Treatment Of Hypotension Research Articles

Expert consensus on diagnosis and treatment of spontaneous intracranial hypotension(2024)

Spontaneous intracranial hypotension is a disease characterized by orthostatic headache caused by spinal cerebrospinal fluid leakage. Patients have to remain bedridden, which significantly affects their quality of life. In severe cases, complications such as subdural hematomas may occur. Clinical practice reveals a high rate of misdiagnosis and insufficient implementation of diagnostic and treatment measures. To improve clinical physicians' understanding of spontaneous intracranial hypotension and to standardize the diagnosis and treatment, the Neurologist Branch of the Chinese Medical Doctor Association and the Headache and Sensory Disorders Committee of the Chinese Research Hospital Association organized experts to develop a total of 30 recommendations on the clinical identification, examination processes, diagnostic criteria, treatment, and follow-up of spontaneous intracranial hypotension based on domestic and international clinical practices and recent literature evidence after extensive discussions.

Fructose-1,6-bisphosphate reverses hypotensive effect caused by L-kynurenine in Wistar male rats.

Hypotension is one of the main characteristics of the systemic inflammation, basically caused by endothelial dysfunction. Studies have shown that the amino acid L-kynurenine (KYN) causes vasodilation in mammals, leading to hypotensive shock. In hypotensive shock, when activated by the KYN, the voltage-gated potassium channel encoded by the family KCNQ (Kv7) gene can cause vasodilation. Fructose-1,6-bisphosphate (FBP) it is being considered in studies an anti-inflammatory, antioxidant, immunomodulator, and a modulator of some ion channels (Ca2+, Na+, and K+). We analyzed the effects of KYN and FBP on mean blood pressure (MBP), systolic and diastolic (DBP) blood pressure, and heart rate variability (HRV) in Wistar rats. Results demonstrated that the administration of KYN significant decreased MBP, DBP, and increased HRV. Importantly, the FBP treatment reversed the KYN effects on MBP, DBP, and HRV. Molecular Docking Simulations suggested that KYN and FBP present a very close estimated free energy of binding and the same position into structure of KCNQ4. Our results did demonstrate that FBP blunted the decrease in BP, provoked by KYN. Results raise new hypotheses for future and studies in the treatment of hypotension resulting from inflammation.

Short-term outcomes in infants following general anesthesia with low-dose sevoflurane/dexmedetomidine/remifentanil versus standard dose sevoflurane (The TREX trial).

The TREX (Trial Remifentanil DEXmedetomidine) trial aimed to determine if, in children < 2 years old, low-dose sevoflurane/dexmedetomidine/remifentanil anesthesia (LD-SEVO) is superior to standard dose sevoflurane (STD-SEVO) anesthesia in terms of global cognitive function at 3 years of age. The aim of the present secondary analyses was to compare incidence of intraoperative hypotension and bradycardia, postoperative pain, time to recovery, need for treatment of intraoperative hypotension and bradycardia, incidence of light anesthesia and need for treatment, need for postoperative pain medications, and morbidity and mortality outcomes at 5 days between the two arms. This Phase III randomized active controlled, parallel group, assessor blinded, multicenter, superiority trial was performed in 20 centers in Australia, Italy, and the United States. Four hundred and fifty-five infants <2 years of age expected to undergo general anesthesia for at least 2 hours were enrolled. They were randomized between LD-SEVO and STD-SEVO. The short-term perioperative outcomes noted above were compared between these two groups. There was less hypotension (risk difference -11.6%, 95% confidence interval (CI) -18.9% to -4.3%) and more bradycardia (risk difference 18.2%, 95% CI 8.8% to 27.7%) in the LD-SEVO compared to the STD-SEVO arm. There were more patients with episodes of light anesthesia (89 vs. 4), and protocol abandonments (1 vs. 0) in the LD-SEVO arm. Time from eye-opening to Post Anesthesia Care Unit (PACU) discharge was similar in both arms, as were morbidity and mortality. One patient in each arm suffered a life-threatening event but neither suffered long-term sequelae. These early postoperative results suggest that in children less than 2 years of age receiving greater than 2 hours of general anesthesia, the low-dose sevoflurane/dexmedetomidine/remifentanil anesthesia technique and the standard sevoflurane anesthesia technique are broadly clinically similar, with no clear evidence to support choosing one technique over the other.

Cervical epidural blood patch treatment is a choice for spontaneous intracranial hypotension.

Epidural blood patch (EBP) is a minimally invasive and effective treatment for spontaneous intracranial hypotension (SIH). But, cervical epidural blood patch for SIH has little attention. In this study, The clinical data was recorded and the treatment efficacy and safety of cervical EBP in SIH were evaluated. : Fifty-nine cases of intractable SIH were examined by computed tomography (CT) guided cervical EBP at the Chinese PLA General Hospital from August 2014 to March 2024. The mean age of the fifty-nine patients at symptom onset was 40.8 ± 9.5 years. 54/59 (91.5%) patients experienced orthostatic headache. Preoperative spine T2 sacns with extensive fluid collection at the upper cervical region in 43/46 (93.5%). 45/59 (76.3%) patients had symptomatic relief with initial cervical EBP, and 14/59 (23.7%) patients received further cervical EBPs. In the first one to three days following the EBP procedure, 11 (18.6%) patients reported pain at the puncture site and 15 (25.4%) experienced neck pain. No other complications were observed during or after the procedure. At the latest follow-up, all patients showed good recovery. The mean follow-up was 28.9 ± 22.7 months. CT-guided cervical EBP is a effective and safe treatment for patients with intractable SIH, especially in patients who had extensive fluid collection at the upper cervical region.

The Pleth Variability Index as a Guide to Fluid Therapy in Dogs Undergoing General Anesthesia: A Preliminary Study.

The aim of this prospective, randomized clinical trial was to evaluate the use of the pleth variability index (PVi) to guide the rate of intraoperative fluid therapy compared to a traditional fixed-fluid-rate approach in ASA 1-2 dogs undergoing surgery. Twenty-seven dogs met the inclusion criteria and were randomly assigned to the conventional fluid management group (CFM, n = 12) or the PVi-guided group (PVi, n = 15). The CFM group received a fixed rate of 5 mL kg-1 h-1 of crystalloid solution, while in the PVi group the rate was continuously adjusted based on the PVi: PVi < 14% = 3 mL kg-1 h-1; 14% ≤ PVi ≥ 20% = 10 mL kg-1 h-1; and PVi > 20% = 15 mL kg-1 h-1. Hypotension (MAP < 65 mmHg) in the CFM was treated with a maximum of two fluid boluses (5 mL kg-1 in 10 min) and in the case of no response, dobutamine (1-3 mcg kg-1 min-1) was administered. In the PVi group, the treatment of hypotension was similar, except when the PVi > 14%, when dobutamine was started directly. Total fluid volume was significantly lower in the PVI group (0.056 ± 0.027 mL kg-1 min-1) compared to the CFM group (0.132 ± 0.115 mL kg-1 min-1), and the incidence of hypotension was lower (p = 0.023) in the PVi group (0%) compared to the CFM group (41%). The mean arterial pressure (MAP) was significantly higher in the PVi group during surgery. Dobutamine was never administered in either group. Preliminary data suggest that the PVi may be considered as a potential target to guide fluid therapy in dogs; larger studies are needed, especially in cases of cardiovascular instability.

Factors related to blood pressure assessment during pregnancy in Ethiopia: Multilevel analysis using the 2019 mini demographic and health survey data.

Blood pressure assessment is an essential strategy for early detection and treatment of hypertension and hypotension. Hypertensive disorders of pregnancy (HDP) are major public health problems resulting in a significant burden of perinatal and maternal morbidity and mortality. In Ethiopia, among pregnancies complicated by HDP, 25% end up with perinatal death. Perinatal and maternal mortality related to HDP were found to be higher in Ethiopia compared to high-income and most of the low- and middle-income countries. Despite its importance, there is limited evidence on blood pressure assessment during pregnancy. Therefore, this study aimed to determine the prevalence of blood pressure assessment during pregnancy and its associated factors in Ethiopia. This study was based on the 2019 Mini Ethiopian Demographic and Health Survey data. A total weighted sample of 2923 women who had a live birth five years before the survey were included and Stata version 16 software was used for statistical analysis. To identify associated factors, a multilevel robust Poisson regression model was fitted since the prevalence of blood pressure assessment was higher than 10%. Variables with p-value < 0.2 in the bi-variable analysis were exported to the multivariable analysis. In the multivariable analysis, the adjusted prevalence ratio with its 95% confidence interval was used to declare a statistically significant association. In Ethiopia, the prevalence of blood pressure assessment during pregnancy was 88.1% (95% CI: 86.9%, 89.2%). In the multivariable multilevel robust Poisson analysis, primary education and secondary education, grand-multiparity, initiation of antenatal care before three months and 3-6 months, four and above antenatal care visits, being counselled by a health professional, being from richer and richest households, residing in Afar and Amhara regions were significantly associated with BP assessment during pregnancy in Ethiopia. To reduce the high burden of mortality related to hypertensive disorders of pregnancy in the country, blood pressure assessment should be improved. Therefore, policymakers should design interventions that empower women in terms of education and economy, promoting early initiation of antenatal care visits and prenatal counselling could improve blood pressure assessment.

The use of hyperinsulinemia‐euglycaemia therapy in the treatment of amlodipine overdose in a dog

AbstractA 1‐year‐old, female, spayed, mixed breed dog presented for lethargy, ataxia and possible ingestion of amlodipine. Based on clinical signs, history and clinicopathological findings, a diagnosis of amlodipine toxicosis was made. The patient's clinical signs and bloodwork derangements were refractory to traditional medical management for calcium channel blocker toxicosis, but a significant improvement was made after initiation of hyperinsulinemia‐euglycaemia therapy. The dog survived and made a full recovery. The use of hyperinsulinemia‐euglycaemia therapy for amlodipine toxicosis has not previously been reported in dogs. Hyperinsulinemia‐euglycaemia therapy can be used for treatment of hypotension as well as other clinical signs associated with calcium channel blocker toxicosis. The use of hyperinsulinemia‐euglycaemia therapy should be considered for amlodipine toxicosis in dogs.

Epidural Blood Patch for the Treatment of Spontaneous Intracranial Hypotension: A Case Series.

Epidural blood patch (EBP) is frequently used for the treatment of spontaneous intracranial hypotension (SIH) and anesthesiologists are often involved in performing such procedures. However, the optimal technique and approach of EBP remains uncertain. This case series included adult patients with SIH who underwent EBPs at London Health Science Centre, Ontario, Canada between 2010 and 2022. Demographics, clinical presentations, investigations, and EBP treatment details were collected and analyzed. Univariate analysis was used to investigate the association of the variables with the likelihood of EBP 1-month efficacy and the efficacy duration of EBP. The study included 36 patients with SIH who received at least 1 EBP. EBPs provided immediate relief in almost all patients, albeit with diminishing effects over time. The 1-month efficacy improved with increasing number of EBP attempts (P=0.032, Fisher exact test), though no particular EBP technique or volume of injectate was associated with better efficacy (P=0.38, Fisher exact test). Though permanent resolution of symptoms was observed in only 24 of 82 EBPs (29%), 24 of 36 patients (67%) had permanent symptom resolution following repeated EBPs. EBP is a promising treatment and symptomatic relief option in patients suffering from the debilitating symptoms of SIH. Tailored EBP techniques, including use of targeted higher volume EBP and a multi-level catheter guided technique for refractory cases, showed efficacy in our institutional setting. Despite its limitations, this study contributes valuable insights and experiences into the use of EBP for treatment of SIH.

Perioperative hypotension and use of vasoactive agents in non-cardiac surgery: A scoping review.

Perioperative hypotension is common and associated with adverse patient outcomes. Vasoactive agents are often used to manage hypotension, but the ideal drug, dose and duration of treatment has not been established. With this scoping review, we aim to provide an overview of the current body of evidence regarding the vasoactive agents used to treat perioperative hypotension in non-cardiac surgery. We included all studies describing the use of vasoactive agents for the treatment of perioperative hypotension in non-cardiac surgery. We excluded literature reviews, case studies, and studies on animals and healthy subjects. We posed the following research questions: (1) in which surgical populations have vasoactive agents been studied? (2) which agents have been studied? (3) what doses have been assessed? (4) what is the duration of treatment? and (5) which desirable and undesirable outcomes have been assessed? We included 124 studies representing 10 surgical specialties. Eighteen different agents were evaluated, predominantly phenylephrine, ephedrine, and noradrenaline. The agents were administered through six different routes, and numerous comparisons between agents, dosages and routes were included. Then, 88 distinct outcome measures were assessed, of which 54 were judged to be non-patient-centred. We found that studies concerning vasoactive agents for the treatment of perioperative hypotension varied considerably in all aspects. Populations were heterogeneous, interventions and exposures included multiple agents compared against themselves, each other, fluids or placebo, and studies reported primarily non-patient-centred outcomes.

Hypotension prediction index for prevention of intraoperative hypotension in patients undergoing general anesthesia: a randomized controlled trial

BackgroundIntraoperative hypotension is a common side effect of general anesthesia. Here we examined whether the Hypotension Prediction Index (HPI), a novel warning system, reduces the severity and duration of intraoperative hypotension during general anesthesia.MethodsThis randomized controlled trial was conducted in a tertiary referral hospital. We enrolled patients undergoing general anesthesia with invasive arterial monitoring. Patients were randomized 1:1 either to receive hemodynamic management with HPI guidance (intervention) or standard of care (control) treatment. Intraoperative hypotension treatment was initiated at HPI > 85 (intervention) or mean arterial pressure (MAP) < 65 mmHg (control). The primary outcome was hypotension severity, defined as a time-weighted average (TWA) MAP < 65 mmHg. Secondary outcomes were TWA MAP < 60 and < 55 mmHg.ResultsOf the 60 patients who completed the study, 30 were in the intervention group and 30 in the control group. The patients’ median age was 62 years, and 48 of them were male. The median duration of surgery was 490 min. The median MAP before surgery presented no significant difference between the two groups. The intervention group showed significantly lower median TWA MAP < 65 mmHg than the control group (0.02 [0.003, 0.08] vs. 0.37 [0.20, 0.58], P < 0.001). Findings were similar for TWA MAP < 60 mmHg and < 55 mmHg. The median MAP during surgery was significantly higher in the intervention group than that in the control group (87.54 mmHg vs. 77.92 mmHg, P < 0.001).ConclusionsHPI guidance appears to be effective in preventing intraoperative hypotension during general anesthesia. Further investigation is needed to assess the impact of HPI on patient outcomes.Trial registrationClinicalTrials.gov (NCT04966364); 202105065RINA; Date of registration: July 19, 2021; The recruitment date of the first patient: July 22, 2021.

How to find and overcome reason of the pain - an overview of the possible approaches in intracranial hypotension treatment

How to find and overcome reason of the pain - an overview of the possible approaches in intracranial hypotension treatment

Diagnosis and Treatment of Spontaneous Intracranial Hypotension: Role of Epidural Blood Patching.

This review focuses on the challenges of diagnosing and treating spontaneous intracranial hypotension (SIH), a condition caused by spinal CSF leakage. It emphasizes the need for increased awareness and advocates for early and thoughtful use of empirical epidural blood patches (EBPs) in suspected cases. SIH diagnosis is hindered by variable symptoms and inconsistent imaging results, including normal brain MRI and unreliable spinal opening pressures. It is crucial to consider SIH in differential diagnoses, especially in patients with connective tissue disorders. Early EBP intervention is shown to improve outcomes. SIH remains underdiagnosed and undertreated, requiring heightened awareness and understanding. This review promotes proactive EBP use in managing suspected SIH and calls for continued research to advance diagnostic and treatment methods, emphasizing the need for innovative imaging techniques for accurate diagnosis and timely intervention.

Hypotension with neurovascular changes and cognitive dysfunction: An epidemiological, pathobiological, and treatment review.

Hypotension is a leading cause of age-related cognitive impairment. The available literature evidences that vascular factors are associated with dementia and that hypotension alters cerebral perfusion flow and can aggravate the neurodegeneration of Alzheimer's disease (AD). Despite the discovery of biomarkers and the recent progress made in neurovascular biology, epidemiology, and brain imaging, some key issues remain largely unresolved: the potential mechanisms underlying the neural deterioration observed in AD, the effect of cerebrovascular alterations on cognitive deficits, and the positive effects of hypotension treatment on cognition. Therefore, further well-designed studies are needed to unravel the potential association between hypotension and cognitive dysfunction and reveal the potential benefits of hypotension treatment for AD patients. Here, we review the current epidemiological, pathobiological, and treatment-related literature on neurovascular changes and hypotension-related cognitive dysfunction and highlight the unsettled but imminent issues that warrant future research endeavors.

Population kinetic/pharmacodynamic modelling of the haemodynamic effects of cafedrine/theodrenaline (Akrinor) under general anaesthesia.

The 20:1 combination of cafedrine and theodrenaline (C/T) is widely used in Germany for the treatment of arterial hypotension. Since there is little knowledge about the impact of covariates on the effect, the aim was to develop a kinetic/pharmacodynamic covariate model describing mean arterial pressure (MAP), systolic (SBP) and diastolic blood pressure (DBP), and heart rate (HR) for 30 min after the administration of C/T. Data of patients receiving C/T from the HYPOTENS study (NCT02893241, DRKS00010740) were analysed using nonlinear mixed-effects modelling techniques. Overall, 16 579 measurements from 315 patients were analysed. The combination of two kinetic compartments and a delayed effect model, coupled with distinct Emax models for HR, SBP and DBP, described the data best. The model included age, sex, body mass index (BMI), antihypertensive medication, American Society of Anaesthesiologists (ASA) physical status classification grade, baseline SBP at the time of hypotension and pre-surgery HR as covariates (all P < .001). A higher baseline SBP led to a lower absolute increase in MAP. Patients with higher age, higher BMI and lower ASA grade showed smaller increases in MAP. The initial increase was similar for male and female patients. The long-term effect was higher in women. Concomitant antihypertensive medication caused a delayed effect and a lower maximum MAP. The HR increased only slightly (median increase 2.6bpm, P < .001). Seven covariates with an impact on the effect of C/T could be identified. The results will enable physicians to optimize the dose with respect to individual patients.

Treatment of Orthostatic Hypotension During Acute Inpatient Rehabilitation After Spinal Cord Injury: Usual Care vs. Anti-hypotensive Therapy.

To compare the pharmacological treatment of hypotension and orthostatic hypotension (OH) initiated based upon a blood pressure (BP) threshold, regardless of symptoms (TXT), to usual care pharmacological treatment of symptomatic hypotension (UC), during acute inpatient rehabilitation (AIR) following spinal cord injury (SCI). Block randomization, based on the neurological level of injury as: cervical lesions (C1-C8); high thoracic lesions (T1-T5), and low thoracic lesions (T6-T12), was used to determine responses to the primary question "was the therapy session affected by low BP or concern for low BP development?" Study participants and therapists were unaware of the group assignment. A total of 66 participants enrolled; 25 (38%) in the TXT group, 29 (44%) in the UC group, and 12 (18%) withdrew. Responses to the primary question were recorded for 32 participants, 15 in the TXT, and 17 in the UC group. There was an average of 81 ± 51 therapy sessions/participant in the TXT and 60 ± 27 sessions/participant in the UC group. Of those therapy sessions, low BP or concerns for low BP affected an average of 9 ± 8 sessions/participant in the TXT group and 10 ± 12 sessions/participant in the UC group. Neither the total number of therapy sessions (P = 0.16) nor group assignment (P = 0.83) significantly predicted the number of sessions affected by low BP. These data are not conclusive but indicate that the treatment of asymptomatic hypotension and OH does not increase time spent in therapy compared to UC treatment of symptomatic hypotension and OH in newly injured patients with SCI. #NCT02919917.

Treatment of Hypotension with Phenylephrine Increases Cerebral Microvascular Perfusion in a Rat Model of Acute Hemodilution

Intraoperative blood loss is associated with reduced mean arterial blood pressure (MAP), which may endanger vital organ perfusion, including the brain. Phenylephrine (PE), an α1-receptor agonist, is clinically utilized to treat intraoperative hypotension through vasoconstriction of resistance arterioles. Clinical studies suggest that raising MAP with PE may decrease perfusion to vital organs such as the brain. Experimental studies suggest that lower α-receptor density in the cerebral resistance arteries may lead to preserved brain perfusion after PE administration. We hypothesize that treatment of hypotension with PE will result in preserved brain perfusion due to different microvascular blood flow and tissue oxygen tension (pO2) responses in the brain and skeletal muscle in an experimental rat model. With Animal Care and Use Committee approval in accordance with ARRIVE-2 guidelines, spontaneously breathing anesthetized rats (1.5% isoflurane) underwent hemodilution by exchanging 40-50% estimated blood volume 1:1 with saline over 10 minutes to achieve a 10-20 mmHg drop in MAP. MAP (tail artery) was measured continuously. Hypotension was treated with PE (10-20 μg/kg/min iv) to increase MAP to a target above baseline MAP. Shed blood was re-infused after stopping the PE infusion. Microvascular blood flow (Oxyflo; Oxford Optronix, Oxford, UK, n=7) or microvascular pO2 (OxyLED, Oxyphor G4, Oxygen Enterprises Ltd., Philadelphia, PA, n=6) were measured continuously in the cerebral cortex (burr hole) and biceps femoris muscle simultaneously in each rat. Results were analyzed via one or two-way ANOVA, with significance achieved at p&lt;0.05. Baseline and post-hemodilution MAP values were comparable in both groups. PE infusion increased MAP to a mean level near 100 mmHg in both groups (p&lt;0.05). Microvascular blood flow and tissue pO2 were greater in the brain as compared to the muscle at all time points (p&lt;0.01 for both). PE infusion resulted in an increase in cerebral microvascular blood flow from baseline (1465±689 vs. 687±453 blood perfusion units (BPU); p&lt;0.001) that was sustained after discontinuing PE and during blood reinfusion. No changes in muscle microvascular flow were observed after PE infusion (294±129 vs. 168±113 BPU). A sustained increase in cerebral microvascular pO2 was measured following PE infusion (50.2±8.6 vs. 40.6±4.6 mmHg; p=0.02), whereas muscle tissue pO2 did not change (22.2±5.6 vs. 25.0±2.5 mmHg). A differential blood flow and microvascular pO2 response was observed following PE infusion in brain and skeletal muscle. Both cerebral microvascular blood flow and tissue pO2 demonstrated sustained increases after PE infusion. By contrast, no changes were observed in muscle microvascular blood flow and pO2. These results suggest that treatment of hypotension with PE administration preferentially increased cerebral vs. muscle perfusion in an experimental model of acute blood loss and fluid resuscitation. Canadian Anesthesiologists’ Society and University of Toronto Merit Award Support. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

6290035 An approach to prevention and treatment of hypotension in elective caesarean sections under spinal anaesthesia: A survey from a developing nation

6290035 An approach to prevention and treatment of hypotension in elective caesarean sections under spinal anaesthesia: A survey from a developing nation

Orthostatic Hypotension and Antihypertensive Treatment in Lung Transplant Recipients: A Cross-Sectional Study.

Lung transplant is the ultimate treatment of many end-stage lung diseases. Calcineurin inhibitors, crucial in immunosuppression for lung transplant recipients, are linked to secondary hypertension, necessitating antihypertensive treatment. In addition, lung transplant recipients frequently experience orthostatic hypotension, occasionally stemming from autonomic dysfunction, but also commonly attributed as a negative side effect of antihypertensive treatment. Our study aimed to evaluate the frequency of orthostatic blood pressure irregularities and investigate the involvement of antihypertensive treatment as a potential risk factor in the occurrence among lung transplant recipients. Fifty-six consecutive lung transplant recipients, both inpatient and outpatient, at the University Hospital Zurich (Switzerland) were monitored from 1999 to 2013. Transplant recipients underwent a Schellong test (an active standing test). Our evaluation encompassed their initial traits, such as the existence of supine hypertension. We computed the odds ratio for the comparison of the likelihood of experiencing orthostatic hypotension while using a minimum of 1 type of antihypertensive medication versus absence of antihypertensive drugs. Of the lung transplant recipients, 25% showed a positive Schellong test. Within this group, 64% had supine hypertension, and 29% displayed symptoms of orthostatic hypotension. Among the patients, 71% were using at least 1 type of antihypertensive medication. The odds ratio for showing orthostatic hypotension while taking at least 1 type of antihypertensive drug versus the absence of antihypertensive medications was 1.64 (95% exact CI, 0.39-6.90) with P = .50. This finding remained consistent regardless of age, sex, inpatient or outpatient status, and the duration since transplant. Orthostatic blood pressure dysregulation is prevalent among lung transplant recipients, frequently without noticeable symptoms. In our cohort, the use of antihypertensive medications did not elevate the risk of orthostatic hypotension.

Surgical treatment of spontaneous intracranial hypotension

Surgical treatment of spontaneous intracranial hypotension

Effective bolus dose of remimazolam for i-gel® insertion in nonparalyzed patients: a dose-finding study

PurposeRemimazolam is a recently developed ultra-short-acting benzodiazepine used for anesthesia induction and maintenance. Nevertheless, the effective bolus dose of remimazolam for i-gel® (Intersurgical Ltd., Wokingham, Berkshire, UK) insertion without the use of neuromuscular blocking agents (NMBAs) has not been well established.MethodsThis study included 25 adult patients scheduled for surgery under general anesthesia who were eligible for i-gel use. Anesthesia was induced with predetermined bolus doses of remimazolam, starting at 0.3 mg·kg−1 for the first patient, without the use of NMBAs. All patients concurrently received remifentanil using target-controlled infusion (TCI) at a fixed effect-site concentration (Ce) of 3.0 ng·mL−1. Insertion of the i-gel was attempted 90 sec after remimazolam administration, and insertion conditions were assessed. Subsequent doses of remimazolam were decreased or increased by 0.05 mg·kg−1, depending on the success or failure of i-gel insertion.ResultsThe mean (standard deviation) 50% effective dose (ED50) of a remimazolam bolus for successful i-gel insertion as determined by the modified Dixon’s up-and-down method was 0.100 (0.027) mg·kg−1. The ED50 and ED95 estimated by isotonic regression were 0.111 (83% confidence interval [CI], 0.096 to 0.131) mg·kg−1 and 0.182 (95% CI, 0.144 to 0.195) mg·kg−1, respectively. None of the patients required treatment for hypotension or bradycardia during anesthesia induction.ConclusionBased on the ED95 of remimazolam bolus dose determined in our study, we recommend using 0.182 mg·kg−1 of remimazolam in combination with remifentanil TCI at a Ce of 3.0 ng·mL−1 for successful i-gel insertion without NMBAs in adult patients. This regimen seems effective with a low risk of hemodynamic instability during anesthesia induction.Study registrationClinicalTrials.gov (NCT05298228); first submitted 6 March 2022.