BACKGROUND: Confirming a successful caudal block is challenging in the pediatric population. Pulse transit time (PTT) may reflect the decrease in arterial resistance and may act as a potential indicator for confirming successful peripheral nerve or axial block. Heart rate variability (HRV) is also a possible candidate because it may be influenced by variation in sympathetic tone. We expected an increasing PTT pattern and change in HRV parameters after caudal block. METHODS: We enrolled 27 male patients (range, 1–4 years old) who were scheduled for urological surgeries. Caudal block was performed with 1 ml/kg of 0.25% ropivacaine and 1 : 200,000 epinephrine under sevoflurane anesthesia after the surgery. Successful block was confirmed by auscultation and ultrasonography. PTT and HRV parameters, such as standard deviation of normal-to-normal intervals, root mean square of successive differences, very low-frequency power, low-frequency power (LF), high-frequency power (HF), LF/HF ratio, approximate entropy (ApEn) were calculated based on electrocardiography from 1 min before to 5 min after the block. Those variables were analyzed by repeated measures analysis of variance. RESULTS: No significant change was found in PTT with time interval after caudal block. Heart rate and ApEn of the R-R interval decreased with time interval (P = 0.001, 0.033, respectively). Some HRV parameters showed notable changes, although statistically insignificant. CONCLUSIONS: The PTT pattern may not be an indicator for successful caudal block. However, heart rate with parameters of HRV analysis may be alternatives.
Anesthesia ; Anesthesia, Caudal ; Anesthesia, General* ; Auscultation ; Child* ; Electrocardiography ; Entropy ; Epinephrine ; Heart Rate* ; Heart* ; Humans ; Male ; Peripheral Nerves ; Pulse Wave Analysis* ; Ultrasonography

Background/Aims: The molecular underpinnings of colorectal cancer (CRC) vary according to the tumor location. The advantages of a palliative primary tumor resection in patients with metastatic CRC are controversial. This study examined the survival outcomes of a palliative primary tumor resection based on the tumor location in patients with metastatic CRC. Methods: The medical records of 600 patients diagnosed with metastatic CRC between January 2000 and June 2018 were reviewed retrospectively. Patients undergoing surgery for both the primary tumor and metastatic lesions were excluded. The clinical factors affecting the long-term outcomes were evaluated according to the primary tumor location, and the long-term survival was compared between patients with and without a palliative primary tumor resection. The data were analyzed using the Kaplan-Meier estimator and multivariate Cox regression models. Results: The median follow-up duration was 18 months (interquartile range, 10-28). Patients with right-sided CRC had a poor overall- and progression-free survival compared to those with left-sided CRC. In multivariate Cox regression analysis, the palliative primary tumor resection was an independent prognostic factor predicting better overall survival in patients with metastatic CRC, regardless of the primary tumor location. Conclusions The primary tumor location influences the prognosis, and that a primary tumor resection can improve the overall survival in patients with metastatic CRC, regardless of the primary tumor location.