Prediction of hemodynamic fluctuations after induction of general anesthesia using propofol in non-cardiac surgery: a retrospective cohort study

Effectiveness of different doses of dexmedetomidine on intraoperative haemodynamic profiles and postoperative pain in patients undergoing abdominal surgery at Dilla University Referral Hospital, Ethiopia, 2024: a double-blind randomized controlled trial

Background and objective

Abdominal surgery stands as one of the most frequently conducted procedures across surgical specialties, accounting for up to half of surgery-related expenses. Hemodynamic instability emerges as a significant concern during anaesthesia and surgery, provoked by the stress of intubation, surgical incision, and anaesthetic agents. Following abdominal surgery, pain is an inevitable consequence, typically managed with opioid-based analgesia. However, the adverse effects associated with opioids often overshadow their analgesic benefits, particularly in the context of abdominal surgery. Consequently, there exists a necessity to explore and assess alternative non-opioid pain management options post-abdominal surgery as part of a broader strategy to reduce opioid usage. The primary aim of this investigation is to assess the effectiveness of varying doses of dexmedetomidine in regulating intraoperative hemodynamics and alleviating postoperative pain in patients undergoing abdominal surgery.

Methods

Ethical clearance and institutional review board were obtained from the ethical clearance committee of Dilla University College of Medicine and Health Sciences with protocol unique number of duirb/008/22-01. Our trial has been prospectively registered on the Pan African Clinical Trial Registry with a unique identification number for the registry PACTR202208813896934. Statistical package and analysis were performed by using SPSS version 25. The distribution of data was checked by using Shapiro-Wilk test and the homogeneity of variance was checked by Levene's test. Analysis of variance (ANOVA) and Kruskal-Wallis H test were used for normally distributed continuous data and non-normally distributed or non-parametric data, respectively. P value less than 0.05 with a power of 90% was considered statistically significant.

Result

There was a statistically significant increase in mean SBP in the control group at the different critical time points (P<0.05), as compared to the baseline value, while there was no significant difference in mean systolic blood pressure (SBP) between the baseline and all other levels for group 2 and group 3. A statistically significant increase in mean arterial pressure (MAP) was detected in the control group at immediately after intubation (P=0.009) as compared to the baseline value, while a statistically significant reduction in mean heart rate (HR) was observed in group 3 at 15th min after infusion and at 30th 30 min after induction compared to baseline with a P value of 0.002 and 0.008, respectively.Conclusion:Perioperative low-dose infusion of dexmedetomidine at the rate of 0.4 mcg/kg/h is a useful anaesthesia adjuvant to control hemodynamic stress response to critical periods. It is wise to use this infusion dose as part of general anaesthesia to achieve better hemodynamic stability.

Machine learning approach for predicting post-intubation hemodynamic instability (PIHI) index values: towards enhanced perioperative anesthesia quality and safety

BACKGROUND

Adequate preoperative evaluation of the post-intubation hemodynamic instability (PIHI) is crucial for accurate risk assessment and efficient anesthesia management. However, the incorporation of this evaluation within a predictive framework have been insufficiently addressed and executed. This study aims to developed a machine learning approach for preoperatively and precisely predicting the PIHI index values.

METHODS

In this retrospective study, the valid features were collected from 23,305 adult surgical patients at Peking Union Medical College Hospital between 2012 and 2020. Three hemodynamic response sequences including systolic pressure, diastolic pressure and heart rate, were utilized to design the post-intubation hemodynamic instability (PIHI) index by computing the integrated coefficient of variation (ICV) values. Different types of machine learning models were constructed to predict the ICV values, leveraging preoperative patient information and initiatory drug infusion. The models were trained and cross-validated based on balanced data using the SMOTETomek technique, and their performance was evaluated according to the mean absolute error (MAE), root mean square error (RMSE), mean absolute percentage error (MAPE) and R-squared index (R2).

RESULTS

The ICV values were proved to be consistent with the anesthetists' ratings with Spearman correlation coefficient of 0.877 (P < 0.001), affirming its capability to effectively capture the PIHI variations. The extra tree regression model outperformed the other models in predicting the ICV values with the smallest MAE (0.0512, 95% CI: 0.0511-0.0513), RMSE (0.0792, 95% CI: 0.0790-0.0794), and MAPE (0.2086, 95% CI: 0.2077-0.2095) and the largest R2 (0.9047, 95% CI: 0.9043-0.9052). It was found that the features of age and preoperative hemodynamic status were the most important features for accurately predicting the ICV values.

CONCLUSIONS

Our results demonstrate the potential of the machine learning approach in predicting PIHI index values, thereby preoperatively informing anesthetists the possible anesthetic risk and enabling the implementation of individualized and precise anesthesia interventions.

Relationship between preinduction electroencephalogram patterns and propofol sensitivity in adult patients

PURPOSE

To determine the precise induction dose, an objective assessment of individual propofol sensitivity is necessary. This study aimed to investigate whether preinduction electroencephalogram (EEG) data are useful in determining the optimal propofol dose for the induction of general anesthesia in healthy adult patients.

METHODS

Seventy healthy adult patients underwent total intravenous anesthesia (TIVA), and the effect-site target concentration of propofol was observed to measure each individual's propofol requirements for loss of responsiveness. We analyzed preinduction EEG data to assess its relationship with propofol requirements and conducted multiple regression analyses considering various patient-related factors.

RESULTS

Patients with higher relative delta power (ρ = 0.47, p < 0.01) and higher absolute delta power (ρ = 0.34, p = 0.01) required a greater amount of propofol for anesthesia induction. In contrast, patients with higher relative beta power (ρ = -0.33, p < 0.01) required less propofol to achieve unresponsiveness. Multiple regression analysis revealed an independent association between relative delta power and propofol requirements.

CONCLUSION

Preinduction EEG, particularly relative delta power, is associated with propofol requirements during the induction of general anesthesia. The utilization of preinduction EEG data may improve the precision of induction dose selection for individuals.

Coronary Artery Occlusion with Sharp Blood Pressure Drop during General Anesthesia Induction: A Case Report

Most anesthetics reduce cardiac functions and lower blood pressure (BP), potentially causing excessive BP reduction in dehydrated patients or those with heart conditions, such as coronary artery disease (CAD). Considering the increased prevalence of cardiovascular disease with age, anesthesiologists must be cautious about BP reduction during general anesthesia in older adults. In the present case, a 76-year-old male patient with undiagnosed CAD in a hypovolemic state experienced a significant drop in systolic BP to the fifties during propofol and sevoflurane anesthesia. Despite the use of vasopressors, excessive hypotension persisted, leading to anesthesia suspension. Subsequent cardiac examinations, including computed tomography heart angio and calcium score, and coronary angiogram, revealed a near total occlusion of the proximal left anterior descending coronary artery (pLAD) and the formation of collateral circulation. After 5 days of hydration and anticoagulation medications and confirmation of normovolemic state, general anesthesia was attempted again and successfully induced; a normal BP was maintained throughout the surgery. Thus, it is important to conduct a thorough cardiac evaluation and maintain normovolemia for general anesthesia in older adults.

Comparison of the hemodynamic effects of opioid-based versus lidocaine-based induction of anesthesia with propofol in older adults: a randomized controlled trial

BACKGROUND

The present study aims to compare the hemodynamic profile of lidocaine and fentanyl during propofol induction of general anesthesia.

METHODS

This randomized controlled trial included patients aged above 60 years undergoing elective non-cardiac surgery. The included patients received either 1 mg/kg lidocaine (n = 50) or 1 mcg/kg fentanyl (n = 50) based on total body weight with propofol induction of anesthesia. Patient's hemodynamics were recorded every minute for the first 5 min then every 2 min until 15 min after induction of anesthesia. Hypotension (mean arterial pressure [MAP] <65 mmHg or >30% reduction from baseline) was treated by intravenous 4 mcg bolus of norepinephrine. Outcomes included norepinephrine requirements (primary), the incidence of postinduction hypotension, MAP, heart rate, intubation condition, and postoperative delirium via the cognitive assessment method.

RESULTS

Forty-seven patients in the lidocaine group and 46 patients in the fentanyl group were analyzed. None in the lidocaine group experienced hypotension, while 28/46 (61%) of patients in the fentanyl group developed at least one episode of hypotension requiring a median (25th and 75th quartiles) norepinephrine dose of 4 (0,5) mcg, p-value <0.001 for both outcomes. The average MAP was lower in the fentanyl group than in the lidocaine group at all time points after anesthesia induction. The average heart rate was comparable between the two groups nearly at all time points after anesthesia induction. The overall intubation condition was comparable between the two groups. None of the included patients developed postoperative delirium.

CONCLUSION

Lidocaine-based regimen for induction of anesthesia reduced the risk of postinduction hypotension in older patients compared to the fentanyl-based regimen.

The effect of age on the induction dose of propofol for general anesthesia in dogs

OBJECTIVE

In people, the dose of propofol (DOP) required for procedural sedation and anesthesia decreases significantly with age. The objective of this study was to determine if the DOP required to perform endotracheal intubation decreases with age in dogs.

STUDY DESIGN

Retrospective case series.

ANIMALS

1397 dogs.

METHODS

Data from dogs anesthetized at referral center (2017-2020) were analyzed with three multivariate linear regression models with backward elimination using a combination of either absolute age, physiologic age, or life expectancy (ratio between age at the time of anesthetic event and expected age of death for each breed obtained from previous literature) as well as other factors as independent variables, and DOP as the dependent variable. The DOP for each quartile of life expectancy (<25%, 25-50%, 50-75%, 75-100%, >100%) was compared using one-way ANOVA. Significance was set at alpha = 0.025.

RESULTS

Mean age was 7.2 ± 4.1 years, life expectancy 59.8 ± 33%, weight 19 ± 14 kg, and DOP 3.76 ± 1.8 mg kg-1. Among age models, only life expectancy was a predictor of DOP (-0.37 mg kg-1; P = 0.013) but of minimal clinical importance. The DOP by life age expectancy quartile was 3.9 ± 2.3, 3.8 ± 1.8, 3.6 ± 1.8, 3.7 ± 1.7, and 3.4 ± 1.6 mg kg-1, respectively (P = 0.20). Yorkshire Terrier, Chihuahua, Maltese, mixed breed dogs under 10 kg, and Shih Tzu required higher DOP. Status of neutered male, ASA E, and Boxer, Labrador and Golden Retriever breeds decreased DOP, along with certain premedication drugs.

CONCLUSIONS AND CLINICAL RELEVANCE

In contrast to what is observed in people, an age cut-off predictive of DOP does not exist. Percentage of elapsed life expectancy along with other factors such as breed, premedication drug, emergency procedure, and reproductive status significantly alter DOP. In older dogs, the dose of propofol can be adjusted based on their elapsed life expectancy.

Inducción Anestésica: Propofol, Ketamina o Ketofol ¿Cuándo utilizarlos?

Introducción: La anestesia general se subdivide en diferentes etapas donde una de las más importantes es la etapa de la inducción anestésica y los fármacos que se utilizan en ella, siendo el Propofol y la Ketamina los más nombrados Objetivo: Realizar una revisión de las propiedades farmacocinéticas y farmacodinámicas de estos dos medicamentos, para la toma de decisiones sobre en qué situaciones debería usarse cada uno de ellos o de forma concomitante Materiales y métodos: Se realizaron 4 búsquedas separadas en la base de datos de PUBMED, obteniendo un total de 27 bibliografías utilizadas para la revisión. Resultados: El propofol es un agente hipnótico útil para procedimientos cortos, en pacientes estables hemodinámicamente. La ketamina tiene un perfil farmacodinámico ideal para pacientes con inestabilidad hemodinámica. El ketofol es una alternativa que logra adecuado sinergismo permitiendo mantener los beneficios de cada uno de estos medicamentos y disminuyendo la probabilidad de efectos adversos. Conclusión: Dependiendo de la cirugía que se vaya a realizar y de la estabilidad hemodinámica de cada paciente se puede preferir un medicamento sobre otro.

TRPA1 Polymorphisms Modify the Hypotensive Responses to Propofol with No Change in Nitrite or Nitrate Levels

Anesthesia with propofol is frequently associated with hypotension. The TRPA1 gene contributes to the vasodilator effect of propofol. Hypotension is crucial for anesthesiologists because it is deleterious in the perioperative period. We tested whether the TRPA1 gene polymorphisms or haplotypes interfere with the hypotensive responses to propofol. PCR-determined genotypes and haplotype frequencies were estimated. Nitrite, nitrates, and NOx levels were measured. Propofol induced a more expressive lowering of the blood pressure (BP) without changing nitrite or nitrate levels in patients carrying CG+GG genotypes for the rs16937976 TRPA1 polymorphism and AG+AA genotypes for the rs13218757 TRPA1 polymorphism. The CGA haplotype presented the most remarkable drop in BP. Heart rate values were not impacted. The present exploratory analysis suggests that TRPA1 genotypes and haplotypes influence the hypotensive responses to propofol. The mechanisms involved are probably other than those related to NO bioavailability. With better genetic knowledge, planning anesthesia with fewer side effects may be possible.

Effect of Propofol Intravenous Anesthesia Combined with Press-Needle Therapy on Analgesic Effect during Painless Abortion

Objective

To discover the effect of propofol intravenous anesthesia along with press-needle therapy on analgesic effect during painless abortion.

Methods

A total of 128 cases who experienced painless abortion in our hospital from January 2019 to August 2021 were recruited as the research subjects. They were categorized into control and observation groups through the haphazard number table approach, with 64 patients in each group. Propofol intravenous anesthesia was given to the control group, and the observation group was given combined anesthesia with press-needle on this basis. Ramsay score, hemodynamic indexes, operation-related indexes, and postoperative recovery were studied between the two groups before anesthesia (T0), at the time of uterine aspiration (T1), promptly following the operation (T2), and at the recovery time of directional force (T3). The stress state and the level of pain mediators in the two groups of sufferers were observed at each time period, and the visual analogue scale (VAS) was employed to assess the degree of postoperative uterine contraction pain.

Results

Ramsay score at T1 and T2 time points in observation group was lesser than that in control group (P < 0.05). There existed no meaningful discrepancies in operation time and recovery time between both groups (P > 0.05). The total dosage of propofol in the observation group was lesser compared to that in the control group, and the recovery time of directional force was much shorter compared to that in the control group (P < 0.05). There existed no meaningful discrepancies in perioperative diastolic blood pressure (DBP), systolic blood pressure (SBP), and heart rate (HR) between both groups (P > 0.05). The levels of norepinephrine (NE), cortisol (Cor), glucose (GLU) and substance P (SP), prostaglandin E2 (PGE2), and 5-hydroxytryptophan (5-HT) in the observation group were lesser than those in the control group immediately after surgery and 24 hours following the operation (P < 0.05). There existed no meaningful discrepancies in vaginal bleeding time, endometrial thickness 3 weeks after operation, and time to start menstruating between both groups (P > 0.05). The score of VAS for the observation group was lesser than that of the control group at 10 min and 30 min after operation (P < 0.05). There existed no substantial discrepancy in the incidence of negative reactions between both groups (P > 0.05).

Conclusion

Propofol intravenous anesthesia combined with press-needle therapy can ameliorate the analgesic impacts during painless abortion, reduce postoperative uterine contraction pain, inhibit the release of postoperative pain mediators, and improve the stress state of the body.

Application effects of remimazolam and propofol on elderly patients undergoing hip replacement

Objective

To explore the anesthetic and analgesic effects of remimazolam and propofol in elderly patients undergoing hip replacement and their effects on respiratory and circulatory systems, stress and cognitive function.

Methods

Sixty elderly patients undergoing elective hip replacement in the hospital were selected as the research subjects, and they were divided into the remimazolam group and the propofol group according to the admission sequence of patients. The remimazolam group was anesthetized with remimazolam, and the propofol group was anesthetized with propofol. The anesthesia-related indicators, perioperative pain degree [Visual Analogue Scale (VAS)], circulatory indicators [heart rate, mean arterial pressure (MAP)] before anesthesia (T₀), immediately before laryngeal mask insertion (T₁), at 5 min after laryngeal mask insertion (T₂), at 30 min after laryngeal mask insertion (T₃) and at 5 min after laryngeal mask removal (T₄), stress response indicators (plasma epinephrine, norepinephrine, cortisol) before anesthesia induction and at 24 h and 72 h after surgery, cognitive function [Mini-Mental State Examination (MMSE)] and adverse reactions were compared between the two groups.

Results

Among the 60 enrolled patients, only 1 case was excluded due to withdrawal, thus 30 cases in the remimazolam group and 29 cases in the propofol group were included. There were statistically significant differences in the heart rate, MAP, plasma epinephrine, norepinephrine, cortisol and VAS score in the two groups from the aspects of interaction effect and time-point effect (P < 0.05). The heart rate and MAP at T₁, T₂ and T₃ in the two groups were significantly decreased compared with those at T₀, but the heart rate and MAP in the remimazolam group at T₁, T₂ and T₃ were significantly higher than those in the propofol group (P < 0.05). There were no statistical differences in the anesthesia time, awakening time and extubation time between the remimazolam group and the propofol group (P > 0.05). The levels of plasma epinephrine, norepinephrine and cortisol in the two groups were significantly higher at 24 h and 72 h after surgery than those before anesthesia induction, and the above levels were significantly lower in the remimazolam group than those in the propofol group (P < 0.05). The VAS scores at each time point in the two groups were significantly reduced compared to before surgery, but there was no statistically significant difference between the two groups after surgery (P > 0.05). The MMSE scores of the two groups were significantly lower at 1 d and 3 d after surgery compared with those before anesthesia induction, but the score in the remimazolam group was significantly higher than that in the propofol group (P < 0.05). In addition, the incidence rates of adverse reactions were significantly lower in the remimazolam group compared to the propofol group (P < 0.05).

Conclusion

Compared with propofol, remimazolam can achieve equivalent anesthetic and analgesic effects in elderly patients undergoing hip replacement. However, the latter one can significantly relieve respiratory and circulatory suppression, stress response and cognitive dysfunction, with good safety.

Trial registration

This single-center, prospective, RCT has completed the registration of the Chinese Clinical Trial Center at 31/12/2021 with the registration number ChiCTR2100055039.

Preoperative ultrasonographic evaluation of subclavian vein and inferior vena cava for predicting hypotension associated with induction of general anesthesia

Introduction:

Induction of general anesthesia is often associated with hypotension and is a common scenario faced by anesthesiologists. Intraoperative hypotension can have detrimental effects and cause various adverse effects leading to an extended hospital stay. Patients' preinduction volume status can have an effect on postinduction blood pressure. Ultrasonography is a useful tool for measuring intravascular volume status. We studied the ability of ultrasonographic measurement of subclavian vein (SCV) and inferior vena cava (IVC) diameter, collapsibility index (CI) to predict hypotension after induction of general anesthesia.

Materials and Methods:

We included 120 patients in our study. SCV measurements during spontaneous and deep inspiration and IVC measurements were taken before induction and postinduction blood pressure was monitored. Patients with mean arterial blood pressure <60 mmHg or with a 30% decrease from baseline were considered to be having hypotension.

Results:

The CI of IVC with a cutoff 37% showed sensitivity of 94% and specificity of 84% which was statistically significant. The CI of 36% of SCV during deep breathing was found to have high sensitivity and specificity of 90% and 87%.

Conclusion:

Our study in spontaneously breathing preoperative patients shows that SCV CI in deep breathing and IVC CI is very sensitive and reliable in predicting postinduction hypotension. Bedside ultrasound measurements can be easily done to obtain valuable information to recognize patients who could be at risk from postinduction hypotension.

"Awake" Spinal Cord Monitoring Under Local Anesthesia and Conscious Sedation in Fenestrated and Branched Endovascular Aortic Repair

INTRODUCTION

Endovascular repair of thoracoabdominal aortic aneurysms carries a risk of spinal cord ischemia, the causes of which remain uncertain. We hypothesized that local anesthesia (LA) with conscious sedation could abrogate the potential suppressive cardiovascular effects of general anesthesia (GA) and facilitate intraoperative monitoring of neurological function. Here, we examine the feasibility of this technique during fenestrated (FEVAR) or branched endovascular aortic repair (BEVAR).

MATERIALS AND METHODS

Consecutive patients undergoing FEVAR or BEVAR under LA and conscious sedation by a team at a single center were analyzed. Patients received conscious sedation using intravenous remifentanil and propofol infusions in conjunction with a local anesthetic agent. No patient had a prophylactic spinal drain inserted. Outcome measures included conversion to GA, need for vasopressors and/or spinal drainage, length of stay, complications, and patient survival.

RESULTS

A total of 44 patients underwent FEVAR or BEVAR under LA and conscious sedation. The cohort included thoracoabdominal aortic aneurysms (n=41) and pararenal aneurysms treated with endografts covering the supraceliac segment (n=3). Four patients (9%) required conversion to GA at a median operative duration of 198 minutes (range 97-495 minutes). Vasopressors were required intraoperatively in 3 of the cases that were converted to GA. No patient developed spinal cord ischemia and none had insertion of a spinal drain. The median hospital length of stay was 4 days (range 2-41 days). Postoperative delirium and hospital-acquired pneumonia was seen in 7% of patients. All patients survived to 30 days, with 95% alive at a median follow-up of 15 months (range 3-26 months).

CONCLUSION

LA and conscious sedation is a feasible anesthetic technique for the endovascular repair of thoracoabdominal aortic aneurysms.

Gene-gene interactions in the protein kinase C/endothelial nitric oxide synthase axis impact the hypotensive effects of propofol

Anaesthesia with propofol is frequently associated with hypotension, which is at least partially attributable to increased nitric oxide (NO) formation derived from the activation of protein kinase C (PKC)/endothelial NO synthase (NOS3) axis. In this cross-sectional study, we tested whether PRKCA (which encodes PKCα) polymorphisms, or haplotypes, and interactions among PRKCA and NOS3 polymorphisms affect the hypotensive responses to propofol. We collected venous blood samples from 164 patients before and 10 min after propofol administration. Genotypes were determined by PCR and haplotype frequencies were estimated. Nitrite and NO_x (nitrites+nitrates) levels were measured by using an ozone-based chemiluminescence assay and the Griess reaction, respectively. We used multifactor dimensionality reduction to test interactions among PRKCA and NOS3 polymorphisms. Propofol promoted enhanced blood pressure-lowering effects and increased nitrite levels in subjects carrying GA + AA genotypes for the rs16960228 and TC + CC genotypes for the rs1010544 PRKCA polymorphisms, and the CCG haplotype. Moreover, genotypes for the rs1010544 PRKCA polymorphism were associated with higher or lower blood pressure decreases in response to propofol depending on the genotypes for the rs2070744 NOS3 polymorphism. Our findings suggest that PRKCA genotypes and haplotypes impact the hypotensive responses to propofol, possibly by modifying NO bioavailability, and that PRKCA-NOS3 interactions modify the blood pressure-lowering effects of propofol.

Measurements of Cardiac Output and Management of Blood Transfusions During Burn Surgery-An Observational Prospective Study

Burn surgery can cause extensive bleeding, which lead to perioperative blood transfusions. The purpose of this study was to investigate whether blood transfusions during burn surgery, guided by standard monitoring with inspection of the operative field, measurements of blood pressure, heart rate, hourly diuresis, and concentrations of hemoglobin and lactate could sustain the preoperative cardiac output (CO) till end of surgery. We investigated 15 patients ≥18 years of age scheduled for burn surgery, where the perioperative monitoring included an arterial line. After induction of anesthesia and before start of surgery, we measured baseline values of CO with the minimally invasive LiDCOrapid, mean arterial pressure, and concentrations of hemoglobin and lactate in arterial blood. We measured these values every 30 minutes through surgery. The primary outcome was change in CO from baseline till end of surgery. Secondary outcomes included the change in concentrations of hemoglobin and lactate from baseline till end of surgery. We found no statistically significant change in CO from baseline till end of surgery (6.6 [±2.4] liters/min; 7.2 [±3.2] liters/min; P = .26). We found a statistically significant decrease in concentration of hemoglobin (7.2 [±0.8] mmol/liter; 6.2 [±0.9] mmol/liter; P = .0002), and a statistically significant increase in concentration of lactate (1.3 [±0.5] mmol/liter; 1.7 [±1] mmol/liter; P = .02). The perioperative blood transfusion guided by standard monitoring seemed to sustain CO from baseline till end of surgery; however, further research is needed to confirm this.

QA project: Hemodynamic safety of endobronchial administration of phenylephrine for control of airway bleeding by bronchoscopy

BACKGROUND

Phenylephrine has been administered endobronchially for airway bleeding during bronchoscopy as an alternative to epinephrine. Topical phenylephrine, often used in nasal surgery as a vasoconstrictor agent has been linked to cardiovascular morbidity.

OBJECTIVE

To evaluate the safety of bronchoscopic instillation of phenylephrine during bronchoscopy.

METHODS

We retrospectively reviewed patients who received endobronchial phenylephrine in our endoscopy suite. We compared the changes in blood pressure and heart rate before and after endobronchial phenylephrine administration. The safety of endobronchial phenylephrine was assessed with regards to the changes in hemodynamics and acute cardiovascular event, and 30-day mortality. Acute cardiovascular complications included acute coronary syndrome, aortic dissection, tachyarrhythmias, pulmonary edema and stroke.

RESULTS

We identified 30 patients who received endobronchial phenylephrine 100mcg/ml with a mean total volume of 6.5 ± 10.6 ml. They were given mainly for balloon dilation and cryobiopsy procedure (96.7%). On excluding patients who received concurrent IV pressor, there was a statistically significant increase of mean arterial pressure (MAP) by 12 ± 21 mmHg, p = 0.01 within 30 min of endobronchial phenylephrine compared to procedure day MAP baseline. There was 27% of patients with more than 20% increase in their MAP but none of the patients had MAP more than 140 nor the occurrence of acute cardiovascular event. There was no significant change in the patients' heart rate following endobronchial phenylephrine.

CONCLUSION

In our review, endobronchial phenylephrine with dose comparable to IV administration can cause significant raise in MAP but their absolute levels did not go beyond 180/120 mmHg nor resulted in acute cardiovascular complications.

Outcomes of Transfemoral Transcatheter Aortic Valve Replacement Performed With General Anesthesia Using a Supraglottic Airway Versus Monitored Anesthesia Care

OBJECTIVE

Compare general anesthesia with a supraglottic airway versus monitored anesthesia care for transfemoral transcatheter aortic valve replacement (TF-TAVR) in patients with aortic stenosis. The authors hypothesized that the supraglottic airway group would have similar operating room and procedure times, postanesthesia care unit (PACU) and hospital stays, and similar rates of intraprocedural and postprocedural complications compared with the monitored anesthesia care group.

STUDY DESIGN

Retrospective chart review with 1:1 propensity score matching of supraglottic airway to monitored anesthesia care patients.

SETTING

Tertiary care academic medical center.

PARTICIPANTS

TF-TAVR patients between 2017 and 2019.

INTERVENTIONS

Supraglottic airway or monitored anesthesia care.

MEASUREMENTS AND MAIN RESULTS

One hundred forty-eight supraglottic airway patients were matched with 148 monitored anesthesia care patients. Monitored anesthesia care patients had slightly shorter operating room (p < 0.001) and procedure times (p = 0.015). No difference was observed in hospital length of stay (p = 0.34). Fewer patients in the supraglottic airway group required a PACU stay >2 hours (p < 0.001). Use of intraprocedural vasopressors (p < 0.001) and fentanyl dosage (p < 0.001) was higher in the supraglottic airway group. No differences were observed in postoperative complications or procedural success rates.

CONCLUSIONS

In this, the first study to compare these 2 modalities, supraglottic airway use was demonstrated to be a safe, feasible alternative to monitored anesthesia care during TF-TAVR and did not increase organ-specific morbidity, 30-day mortality, hospital length of stay, or PACU length of stay. Even though supraglottic airway was associated with slight increases in procedure and operating room times, these were not clinically significant.

Pre-anaesthesia ultrasonography of the subclavian/infraclavicular axillary vein for predicting hypotension after inducing general anaesthesia: A prospective observational study

BACKGROUND

Bedside sonography of the inferior vena cava has been demonstrated to be a reliable tool for assessing intravascular volume status. Subclavian vein (SCV) assessment was proposed as a reasonable adjunct for measuring the inferior vena cava.

OBJECTIVE

We examined whether the preoperative diameter and collapsibility index of the SCV or the infraclavicular axillary vein could predict the incidence of hypotension after induction of general anaesthesia in patients undergoing laparoscopic cholecystectomy.

DESIGN

Prospective, observational study.

SETTING

Tertiary university hospital.

PATIENTS

Adults scheduled for laparoscopic cholecystectomy.

INTERVENTION

Sonographic evaluation of the SCV or the axillary vein (SCV-AV) before induction of anaesthesia.

MAIN OUTCOME MEASURES

The main outcome was the association between the SCV-AV measurements (diameter an collapsibility index) and intra-operative hypotension (IOH) after induction of anaesthesia.

RESULTS

Patients who developed IOH had a higher collapsibility index of the SCV-AV during spontaneous breathing (P = 0.009) and deep inspiration (P = 0.002). After adjusting for confounding variables, the collapsibility index of the SCV-AV during spontaneous breathing was not a significant predictor of a decrease in mean arterial blood pressure (MAP) after inducing anaesthesia (P = 0.127), whereas the collapsibility index of the SCV-AV during deep inspiration was a significant predictor (P < 0.001).

CONCLUSION

The collapsibility index of the SCV-AV during deep inspiration was a significant predictor of IOH occurrence and the percentage decrease in MAP after inducing anaesthesia. Further studies in patients with higher collapsibility index are needed to confirm our findings, before the collapsibility index of the SCV-AV can be recommended unequivocally for clinical use.

TRIAL REGISTRATION

This trial was registered on 8 September 2017 at the Clinical Trial Registry of Korea (https://cris.nih.go.kr/cris/index.jsp; Identifier: KCT0001078KCT0002457), and the first patient was enrolled on 14 October 2017.

Anesthetic Agents Isoflurane and Propofol Decrease Maximal Ca2+-Activated Force and Thus Contractility in the Failing Myocardium

In the normal heart, frequently used anesthetics such as isoflurane and propofol can reduce inotropy. However, the impact of these agents on the failing myocardium is unclear. Here, we examined whether and how isoflurane and propofol influence cardiac contractility in intact cardiac muscles from rats treated with monocrotaline to induce heart failure. We measured force and intracellular Ca²⁺ ([Ca^{2 +}]_i) in trabeculae from the right ventricles of the rats in the absence or presence of propofol or isoflurane. At low to moderate concentrations, both propofol and isoflurane dose-dependently depressed cardiac force generation in failing trabeculae without altering [Ca²⁺]_i At high doses, propofol (but not isoflurane) also decreased amplitude of [Ca²⁺]_i transients. During steady-state activation, both propofol and isoflurane impaired maximal Ca²⁺-activated force (F_max) while increasing the amount of [Ca²⁺]_i required for 50% of maximal activation (Ca₅₀). These events occurred without apparent change in the Hill coefficient, suggesting no impairment of cooperativity. Exposing these same muscles to the anesthetics after fiber skinning resulted in a similar decrement in F_max and rise in Ca₅₀ but no change in the myofibrillar ATPase-Ca²⁺ relationship. Thus, our study demonstrates that challenging the failing myocardium with commonly used anesthetic agents such as propofol and isoflurane leads to reduced force development as a result of lowered myofilament responsiveness to Ca²⁺ SIGNIFICANCE STATEMENT: Commonly used anesthetics such as isoflurane and propofol can impair myocardial contractility in subjects with heart failure by lowering myofilament responsiveness to Ca²⁺. High doses of propofol can also reduce the overall amplitude of the intracellular Ca²⁺ transient. These findings may have important implications for the safety and quality of intra- and perioperative care of patients with heart failure and other cardiac disorders.