of tumor ribonucleic acid with specific oligonucleotides amplified high levels of V1 receptor signal compared with normal adrenocortical ribonucleic acid. Specific oligonucleotides for the V2 or V3 receptors amplified only a faint signal. This is the first report describing a mild case of Cushing's syndrome caused by an AVP-sensitive cortisol-producing adenoma. The direct effect of AVP on cultured tumor cells was mediated through the V1 type of vasopressin receptor, similar to that previously characterized in normal human fasciculata cells, suggesting that the tumor expressed an eutopic V1 AVP receptor and exhibited overresponsiveness to AVP.

Lysine vasopressin stimulation of cortisol secretion in patients with adrenocorticotropin-independent macronodular adrenal hyperplasia.

We present two patients with Cushing's syndrome due to ACTH-independent macronodular adrenal hyperplasia who showed marked plasma cortisol response to lysine-8-vasopressin (LVP) injection (from 930 and 731 pmol/L to 2177 and 1920 pmol/L, respectively), while plasma ACTH levels remained undetectable. The ACTH independence of cortisol secretion in the two patients was determined from the following endocrinological findings. Plasma cortisol levels were not increased by corticotropin-releasing hormone injections and were not suppressed by high dose (16 mg) dexamethasone administrations. The plasma ACTH levels, measured by two independent sensitive immunoassays, were persistently undetectable even after corticotropin-releasing hormone injection, metyrapone administration, and bilateral adrenalectomy. The particular pathological finding of the two cases, atrophic lesions in nonnodular parts of the adrenal cortexes, also indicated ACTH independence of the macronodular hyperplasia. In vitro examination revealed a direct effect of LVP on cortisol secretion from the adrenal cells of the macronodules. We also examined seven patients with Cushing's syndrome caused by adrenal adenoma and found a statistically significant plasma cortisol response to LVP injection. The direct effect of LVP was also demonstrated in cultured adenoma cells. In conclusion, we discovered a direct adrenal effect of LVP on cortisol secretion in patients with ACTH-independent macronodular hyperplasia and, to a lesser extent, in patients with cortisol-producing adrenal adenoma. The cortisol response to LVP may serve to facilitate their diagnosis and choice of therapy.

Isolated adrenocorticotropic hormone deficiency secondary to hypothalamic deficit of corticotropin releasing hormone.

A 42-year-old man and a 51-year-old woman with a positive history of weakness and gastrointestinal complaints were shown to have low basal plasma cortisol and ACTH levels, and low daily urinary excretion of free cortisol. An empty sella was found in patient no. 1, while patient no. 2 was hypothyroid. Both patients showed a normal plasma cortisol response to ACTH and an increment in plasma ACTH and lipotropin levels after ovine CRH (oCRH), lysine vasopressin (LVP) and oCRH-LVP stimulation tests. These studies clearly report an isolated idiopathic ACTH deficiency due to a deficit in CRH in two adult subjects.

Effects of repetitive administration of corticotropin-releasing hormone combined with lysine vasopressin on plasma adrenocorticotropin and cortisol levels in secondary adrenocortical insufficiency.

To examine the functioning of the hypothalamo-pituitary-adrenocortical axis in secondary adrenocortical insufficiency, we administered 100 micrograms synthetic human CRH, iv, plus 10 U lysine-8-vasopressin (LVP), im, three times daily for 3 consecutive days. The changes in plasma ACTH and cortisol levels during the administration and the response to an insulin tolerance test (ITT) conducted before and after the administration were determined. In three patients with isolated ACTH deficiency, basal plasma ACTH and cortisol levels were undetectablly low, and there was no response noted in the ITT or during CRH-LVP administration throughout the observation period. In four patients with adrenocortical insufficiency who had undergone successful transsphenoidal microadenomectomy for Cushing's disease and in six patients who had undergone curative unilateral adrenalectomy for Cushing's syndrome, basal plasma ACTH levels were low, but responded considerably to both stimulation tests. Along with the 3 days of CRH-LVP stimulation, however, neither the peak nor the time-integrated ACTH response was significantly enhanced, because of the variability of the responses among the patients. Compared with the ACTH response on the last day of CRH-LVP stimulation, the subsequent ITT tended to induce a lower ACTH response in the post-Cushing's disease patients and a higher response in the post-Cushing's syndrome patients. Regarding the plasma cortisol levels, the basal, peak, and integrated responses tended to increase daily during CRH-LVP administration. Conversely, the ITT after repetitive CRH-LVP administration induced a higher cortisol response than the test before CRH-LVP administration in the post-Cushing's disease patients. No serious complications were noted in any of the patients during or after the treatment. The present findings indicate that 1) repetitive administration of CRH in combination with LVP is a safe and valuable provocation test to examine the pituitary ACTH reserve and the integrity of the pituitary-adrenocortical axis; 2) isolated ACTH deficiency is usually due to a defect at the pituitary level; 3) with respect to adrenocortical responsiveness, post-Cushing's disease patients show a better accumulation of the provocative effect than do post-Cushing's syndrome patients; and 4) both hypothalamic and pituitary dysfunction are responsible for adrenal hypofunction in patients after hypercortisolemia, but post-Cushing's syndrome patients (especially those with a short period of hypercortisolemia) appeared to have less impairment of hypothalamic ACTH-releasing activity than post-Cushing's disease patients.

The corticotropin-releasing factor test in the differential diagnosis of Cushing's syndrome: a comparison with the lysine-vasopressin test.

The diagnostic accuracy of the CRH test was compared with that of the LVP test in 28 consecutive patients with ACTH-dependent Cushing's syndrome. A false negative response to CRH was found in 3 of 21 patients with pituitary-dependent Cushing's disease and to LVP in 4. The 7 patients with ectopic ACTH secretion were unresponsive to CRH, whereas 2 did respond to LVP. CRH and high-dose dexamethasone tests combination led to concordant results in 79% of patients. In all cases the etiological diagnosis suggested was correct. LVP and high-dose dexamethasone tests combination led to concordant results in only 71% of patients and the etiological diagnosis suggested was erroneous in one. Individual tolerance to the CRH test was also clearly better than that to the LVP test. It is concluded that the CRH test, alone or in combination with the high-dose dexamethasone test must be preferentially used to the LVP test in the differential diagnosis of ACTH-dependent Cushing's disease.