Predicting hypotension during anesthesia: Variation in pulse oximetry plethysmography predicts propofol-induced hypotension in children.

BACKGROUND: The development of hypotension on administration of intravenous propofol is common and independently associated with adverse outcomes. Identifying patients with a high risk for anesthesia-induced hypotension may help anesthesiologists prepare for such an event. AIM: The authors hypothesized that propofol-induced hypotension is predictable by variables related to fluid responsiveness and investigated such variables to determine the factors which can predict hypotensive events. METHODS: Patients 3-6 years of age who underwent general were included. Intravenous midazolam 0.1 mg kg-1 was administered as premedication, and preoperative noninvasive blood pressure, heart rate, perfusion index, pleth variability index, and respiratory variation of pulse oximetry plethysmographic waveform were measured. Intravenous propofol 2.5 mg kg-1 was given, and blood pressure was measured 5 times at 1-min intervals. Subjects with significant hypotension (mean blood pressure decrease ≥20%) were allocated to the hypotensive group; those without significant hypotension were allocated to the relatively normotensive group. RESULTS: Of 77 patients, 50 (64.9%) developed significant hypotension. Patients in the hypotensive group exhibited significantly higher respiratory variation of pulse oximetry plethysmographic waveform (mean difference 11 [3.3] [95% confidence interval 4.9-18.1]; p = .001) and higher pleth variability index (mean difference 7.1 [2.8] [95% confidence interval 1.6-12.6]; p = .013) than the normotensive group. The areas under the receiver operating characteristic curve for respiratory variation of pulse oximetry plethysmographic waveform and pleth variability index were 0.722 and 0.649, respectively. CONCLUSION: High preoperative respiratory variation of pulse oximetry plethysmographic waveform and pleth variability index were both independently associated with propofol-induced hypotension in children.

Safety margin for needle placement during lumbar plexus block: An anatomical study using magnetic resonance imaging.

PURPOSE: We aimed to provide anatomic characteristics of the lumbar plexus and a safety margin for needle placement during lumbar plexus block in adults. METHODS: Lumbar spine magnetic resonance images from 377 adults were reviewed. We determined the depth of the lumbar plexus from the needle insertion point for the modified traditional and Capdevila's approaches at the L4 and L5 levels. The relationship of age, height, and body weight with lumbar plexus depth, and the presence of the kidney on the transverse plane at the L4 level were assessed. RESULTS: The lumbar plexus was deeper at the L5 level than at the L4 level for both approaches (mean difference 3.2 mm [95% confidence interval (CI), 2.4 to 4.0] for the modified traditional approach; mean difference 4.4 mm [95% CI, 3.7 to 5.2] for Capdevila's approach). Eighty-six (22.8%) patients had an L4 transverse process shorter than 40 mm, which implies that the needle may not contact the L4 transverse process with the modified traditional approach. The mean (standard deviation) of safety margins for needle insertion, defined as the distance from the posterior aspect of the L4 transverse process to the anterior margin of the psoas muscle, were 45 (8) and 44 (6) mm, respectively for the modified traditional and Capdevila's approach (mean difference, 0.5 mm; 95% CI, -0.1 to 1.1]). The lumbar plexus depth for each approach at the L4 level was predicted using the following equations: Depth (mm) = 87.24 - 0.36 × height (cm) + 0.69 × weight (kg) for the modified traditional approach (r2 = 0.37) and Depth (mm) = 86.51 - 0.35 × height (cm) + 0.61 × weight (kg) for Capdevila's approach (r2 = 0.33). The kidney was observed at the L4 level in 60 (15.9%) patients, with higher incidence in patients over 70 yr and those shorter than 150 cm. CONCLUSION: The surface anatomic relations of the lumbar plexus found in this study may be useful for performing successful and safe lumbar plexus block.

RéSUMé: OBJECTIF: Nous avons cherché à fournir des données anatomiques du plexus lombaire et de la marge de sécurité pour le positionnement de l'aiguille au cours d'un bloc lombaire chez l'adulte. MéTHODES: Les images par résonance magnétique de la colonne vertébrale lombaire de 377 adultes ont été analysées. Nous avons déterminé la profondeur du plexus lombaire à partir du point d'insertion de l'aiguille pour les approches traditionnelle modifiée et de Capdevila aux niveaux L4 et L5. Les corrélations de l'âge, de la taille et du poids corporel avec la profondeur du plexus lombaire et la présence du rein sur le plan de l'apophyse transverse au niveau de L4 ont été évaluées. RéSULTATS: Le plexus lombaire était plus profond à l'étage L5 qu'à l'étage L4 pour les deux approches (différence moyenne : 3,2 mm [intervalle de confiance (IC) à 95 % : 2,4 à 4,0] pour l'approche traditionnelle modifiée; différence moyenne : 4,4 mm [IC à 95 % : 3,7 à 5,2] pour l'approche de Capdevila). Quatre-vingt-six patients (22,8 %) avaient l'apophyse transverse de L4 mesurant moins de 40 mm, ce qui implique que l'aiguille pourrait ne pas faire contact avec cette apophyse avec l'approche traditionnelle modifiée. Les marges de sécurité pour l'insertion de l'aiguille, définies comme étant la distance moyenne (écart-type) entre la face postérieure de l'apophyse transverse de L4 et la marge antérieure du muscle psoas, étaient de 45 (8) mm et 44 (6) mm pour, respectivement, l'approche traditionnelle modifiée et l'approche de Capdevila (différence des moyennes, 0,5 mm; IC à 95 % : −0,1 à 1,1). La profondeur du plexus lombaire pour chaque approche au niveau L4 a été prédite à l'aide des équations suivantes : Profondeur (mm) = 87,24 − 0,36 × taille (cm) + 0,69 × poids (kg) pour l'approche traditionnelle modifiée (r2 = 0,37) et Profondeur (mm) = 86,51 − 0,35 × taille (cm) + 0,61 × poids (kg) pour l'approche de Capdevila (r2 = 0,33). Le rein a été observé au niveau L4 chez 60 patients (15,9 %) avec une plus grande incidence chez les patients âgés de plus de 70 ans et chez ceux dont la taille était inférieure à 150 cm. CONCLUSION: Les rapports anatomiques de la surface du corps et du plexus lombaire identifiés dans cette étude peuvent contribuer à la réalisation d'un bloc lombaire efficace et sécuritaire.

Comparison of rocuronium requirement in children with continuous infusion versus intermittent bolus: A randomised controlled trial.

BACKGROUND: Minimising rocuronium administration during paediatric surgery helps to reduce the incidence of residual muscular blockade. OBJECTIVE: To determine whether intermittent bolus injection (Bolus group) or continuous infusion (group) requires the lesser amount of rocuronium. DESIGN: A randomised, single-blind controlled trial. SETTING: A single university hospital from March to June 2017. PATIENTS: Sixty-six children undergoing general anaesthesia. INTERVENTIONS: Dose of rocuronium for maintenance of muscle relaxation in either Bolus or continuous infusion group. Train-of-four (TOF) count of two was maintained during surgery. When TOF count reached three, 0.1 mg kg of rocuronium was administered in Bolus group or infused at an increased rate of 0.1 mg kg h in continuous infusion group. MAIN OUTCOME MEASURES: Primary outcome was the dose of rocuronium given (µg kg min). The recovery time from the TOF count four to TOF 0.7 (RT0.7), and 0.9 (RT0.9) were recorded. All adverse events were recorded up to 30 min after extubation. RESULTS: Mean (SD) rocuronium dose in the Bolus group was 6.1 (0.9), [95% confidence interval (95% CI) 5.7 to 6.4] µg kg min and 4.9 (1.0), (95% CI 4.6 to 5.3) µg kg min in the continuous infusion group (P = 0.001). RT0.7 was 24.0 (13.7), 95% CI 19.3 to 28.7) min in the Bolus group, and 25.7 (16.0), (95% CI 20.2 to 31.2) min in the continuous infusion group (P = 0.73). RT0.9 was 30.7 (17.1), (95% CI 24.9 to 36.5) min in the Bolus group, and 30.0 (17.6), (95% CI 24.0 to 36.0) min in the continuous infusion group (P = 0.91). The incidence of adverse events was not significantly different between two groups. CONCLUSION: In children undergoing general anaesthesia, the dose of rocuronium given by continuous administration was less than that with intermittent bolus. TRIAL REGISTRATION: ClinicalTrials.gov (identifier: NCT03060707).

Comparison of remifentanil consumption in pupillometry-guided versus conventional administration in children: a randomized controlled trial.

BACKGROUND: Remifentanil is a commonly used opioid analgesic during anesthesia in children. Objective measurement of pain is required for adequate dosing of remifentanil. We investigated whether pupillometry-guided remifentanil administration can reduce intraoperative consumption of remifentanil in children. METHODS: We performed a single-blinded, prospective, randomized controlled trial from December 2018 through June 2019. Children who were 3-12 years of age and classified as having an American Society of Anesthesiologists physical status I-II and undergoing elective surgery under general anesthesia were included. Fifty-six fulfilled the inclusion criteria, and fifty-four completed the study. Participants were randomly assigned to either a pupillometry or conventional group. Patients in both groups received target-controlled infusion of remifentanil. In the pupillometry group, the adjustment of the remifentanil effect site concentration was determined by the pupillary diameter, whereas in the conventional group, the adjustment was based on the anesthesiologist's experience. Primary outcome was intraoperative remifentanil consumption, divided by patient weight and infusion time (ng kg-1 min-1). RESULTS: Remifentanil consumption was reduced by 25% in the pupillometry group compared to the conventional group (116.7±56.0 ng kg-1 min-1 vs. 155.8±64.9 ng kg-1 min-1, respectively; P=0.02). There were no differences in intra- and postoperative blood pressure and heart rate. The incidences of postoperative desaturation or nausea/vomiting were not significantly different. CONCLUSIONS: Pupillometry-guided remifentanil administration in children undergoing general anesthesia can reduce the intraoperative remifentanil consumption.

Microvolt T-wave alternans at the end of surgery is associated with postoperative mortality in cardiac surgery patients.

Microvolt T-wave alternans (MTWA), which reflects electrical dispersion of repolarization, is known to be associated with arrhythmia or sudden cardiac death in high risk patients. In this study we investigated the relationship between MTWA and postoperative mortality in 330 cardiac surgery patients. Electrocardiogram, official national data and electric chart were analysed to provide in-hospital and mid-term outcome. MTWA at the end of surgery was significantly associated with in-hospital mortality in both univariate analysis (OR = 27.378, 95% CI 5.616-133.466, p < 0.001) and multivariate analysis (OR = 59.225, 95% CI 6.061-578.748, p < 0.001). Cox proportional hazards model revealed MTWA at the end of surgery was independently associated with mid-term mortality (HR = 4.337, 95% CI 1.594-11.795). The area under the curve of the model evaluating MTWA at the end of surgery was 0.764 (95% CI, 0.715-0.809) and it increased to 0.929 (95% CI, 0.896-0.954) when combined with the EuroSCORE II. MTWA positive at the end of surgery had a 60-fold increase in in-hospital mortality and a 4-fold increase in mid-term mortality. Moreover, MTWA at the end of surgery could predict in-hospital mortality and this predictability is more robust when combined with the EuroSCORE II.

The association between intraoperative urine output and postoperative acute kidney injury differs between partial and radical nephrectomy.

We sought to investigate the association between intraoperative urine output and postoperative acute kidney injury (AKI) in patients undergoing radical and partial nephrectomy. We retrospectively reviewed data of 742 patients. Postoperative AKI was defined by the Kidney Disease: Improving Global Outcomes criteria. The relationship between intraoperative urine output and the risk of AKI was evaluated by multivariable logistic regression analysis in radical and partial nephrectomy, separately. Minimum P-value approach was used to find the optimal threshold of intraoperative oliguria associated with the risk of AKI. The incidence of AKI was 14.4% (67/466) after partial nephrectomy and 57.6% (159/276) after radical nephrectomy. For partial nephrectomy, multivariable analysis showed that renal ischemic time, operation time, open surgery and intraoperative transfusion were significantly associated with AKI. For radical nephrectomy, history of hypertension, baseline glomerular filtration rate and intraoperative mean urine output were significantly associated with AKI. Intraoperative mean urine output during radical nephrectomy was associated with AKI after radical nephrectomy, while not after partial nephrectomy. Mean urine output <1.0 mL/kg/h was determined to be an optimal cutoff of AKI after radical nephrectomy. Intraoperative oliguria may have different clinical implication for AKI between partial and radical nephrectomy.

Intraoperative hyponatremia is an independent predictor of one-year mortality after liver transplantation.

Preoperative hyponatremia is associated with an increased risk of mortality on the liver transplantation (LT) waiting list. We sought to investigate the impact of pre- and intraoperative serum sodium levels on the one-year mortality after LT. We identified 1,164 patients for whom preoperative and intraoperative serum sodium levels were available. Cox regression analysis with multivariable adjustment was performed for one-year mortality. A propensity score matching analysis was performed for preoperative and intraoperative serum sodium groups to compare one-year survival. The cutoff of sodium level with minimal p-value was 130 mEq/L for both preoperative and intraoperative sodium. Intraoperative hyponatremia was an independent predictor of one-year mortality in the multivariable Cox regression analysis, while preoperative hyponatremia was not. Kaplan-Meier curve showed that there was a significant difference in the one-year mortality between preoperative and intraoperative serum sodium groups. However, after propensity score matching, there was no difference in the one-year mortality among the preoperative sodium groups, while there was a significant difference among the intraoperative sodium groups. Intraoperative hyponatremia defined by mean sodium <130 mEq/L was independently associated with a significantly high one-year mortality. Mean intraoperative serum sodium levels may be a better prognostic predictor than preoperative serum sodium levels.

Pediatric Clinical Trials Conducted in South Korea from 2006 to 2015: An Analysis of the South Korean Clinical Research Information Service, US ClinicalTrials.gov and European Clinical Trials Registries.

BACKGROUND: The status of pediatric clinical trials performed in South Korea in the last decade, including clinical trials of drugs with unapproved indications for children, has not been previously examined. OBJECTIVE: The aim was to provide information regarding the current state of pediatric clinical trials and create a basis for future trials performed in South Korea by reviewing three databases of clinical trials registrations. METHODS: We searched for pediatric clinical studies (participants <18 years old) conducted in South Korea between 2006 and 2015 registered on the Clinical Research Information Service (CRIS), ClinicalTrials.gov, and the European Clinical Trials Registry (EuCTR). Additionally, we reviewed whether unapproved indications were involved in each trial by comparing the trials with a list of authorized trials provided by the Ministry of Food and Drug Safety (MFDS). The primary and secondary outcomes were to determine the change in number of pediatric clinical trials with unapproved indications over time and to assess the status of unauthorized pediatric clinical trials from the MFDS and the publication of articles after these clinical trials, respectively. RESULTS: We identified 342 clinical studies registered in the CRIS (n = 81), ClinicalTrials.gov (n = 225), and EuCTR (n = 36), of which 306 were reviewed after excluding duplicate registrations. Among them, 181 studies were interventional trials dealing with drugs and biological agents, of which 129 (71.3%) involved unapproved drugs. Of these 129 trials, 107 (82.9%) were authorized by the MFDS. CONCLUSIONS: Pediatric clinical trials in South Korea aiming to establish the safety and efficacy of drugs in children are increasing; however, non-MFDS-authorized studies remain an issue.