asopressin nitiation as a econd-Line Vasoressor in Early eptic hock (VISPSS)

BACKGROUND

Vasopressin is recommended as a second-line vasoactive agent for the management of septic shock; however, a paucity of data to guide its optimal use remains. The aim was to evaluate the effect of time-to vasopressin initiation and norepinephrine (NE) dose at vasopressin initiation on clinical outcomes in patients presenting with septic shock.

METHODS

This was a multi-centered, retrospective, observational study conducted in patients with septic shock. Patients were divided into 2 groups: patients initiated on vasopressin when NE-equivalent dose (NEE) < 0.25 mcg/kg/min or ≥ 0.25 mcg/kg/min. The primary outcome was time-to-vasopressor discontinuation (hours). Secondary outcomes included 28-day in-hospital mortality, intensive care unit (ICU) length of stay (LOS), fluid balance after 72 hours, and the change in NEE at 12 hours.

RESULTS

A total of 302 patients were included in this study. After propensity-score matching, 73 patients in each group were identified for analysis. There was no significant difference in the time-to-vasopressor discontinuation (hours) between the groups (88.8 [55-187.5] vs 86.7 [47-172]); p = 0.7815). Fluid balance (mL) at 72 hours was significantly lower when vasopressin was initiated at NEE < 0.25 mcg/kg/min (1769 [71-7287] vs 5762 [1463-8813]; p = 0.0077). A multivariable linear regression showed shorter time to shock resolution with earlier vasopressin initiation, defined as within 4 hours (p < 0.05).

CONCLUSION

In this propensity-score matched cohort, vasopressin initiation at NEE < 0.25 mcg/kg/min was not associated with shorter vasopressor duration. There was a lower fluid balance at 72 hours when vasopressin was initiated at lower NE doses.

Tmem117 in AVP neurons regulates the counterregulatory response to hypoglycemia

The counterregulatory response to hypoglycemia (CRR), which ensures a sufficient glucose supply to the brain, is an essential survival function. It is orchestrated by incompletely characterized glucose-sensing neurons, which trigger a coordinated autonomous and hormonal response that restores normoglycemia. Here, we investigate the role of hypothalamic Tmem117, identified in a genetic screen as a regulator of CRR. We show that Tmem117 is expressed in vasopressin magnocellular neurons of the hypothalamus. Tmem117 inactivation in these neurons increases hypoglycemia-induced vasopressin secretion leading to higher glucagon secretion in male mice, and this effect is estrus cycle phase dependent in female mice. Ex vivo electrophysiological analysis, in situ hybridization, and in vivo calcium imaging reveal that Tmem117 inactivation does not affect the glucose-sensing properties of vasopressin neurons but increases ER stress, ROS production, and intracellular calcium levels accompanied by increased vasopressin production and secretion. Thus, Tmem117 in vasopressin neurons is a physiological regulator of glucagon secretion, which highlights the role of these neurons in the coordinated response to hypoglycemia.

High-dose vasoactive agents in aeromedical retrievals for septic shock: A role for vasopressin?

OBJECTIVE

To determine the number of patients retrieved by aeromedical teams for septic shock requiring vasopressor support who meet criteria for vasopressin therapy under the Surviving Sepsis Campaign 2021 guidelines.

METHODS

Retrospective chart review of patients transferred by LifeFlight Retrieval Medicine on vasopressors over 2 years.

RESULTS

One thousand one hundred and fifty-eight patients were retrieved on vasopressor therapy, with 428 requiring infusions for septic shock. One hundred and fifteen of these met criteria for administration of vasopressin under Surviving Sepsis Campaign guidelines.

CONCLUSION

A sufficient percentage of patients on vasopressors for septic shock require vasopressin therapy to meet current best treatment guidelines, and the inclusion of vasopressin in retrieval drug kits should be considered by Australian aeromedical services.

Effect of Vasopressin and Methylprednisolone vs Placebo on Return of Spontaneous Circulation in Patients With In-Hospital Cardiac Arrest: A Randomized Clinical Trial

IMPORTANCE

Previous trials have suggested that vasopressin and methylprednisolone administered during in-hospital cardiac arrest might improve outcomes.

OBJECTIVE

To determine whether the combination of vasopressin and methylprednisolone administered during in-hospital cardiac arrest improves return of spontaneous circulation.

DESIGN, SETTING, AND PARTICIPANTS

Multicenter, randomized, double-blind, placebo-controlled trial conducted at 10 hospitals in Denmark. A total of 512 adult patients with in-hospital cardiac arrest were included between October 15, 2018, and January 21, 2021. The last 90-day follow-up was on April 21, 2021.

INTERVENTION

Patients were randomized to receive a combination of vasopressin and methylprednisolone (n = 245) or placebo (n = 267). The first dose of vasopressin (20 IU) and methylprednisolone (40 mg), or corresponding placebo, was administered after the first dose of epinephrine. Additional doses of vasopressin or corresponding placebo were administered after each additional dose of epinephrine for a maximum of 4 doses.

MAIN OUTCOMES AND MEASURES

The primary outcome was return of spontaneous circulation. Secondary outcomes included survival and favorable neurologic outcome at 30 days (Cerebral Performance Category score of 1 or 2).

RESULTS

Among 512 patients who were randomized, 501 met all inclusion and no exclusion criteria and were included in the analysis (mean [SD] age, 71 [13] years; 322 men [64%]). One hundred of 237 patients (42%) in the vasopressin and methylprednisolone group and 86 of 264 patients (33%) in the placebo group achieved return of spontaneous circulation (risk ratio, 1.30 [95% CI, 1.03-1.63]; risk difference, 9.6% [95% CI, 1.1%-18.0%]; P = .03). At 30 days, 23 patients (9.7%) in the intervention group and 31 patients (12%) in the placebo group were alive (risk ratio, 0.83 [95% CI, 0.50-1.37]; risk difference: -2.0% [95% CI, -7.5% to 3.5%]; P = .48). A favorable neurologic outcome was observed in 18 patients (7.6%) in the intervention group and 20 patients (7.6%) in the placebo group at 30 days (risk ratio, 1.00 [95% CI, 0.55-1.83]; risk difference, 0.0% [95% CI, -4.7% to 4.9%]; P > .99). In patients with return of spontaneous circulation, hyperglycemia occurred in 77 (77%) in the intervention group and 63 (73%) in the placebo group. Hypernatremia occurred in 28 (28%) and 27 (31%), in the intervention and placebo groups, respectively.

CONCLUSIONS AND RELEVANCE

Among patients with in-hospital cardiac arrest, administration of vasopressin and methylprednisolone, compared with placebo, significantly increased the likelihood of return of spontaneous circulation. However, there is uncertainty whether this treatment results in benefit or harm for long-term survival.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03640949.

Vasopressor-Sparing Action of Methylene Blue in Severe Sepsis and Shock: A Narrative Review

Shock is a serious acute circulatory failure leading to inadequate oxygen delivery to the cells. Its treatment is mainly based on circulating fluid optimization, and vasopressors to provide an adequate mean arterial pressure and microcirculatory flow. Norepinephrine is the drug of choice, but high dosages may be responsible for several side effects, including increased myocardial oxygen consumption, dysrhythmias, and peripheral and organ ischemia. Moreover, some patients are “non-responders” to first-line norepinephrine treatment. Hence, other drugs have been proposed to reach and maintain the hemodynamic target. In general, they are described as catecholamine-sparing agents. Among others, the most used are vasopressin, corticosteroids, and angiotensin II. Methylene blue (MB) represents a further option, even though its use is still a topic of controversy. This review article tries to summarize what is known and unknown about the actions of MB in patients in shock. It reduces excessive production of nitric oxide via blockade of guanylate cyclase in shock states. At present, it appears the MB provides positive results in septic shock, if administered early. Further randomized controlled trials are warranted regarding its use to provide more precise indications to physicians involved in the treatment of such patients.

Aldosterone Decreases Vasopressin-Stimulated Water Reabsorption in Rat Inner Medullary Collecting Ducts

Aldosterone indirectly regulates water reabsorption in the distal tubule by regulating sodium reabsorption. However, the direct effect of aldosterone on vasopressin-regulated water and urea permeability in the rat inner medullary collecting duct (IMCD) has not been tested. We investigated whether aldosterone regulates osmotic water permeability in isolated perfused rat IMCDs. Adding aldosterone (500 nM) to the bath significantly decreased osmotic water permeability in the presence of vasopressin (50 pM) in both male and female rat IMCDs. Aldosterone significantly decreased aquaporin-2 (AQP2) phosphorylation at S256 but did not change it at S261. Previous studies show that aldosterone can act both genomically and non-genomically. We tested the mechanism by which aldosterone attenuates osmotic water permeability. Blockade of gene transcription with actinomycin D did not reverse aldosterone-attenuated osmotic water permeability. In addition to AQP2, the urea transporter UT-A1 contributes to vasopressin-regulated urine concentrating ability. We tested aldosterone-regulated urea permeability in vasopressin-treated IMCDs. Blockade of gene transcription did not reverse aldosterone-attenuated urea permeability. In conclusion, aldosterone directly regulates water reabsorption through a non-genomic mechanism. Aldosterone-attenuated water reabsorption may be related to decreased trafficking of AQP2 to the plasma membrane. There may be a sex difference apparent in the inhibitory effect of aldosterone on water reabsorption in the inner medullary collecting duct. This study is the first to show a direct effect of aldosterone to inhibit vasopressin-stimulated osmotic water permeability and urea permeability in perfused rat IMCDs.

[Complete tachyphylaxis for vasopressin in a patient with subarachnoid haemorrhage]

In this case report, we present a 28-year-old woman who was admitted to a neuro-intensive care unit with sub-arachnoid haemorrhage. She was intubated and haemodynamically unstable. Over five days the need for norepinephrine reached the level of 1.2 µg/kg/min to insure a sufficient cerebral perfusion pressure. Epinephrine and vasopressin were without effect in raising the blood pressure. On suspicion of tachyphylaxis the norepinephrine infusion was stopped, and no decline in blood pressure was observed. After two days without use of any vasopressor agents, the efficacy of norepinephrine returned to normal.

Association of Vasopressin Plus Catecholamine Vasopressors vs Catecholamines Alone With Atrial Fibrillation in Patients With Distributive Shock: A Systematic Review and Meta-analysis

IMPORTANCE

Vasopressin is an alternative to catecholamine vasopressors for patients with distributive shock-a condition due to excessive vasodilation, most frequently from severe infection. Blood pressure support with a noncatecholamine vasopressor may reduce stimulation of adrenergic receptors and decrease myocardial oxygen demand. Atrial fibrillation is common with catecholamines and is associated with adverse events, including mortality and increased length of stay (LOS).

OBJECTIVES

To determine whether treatment with vasopressin + catecholamine vasopressors compared with catecholamine vasopressors alone was associated with reductions in the risk of adverse events.

DATA SOURCES

MEDLINE, EMBASE, and CENTRAL were searched from inception to February 2018. Experts were asked and meta-registries searched to identify ongoing trials.

STUDY SELECTION

Pairs of reviewers identified randomized clinical trials comparing vasopressin in combination with catecholamine vasopressors to catecholamines alone for patients with distributive shock.

DATA EXTRACTION AND SYNTHESIS

Two reviewers abstracted data independently. A random-effects model was used to combine data.

MAIN OUTCOMES AND MEASURES

The primary outcome was atrial fibrillation. Other outcomes included mortality, requirement for renal replacement therapy (RRT), myocardial injury, ventricular arrhythmia, stroke, and LOS in the intensive care unit and hospital. Measures of association are reported as risk ratios (RRs) for clinical outcomes and mean differences for LOS.

RESULTS

Twenty-three randomized clinical trials were identified (3088 patients; mean age, 61.1 years [14.2]; women, 45.3%). High-quality evidence supported a lower risk of atrial fibrillation associated with vasopressin treatment (RR, 0.77 [95% CI, 0.67 to 0.88]; risk difference [RD], -0.06 [95% CI, -0.13 to 0.01]). For mortality, the overall RR estimate was 0.89 (95% CI, 0.82 to 0.97; RD, -0.04 [95% CI, -0.07 to 0.00]); however, when limited to trials at low risk of bias, the RR estimate was 0.96 (95% CI, 0.84 to 1.11). The overall RR estimate for RRT was 0.74 (95% CI, 0.51 to 1.08; RD, -0.07 [95% CI, -0.12 to -0.01]). However, in an analysis limited to trials at low risk of bias, RR was 0.70 (95% CI, 0.53 to 0.92, P for interaction = .77). There were no significant differences in the pooled risks for other outcomes.

CONCLUSIONS AND RELEVANCE

In this systematic review and meta-analysis, the addition of vasopressin to catecholamine vasopressors compared with catecholamines alone was associated with a lower risk of atrial fibrillation. Findings for secondary outcomes varied.

Does Vasopressin Exacerbate Cerebral Edema in Patients with Severe Traumatic Brain Injury?

Arginine vasopressin (AVP) is often used as an alternative pressor to catecholamines (CATs). However, unlike CATs, AVP is a powerful antidiuretic that could promote edema. We tested the hypothesis that AVP promoted cerebral edema and/or increased requirements for osmotherapy, relative to those who received CATs, for cerebral perfusion pressure (CPP) management after traumatic brain injury (TBI). This is a retrospective review of 286 consecutive TBI patients with intracranial pressure monitoring at a single institution from September 2008 to January 2015. Cerebral edema was quantitated using CT attenuation in prespecified areas of gray and white matter.

RESULTS

To maintain CPP >60 mm Hg, 205 patients required no vasopressors, 41 received a single CAT, 12 received AVP, and 28 required both. Those who required no pressors were generally less injured; required less hyperosmolar therapy and less total fluid; and had lower plasma Na, lower intracranial pressure, less edema, and lower mortality (all P < 0.05). Edema; daily mean, minimum, and maximum Na levels; and mortality were similar with AVP versus CATs, but the daily requirement of mannitol and 3 per cent NaCl were reduced by 45 and 35 per cent (both P < 0.05). In patients with TBI who required CPP therapy, AVP reduced the requirements for hyperosmolar therapy and did not delay resolution or increase cerebral edema compared with CATs.

Hemodynamic Instability Secondary to Vasopressin Withdrawal in Septic Shock

RATIONALE

Vasopressors such as norepinephrine are first line for support of mean arterial pressure (MAP) in the management of septic shock. Their use, however, is commonly associated with many adverse events. These detriments frequently trigger the use of alternative, noncatecholamine therapies, including vasopressin. Vasopressin deficiency is a known physiologic consequence of septic shock, and while guidelines recommend vasopressin in addition to norepinephrine, no consensus exists on the duration of deficiency or ideal time of cessation. Studies have suggested that vasopressin discontinuation prior to other vasopressors may lead to hypotension; however, data are limited. This study evaluates the optimal sequence for the discontinuation of vasopressin therapy in septic shock.

METHODS

This was a 1-year retrospective study of 152 patients admitted to the medical intensive care unit (ICU) with septic shock who received concurrent norepinephrine and vasopressin for vasoactive support. Patients were excluded if death occurred on vasopressors, within 24 hours after discontinuation of vasopressors, or within 48 hours of ICU admission. The primary outcome of hemodynamic instability included incidence of hypotension after vasopressor discontinuation (2 consecutive MAPs < 60 mm Hg), fluid bolus administration, greater than 0.05 μg/kg/min increase in norepinephrine requirements, or addition of an alternative vasopressor. Secondary outcomes included time to hypotension, total vasopressor duration, arrhythmias, mortality, and length of stay.

RESULTS

Ninety-one patients met exclusion criteria, resulting in 61 patients for evaluation. Vasopressin was the first vasoactive therapy to be discontinued in 19 patients and last in 42 patients. Baseline characteristics and the use of potentially confounding treatments known to effect MAP were similar between groups. Discontinuation of vasopressin first was associated with a significant increase in hemodynamic instability (74% vs 16.7%, P < .01), with a shorter time to hemodynamic instability (5 vs 15 hours, P < .01). Secondary outcomes were similar.

CONCLUSION

Vasopressin discontinuation prior to cessation of norepinephrine infusion was associated with an increased risk of hemodynamic instability.

Non-Adrenergic Vasopressors in Patients with or at Risk for Vasodilatory Shock. A Systematic Review and Meta-Analysis of Randomized Trials

Introduction

Hypotensive state is frequently observed in several critical conditions. If an adequate mean arterial pressure is not promptly restored, insufficient tissue perfusion and organ dysfunction may develop. Fluids and catecholamines are the cornerstone of critical hypotensive states management. Catecholamines side effects such as increased myocardial oxygen consumption and development of arrhythmias are well known. Thus, in recent years, interest in catecholamine-sparing agents such as vasopressin, terlipressin and methylene blue has increased; however, few randomized trials, mostly with small sample sizes, have been performed. We therefore conducted a meta-analysis of randomized trials to investigate the effect of non-catecholaminergic vasopressors on mortality.

Methods

PubMed, BioMed Central and Embase were searched (update December 31^st, 2014) by two independent investigators. Inclusion criteria were: random allocation to treatment, at least one group receiving a non-catecholaminergic vasopressor, patients with or at risk for vasodilatory shock. Exclusion criteria were: crossover studies, pediatric population, non-human studies, studies published as abstract only, lack of data on mortality. Studied drugs were vasopressin, terlipressin and methylene blue. Primary endpoint was mortality at the longest follow-up available.

Results

A total of 1,608 patients from 20 studies were included in our analysis. The studied settings were sepsis (10/20 studies [50%]), cardiac surgery (7/20 [35%]), vasodilatory shock due to any cause (2/20 [19%]), and acute traumatic injury (1/20 [5%]). Overall, pooled estimates showed that treatment with non-catecholaminergic agents improves survival (278/810 [34.3%] versus 309/798 [38.7%], risk ratio = 0.88, 95% confidence interval = 0.79 to 0.98, p = 0.02). None of the drugs was associated with significant reduction in mortality when analyzed independently. Results were not confirmed when analyzing studies with a low risk of bias.

Conclusions

Catecholamine-sparing agents in patients with or at risk for vasodilatory shock may improve survival. Further researches on this topic are needed to confirm the finding.

Neural injury after use of vasopressin and adrenaline during porcine cardiopulmonary resuscitation

BACKGROUND

Our aim was to investigate cerebral and cardiac tissue injury subsequent to use of vasopressin and adrenaline in combination compared with vasopressin alone during cardiopulmonary resuscitation (CPR).

METHODS

In a randomized, prospective, laboratory animal study 28 anesthetized piglets were subject to a 12-min untreated cardiac arrest and subsequent CPR. After 1 min of CPR, 10 of the piglets received 0.4 U/kg of arg(8)-vasopressin (V group), and 10 piglets received 0.4 U/kg of arg(8)-vasopressin, 1 min later followed by 20 µg/kg body weight of adrenaline, and another 1 min later continuous administration (10 µg/kg/min) of adrenaline (VA group). After 8 min of CPR, the piglets were defibrillated and monitored for another 3 h. Then they were killed and the brain immediately removed pending histological analysis.

RESULTS

During CPR, the VA group had higher mean blood pressure and cerebral cortical blood flow (CCBF) but similar coronary perfusion pressure. After restoration of spontaneous circulation there was no difference in the pressure variables, but CCBF tended to be (36% ± 16%) higher in the V group. Neuronal injury and signs of a disrupted blood-brain barrier (BBB) were greater, 20% ± 4% and 21% ± 4%, respectively, in the VA group. In a background study of repeated single doses of adrenaline every third minute after 5 min arrest but otherwise the same protocol, histological measurements showed even worse neural injury and disruption of the BBB.

CONCLUSION

Combined use of vasopressin and adrenaline caused greater signs of cerebral and cardiac injury than use of vasopressin alone during experimental cardiopulmonary resuscitation.

Long-term administration of vasopressin can cause Ménière's disease in mice

CONCLUSION

A new murine model of Ménière's disease has been developed, based on long-term administration of vasopressin. Induction of vestibular dysfunction in the present animal model can cause additional stress, by reducing inner ear blood flow. Latanoprost, a selective agonist for the FP prostanoid receptor, may become a new remedy for Ménière's disease.

OBJECTIVE

The purpose of this study was to develop a more suitable animal model, with a closer resemblance to the pathophysiological process in Ménière's disease.

METHODS

Adult CBA/J or ICR mice were treated by subcutaneous injection of vasopressin for 5 days up to 8 weeks. Morphological analyses were performed of the cochlea, vestibular end organs and endolymphatic sac. The effect of latanoprost on the development of endolymphatic hydrops was also examined.

RESULTS

All experimental animals showed mild to moderate endolymphatic hydrops, increasing in severity as the vasopressin treatment was prolonged. Animals treated with vasopressin for 8 weeks showed severe endolymphatic hydrops with partial loss of outer hair cells and spiral ganglion cells. These animals also had a reversible vestibular dysfunction following intratympanic injection of epinephrine. Latanoprost inhibited the development of endolymphatic hydrops caused by vasopressin.

Storage of polyvinylpyrrolidone (PVP) in tissues following long-term treatment with a PVP-containing vasopressin preparation

The parenteral use of polyvinylpyrrolidone (PVP) leads to PVP retention in the human organism. Four case histories dealing with patients on long-term treatment with a PVP-containing vasopressin preparation are presented and the possibility of a harmful effect of the PVP storage is discussed. The presence of PVP in serum, demonstrated by lipoprotein electrophoresis, is described. Based on the literature and the present findings, a withdrawal of PVP-containing preparations for injectional purposes is advocated.

[Severe hypotension as a complication of intramyometrial injection of vasopressin: a case report]

A thirty-year-old woman was scheduled for laparoscopic myomectomy. After insertion of an epidural catheter at the L4-5 interspace, general anesthesia was induced with thiopental 250 mg followed by vecuronium 8mg intravenously to facilitate tracheal intubation. General anesthesia was maintained with sevoflurane and nitrous oxide. Just after intramyometrial injection of vasopressin, blood pressure decreased from 122/66 to 45/25 mmHg, and heart rate decreased from 52 to 45 beats x min(-1). The patient was ventilated with 100% oxygen, and we administered atropine 0.25 mg and ephedrine 16 mg intravenously. Blood pressure increased to 150/100 mmHg and heart rate increased to 135 beats x min(-1). Since electrocardiogram showed ST-segment depression and premature ventricular contraction, we administered nicorandil 3 mg followed by continuous infusion at a rate of 3 mg x hr(-1), and lidocaine 60 mg, intravenously. The ST depression and premature ventricular contraction disappeared immediately. To decrease blood pressure and heart rate, we increased inspiratory concentrations of sevoflurane and nitrous oxide and administered local anesthetics via epidural catheter, and hemodynamic parameters became gradually stable. We estimate that severe hypotension observed in this case is associated with intramyometrial injection of vasopressin. Increased blood concentration of vasopressin might cause vasoconstriction of coronary artery, increases in afterload, and/or direct myocardial depression resulting in decreased cardiac output.

Vasopressin versus norepinephrine infusion in patients with septic shock

BACKGROUND

Vasopressin is commonly used as an adjunct to catecholamines to support blood pressure in refractory septic shock, but its effect on mortality is unknown. We hypothesized that low-dose vasopressin as compared with norepinephrine would decrease mortality among patients with septic shock who were being treated with conventional (catecholamine) vasopressors.

METHODS

In this multicenter, randomized, double-blind trial, we assigned patients who had septic shock and were receiving a minimum of 5 microg of norepinephrine per minute to receive either low-dose vasopressin (0.01 to 0.03 U per minute) or norepinephrine (5 to 15 microg per minute) in addition to open-label vasopressors. All vasopressor infusions were titrated and tapered according to protocols to maintain a target blood pressure. The primary end point was the mortality rate 28 days after the start of infusions.

RESULTS

A total of 778 patients underwent randomization, were infused with the study drug (396 patients received vasopressin, and 382 norepinephrine), and were included in the analysis. There was no significant difference between the vasopressin and norepinephrine groups in the 28-day mortality rate (35.4% and 39.3%, respectively; P=0.26) or in 90-day mortality (43.9% and 49.6%, respectively; P=0.11). There were no significant differences in the overall rates of serious adverse events (10.3% and 10.5%, respectively; P=1.00). In the prospectively defined stratum of less severe septic shock, the mortality rate was lower in the vasopressin group than in the norepinephrine group at 28 days (26.5% vs. 35.7%, P=0.05); in the stratum of more severe septic shock, there was no significant difference in 28-day mortality (44.0% and 42.5%, respectively; P=0.76). A test for heterogeneity between these two study strata was not significant (P=0.10).

CONCLUSIONS

Low-dose vasopressin did not reduce mortality rates as compared with norepinephrine among patients with septic shock who were treated with catecholamine vasopressors. (Current Controlled Trials number, ISRCTN94845869 [controlled-trials.com].).

[Vasopressin for treatment of hemodynamic disorders]

Vasopressin is a 9-amino acid peptide synthesized by magnocellular neurons of the hypothalamus and released from posterior pituitary gland. The primary physiological role of vasopressin is the maintenance of fluid homeostasis. In this review, the classification of vasopressin receptors, namely V1 vascular, V2 renal, V3 pituitary, oxytocin receptors, and purinergic receptors, and the effects of vasopressin on vascular smooth muscles, the heart, and the kidneys are discussed. Mortality rates of vasodilatory (or distributive), for example septic shock, are high. The use of vasopressin is an alternative therapy for vasodilatory shock with better outcome. Vasopressin is effective in resuscitation of adults after ventricular fibrillation or pulseless tachycardia, when epinephrine is not effective.

Addition of Vasopressin to Norepinephrine as Independent Predictor of Mortality in Patients with Refractory Septic Shock: An Observational Study

OBJECTIVE

To identify predictors of 28-day mortality among patients with refractory septic shock treated with norepinephrine with or without vasopressin.

DESIGN

Prospective observational cohort study.

SETTING

A 1,200-bed academic medical center.

PATIENTS

One hundred thirty-seven patients with septic shock treated with norepinephrine with or without vasopressin.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The 28-day mortality rate was 37.2% (n = 51). By multivariate analysis, significant predictors of death were norepinephrine plus vasopressin administration (adjusted odds ratio [AOR], 13.96; 95% confidence interval [CI] 6.47, 30.08; p = 0.001), lack of goal-directed fluid administration during initial resuscitation (AOR 15.82; 95% CI 6.16, 40.61; p = 0.003), inappropriate initial antimicrobial therapy (AOR 8.95; 95% CI 2.93, 27.33; p = 0.05), and higher Acute Physiology and Chronic Health Evaluation (APACHE) II score (AOR 1.14; 95% CI 1.07, 1.21; p = 0.033). Patients who received norepinephrine plus vasopressin (n = 68) had a significantly higher mortality rate than patients managed with norepinephrine alone (n = 69) 28 days after the initiation of vasopressors (54.4% vs. 20.3%; p < 0.001). This finding was confirmed in patients matched optimally across treatment groups.

CONCLUSIONS

Our study found an association between the use of norepinephrine plus vasopressin and 28-day mortality in refractory septic shock. In view of its known mechanism of action, vasopressin contributed to this excess mortality. Further recommendations regarding the use of vasopressin await the results of large randomized trials evaluating its efficacy and safety for septic shock.

Vasopressin for the septic burn patient

BACKGROUND

Exogenous arginine vasopressin (VP) has been increasingly used in the hemodynamic management of critically ill patients with septic shock, but its use in septic burn patients has not been systematically examined.

PURPOSE

To review our experience with the use of VP in septic burn patients.

METHODS

Retrospective review of all patients who received VP at a tertiary care adult regional burn centre. Only patients who strictly met the American College of Chest Physicians/Society of Critical Care Medicine Consensus Criteria for sepsis at the time of VP initiation were analysed.

RESULTS

There were 30 septic burn patients treated on 43 distinct occasions with VP. This group had a mean (+/-S.D.) age of 49+/-19 years, a mean % TBSA burn of 41+/-15% and a 37% incidence of inhalation injury. A significant increase in mean arterial pressure (MAP), a significant decrease in heart rate (HR), and a trend towards increased urine output (UO) occurred following initiation of VP. When VP was added to an existing infusion of norepinephrine (NE), there was a significant NE sparing effect. VP was implicated in the death of one patient who developed diffuse upper gastrointestinal necrosis while on VP. Other complications in patients treated with VP included peripheral ischemia (2), skin graft failure (1) and donor site conversion (1). In all complications, VP had been administered in combination with prolonged NE infusions (mean of 10 microg/min over a mean of 177 h).

CONCLUSION

VP is a useful adjunctive pressor that spares NE requirements in septic burn patients, but its use is not without risks, particularly when VP is combined with sustained moderate to high infusions of NE.

Skin necrosis after a low-dose vasopressin infusion through a central venous catheter for treating septic shock

This is a report on a case of severe skin necrosis in a vasodilatory septic shock patient after the infusion of low-dose vasopressin through a central venous catheter. An 84-year-old male was hospitalized for edema on both legs at Asan Medical Center, Seoul, Korea. On hospital day 8, the patient began to complain of dyspnea and he subsequently developed severe septic shock caused by E. coli. After being transferred to the medical intensive care unit, his hypotension, which was refractory to norepinephrine, was controlled by an infusion of low-dose vasopressin (0.02 unit/min) through a central venous catheter into the right subclavian vein. After the infusion of low-dose vasopressin, severe skin necrosis with bullous changes developed, necessitating discontinuation of the low-dose vasopressin infusion. The patient expired from refractory septic shock. Although low-dose vasopressin can control hypotension in septic shock patients, low-dose vasopressin must be used with caution because ischemic complications such as skin necrosis can develop even with administration through a central venous catheter.

Intramyometrial injection of vasopressin causes bradycardia and cardiac arrest--report of two cases

Vasopressin has been documented to effectively reduce blood loss in gynecologic practice. However, local infiltration of vasopressin may cause lethal cardiopulmonary complications in spite of rarity of reported cases. Severe bradycardia and cardiac arrest were encountered after intramyometrial injection of vasopressin in our two healthy patients undergoing open uterine myomectomy. We herewith discuss the associated complications and the anesthetic considerations.

Vasopressin during cardiopulmonary resuscitation and different shock states: a review of the literature

Vasopressin administration may be a promising therapy in the management of various shock states. In laboratory models of cardiac arrest, vasopressin improved vital organ blood flow, cerebral oxygen delivery, the rate of return of spontaneous circulation, and neurological recovery compared with epinephrine (adrenaline). In a study of 1219 adult patients with cardiac arrest, the effects of vasopressin were similar to those of epinephrine in the management of ventricular fibrillation and pulseless electrical activity; however, vasopressin was superior to epinephrine in patients with asystole. Furthermore, vasopressin followed by epinephrine resulted in significantly higher rates of survival to hospital admission and hospital discharge. The current cardiopulmonary resuscitation guidelines recommend intravenous vasopressin 40 IU or epinephrine 1mg in adult patients refractory to electrical countershock. Several investigations have demonstrated that vasopressin can successfully stabilize hemodynamic variables in advanced vasodilatory shock. Use of vasopressin in vasodilatory shock should be guided by strict hemodynamic indications, such as hypotension despite norepinephrine (noradrenaline) dosages >0.5 mug/kg/min. Vasopressin must never be used as the sole vasopressor agent. In our institutional routine, a fixed vasopressin dosage of 0.067 IU/min (i.e. 100 IU/50 mL at 2 mL/h) is administered and mean arterial pressure is regulated by adjusting norepinephrine infusion. When norepinephrine dosages decrease to 0.2 microg/kg/min, vasopressin is withdrawn in small steps according to the response in mean arterial pressure. Vasopressin also improved short- and long-term survival in various porcine models of uncontrolled hemorrhagic shock. In the clinical setting, we observed positive effects of vasopressin in some patients with life-threatening hemorrhagic shock, which had no longer responded to adrenergic catecholamines and fluid resuscitation. Clinical employment of vasopressin during hemorrhagic shock is experimental at this point in time.

Efficacy and efficiency of gastric electrical stimulation with short pulses in the treatment of vasopressin-induced emetic responses in dogs

The aim of this study was to determine the most effective and efficient anti-emetic parameters of short-pulse gastric electrical stimulation (GES) in dogs. Seven female beagle dogs implanted with four pairs of gastric electrodes were studied in eight randomized sessions (saline, vasopressin, and six GES sessions with different parameters). Each session consisted of four 20-min recordings of gastric slow waves and symptoms. In sessions 1 and 2, saline and vasopressin, respectively, were infused during the second 20-min period. The protocol of the other six sessions was the same as session 2 except that GES was continuously applied. It was found that: (1) vasopressin induced gastric dysrhythmia and emetic response (P < 0.01, anova); (2) short-pulse GES with a frequency of 14 or 40 Hz and pulse width of 0.1 or 0.3 ms, but not 0.6 ms was able to reduce symptoms induced by vasopressin; (3) short-pulse GES with a pulse width of 0.3 ms was the most effective in preventing vasopressin-induced symptoms; (4) none of the tested GES methods improved vasopressin-induced gastric dysrhythmia. We conclude that vasopressin induces gastric dysrhythmia and symptoms. Short-pulse GES with a pulse width of 0.3 ms and frequency of 14 Hz is most effective and efficient in preventing vasopressin-induced emetic responses in dogs.

The safety and efficacy of the use of vasopressin in sepsis and septic shock

Sepsis remains a significant problem and cause of morbidity and mortality in intensive care. Vasopressin infusions are currently used as rescue therapy for the treatment of vasodilatory, catecholamine-resistant septic shock. At present, there are no large randomised, controlled trials in the literature investigating vasopressin in this role, although two such studies are currently ongoing in Canada. This review outlines the pathophysiology of sepsis and that of vasopressin in sepsis and reviews the available evidence for the use of vasopressin in sepsis and septic shock. A review of the safety data for vasopressin in this indication is included. Recommendations for the use of vasopressin in septic shock, along with suggestions for the direction of further work in the field are presented.

Vasopressin in Cardiac Arrest

Objective:

To review the efficacy and safety of vasopressin in cardiac arrest.

Data Sources:

MEDLINE, EMBASE, and PubMed were searched (all to June 2005) for full-text English-language publications describing trials in humans. Search terms were vasopressin, epinephrine, adrenaline, heart arrest, cardiac arrest, and clinical trial.

Study Selection and Data Extraction:

Prospective, randomized, controlled trials that evaluated efficacy or safety endpoints of vasopressin in the management of cardiac arrest were included. Efficacy outcomes included return of spontaneous circulation, successful resuscitation, survival to hospital admission, 2hour survival, and survival to hospital discharge. Safety outcomes were as defined by each trial.

Data Synthesis:

Three prospective trials were identified and included in this review. Vasopressin does not appear to offer any therapeutic advantage compared with epinephrine in the treatment of both in-hospital and out-of-hospital cardiac arrest, regardless of the presenting arrest rhythm. Although there is a suggestion that vasopressin may be effective in treatment of asystole, the evidence for this arises from a subgroup analysis that should be viewed as hypothesis generating. There are limited data describing the safety of vasopressin in cardiac arrest.

CONCLUSIONS:

The current evidence for the use of vasopressin in cardiac arrest is indeterminate. Given the similarly equivocal evidence of efficacy for epinephrine, either drug could be considered the first-line agent in cardiac arrest. Placebo-controlled studies with appropriate statistical power are warranted to evaluate meaningful clinical outcomes, such as survival to hospital discharge. Further evaluation of the role of vasopressin in asystolic cardiac arrest and its use in combination with epinephrine is also justified.

Predictors of hospital mortality for patients with severe sepsis treated with Drotrecogin alfa (activated)

STUDY OBJECTIVE

To identify predictors of hospital mortality among patients with severe sepsis who were treated with drotrecogin alfa (activated).

DESIGN

Prospective observational cohort study.

SETTING

A 1400-bed academic medical center.

PATIENTS

One hundred two patients treated with drotrecogin alfa (activated) for severe sepsis.

MEASUREMENTS AND MAIN RESULTS

To identify potential risk factors for hospital mortality, the main outcome evaluated, all patients who received drotrecogin alfa (activated) were segregated according to hospital survival. The following characteristics were recorded: age, sex, weight, surgical or nonsurgical, Acute Physiology and Chronic Health Evaluation (APACHE) II score, number of acquired organ-system derangements, mechanical ventilation, use of vasopressors or dobutamine, patient location 24 hours before receiving drotrecogin alfa (activated), source of infection, microbiologically positive culture, and other process-of-care variables. Of the 102 patients, 43 (42.2%) died during their hospitalization. Potential predictors of hospital mortality identified by univariate analysis included greater APACHE II scores, administration of vasopressin or dobutamine, number of acquired organ-system derangements, time to treatment with drotrecogin alfa (activated), intravenous fluid administered before receiving vasopressors or drotrecogin alfa (activated), number of red blood cell transfusions, and administration of inappropriate initial antimicrobial treatment. Multivariate analysis revealed that vasopressin administration (odds ratio [OR] 3.72, 95% confidence interval [CI] 1.95-7.10), number of acquired organ-system derangements (OR 2.30, 95% CI 1.59-3.31), and administration of inappropriate initial antimicrobial treatment (OR 15.5, 95% CI 6.78-35.6) were independently associated with hospital mortality.

CONCLUSION

Number of acquired organ-system derangements, vasopressin administration, and treatment with an inappropriate initial antimicrobial regimen are independently associated with an increased risk of hospital mortality among patients treated with drotrecogin alfa (activated) for severe sepsis. These findings suggest that other specific medical interventions may increase survival in this patient population.

Two-channel gastric electrical stimulation accelerates delayed gastric emptying induced by vasopressin

The aim of this study was to investigate the effects of two-channel gastric electrical stimulation (GES) on delayed gastric emptying, gastric dysrhythmias, and motion sickness-like symptoms induced by vasopressin. Seven dogs implanted with four pairs of gastric electrodes and a duodenal cannula were studied in four randomized sessions (saline, vasopressin, single-channel GES, and two-channel GES). The experiment in each session was conducted sequentially as follows: 30-min baseline, ingestion of a liquid meal, 30-min iv infusion of vasopressin or saline, and two 30-min postprandial recordings. In the GES sessions, GES was applied via the first pair of electrodes for single-channel GES or the first and third pairs of electrodes for two-channel GES. Gastric emptying was collected every 15 min via the cannula for a period of 90 min. Results were as follows. (1) Vasopressin induced gastric dysrhythmias, motion sickness-like symptoms, and delayed gastric emptying (P < 0.01, ANOVA). (2) GES normalized gastric dysrhythmias (P < 0.01) but showed no effects on vasopressin-induced emetic response. (3) Two-channel GES improved delayed gastric emptying induced by vasopressin. In comparison with the vasopressin session, two-channel GES, but not single-channel GES, significantly increased gastric emptying at 30 min (43.9+/-12.6 vs. 27.5+/-7.7%; P < 0.03), 60 min (75.3+/-15.1 vs. 54.0+/-17.8%; P < 0.05), and 90 min (91.6+/-9.8 vs. 80.3+/-9.0%; P < 0.05). GES with long pulses is able to normalize gastric dysrhythmias. Two-channel GES improves delayed gastric emptying induced by vasopressin.

Blindness in the Intensive Care Unit: Possible Role for Vasopressors?

Blindness caused by ischemic optic neuropathy in the hospital setting occurs perioperatively and in critically ill patients, but its etiology remains ill defined. We describe four critically ill patients who developed blindness within 1 mo of one another. Three cases occurred outside of the operative arena. Potential risk factors for the development of ischemic optic neuropathy, such as use of vasopressors, venous congestion, and hypotension, are described.

Vasopressin and desmopressin in central diabetes insipidus: adverse effects and clinical considerations

The management of central diabetes insipidus has been greatly simplified by the introduction of desmopressin (DDAVP). Its ease of administration, safety and tolerability make DDAVP the first line agent for outpatient treatment of central diabetes insipidus. The major complication of DDAVP therapy is water intoxication and hyponatremia. The risk of hyponatremia can be reduced by careful dose titration when initiating therapy and by close monitoring of serum osmolality when DDAVP is used with other medications affecting water balance. Herein we review the adverse effects of DDAVP and its predecessor, vasopressin, as well as discuss important clinical considerations when using these agents to treat central diabetes insipidus.

Clinical review: Vasopressin and terlipressin in septic shock patients

Vasopressin (antidiuretic hormone) is emerging as a potentially major advance in the treatment of septic shock. Terlipressin (tricyl-lysine-vasopressin) is the synthetic, long-acting analogue of vasopressin, and has comparable pharmacodynamic but different pharmacokinetic properties. Vasopressin mediates vasoconstriction via V₁ receptor activation on vascular smooth muscle. Septic shock first causes a transient early increase in blood vasopressin concentrations; these concentrations subsequently decrease to very low levels as compared with those observed with other causes of hypotension. Infusions of 0.01–0.04 U/min vasopressin in septic shock patients increase plasma vasopressin concentrations. This increase is associated with reduced need for other vasopressors. Vasopressin has been shown to result in greater blood flow diversion from nonvital to vital organ beds compared with adrenaline (epinephrine). Of concern is a constant decrease in cardiac output and oxygen delivery, the consequences of which in terms of development of multiple organ failure are not yet known. Terlipressin (one or two boluses of 1 mg) has similar effects, but this drug has been used in far fewer patients. Large randomized clinical trials should be conducted to establish the utility of these drugs as therapeutic agents in patients with septic shock.

Dobutamine compensates deleterious hemodynamic and metabolic effects of vasopressin in the splanchnic region in endotoxin shock

BACKGROUND

Vasopressin is a potent vasopressor in septic shock, but it may impair splanchnic perfusion. We compared the effects of vasopressin alone and in combination with dobutamine on systemic and splanchnic circulation and metabolism in porcine endotoxin shock.

METHODS

Twelve pigs were randomized to receive either vasopressin (VASO, n = 6) or vasopressin in combination with dobutamine (DOBU, n = 6) during endotoxin shock (E. coli endotoxin infusion). Endotoxin infusion rate was increased to induce hypotension after which vasoactive drugs were started. We aimed to keep systemic mean arterial pressure (MAP) >70 mmHg by vasopressin; the goal of dobutamine infusion was to prevent decrease in cardiac output often associated with vasopressin infusion. Regional blood flows, oxygen delivery and consumption, arterial and regional lactate concentrations were measured.

RESULTS

Mean arterial pressure >70 mmHg was achieved in both the VASO and DOBU groups. After the primary decrease of cardiac output by vasopressin, systemic blood flow remained stable in vasopressin-treated animals. However, vasopressin as a monotherapy decreased portal venous blood flow. This was prevented by dobutamine. Vasopressin also induced splanchnic lactate release and arterial hyperlactatemia, which were not observed when dobutamine was combined with vasopressin.

CONCLUSION

Dobutamine prevents adverse hemodynamic and metabolic effects of vasopressin in septic shock.

The Role of Vasopressin in Vasodilatory Septic Shock

Septic shock that requires therapy with adrenergic agents is associated with high rates of mortality. Inappropriately normal or low serum concentrations of vasopressin contribute to the development of hypotension during sepsis. We critically evaluated the role of administering exogenous vasopressin to patients with septic shock. A computerized search of MEDLINE from January 1966--December 2003 and a manual search of relevant journals for abstracts were conducted. Eleven retrospective, six prospective cohort, and four prospective randomized studies were identified. Most studies evaluated short-term infusions of vasopressin at 0.08 U/minute or less as add-on therapy in patients requiring adrenergic agents. The results show that starting vasopressin in patients with septic shock increases systemic vascular resistance and arterial blood pressure, thus reducing the dosage requirements of adrenergic agents. These effects are rapid and sustained. Substantial enhancement of urine production, likely due to increased glomerular filtration rate, was shown in several studies. A few studies demonstrated clinically significant reduced cardiac output or cardiac index after vasopressin was begun, necessitating cautious use in patients with cardiac dysfunction. Vasopressin was associated with ischemia of the mesenteric mucosa, skin, and myocardium; elevated hepatic transaminase and bilirubin concentrations; hyponatremia; and thrombocytopenia. Limiting the dosage to 0.03 U/minut or less may minimize the development of these adverse effects. Vasopressin 0.03 U/minute or less should be considered if response to one or two adrenergic agents is inadequate or as a method to reduce the dosage of adrenergic agents. At present, vasopressin therapy should not be started as first-line therapy. Additional studies are needed to determine the optimum dosage, duration, and place in therapy of vasopressin relative to adrenergic agents. A multicenter, comparative study of vasopressin 0.03 U/minute as add-on therapy is under way and should provide mortality data.

Effects of continuous vasopressin infusion in patients with septic shock

BACKGROUND

Small studies have reported that vasopressin improves hemodynamic instability in patients with septic shock.

OBJECTIVE

To determine whether vasopressin infusion increases blood pressure, decreases catecholamine vasopressor use, and improves renal function in a large patient population with septic shock when used in a clinical setting.

METHODS

A retrospective chart audit was conducted of critically ill patients who received vasopressin infusion for septic shock from January 2000 through September 2002. Demographic, hemodynamic, laboratory, vasopressor, and adverse event data were collected. Statistical methods included ANOVA with Tukey's test for post hoc analysis.

RESULTS

A total of 102 of 353 patients met study criteria. The mean +/- SD vasopressin dosage regimen was 0.11 +/- 0.17 units/min for 53.8 +/- 71.5 hours. Compared with baseline, vasopressin infusion improved mean arterial pressure (MAP) by 15% within one hour (p < 0.05), reduced heart rate by 9% within 4 hours (p < 0.05), and reduced hourly dopamine dosage by 25% within 8 hours (p < 0.05). These effects persisted through 96 hours. Other hemodynamic variables and catecholamine vasopressor usage parameters were not statistically different from baseline. Urine output, serum creatinine, and serum sodium concentrations were not statistically changed from baseline. Adverse events possibly associated with vasopressin infusion included ischemic digits/extremities, myocardial infarction, and hyponatremia.

CONCLUSIONS

Vasopressin infusion was effective in increasing MAP and reducing heart rate while decreasing the dopamine dosage in patients with septic shock. Comparative studies with catecholamine vasopressors are needed to define the optimal role of vasopressin in septic shock therapy. In the meantime, vasopressin infusion at <or=0.03 units/min should be considered only if response to 1 or 2 catecholamine vasopressors is inadequate or as a method to reduce the dose of these therapies.

Effects of intestinal electrical stimulation on intestinal dysrhythmia and symptoms in dogs

The aim of this study was to investigate the effect of intestinal electrical stimulation on small intestinal dysrhythmia and motion sickness-like symptoms induced by vasopressin. Female dogs chronically implanted with two pairs of electrodes on jejunum serosa were used in a four-session study. Saline and vasopressin were infused in sessions 1 and 2, respectively. Sessions 3 and 4 were the same as session 2, except a long- or short-pulse intestinal electrical stimulation was applied on the proximal pair of electrodes. Intestinal slow waves and motion sickness-like symptoms were recorded in each session. Results were as follows. (1) Vasopressin induced intestinal dysrhythmia, uncoupling of slow waves, and vomiting and motion sickness-like symptoms (P < 0.05, ANOVA). (2) Intestinal electrical stimulation with long pulses, but not short pulses, was capable of preventing vasopressin-induced intestinal dysrhythmia. (3) Intestinal electrical stimulation with short pulses, but not long pulses, prevented vomiting and the motion sickness-like symptoms. It is concluded that vasopressin induces intestinal dysrhythmia. Long-pulse intestinal stimulation normalizes vasopressin-induced intestinal slow-wave abnormalities with no improvement in symptoms. Short-pulse stimulation prevents emetic symptoms induced by vasopressin but has no effect on slow waves. These data suggest different mechanisms involved with different methods of intestinal stimulation.

Transient Diabetes Insipidus After Discontinuation of Therapeutic Vasopressin

The use of vasopressin for the treatment of septic shock is increasing. Few reports of fluid and electrolyte complications of this therapy have been reported. A neurologically impaired, 53-year-old man with a history of syndrome of inappropriate antidiuretic hormone developed apparent transient diabetes insipidus and acute hypernatremia after being treated with vasopressin. He was treated for presumed septic shock with intravenous vasopressin 0.01-0.10 U/minute. His blood pressure did not improve with this therapy, and his course was complicated by hyponatremia during the vasopressin infusion. Discontinuation of the infusion was followed by a profound (8.4 L) diuresis and rapid onset of hypernatremia (serum sodium concentration increased from 132 to 157 mEq/L over 8 hrs). Although urine osmolality was not measured during the patient's diuresis, the rapid changes in serum sodium concentration can be explained only by an inappropriate water diuresis. The diuresis ceased when the vasopressin infusion was resumed. We concluded that these findings are most consistent with transient diabetes insipidus. The safety and efficacy of intravenous vasopressin have not been established in patients with septic shock and underlying disorders of water homeostasis. The drug may have diminished vasoconstrictive effects in this patient population. Careful monitoring of water and sodium balance is warranted in all patients treated with vasopressin for septic shock.