Association of frequent intradialytic hypotension with the clinical outcomes of patients on hemodialysis: a prospective cohort study

Intradialytic hypotension (IDH) is a common complication of hemodialysis (HD), but there is no consensus on its definition. In 2015, Flythe proposed a definition of IDH (Definition 1 in this study): nadir systolic blood pressure (SBP) <90 mmHg during hemodialysis for patients with pre-dialysis SBP <159 mmHg, and nadir SBP <100 mmHg during hemodialysis for patients with pre-dialysis SBP ≥160 mmHg. This prospective observational cohort study investigated the association of frequent IDH based on Definition 1 with clinical outcomes and compared Definition 1 with a commonly used definition (nadir SBP <90 mmHg during hemodialysis, Definition 2). The incidence of IDH was observed over a 3-month exposure assessment period. Patients with IDH events ≥30% were classified as 'frequent IDH'; the others were 'infrequent IDH'. All-cause mortality, cardiovascular mortality, and all-cause hospitalization events were followed up for 36 months. This study enrolled 163 HD patients. The incidence of IDH was 11.1% according to Definition 1 and 10.5% according to Definition 2. The Kaplan-Meier curves showed that frequent IDH patients had higher risks of all-cause mortality (p = 0.009, Definition 1; p = 0.002, Definition 2) and cardiovascular mortality (p = 0.021, Definition 1). Multivariable Cox regression analysis indicated that frequent IDH was independently associated with a higher risk of all-cause mortality (Model 1: HR = 2.553, 95%CI 1.334-4.886, p = 0.005; Model 2: HR = 2.406, 95%CI 1.253-4.621, p = 0.008). In conclusion, HD patients classified as frequent IDH are at a greater risk of all-cause mortality. This highlights the significance of acknowledging and proactively managing frequent IDH within the HD patients.

External validation of the prediction model of intradialytic hypotension: a multicenter prospective cohort study

OBJECTIVE

Intradialytic hypotension (IDH) is a common and serious complication in patients with Maintenance Hemodialysis (MHD). The purpose of this study is to externally verify three IDH risk prediction models recently developed by Ma et al. and recalibrate, update and present the optimal model to improve the accuracy and applicability of the model in clinical environment.

METHODS

A multicenter prospective cohort study of patients from 11 hemodialysis centers in Sichuan Province, China, was conducted using convenience sampling from March 2022 to July 2022, with a follow-up period of 1 month. Model performance was assessed by: (1) Discrimination: Evaluated through the computation of the Area Under Curve (AUC) and its corresponding 95% confidence intervals. (2) Calibration: scrutinized through visual inspection of the calibration plot and utilization of the Brier score. (3) The incremental value of risk prediction and the utility of updating the model were gauged using NRI (Net Reclassification Improvement) and IDI (Integrated Discrimination Improvement). Decision Curve Analysis (DCA) was employed to evaluate the clinical benefit of updating the model.

RESULTS

The final cohort comprised 2235 individuals undergoing maintenance hemodialysis, exhibiting a 14.6% occurrence rate of IDH. The externally validated Area Under the Curve (AUC) values for the three original prediction models were 0.746 (95% CI: 0.718 to 0.775), 0.709 (95% CI: 0.679 to 0.739), and 0.735 (95% CI: 0.706 to 0.764) respectively. Conversely, the AUC value for the recalibrated and updated columnar plot model reached 0.817 (95% CI: 0.791 to 0.842), accompanied by a Brier score of 0.081. Furthermore, Decision Curve Analysis (DCA) exhibited a net benefit within the threshold probability range of 15.2% to 87.1%.

CONCLUSION

Externally validated, recalibrated, updated, and presented IDH prediction models may serve as a valuable instrument for evaluating IDH risk in clinical practice. Furthermore, they hold the potential to guide clinical providers in discerning individuals at risk and facilitating judicious clinical intervention decisions.

Hemodynamic changes in the prone position according to fluid loading after anaesthesia induction in patients undergoing lumbar spine surgery: a randomized, assessor-blind, prospective study

INTRODUCTION

A change from the supine to prone position causes hemodynamic alterations. We aimed to evaluate the effect of fluid preloading in the supine position, the subsequent hemodynamic changes in the prone position and postoperative outcomes.

PATIENTS AND METHODS

This prospective, assessor-blind, randomized controlled trial was conducted between March and June 2023. Adults scheduled for elective orthopaedic lumbar surgery under general anaesthesia were enrolled. In total, 80 participants were randomly assigned to fluid maintenance (M) or loading (L) groups. Both groups were administered intravenous fluid at a rate of 2 ml/kg/h until surgical incision; Group L was loaded with an additional 5 ml/kg intravenous fluid for 10 min after anaesthesia induction. The primary outcome was incidence of hypotension before surgical incision. Secondary outcomes included differences in the mean blood pressure (mBP), heart rate, pleth variability index (PVi), stroke volume variation (SVV), pulse pressure variation (PPV), stroke volume index and cardiac index before surgical incision between the two groups. Additionally, postoperative complications until postoperative day 2 and postoperative hospital length of stay were investigated.

RESULTS

Hypotension was prevalent in Group M before surgical incision and could be predicted by a baseline PVi >16. The mBP was significantly higher in Group L immediately after fluid loading. The PVi, SVV and PPV were lower in Group L after fluid loading, with continued differences at 2-3 time points for SVV and PPV. Other outcomes did not differ between the two groups.

CONCLUSION

Fluid loading after inducing general anaesthesia could reduce the occurrence of hypotension until surgical incision in patients scheduled for surgery in the prone position. Additionally, hypotension could be predicted in patients with a baseline PVi >16. Therefore, intravenous fluid loading is strongly recommended in patients with high baseline PVi to prevent hypotension after anaesthesia induction and in the prone position.

TRIAL NUMBER

KCT0008294 (date of registration: 16 March 2023).

Unruptured giant lateral thoracic meningocele: extremely rare cause of cerebrospinal fluid (CSF) hypotension in neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is a multisystem neurocutaneous disorder. Scoliosis and dural ectasia are features of the associated mesodermal dysplasia. Lateral thoracic meningoceles can develop in NF1 and progressively enlarge due to cerebrospinal fluid (CSF) pulsations. Large meningoceles can cause compressive symptoms in the thorax. We are reporting a case of a NF1 presenting with acute onset respiratory distress, who also had chronic orthostatic headaches. CT chest showed unruptured enlarging bilateral lateral thoracic meningoceles causing lung compression. MRI of the brain and spine showed features of CSF hypotension, explaining the headaches. CSF hypotension with unruptured meningoceles is extremely rare. Management of the condition is challenging since surgical removal is prone to complications due to underlying mesodermal abnormalities. Cystoperitoneal shunting to relieve lung compression may worsen CSF hypotension. A shunt with a programmable valve allowed controlled drainage and successfully relieved lung compression without worsening of orthostatic headaches in our case.

Correlation between geriatric nutritional risk index and intradialytic hypotension in elderly patients undergoing maintenance hemodialysis: a case-control study

BACKGROUND

There is a correlation between nutritional status and treatment outcomes and long-term survival in MHD patients but there is limited research on the relationship between GNRI and IDH. This case-control study aimed to investigate the correlation between Geriatric Nutritional Risk Index (GNRI) and intradialytic hypotension (IDH) in elderly patients undergoing maintenance hemodialysis (MHD).

METHODS

This study was carried out on 129 cases of MHD patients with IDH and 258 non-IDH-controls in Ruijin Hospital, Shanghai Jiaotong University School of Medicine, China, between June 2020 and May 2022. Professional researchers collected patients' general information on gender, primary disease, dialysis-related indicators, anthropometric measures, laboratory biochemicals, and GNRI. Logistic regression analysis was used to evaluate the correlation between GNRI and IDH.

RESULTS

A total of 385 elderly MHD patients were included. Compared with GNRI Q4 group, the odds ratios for the risk of IDH in GNRI Q3 group, GNRI Q2 group, and GNRI Q1 group of elderly MHD patients were 1.227, 2.196, and 8.350, respectively, showing a significant downward trend (P-trend < 0.05). The area under the curve of GNRI for predicting IDH was 0.839 (95% CI: 0.799-0.879). Between different genders, a decrease in GNRI was closely related to an increase in IDH risk (P for trend < 0.05).

CONCLUSIONS

This research shows a significant association between GNRI and the incidence of IDH among elderly MHD patients and has an important warning effect. Encouraging the incorporation of GNRI assessment into the clinical assessment protocols of older patients with MHD may help to improve the nutritional status of those suffering from it and reduce the risk of IDH.

Periprocedural acute haemodynamic decompensation during substrate-based ablation of scar-related ventricular tachycardia: a rare and unpredictable event

AIMS

Patients with structural heart disease (SHD) undergoing catheter ablation (CA) for ventricular tachycardia (VT) are at considerable risk of periprocedural complications, including acute haemodynamic decompensation (AHD). The PAINESD score was proposed to predict the risk of AHD. The goal of this study was to validate the PAINESD score using the retrospective analysis of data from a large-volume heart centre.

METHODS AND RESULTS

Patients who had their first radiofrequency CA for SHD-related VT between August 2006 and December 2020 were included in the study. Procedures were mainly performed under conscious sedation. Substrate mapping/ablation was performed primarily during spontaneous rhythm or right ventricular pacing. A purposely established institutional registry for complications of invasive procedures was used to collect all periprocedural complications that were subsequently adjudicated using the source medical records. Acute haemodynamic decompensation triggered by CA procedure was defined as intraprocedural or early post-procedural (<12 h) development of acute pulmonary oedema or refractory hypotension requiring urgent intervention. The study cohort consisted of 1124 patients (age, 63 ± 13 years; males, 87%; ischaemic cardiomyopathy, 67%; electrical storm, 25%; New York Heart Association Class, 2.0 ± 1.0; left ventricular ejection fraction, 34 ± 12%; diabetes mellitus, 31%; chronic obstructive pulmonary disease, 12%). Their PAINESD score was 11.4 ± 6.6 (median, 12; interquartile range, 6-17). Acute haemodynamic decompensation complicated the CA procedure in 13/1124 = 1.2% patients and was not predicted by PAINESD score with AHD rates of 0.3, 1.8, and 1.1% in subgroups by previously published PAINESD terciles (<9, 9-14, and >14). However, the PAINESD score strongly predicted mortality during the follow-up.

CONCLUSION

Primarily substrate-based CA of SHD-related VT performed under conscious sedation is associated with a substantially lower rate of AHD than previously reported. The PAINESD score did not predict these events. The application of the PAINESD score to the selection of patients for pre-emptive mechanical circulatory support should be reconsidered.

The efficacy and safety of ivabradine hydrochloride in hemodialysis patients with chronic heart failure

INTRODUCTION

There is little evidence for ivabradine hydrochloride in patients undergoing hemodialysis.

METHODS

In this open-label prospective interventional trial of hemodialysis patients with chronic heart failure, during 12 weeks of treatment, changes in Heart rate (HR), frequency of dialysis-related hypotension were examined, and we investigated health-related quality of life (HR-QOL) and adverse effects.

RESULTS

18 patients from 6 facilities were enrolled in the study. HR significantly decreased over time, from 87 ± 12.61/min at baseline to 75.85 ± 8.91/min (p = 0.0003), and systolic blood pressure also increased significantly (p < 0.0001). The frequency of dialysis-related hypotension was markedly reduced (p = 0.0001). The HR-QOL survey showed significant improvements in Social Functioning among others (p = 0.0178). No specific adverse events occurred.

CONCLUSION

Ivabradine hydrochloride improved dialysis-related hypotension. Furthermore, the HR-QOL improvement effect were suggested. These results demonstrated the safety and effectiveness of ivabradine hydrochloride.

Does the choice of induction agent in rapid sequence intubation in the emergency department influence the incidence of post-induction hypotension?

OBJECTIVE

To describe the effects of different induction agents on the incidence of post-induction hypotension (PIH) and its associated interventions during rapid sequence intubation (RSI) in the ED.

METHODS

A single centre retrospective study of patients intubated between 2018 and 2021 was conducted in a regional Australian ED. The impact of induction agent choice, in addition to demographic and clinical factors on the incidence of PIH were determined using descriptive statistics and a multivariate analysis presented as adjusted odds ratios (aORs) and their 95% confidence intervals (CIs).

RESULTS

Ketamine and propofol, used either individually or in conjunction with fentanyl, were significantly associated with PIH (ketamine aOR 4.5, 95% CI 1.35-14.96; propofol aOR 4.88, 95% CI 1.46-16.29). Age >60 years was associated with a greater requirement for vasopressors (aOR 4.46, 95% CI 2.49-7.97) and a higher risk of mortality after RSI (aOR 4.2, 95% CI 1.87-9.40). Patients with a shock index >1.0 were significantly more likely to require vasopressors (aOR 5.13, 95% CI 2.35-11.2) and have a cardiac arrest within 15 min of RSI (aOR 3.56, 95% CI 1.07-11.8).

CONCLUSIONS

Exposure to both propofol and ketamine is significantly associated with PIH after RSI, alongside age and shock index. PIH is likely multifactorial in nature, and this data supports the sympatholytic effect of induction agents as the underlying cause of PIH rather than the choice of agent itself. Further prospective work including a randomised controlled trial between induction agents is justified to further clarify this important clinical question.

Effect of phenylephrine rescue injection on hypotension after spinal anaesthesia for caesarean delivery when guided by both heart rate and SBP during an early warning window: A randomised controlled trial

BACKGROUND

Spinal anaesthesia is now the most common technique for caesarean delivery. However, because of the intermittent nature of noninvasive blood pressure (NIBP) measurements, maternal blood pressure may become hypotensive between the measurements. There is thus an inbuilt delay before the anaesthesiologist can intervene to counteract the hypotension. Based on the principle that changes in blood pressure can induce compensatory changes in the heart rate (HR), combining the NIBP with real-time HR, we designed two warning windows to predict hypotension and hypertension.

OBJECTIVE

To evaluate whether phenylephrine administration guided by these warning windows would help maintain haemodynamic stability.

SETTING

A teaching hospital.

DESIGN

A randomised controlled trial.

PATIENTS

One hundred and ten pregnant women scheduled for elective caesarean delivery were enrolled, from which, after exclusions, 86 were eligible for the study.

INTERVENTIONS

All eligible patients received a continuous intravenous infusion of phenylephrine as soon as spinal anaesthesia was initiated. Thereafter, patients were randomly assigned to two groups. In the test group (Win-Group): rescue phenylephrine administration was triggered by an early warning window of HR above 100 beats per minute (bpm) and SBP 90 to 110 mmHg; pausing the infusion phenylephrine was triggered by a HR lower than 60 bpm and SBP greater than 90 mmHg. In the control group, phenylephrine was guided by BP only when it appeared on the monitor: SBP less than 90 mmHg was the trigger for administering rescue phenylephrine; SBP greater than 110 mmHg was the trigger for pausing the phenylephrine infusion.

MAIN OUTCOME MEASURES

The primary outcome was incidence of hypotension. Secondary outcomes were the incidence of hypertension and other adverse haemodynamic events.

RESULTS

The incidence of hypotension was significantly lower in the Win-Group than in the BP-Group (27.8 vs. 66.7%, P  = 0.001). The minimum SBP was significantly higher in Win-Group than in BP-Group (93.9 ± 9.49 vs. 86.7 ± 11.16 mmHg, P   =  0.004). There was no significant difference in the incidence of hypertension between groups.

CONCLUSION

After spinal anaesthesia for caesarean delivery, when phenylephrine infusion is guided by HR along with BP from a warning window it effectively reduces the incidence of hypotension without any significant effect on incidence of hypertension.

TRIAL REGISTRATION

Chictr.org.cn; Identifier: ChiCTR 2100041812.

Intraoperative hypotension and postoperative acute kidney injury: A systematic review

BACKGROUND

There is no consensus regarding safe intraoperative blood pressure thresholds that protect against postoperative acute kidney injury (AKI). This review aims to examine the existing literature to delineate safe intraoperative hypotension (IOH) parameters to prevent postoperative AKI.

METHODS

PubMed, Cochrane Central, and Web of Science were systematically searched for articles published between 2015 and 2022 relating the effects of IOH on postoperative AKI.

RESULTS

Our search yielded 19 articles. IOH risk thresholds ranged from <50 to <75 ​mmHg for mean arterial pressure (MAP) and from <70 to <100 ​mmHg for systolic blood pressure (SBP). MAP below 65 ​mmHg for over 5 ​min was the most cited threshold (N ​= ​13) consistently associated with increased postoperative AKI. Greater magnitude and duration of MAP and SBP below the thresholds were generally associated with a dose-dependent increase in postoperative AKI incidence.

CONCLUSIONS

While a consistent definition for IOH remains elusive, the evidence suggests that MAP below 65 ​mmHg for over 5 ​min is strongly associated with postoperative AKI, with the risk increasing with the magnitude and duration of IOH.

Implication of Hypotension in the Pathogenesis of Cognitive Impairment and Brain Injury in Chronic Liver Disease

The incidence of chronic liver disease is on the rise. One of the primary causes of hospital admissions for patients with cirrhosis is hepatic encephalopathy (HE), a debilitating neurological complication. HE is defined as a reversible syndrome, yet there is growing evidence stating that, under certain conditions, HE is associated with permanent neuronal injury and irreversibility. The pathophysiology of HE primarily implicates a strong role for hyperammonemia, but it is believed other pathogenic factors are involved. The fibrotic scarring of the liver during the progression of chronic liver disease (cirrhosis) consequently leads to increased hepatic resistance and circulatory anomalies characterized by portal hypertension, hyperdynamic circulatory state and systemic hypotension. The possible repercussions of these circulatory anomalies on brain perfusion, including impaired cerebral blood flow (CBF) autoregulation, could be implicated in the development of HE and/or permanent brain injury. Furthermore, hypotensive insults incurring during gastrointestinal bleed, infection, or liver transplantation may also trigger or exacerbate brain dysfunction and cell damage. This review will focus on the role of hypotension in the onset of HE as well as in the occurrence of neuronal cell loss in cirrhosis.

Teamwork matters: The association between nontechnical skills and cardiac arrest in trauma patients presenting with hypotension

BACKGROUND

The impact of trauma team dynamics on outcomes in injured patients is not completely understood. We sought to evaluate the association between trauma team function, as measured by a modified Trauma Non-Technical Skills assessment, and cardiac arrest in hypotensive trauma patients. We hypothesized that better team function is associated with a decreased probability of developing cardiac arrest.

METHODS

Trauma video review was used to collect data from resuscitations of adult hypotensive trauma patients at 19 centers. Hypotension at emergency department presentation was defined as an initial systolic blood pressure <90 mm Hg or an initial systolic blood pressure ≥90 mm Hg followed by a systolic blood pressure <90 mm Hg within the first 5 minutes. Team dynamics were scored using a modified Trauma Non-Technical Skills assessment composed of 5 domains with combined scores ranging from 5 (best) to 15 (worst). Scores were compared between cardiac arrest/noncardiac arrest cases in the trauma bay. Logistic regression was used to evaluate the independent association between the Trauma Non-Technical Skills assessment and cardiac arrest.

RESULTS

A total of 430 patients were included (median age 43 years [interquartile range: 29-61]; 71.8% male; 36% penetrating mechanism; median Injury Severity Score 20 [10-33]; 11% experienced cardiac arrest in trauma bay). The median total Trauma Non-Technical Skills assessment score was 7 (6-9), higher in patients who experienced cardiac arrest in the trauma bay (9 [6-10] vs 7 [6-9]; P = .016). This association persisted after controlling for age, sex, mechanism, injury severity, initial systolic blood pressure, and initial Glasgow Coma Scale score (adjusted odds ratio: 1.28; 95% confidence interval:1.11-1.48; P < .001), indicating a ∼3% higher predicted probability of cardiac arrest per Trauma Non-Technical Skills point.

CONCLUSION

Better team function is independently associated with a decreased probability of cardiac arrest in trauma patients presenting with hypotension. This suggests that trauma team training may improve outcomes in peri-arrest patients.

Prophylactic norepinephrine combined with 6% hydroxyethyl starch (130/0.4) co-load infusion for preventing postspinal anesthesia hypotension during cesarean section: a randomized, controlled, dose-finding trial

PURPOSE

Colloid and/or co-load may be more effective than crystalloid for preventing postspinal anesthesia hypotension. We tested five different prophylactic norepinephrine dosages combined with colloid co-load infusion in patients receiving cesarean section and spinal anesthesia.

METHODS

Patients were randomly allocated to receive different prophylactic norepinephrine dosages (0 [NE 0 group], 0.025 [NE 25 group], 0.05 [NE 50 group], 0.075 [NE 75 group], or 0.1 [NE 100 group] µg/kg/min) combined with 500 mL 6% hydroxyethyl starch (130/0.4) immediately following spinal anesthesia (n = 35 per group). The primary endpoint was the incidence of postspinal anesthesia hypotension (systolic blood pressure [SBP] < 80% of baseline). Secondary endpoints included severe hypotension, bradycardia, nausea or vomiting, hypertension, SBP stability control versus baseline, the 50% (effective dose, ED50) and 90% (ED90) dose effective for preventing postspinal anesthesia hypotension, Apgar scores, and umbilical cord blood gases.

RESULTS

The incidence of postspinal anesthesia hypotension was 48.6%, 31.3%, 17.1%, 14.3%, and 5.7% in the respective groups. As the prophylactic norepinephrine dosage increased, the incidence of postspinal anesthesia hypotension declined (p < 0.001), and SBP remained stable relative to baseline (median performance error [MDPE], p < 0.001; median absolute performance error [MDAPE], p = 0.001). The ED50 and ED90 values were -0.006 (95% CI -0.046-0.013) and 0.081 (95% CI 0.063-0.119) µg/kg/min. Other endpoints were comparable across the groups.

CONCLUSION

An initial prophylactic norepinephrine dosage of 0.05 µg/kg/min combined with 500 mL 6% hydroxyethyl starch (130/0.4) co-load infusion was optimal for preventing postspinal anesthesia hypotension during cesarean section.

TRIAL REGISTRATION

NCT05133817, registration date: 12 Nov, 2021.

Severe hypotension and postoperative cardiac arrest caused by 5-aminolevulinic acid: a case report

BACKGROUND

Although 5-aminolevulinic acid is useful for the photodynamic diagnosis of bladder tumors, it often causes severe intraoperative hypotension. We report a case of postoperative cardiac arrest in addition to severe intraoperative hypotension, probably owing to the use of 5-aminolevulinic acid.

CASE PRESENTATION

An 81-year-old Japanese man was scheduled to undergo transurethral resection of bladder tumor. The patient took 5-aminolevulinic acid orally 2 hours before entering the operating room. After the induction of anesthesia, his blood pressure decreased to 47/33 mmHg. The patient's hypotension did not improve even after noradrenaline was administered. After awakening from anesthesia, the patient's systolic blood pressure increased to approximately 100 mmHg, but approximately 5 hours after returning to the ward, cardiac arrest occurred for approximately 12 seconds.

CONCLUSION

We experienced a case of postoperative cardiac arrest in a patient, probably owing to the use of 5-aminolevulinic acid. Although the cause of cardiac arrest is unknown, perioperative hemodynamic management must be carefully performed in patients taking 5-aminolevulinic acid.

Effects of neuraxial anesthesia in sitting and lateral positions on maternal hemodynamics in cesarean section: A systematic review and meta-analysis

STUDY OBJECTIVE

During cesarean section, hypotension is a frequent side effect of spinal anesthesia. As a sitting or lateral position is required for spinal anesthesia performance, which of these two positions is more likely to cause intraoperative nausea, vomiting, and hypotension is still unknown. This meta-analysis compared the effects of these two positions on maternal hemodynamics and intraoperative nausea and vomiting.

DESIGN

Systematic review and meta-analysis.

SETTING

Operating room.

PATIENTS

This study included 803 patients from 12 randomized controlled trials (RCTs).

INTERVENTIONS

Neuraxial anesthesia in sitting position vs. lateral position.

MEASUREMENTS

We chose RCTs comparing the effects of spinal anesthesia in the sitting and lateral positions on maternal hemodynamics by thoroughly searching PubMed, Embase, the Cochrane Library, and the Web of Science for articles published from database inception until October 31, 2022. The Cochrane Handbook was used to assess the methodological quality of each RCT; the results were analyzed using RevMan 5.4 software; and the Egger test was used to assess publication bias.

MAIN RESULTS

12 randomised controlled trials with 803 participants were ultimately included in the final analysis. No significant differences were observed between the two positions in terms of the incidence of hypotension(RR, 0.82; 95% CI, 0.58-1.16; P = 0.26; I2 = 66%), lowest systolic blood pressure(MD, -0.81; 95% CI, -7.38-5.75; P = 0.81; I2 = 86%), the dose of ephedrine(MD, -1.19; 95% CI, -4.91-2.52; P = 0.53; I2 = 83%), and number of parturients requiring ephedrine(RR, 0.97; 95% CI, 0.64-1.46; P = 0.88; I2 = 74%). For the incidence of intraoperative nausea and vomiting, there was no statistical difference between the two positions.

CONCLUSION

Parturients undergoing elective cesarean section under spinal anesthesia in the sitting or lateral position experienced similar incidence of hypotension, and there were no significant differences between these two positions in terms of the amount of ephedrine administered or the number of patients needing ephedrine. In both positions, the frequency of nausea and vomiting was comparable. The ideal position for anesthesia can be chosen based on the preferences and individual circumstances of the parturient and anesthesiologist.

Adrenalectomy for the treatment of hypotension in a cat with phaeochromocytoma associated with caudal vena cava syndrome

An 11-year-old spayed female, Persian cat was referred to the Jeonbuk Animal Medical Center for evaluation of a 2-month history of lethargy and anorexia. Physical examination revealed tachycardia and hypotension. Abdominal imaging via sonography and CT identified a right adrenal gland mass causing severe deviation and compression of the caudal vena cava. After stabilising the blood pressure and heart rate through positive inotropes and fluid therapy, right adrenalectomy was performed. Surgery confirmed the adrenal gland mass was severely compressing the caudal vena cava. Histopathological examination revealed that the mass was a pheochromocytoma. After adrenalectomy, blood pressure and heart rate stabilised and remained unaffected 8 months postsurgery. This report describes a rare case of an adrenal pheochromocytoma leading to caudal vena cava compression in a cat presenting with hypotension.

Now You See It, Now You Don't: Point-of-Care Ultrasound Identification of Left Ventricular Thrombus-in-Transit

BACKGROUND

Left-sided intracardiac thrombi are most commonly seen in conditions with decreased cardiac flow, such as myocardial infarction or atrial fibrillation. They can be propagated into the systemic circulation, leading to a cerebrovascular accident. Identification of thrombus-in-transit via point-of-care ultrasound (POCUS) has the potential to change patient management given its association with high patient morbidity and mortality.

CASE REPORT

An intubated 60-year-old man was transferred to our emergency department for management of altered mental status and seizure-like activity. The patient was markedly hypotensive on arrival, and cardiac POCUS was performed to identify potential causes of hypotension. A left ventricular thrombus-in-transit was identified. The thrombus was notably absent on a repeat POCUS examination < 10 min later, which led to concern for thrombus propagation. Furthermore, the patient's vasopressor requirements had significantly increased in that time period. Subsequent emergent neuroimaging revealed a large ischemic stroke in the left internal carotid and middle cerebral artery distribution. The patient was, unfortunately, deemed to not be a candidate for either thrombectomy or thrombolysis and ultimately expired in the hospital. Why Should an Emergency Physician Be Aware of This? Serial POCUS examinations identified the propagation of this patient's thrombus-in-transit, leading the physician to change the initial presumptive diagnosis and treatment course, and pursue further imaging and workup for ischemic stroke. Identification of a thrombus-in-transit is a clue to potentially underlying critical pathology and should be followed with serial POCUS examinations to assess for treatment efficacy and thrombus propagation.

Use of Vasopressin as Rescue Therapy in Refractory Hypoxia and Refractory Systemic Hypotension in Term Neonates with Severe Persistent Pulmonary Hypertension-A Prospective Observational Study

OBJECTIVE

 Persistent pulmonary hypertension of the newborn (PPHN) is a serious cardiorespiratory problem. PPHN is frequently associated with refractory hypoxia and hypotension, and optimal management has the potential to improve important clinical outcomes including mortality. The primary objective is to evaluate the efficacy and safety of rescue vasopressin (VP) therapy in the management of severe (refractory) hypoxia and refractory systemic hypotension in term neonates with severe PPHN.

STUDY DESIGN

 Neonates with refractory hypoxia and refractory hypotension due to severe PPHN needing VP were prospectively enrolled in the study. Refractory hypoxia was defined as oxygenation index (OI) ≥ 25 for at least 4 hours after the commencement of high-frequency oscillatory ventilation and nitric oxide at 20 ppm. Refractory hypotension was defined as mean blood pressure lesser than mean gestational age lasting for more than 15 minutes in spite of dopamine infusion at 10 µg/kg/min, adrenaline infusion at 0.3 µg/kg/min, and noradrenaline infusion at 0.1 µg/kg/min.

RESULTS

 Thirty-two neonates with PPHN were recruited. The baseline OI (mean ± standard deviation [SD]) before starting VP was 33.43 ± 16.54 which started decreasing significantly between 1 and 6 hours after the commencement of VP (p < 0.05). The mean blood pressure also increased concomitantly with a significant effect seen by 1 hour (p < 0.05). The vasoactive infusion score before the commencement of VP was mean 46.07 (SD = 25.72) and started decreasing after 12 to 24 hours of commencement of VP (p < 0.05). Lactate levels (mean ± SD) before starting VP were 7.8 ± 8.6 mmol/L and started decreasing between 6 and 12 hours (p < 0.05). Two neonates died due to refractory hypoxia and refractory hypotension (overall mortality 6.2%) CONCLUSION:  Rescue VP therapy is a useful adjunct in the management of neonates with severe PPHN with refractory hypoxia and/or refractory hypotension. Improvement in oxygenation and hemodynamics with the use of VP results in reduced mortality.

KEY POINTS

· Rescue vasopressin is a useful adjunct in the management of neonates with severe PPHN.. · Vasopressin helps reduce OI.. · Vasopressin reduces the vasoactive inotrope score..

Is crystalloid co-loading necessary to prevent spinal hypotension during elective cesarean delivery? A randomized double-blind trial

BACKGROUND

Hypotension is common during spinal anesthesia for cesarean delivery. Preventive strategies include fluid loading and phenylephrine. We hypothesized that if prophylactic phenylephrine infusion is used, omission of fluid loading would be non-inferior to fluid co-loading in maintaining cardiac output. We assumed that if there was a difference, the increase in cardiac output would be greater in the no-loading than in the co-loading group.

METHODS

Term pregnant women scheduled for elective cesarean delivery were randomized to receive 1 L crystalloid co-loading or maintenance fluids only. Phenylephrine was titrated to maintain blood pressure. Changes in cardiac output following spinal anesthesia were the primary outcome. The study was powered as a non-inferiority trial, allowing the no-loading arm to have a 50% greater change in cardiac output. Heart rate, dose of phenylephrine, occurrence of nausea and vomiting, Apgar scores and neonatal acid base status were secondary outcomes.

RESULTS

Data from 63 women were analyzed. In contrast to our hypothesis, there was 33% less increase in cardiac output with no loading (ratio 0.67, 95% CI 0.15 to 1.36), and 60% greater reduction of cardiac output with no loading (ratio 1.6, 95% CI 1.0 to 2.7). Total dose of phenylephrine was higher in the no-loading group. There may be a less favorable neonatal acid base status without volume loading.

CONCLUSION

Omission of crystalloid co-loading leads to a decrease in cardiac output which has a potentially unfavorable impact on neonatal acid base status. We conclude that crystalloid co-loading may be useful in the presence of phenylephrine infusion.

Intraoperative Blood Pressure Management and Its Effects on Postoperative Delirium After Cardiac Surgery: A Single-Center Retrospective Cohort Study

OBJECTIVES

There is accumulating evidence that blood pressure management might be associated with end-organ dysfunction after cardiac surgery. This study aimed to investigate the impact of intraoperative hypotension (IOH) on adverse neurologic outcomes and mortality.

DESIGN

A single-center retrospective cohort study.

SETTING

The Heart and Diabetes Centre Bad Oeynhausen NRW, Ruhr-University Bochum.

PARTICIPANTS

This retrospective cohort study included 31,315 adult patients who underwent elective cardiac surgery at the authors' institution between January 2009 and December 2018.

INTERVENTIONS

All cardiac surgery procedures except assist device implantation, organ transplantation, and emergency surgery.

MEASUREMENTS AND MAIN RESULTS

Adverse neurologic outcomes were defined as postoperative delirium and stroke. IOH was defined as mean arterial pressure below 60 mmHg for >2 minutes. The frequency of IOH episodes and the cumulative IOH duration were recorded. The association between IOH and adverse neurologic outcomes was examined with unadjusted statistical analysis and multiple logistic regression analysis. Eight hundred forty-nine (2.9%) patients developed postoperative stroke, and 2,401 (7.7%) patients developed postoperative delirium. The frequency of IOH episodes was independently associated with postoperative delirium in the multiple logistic regression analysis (odds ratio 1.02, 95% CI 1.003-1.03, p < 0.001), whereas there was no association between it and stroke.

CONCLUSION

This large retrospective monocentric cohort study revealed that increased episodes of IOH were associated with the risk of developing postoperative delirium after cardiac surgery. This might have important clinical implications with respect to careful and precise hemodynamic monitoring and proactive treatment, especially in patients with increased risk for postoperative delirium.

Effect of using hypotension prediction index versus conventional goal-directed haemodynamic management to reduce intraoperative hypotension in non-cardiac surgery: A randomised controlled trial

STUDY OBJECTIVE

It remains unclear whether it is the hypotension prediction index itself or goal-directed haemodynamic therapy that mitigates intraoperative hypotension.

DESIGN

A single centre randomised controlled trial.

SETTING

Sapporo Medical University Hospital.

PATIENTS

A total of 64 adults patients undergoing major non-cardiac surgery under general anaesthesia.

INTERVENTIONS

Patients were randomly assigned to either group receiving conventional goal-directed therapy (FloTrac group) or combination of the hypotension prediction index and conventional goal-directed therapy (HPI group). To investigate the independent utility of the index, the peak rates of arterial pressure and dynamic arterial elastance were not included in the treatment algorithm for the HPI group.

MEASUREMENTS

The primary outcome was the time-weighted average of the areas under the threshold. Secondary outcomes were area under the threshold, the number of hypotension events, total duration of hypotension events, mean mean arterial pressure during the hypotension period, number of hypotension events with mean arterial pressure < 50 mmHg, amounts of fluids, blood products, blood loss, and urine output, frequency and amount of vasoactive agents, concentration of haemoglobin during the monitoring period, and 30-day mortality.

MAIN RESULTS

The time-weighted average of the area below the threshold was lower in the HPI group than in the control group; 0.19 mmHg (interquartile range, 0.06-0.80 mmHg) vs. 0.66 mmHg (0.28-1.67 mmHg), with a median difference of -0.41 mmHg (95% confidence interval, -0.69 to -0.10 mmHg), p = 0.005. Norepinephrine was administered to 12 (40%) and 5 (17%) patients in the HPI and FloTrac groups, respectively (p = 0.045). No significant differences were observed in the volumes of fluid and blood products between the study groups.

CONCLUSIONS

The current randomised controlled trial results suggest that using the hypotension prediction index independently lowered the cumulative amount of intraoperative hypotension during major non-cardiac surgery.

Recovery and safety with prolonged high-frequency jet ventilation for catheter ablation of atrial fibrillation: A hospital registry study from a New England healthcare network

STUDY OBJECTIVE

To investigate post-procedural recovery as well as peri-procedural respiratory and hemodynamic safety parameters with prolonged use of high-frequency jet ventilation (HFJV) versus conventional ventilation in patients undergoing catheter ablation for atrial fibrillation.

DESIGN

Hospital registry study.

SETTING

Tertiary academic teaching hospital in New England.

PATIENTS

1822 patients aged 18 years and older undergoing catheter ablation between January 2013 and June 2020.

INTERVENTIONS

HFJV versus conventional mechanical ventilation.

MEASUREMENTS

The primary outcome was post-anesthesia care unit (PACU) length of stay. In secondary analyses we assessed the effect of HFJV on intra-procedural hypoxemia, defined as the occurrence of peripheral hemoglobin oxygen saturation (SpO2) <90%, post-procedural respiratory complications (PRC) as well as intra-procedural hypocarbia and hypotension. Multivariable negative binomial and logistic regression analyses, adjusted for patient and procedural characteristics, were applied.

MAIN RESULTS

1157 patients (63%) received HFJV for a median (interquartile range [IQR]) duration of 307 (253-360) minutes. The median (IQR) length of stay in the PACU was 244 (172-370) minutes in patients who underwent ablation with conventional mechanical ventilation and 226 (163-361) minutes in patients receiving HFJV. In adjusted analyses, patients undergoing HFJV had a longer PACU length of stay (adjusted absolute difference: 37.7 min; 95% confidence interval [CI] 9.7-65.8; p = 0.008). There was a higher risk of intra-procedural hypocarbia (adjusted odds ratio [ORadj] 5.90; 95%CI 2.63-13.23; p < 0.001) and hypotension (ORadj 1.88; 95%CI 1.31-2.72; p = 0.001) in patients undergoing HFJV. No association was found between the use of HFJV and intra-procedural hypoxemia or PRC (p = 0.51, and p = 0.97, respectively).

CONCLUSION

After confounder adjustment, HFJV for catheter ablation procedures for treatment of atrial fibrillation was associated with a longer length of stay in the PACU. It was further associated with an increased risk of intra-procedural abnormalities including abnormal carbon dioxide homeostasis, as well as intra-procedural arterial hypotension.