Population pharmacokinetics and analgesic potency of oxycodone Choi, Byung‐Moon; Lee, Yong‐Hun; An, Sang‐Mee ...
BJCP. British journal of clinical pharmacology/British journal of clinical pharmacology,
February 2017, Letnik:
83, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Aims
This prospective study aimed to characterize the population pharmacokinetics of intravenous oxycodone and to determine the minimum effective concentration (MEC) and minimum effective analgesic ...concentration (MEAC) of oxycodone for major open intra‐abdominal surgery.
Methods
In the pharmacokinetic study, patients were administered intravenous oxycodone (0.1 mg kg−1), and arterial blood was sampled at pre‐set intervals. In the analgesic‐potency study, patients were administered intravenous oxycodone (0.1 mg kg−1) 30 min before the end of the surgery, were placed in the postoperative anaesthesia care unit (PACU), and were asked to rate their pain every 10 min using a visual analogue scale (0 = no pain, 10 = most severe pain). On the first occasion that wound pain at rest and during compression was rated as ≥3 or ≥5, respectively, the first blood sample was obtained to determine the MEC. A second blood sample was obtained after titration with 2 mg of oxycodone to yield wound pain <3 at rest and <5 during wound compression, and MEAC was determined. MEC and MEAC were determined again in each patient.
Results
In the population pharmacokinetic study (n = 54), oxycodone plasma concentration over time was well described by a three‐compartment mammillary model. Lean body mass and age were significant covariates for the volume of distribution and metabolic clearance of the pharmacokinetic model of oxycodone, respectively. The analgesic‐potency study (n = 50) showed that the median (95% CI) MEC and MEAC were 31.5 (19.2–42.8) and 74.1 (29.2–128.3) ng ml−1 (first measurements) and 63.4 (15.6–120.1) and 76.1 (32.9–132.7) ng ml−1 (second measurements), respectively.
Conclusions
In major intra‐abdominal open surgery, the MEAC and analgesic potency of oxycodone were 75 ng ml−1 and 60 ng ml−1, respectively.
Background/Objectives: The psoas: lumbar vertebral index (PLVI) is a simple and convenient measure to assess central sarcopenia. Recent studies have utilized the psoas area to indirectly assess ...sarcopenia and frailty, exploring their associations with various health outcomes. This study aims to investigate the relationship between the PLVI and postherpetic neuralgia (PHN) in patients aged 60 years and above following a herpes zoster (HZ) infection. Methods: We conducted a retrospective analysis of data from 351 patients (≥60 years) who developed HZ between January 2019 and December 2023; the patients were divided into two groups based on the presence or absence of PHN after HZ onset. Results: The analyses using receiver operating characteristic curves revealed a value for the area under the curve of 0.813 for PLVI and 0.769 for the modified frailty index (mFI). In a multivariate logistic regression analysis, numerical rating scale scoring, a low PLVI, and a greater number of categorical mFI variables (adjusted odds ratio: 1.30, 3.27, and 2.46, respectively) were found to be significant independent predictors of PHN. Conclusions: Our findings highlight the association between a low PLVI and PHN in an older population. The PLVI may have potential as a predictive tool for PHN in older patients with HZ, but further research is needed to confirm these results.
The beach chair position (BCP) is widely used in shoulder surgery; however, it frequently leads to hypotension. Hypotension in BCP is prevalent among older patients who are at risk of secondary ...complications such as ischemic injuries. Therefore, this prospective study aimed to investigate the association and predictive value of frailty, as assessed by ultrasound-measured quadriceps depth and questionnaire, in patients aged ≥65 years undergoing elective shoulder surgery under general anesthesia. A multivariable logistic regression analysis was performed to identify independent risk factors for hypotension in BCP under general anesthesia. Receiver operating characteristic curves were constructed to assess the predictive values of various parameters. The results indicated that a quadriceps depth < 2.3 cm and BCP for an extended period significantly increased the risk of hypotension. The combined consideration of quadriceps depth < 2.3 cm and frailty demonstrated markedly superior predictive power compared with each factor individually. In conclusion, the study findings facilitate the screening and identification of risk factors for older patients undergoing surgery in BCP, thereby enhancing perioperative management.
Backgrounds
We sought to identify short‐ and long‐term changes in postoperative left ventricular systolic function in patients with rheumatic heart disease (RHD) who underwent combined aortic and ...mitral valve replacement.
Methods
We analyzed 146 patients according to their preoperative left ventricular ejection fraction (LVEF) (113 with preoperative LVEF ≥50% and 33 with preoperative LVEF <50%). A restricted cubic spline model was used to assess the effect of time on the postoperative changes in echocardiographic parameters.
Results
There were no significant difference in preoperative and immediately postoperative LVEF before discharge in either group. During median follow‐up of 3.2 years (interquartile range: 1.3–4.7 years) after surgery, postoperative LVEF increased slightly and then plateaued in patients with preoperative LVEF ≥50%, whereas it increased over 3–4 years after surgery and then gradually decreased in patients with preoperative LVEF <50% (p < .001).
Conclusion
Long‐term postoperative LVEF showed a downward trend in RHD patients with reduced preoperative LVEF, whereas it reached a plateau in RHD patients with normal preoperative LVEF.
Although serum aminotransferase levels are frequently measured for preoperative evaluation, their prognostic value to postoperative outcomes remain unclear. This study aimed to investigate the ...relationship between preoperative serum aminotransferase levels and postoperative 90-day mortality in patients undergoing cardiovascular surgery. We included adult patients (n=6264) who underwent cardiovascular surgery between January 2010 and December 2016 at a tertiary academic hospital. Preoperative serum alanine aminotransferase (ALT), serum aspartate aminotransferase (AST), and De Ritis ratio (defined as AST/ALT) were categorized into three groups: low (≤20th percentile), middle (20th-80th percentile), and high (>80th percentile). Of the 6264 patients enrolled (40.4% women; median age, 62 years), 183 (2.9%) died within 90 days postoperatively. Multivariable-adjusted analyses revealed low ALT (hazard ratio 1.58, 95% confidence interval, 1.14-2.18) and high De Ritis ratio (hazard ratio 1.59, 95% confidence interval, 1.15-2.20) were independent predictors of postoperative mortality, but AST did not have a statistically significant association. The association of low ALT and high De Ritis ratio with 90-day mortality was more pronounced in patients older than 60 years (
-values for interaction <0.05). Therefore, preoperative serum aminotransferase levels may be a valuable prognostic marker in patients with cardiovascular surgery, particularly in the elderly.
The objective of this study was to investigate the time-course of the expression of TNF-α, IL-6, and IL-1β after L5 spinal nerve transection (SNT), and to determine the effect of small interfering ...RNA (siRNA) targeting these cytokines on neuropathic pain.
Rats received control siRNA (CON group, n = 80) or a cocktail of siRNAs targeting these cytokines (COCK group, n = 70). The siRNAs were given via intrathecal catheter 1 d prior to SNT, on the operation day, and 1, 2 and 3 d postoperatively. Behavioral tests and levels of the cytokine mRNAs and proteins as well as glial cell activity were following the L5 SNT.
In the CON group, TNF-α and IL-1β mRNA levels increased immediately after SNT and remained high for 6 d, while IL-6 transcripts only began to increase after 12 h. TNF-α and IL-1β mRNA levels in the COCK group were lower than in the CON group at all time points (P < 0.05). In the behavioral tests, allodynia and hyperalgesia were significantly lower in the COCK group from 2 d after SNT (P < 0.05).
The time courses of TNF-α, IL-6 and IL-1β mRNA expression after L5 SNT differ. RNA interference may be a method of reducing the development of mechanical allodynia and hyperalgesia in response to nerve injury.
Monitoring end-tidal carbon dioxide partial pressure (P
CO
) is a noninvasive, continuous method, but its accuracy is reduced by prolonged capnoperitoneum and the steep Trendelenburg position in ...robot-assisted radical prostatectomy (RARP). Transcutaneous carbon dioxide partial pressure (P
CO
) monitoring, which is not affected by ventilator-perfusion mismatch, has been suggested as a suitable alternative. We compared the agreement of noninvasive measurements with the arterial carbon dioxide partial pressure (PaCO
) over a long period of capnoperitoneum, and investigated its sensitivity and predictive power for detecting hypercapnia.
The patients who underwent RARP were enrolled in this study prospectively. Intraoperative measurements of P
CO
, P
CO
, and PaCO
were analyzed. The primary outcome was the agreement of noninvasive monitoring with PaCO
during prolonged capnoperitoneum. Bias and precision between noninvasive measurements and PaCO
were assessed using Bland-Altman analysis. The bias and mean absolute difference were compared using a two-tailed Wilcoxon signed-rank test for pairs. The secondary outcome was the sensitivity and predictive power for detecting hypercapnia. To assess this, the Yates corrected chi-square test and the area under the receiver operating characteristic curve were used.
The study analyzed 219 datasets from 46 patients. Compared with P
CO
, P
CO
had lower bias, greater precision, and better agreement with PaCO
throughout the RARP. The mean absolute difference in P
CO
and PaCO
was larger than that of P
CO
and PaCO
and continued to exceed the clinically acceptable range of 5 mmHg after 1 hour of capnoperitoneum. The sensitivity during capnoperitoneum and overall predictive power of P
CO
for detecting hypercapnia were significantly higher than those of P
CO
, suggesting a greater contribution to ventilator adjustment, to treat hypercapnia.
P
CO
monitoring measured PaCO
more accurately than P
CO
monitoring during RARP requiring prolonged capnoperitoneum and a steep Trendelenburg position. P
CO
monitoring also provides more sensitive measurements for ventilator adjustment and detects hypercapnia more effectively than P
CO
monitoring.
PDF
