Various opioids are added to local anesthetic solutions for spinal anesthesia. This may change the final density of the local anestetic (LA) mixture. This effect regarding current concepts in spinal anesthesia needs to be re-evaluated. In order to re-evaluate such effects, hyperbaric and isobaric local anesthetic (LA) solutions were mixed with opioid adjuvants (A) using the equipment available in the operating room. Ten density measurements for each composition (LA-A) were performed. The density change of 0.0006 g/mL was regarded as significant. Measured densities were also compared with theoretical values calculated using Hare’s. As a result, the addition of an opioid adjuvant caused a significant reduction in the final density of the LA-A solution. In hyperbaric LA mixtures, it did not change the baricity from hyperbaric to isobaric. However, the addition of highly hypobaric fentanyl 0.99360 g/mL (SD ± 0.00004) changes all isobaric LA solutions baricity to hypobaric. The comparison of measured and theoretical densities revealed significant differences (p > 0.05). However, the absolute reduction reached 0.0006 g/mL in only two LA-A compositions. We conclude that the addition of fentanyl to isobaric LA results in a hypobaric solution that may affect the distribution of the block. The inadequacy of LA-A in a clinical setting is unlikely to influence block characteristics.
15 December 2020 in Anaesthesiology Intensive Therapy
The SARS-CoV-2-related disease has an undoubted impact on the healthcare system. In the treatment of severe COVID-19 cases, the main focus is on respiratory failure. However, available data suggest an important contribution of haemodynamic impairment in the course of this disease. SARS-CoV-2 may affect the circulatory system in various ways that are universal for septic conditions. Nonetheless, unique features of this pathogen, e.g. direct insult leading to myocarditis and renin-angiotensin-aldosterone axis dysregulation, must be taken into account. Although current recommendations on COVID-19 resemble previous septic shock guidelines, special attention to haemodynamic monitoring and treatment is necessary. Regarding treatment, one must take into account the potential profound hypovolaemia of severe COVID-19 patients. Pharmacological cardiovascular support should follow existing guidelines and practice. Interesting concepts of decatecholaminisation and the effect of vasopressors on pulmonary circulation are also presented in this review on COVID-19-related haemodynamic failure.
Dexmedetomidine, a central α-2 agonist, is used for procedural sedation and for conscious sedation influences on heart rate and blood pressure. Authors verified whether it is possible to predict bradycardia and hypotension with the use of heart rate variability (HRV) analysis for an autonomic nervous system (ANS) activity assessment. The study included adult patients of both sexes with an ASA score of I or II scheduled for ophthalmic surgery to be performed under sedation. The loading dose of dexmedetomidine was followed by a 15 min infusion of the maintenance dose. The frequency domain heart rate variability parameters from the 5-min Holter electrocardiogram recordings before dexmedetomidine administration were used for the analysis. The statistical analysis also included pre-drug heart rate and blood pressure as well as patient age and sex. The data from 62 patients were analysed. There was no relationship between the decrease in heart rate (42% of cases) and initial HRV parameters, haemodynamic parameters or sex and age of patients. In multivariate analysis, the only risk factor for a decrease in mean arterial pressure (MAP) > 15% from the pre-drug value (39% of cases) was the systolic blood pressure before dexmedetomidine administration as well as for a >15% decrease in MAP sustained at more than one consecutive time point (27% of cases). The initial condition of the ANS did not correlate with the incidence of bradycardia or hypotension; HRV analysis was not helpful in predicting the abovementioned side effects of dexmedetomidine.
Background: Placenta accreta spectrum (PAS) is a condition in which villous tissue pathologically adheres to or invades the uterine wall, which may result in massive bleeding with substantial maternal morbidity and mortality. Despite the constantly increasing prevalence of this condition, an optimal anesthetic management method for this condition has not been fully established. A scoping review of the literature was performed to evaluate current anesthetic management strategies for PAS. Methods: This review was conducted using the Joanna Briggs Institute (JBI) methodology for scoping reviews. A search of five databases (MEDLINE, EMBASE, CINAHL Complete, Scopus, and Web of Science) was conducted to identify articles containing data on seven prespecified aspects of PAS anesthetic management. Studies that described the management of miscarriage and abortion procedures were excluded. Results: One hundred thirty articles encompassing numerous approaches to PAS management were included in the final review. Data were mostly extracted from case reports (n = 56) and observational studies (n = 64). The most commonly adopted strategy (n = 62) was the creation of a multidisciplinary team comprising various specialists, including anesthesiologists. Conclusions: Due to the limited number of interventional studies, the most effective methods of anesthetic management for this condition could not be fully established. However, the safe and effective anesthetic management of PAS patients is feasible. Future research in this field should focus on resolving the identified knowledge gaps and increasing the quality of published studies.
Introduction Ophthalmic surgery is assumed to be safe, but some operations require general anaesthesia which is associated with a number of potential complications. In addition, adverse cardiovascular symptoms, such as severe slowing of the heart rate and, in some cases, cardiac arrest may occur due to the surgical technique. The aim of this study was to determine whether it is possible to predict the occurrence of oculocardiac reflex (OCR) based on heart rate variability (HRV) analysis for autonomic nervous system (ANS) activity assessment measured prior to the induction of anaesthesia and immediately before eyeball traction. Methods Fifty-two adults of both sexes (age range 18–65 years) with American Society of Anesthesiologists (ASA) physical status class 1 and 2 were enrolled in this study. All patients had underwent episcleral buckling under general anaesthesia. High-frequency (HF) changes in HRV are thought to reflect parasympathetic impulse transmission, whereas low-frequency (LF) changes reflect both sympathetic and parasympathetic activity. However, in practice, LF changes can be considered to reflect sympathetic changes. Thus, the LF/HF ratio reflects the actual balance between sympathetic and parasympathetic activity. Based on that, frequency domain HRV parameters from 5-min Holter electrocardiogram recordings before anaesthesia induction and before eyeball traction were used for the analysis. The statistical analysis also included patient age, sex, ASA status and preanaesthesia and premanoeuvre heart rate and blood pressure. Results Data from 42 patients were analysed. Oculocardiac reflex was observed in 32 patients (76.2%). No difference was found in the analysed parameters between patients with and without oculocardiac reflex. There was no relationship between the incidence of the OCR and the analysed parameters. Conclusion The prediction of OCR based on initial ANS tone was not possible, and the initial heart rate, blood pressure, age, sex, and ASA status were not helpful for the identification of patients at risk of this reflex. Trial registration ClinicalTrials.gov identifier no.: NCT01714362
31 October 2018 in Anaesthesiology Intensive Therapy
Background: Salbutamol is a short acting beta-2 mimetic commonly used among intensive care unit patients. There are data suggesting that his mechanism of action can be a potential factor triggering arrhythmias. The aim of this study was to assess whether nebulized salbutamol causes systemic effects resulting in electrocardiographic alterations associated with atrial fibrillation occurrence in mechanically ventilated patients. Methods: 50 individuals were randomly allocated to receive either 2.5 or 5 mg of nebulized salbutamol for 20 minutes. 60 minutes prior to the start of nebulization, 12 lead surface electrocardiogram has been recorded. Electrocardiographic parameters associated with atrial activity — P wave and PR interval, and their derivates: P wave dispersion and PR interval dispersion were analysed Results: Both doses of inhaled salbutamol caused changes of P wave indices — maximal, minimal and mean P wave duration, from simultaneously recorded leads, and concomitant decrease of P wave dispersion. Prolongation of P wave affected predominantly minimal P wave duration (11.93 ms [95% CI: 8.69–15.17]) comparing with maximal P wave duration (2.61 [95% CI: 021–5.43]). Atrio-ventricular conduction — PR interval was also prolonged, however minimal PR interval duration from simultaneously recorded leads was shortened in group receiving 5 mg of salbutamol. Conclusions: Nebulized salbutamol in ICU patient possess systemic effects which causes changes in P wave indices in surface ECG recordings. This electrophysiological influence may be associated with the increased risk of atrial fibrillation among this group of patients Background: Salbutamol is a short acting beta-2 mimetic commonly used among intensive care unit patients. There are data suggesting that his mechanism of action can be a potential factor triggering arrhythmias. The aim of this study was to assess whether nebulized salbutamol causes systemic effects resulting in electrocardiographic alterations associated with atrial fibrillation occurrence in mechanically ventilated patients. Methods: 50 individuals were randomly allocated to receive either 2.5 or 5 mg of nebulized salbutamol for 20 minutes. 60 minutes prior to the start of nebulization, 12 lead surface electrocardiogram has been recorded. Electrocardiographic parameters associated with atrial activity — P wave and PR interval, and their derivates: P wave dispersion and PR interval dispersion were analysed Results: Both doses of inhaled salbutamol caused changes of P wave indices — maximal, minimal and mean P wave duration, from simultaneously recorded leads, and concomitant decrease of P wave dispersion. Prolongation of P wave affected predominantly minimal P wave duration (11.93 ms [95% CI: 8.69–15.17]) comparing with maximal P wave duration (2.61 [95% CI: 021–5.43]). Atrio-ventricular conduction — PR interval was also prolonged, however minimal PR interval duration from simultaneously recorded leads was shortened in group receiving 5 mg of salbutamol. Conclusions: Nebulized salbutamol in ICU patient possess systemic effects which causes changes in P wave indices in surface ECG recordings. This electrophysiological influence may be associated with the increased risk of atrial fibrillation among this group of patients