The hemodynamic effects of intravenous paracetamol (acetaminophen) vs normal saline in cardiac surgery patients: A single center placebo controlled randomized study

The Three W's of Acetaminophen In Children: Who, Why, and Which Administration Mode

Acetaminophen is one of the oldest medications commonly administered in children. Its efficacy in treating fever and pain is well accepted among clinicians. However, the available evidence supporting the use of acetaminophen's different modes of administration remains relatively scarce and poorly known. This short report summarizes the available evidence and provides a framework to guide clinicians regarding a rational use of acetaminophen in children.

Acetaminophen-induced hypotension in sepsis

Background

Acetaminophen-induced hypotension has been reported in critically ill patients; however, it remains unclear whether mannitol, present as a stabilizing compound in acetaminophen formulations, affects hemodynamic changes. The objectives of this study were to clarify the direct effect of acetaminophen on blood pressure by comparing blood pressure changes after acetaminophen and intravenous immunoglobulin (IVIG) administration, both containing mannitol, in patients with sepsis and understand the risk factors for reduced blood pressure following acetaminophen administration.

Methods

This was a retrospective cohort study. Adult patients who were diagnosed with sepsis at Nippon Medical School Hospital, and who were undergoing continuous arterial blood pressure measurement and received intravenous acetaminophen or IVIG, were included.

Results

Overall, 185 patients were included, with 92 patients in the IVIG group and 93 in the acetaminophen group. The incidence of hypotension was 36.9% in the IVIG group (34 of 92 patients) and 58.0% in the acetaminophen group (54 of 93 patients) (OR = 8.26, p = 0.004). In a propensity score-matched cohort, 80 matched patients were selected. The incidence of hypotension was 37.5% in the IVIG group (15 of 40 patients) and 67.5% in the acetaminophen group (27 of 40 patients) (OR = 7.21, p = 0.007).

Conclusions

Acetaminophen induced substantially greater hypotension than IVIG in patients with sepsis, with both containing mannitol. Further studies are needed to clarify the effects on hemodynamics of mannitol contained in acetaminophen formulations.

Kounis syndrome: from an unexpected case in the Emergency Room to a review of the literature

Kounis syndrome (KS) is a coronary syndrome in the setting of allergic/anaphylactic reactions and can be classified in three variants: vasospastic allergic angina (type I), allergic myocardial infarction (type II) and stent thrombosis (type III). The early diagnosis is of paramount importance for the correct management and the prognosis, being KS a life-threatening emergency condition. KS is not uncommon, but it is frequently unrecognized or undiagnosed in virtue of its broad clinical manifestations. The diagnosis should be based on the combination of cardiovascular and allergic/anaphylactic clinical symptoms and signs, as well as on laboratory, electrocardiographic, echocardiographic, and angiographic evidence. ECG monitoring, cardiac enzymes and troponin are mandatory to confirm or exclude KS in a patient with subclinical or clinical, acute or chronic allergic reactions. Nevertheless, the treatment is a real challenge for the emergency clinicians because guidelines have not been established yet, and the therapy is based on the variant type. We herein report the case of type I KS in a woman with no prior history of allergy, admitted to our emergency department for abdominal pain, nausea and hematochezia. Starting from this case we conducted a systematic search of the following databases: PubMed, Google Scholar, Science Direct, Medline, using the keywords of "Kounis syndrome", "coronary spams", "cardiac arrest", "sudden death", "allergy", and "anaphylaxis". The main purpose of this review is to remind emergency clinicians to keep a high index of suspicion regarding KS when dealing with patients with allergic reactions or anaphylaxis to promptly identify and correctly manage KS.

The protective effect of carvacrol on acetaminophen-induced renal damage in male rats

BACKGROUND

Acetaminophen overdose causes renal injury via oxidative stress and apoptosis induction. Carvacrol has several pharmacological properties such as antioxidant, anti-inflammation and anti-apoptotic effect. The aim of this study was to determine the protective effect of carvacrol on acetaminophen-induced renal damage in rats.

METHODS AND RESULTS

Forty male Wistar rats were randomly divided to five groups (n = 8) including control, carvacrol 10 mg/kg, acetaminophen, acetaminophen + carvacrol 5 mg/kg, and acetaminophen + carvacrol 10 mg/kg. Animals received a single dose of acetaminophen (500 mg/kg), then were treated with carvacrol for 1 week (daily). Afterwards, renal blood flow (RBF), mean arterial pressure, renal perfusion pressure, renal vascular resistance (RVR), blood urea nitrogen (BUN), and serum creatinine were measured. Also, malondialdehyde (MDA) concentration, glutathione peroxidase (GPx) and superoxide dismutase (SOD) activity levels were measured in the kidney tissue. Hematoxylin and eosin method was used for histological assessment. The Western blotting analysis was used to determine the Bax, Bcl-2 and cleaved caspase-3 proteins expression level in the kidney tissue. Carvacrol (10 mg/kg) significantly increased the RBF, GPx and SOD activities and also reduced the RVR, serum creatinine, BUN, and MDA in the acetaminophen + carvacrol 10 mg/kg group versus acetaminophen group (P < 0.05). Also, carvacrol significantly decreased the cleaved caspase-3, Bax proteins expression level, and kidney tissue damage score in the acetaminophen + carvacrol 10 mg/kg group versus acetaminophen group (P < 0.05).

CONCLUSIONS

This study showed that carvacrol can attenuate the acetaminophen induced acute kidney damage via suppressing oxidative stress and apoptosis biochemical factors.

Preclinical models of acute liver failure: a comprehensive review

Acute liver failure is marked by the rapid deterioration of liver function in a previously well patient over period of days to weeks. Though relatively rare, it is associated with high morbidity and mortality. This makes it a challenging disease to study clinically, necessitating reliance on preclinical models as means to explore pathophysiology and novel therapies. Preclinical models of acute liver failure are artificial by nature, and generally fall into one of three categories: surgical, pharmacologic or immunogenic. This article reviews preclinical models of acute liver failure and considers their relevance in modeling clinical disease.

The hemodynamic effects of intravenous paracetamol (acetaminophen) in patients with chronic liver disease undergoing liver transplantation: a pilot study

OBJECTIVE

We performed a single-center double-blinded, randomized trial to investigate the hemodynamic effects of IV paracetamol in patients with chronic liver disease (CLD) undergoing liver transplantation surgery. Patients with CLD are particularly susceptible to hemodynamic derangements given their low systemic vascular resistance state. Accordingly, hypotension is common in this setting. The hemodynamic effects of IV paracetamol in patients undergoing elective liver transplantation are unknown, therefore we evaluated whether the intraoperative administration of IV paracetamol in patients with chronic liver disease undergoing liver transplantation results in adverse hemodynamic effects. The primary end point was a change in systolic blood pressure 30-min after the preoperative infusion.

RESULTS

Twenty-four participants undergoing liver transplantation surgery were randomly assigned to receive a single bolus of IV paracetamol (1 g paracetamol + 3.91 g mannitol per 100 mL) (n = 12) or placebo (0.9% Saline 100 mL) (n = 12). All participants completed their study intervention, and there were no breaches or violations of the trial protocol. Baseline characteristics were similar in both groups. There were no significant differences regarding surgical duration, intraoperative use of fluids, and intraoperative noradrenaline use. After the administration of paracetamol there were no significant differences observed in blood pressure or other hemodynamic parameters when compared to placebo.

A narrative review of paracetamol-induced hypotension: Keeping the patient safe

Aim

To understand the prevalence and epidemiology of paracetamol‐induced hypotension and clinical implications for contemporaneous practice.

Design

Narrative review.

Methods

In May and June 2020, an open‐date literature search of English publications indexed in ProQuest, PubMed, and EBSCO was conducted with the search terms ‘acetaminophen’ and ‘hypotension’ and related search combinations (‘paracetamol’, ‘propacetamol’, ‘low blood pressure’, ‘fever’, ‘sepsis’, and ‘shock’) to identify peer‐reviewed publications of blood pressure changes after paracetamol administration in humans.

Results

A pattern of blood pressure reduction following the administration of paracetamol is demonstrated in the 27 studies included in this review. Haemodynamic intervention often followed persistent blood pressure reduction, and was greatest in febrile critically ill patients who received parenteral paracetamol.

Kounis Syndrome—not a Single-organ Arterial Disorder but a Multisystem and Multidisciplinary Disease

Coronary symptoms associated with conditions related to mast cell activation and inflammatory cell interactions, such as those involving T-lymphocytes and macrophages, further inducing allergic, hypersensitivity, anaphylactic, or anaphylactic insults, are currently referred to as the Kounis syndrome. Kounis syndrome is caused by inflammatory mediators released during allergic insults, post-inflammatory cell activation, and interactions via multidirectional stimuli. A platelet subset of 20% with high- and low-affinity IgE surface receptors is also involved in this process. Kounis syndrome is not just a single-organ but also a complex multisystem and multi-organ arterial clinical condition; it affects the coronary, mesenteric, and cerebral arteries and is accompanied by allergy–hypersensitivity–anaphylaxis involving the skin, respiratory, and vascular systems in the context of anesthesia, surgery, radiology, oncology, or even dental and psychiatric medicine; further, it has significantly influences both morbidity and mortality. Kounis syndrome might be caused by numerous and continuously increasing causes, with broad clinical symptoms and signs, via multi-organ arterial system involvement, in patients of any age, thereby demonstrating predominant anaphylactic features in terms of a wide spectrum of mast cell-association disorders. Cardiac symptoms, such as chest pain, coronary vasospasm, angina pectoris, myocardial infarction, stent thrombosis, acute cardiac failure, and sudden cardiac death associated with subclinical, clinical, acute, or chronic allergic reactions, constitute the clinical manifestations of this syndrome. Since its first description, a common pathway between allergic and non-allergic coronary events has been demonstrated. The hypothesis is based on the existence of a much higher degree of mast cell degranulation at plaque erosion or rupture sites compared with at the adjacent areas or even more distant segments in post-acute myocardial infarction of non-allergic etiology. Although mast cell activation, differentiation, and mediator release takes days or weeks, the mast cell degranulation may occur just before any acute coronary event, further resulting in coronary artery vasoconstriction and atheromatous plaque rupture. It seems that medications and natural molecules stabilizing the mast cell membrane as well as monoclonal antibodies protecting the mast cell surface can emerge as novel therapeutic modalities for acute coronary and cerebrovascular event prevention.

Intravenous Acetaminophen-Induced Hypotension: A Review of the Current Literature

Objective: Recent literature suggests that intravenous (IV) administration may cause hypotension in hospitalized patients; data further suggest that this effect is most pronounced in the critically ill. The purpose of this review is to identify and evaluate current literature that addresses the incidence and implications of IV acetaminophen-induced hypotension. Data Sources: A literature search of MEDLINE, Cochrane, and EMBASE databases was performed (2002-2019) using the following terms: acetaminophen, paracetamol, intravenous, and hypotension. Abstracts and peer-reviewed publications were reviewed. Study Selection and Data Extraction: Relevant English-language studies conducted in humans evaluating the hemodynamic effects of IV acetaminophen were considered. Data Synthesis: A majority of the 19 studies included in this review identified a statistically significant drop in hemodynamic variables after the administration of 500 to 1000 mg IV acetaminophen as measured by changes in systolic blood pressure, diastolic blood pressure, or mean arterial pressure. Of the trials reporting vasopressor use, the authors found a significant increase in vasopressor requirements following IV acetaminophen administration. Relevance to Patient Care and Clinical Practice: This review represents the first comprehensive review of IV acetaminophen-induced hypotension. The findings raise the question of whether IV acetaminophen is an appropriate choice for inpatient pain or temperature management in the critically ill. Conclusions: Available evidence indicates that the administration of IV acetaminophen may be harmful in the critically ill. Additional monitoring is likely required when using IV acetaminophen in this specific population, particularly if a patient is hemodynamically unstable prior to administration.