Background A simple measurement of central venous pressure (CVP)-mean by the digital monitor display has become increasingly popular. However, the agreement between CVP-mean and CVP-end (a standard method of CVP measurement by analyzing the waveform at end-expiration) is not well determined. This study was designed to identify the relationship between CVP-mean and CVP-end in critically ill patients and to introduce a new parameter of CVP amplitude (ΔCVP= CVPmax - CVPmin) during the respiratory period to identify the agreement/disagreement between CVP-mean and CVP-end.Methods In total, 291 patients were included in the study. CVP-mean and CVP-end were obtained simultaneously from each patient. CVP measurement difference (|CVP-mean - CVP-end|) was defined as the difference between CVP-mean and CVP-end. The ΔCVP was calculated as the difference between the peak (CVPmax) and the nadir value (CVPmin) during the respiratory cycle, which was automatically recorded on the monitor screen. Subjects with |CVP-mean - CVP-end|≥ 2 mmHg were divided into the inconsistent group, while subjects with |CVP-mean - CVP-end| < 2 mmHg were divided into the consistent group.Results ΔCVP was significantly higher in the inconsistent group [7.17(2.77) vs.5.24(2.18), P<0.001] than that in the consistent group. There was a significantly positive relationship between ΔCVP and |CVP-mean - CVP-end| (r=0.283, P <0.0001). Bland-Altman plot showed the bias was -0.61 mmHg with a wide 95% limit of agreement (-3.34, 2.10) of CVP-end and CVP-mean. The area under the receiver operating characteristic curves (AUC) of ΔCVP for predicting |CVP-mean - CVP-end| ≥ 2 mmHg was 0.709. With a high diagnostic specificity, using ΔCVP<3 to detect |CVP-mean - CVP-end| lower than 2mmHg (consistent measurement) resulted in a sensitivity of 22.37% and a specificity of 93.06%. Using ΔCVP>8 to detect |CVP-mean - CVP-end| >8 mmHg (inconsistent measurement) resulted in a sensitivity of 31.94% and a specificity of 91.32%.Conclusions CVP-end and CVP-mean have statistical discrepancies in specific clinical scenarios. ΔCVP during the respiratory period is related to the variation of the two CVP methods. A high ΔCVP indicates a poor agreement between these two methods, whereas a low ΔCVP indicates a good agreement between these two methods.
Humans ; Central Venous Pressure ; Respiration ; ROC Curve

Objective: To investigate the incidence and risk factors of deep venous thrombosis (DVT) of lower extremity in patients with stage Ⅲ and Ⅳ pressure ulcer on admission. Methods: A retrospective case series study was conducted. A total of 241 patients with stage Ⅲ and Ⅳ pressure ulcers who met the inclusion criteria and were discharged from the Department of Wound Repair of the First People's Hospital of Zhengzhou from January 1, 2015 to December 31, 2019 were enrolled in this study, including 134 males and 107 females, aged 22 to 93 years, with a median age of 68 years; 37 patients were with stage Ⅲ pressure ulcers and 204 patients were with stage Ⅳ pressure ulcers. The DVT occurrence of patients was recorded. According to whether DVT of lower extremity veins was diagnosed by color Doppler ultrasound within 48 h after admission or not, the patients were divided into DVT group (n=37) and non-DVT group (n=204). Data of patients in the two groups were collected and compared, including gender, age, duration of pressure ulcer, time in bed, and combination with diabetes, hypertension, coronary heart disease, cerebral infarction, pneumonia, sepsis/septic shock, and paraplegia, and the plasma D-dimer level and Caprini score within 24 h after admission. Data were statistically analyzed with independent sample t test, Mann-Whitney U test, chi-square test, and Fisher's exact probability test. The indicators with statistically significant differences between the two groups were analyzed with multivariate logistic regression analysis to screen the independent risk factors influencing the DVT of lower extremity in 241 patients with stage Ⅲ and Ⅳ pressure ulcers on admission. Results: The incidence of DVT of lower extremity was 15.4% (37/241), of which 86.5% (32/37) were asymptomatic DVT. Among the DVT of 46 lower limbs, only 29 involved the inferior genicular veins, accounting for 63.0%. There were no statistically significant differences in gender, duration of pressure ulcer, combination with diabetes, hypertension, coronary heart disease, cerebral infarction, pneumonia, and sepsis/septic shock of patients between the two groups (P>0.05), while there were statistically significant differences in age, time in bed, combination with paraplegia, the plasma D-dimer level and Caprini score of patients between the two groups(t=-3.19, Z=-2.04, χ²=4.44, Z=-3.89, t=-2.14, respectively, P<0.05 or P<0.01). Multivariate logistic regression analysis showed that age and plasma D-dimer level were independent risk factors influencing the DVT of lower extremity in 241 patients with stage Ⅲ and Ⅳ pressure ulcers on admission (with odds ratios of 1.03 and 1.18, respectively, with 95% confidence intervals of 1.00-1.06 and 1.05-1.33, respectively, P<0.05 or P<0.01). Conclusions: The patients with stage Ⅲ and Ⅳ pressure ulcers have a higher incidence of DVT on admission, with age and plasma D-dimer level being the independent risk factors for DVT of lower extremity. It is necessary to pay attention to the targeted screening of DVT and education of its prevention.
Aged ; Female ; Humans ; Hypertension ; Lower Extremity ; Male ; Paraplegia ; Pressure Ulcer/epidemiology* ; Prevalence ; Retrospective Studies ; Risk Factors ; Shock, Septic ; Venous Thrombosis/epidemiology*

The purpose of this study was to evaluate the effects of apical constriction (AC) diameter, irrigant flow rate, and needle tip design on apical pressure (AP) during the root canal irrigation. Five extracted human mandibular premolars were instrumented up to #35 (0.06 taper) using nickel-titanium rotary instruments. AC was determined at 1 mm from the apical foramen. Three needles with different tip designs (notched, side-vented, and flat) were placed 3 mm from AC. APs were measured with varying flow rates of 0.05, 0.1, 0.2, and 0.3 mL/s. The AC diameter of the teeth was enlarged to #40 and #45 (0.06 taper) successively, and the aforementioned measurement procedure was repeated (n=5). When the other conditions were controlled, AP increased with decreasing AC diameter or increasing irrigant flow rate, and the AP of flat needle was the highest, followed by notched, and side-vented needle (p<0.05). The APs with 0.05 mL/s flow rate were lower than central venous pressure (5.88 mmHg) for all conditions. Under the conditions of the present study, flat needle is not recommended in narrow AC (0.35 mm), as the value of the AP with a flow rate of 0.05 mL/s is similar to the central venous pressure. However, in AC diameter of >0.35 mm, open-end (notched or flat) needles can be used to improve irrigant replacement in the apical portion using a flow rate of 0.05 mL/s.
Bicuspid ; Central Venous Pressure ; Constriction ; Dental Pulp Cavity ; Humans ; Needles ; Tooth ; Tooth Apex

To observe the safety and impact on the short-term prognosis for patients of stroke volume variation (SVV) goal-directed fluid therapy (GDFT) in laparoscopic precision hepatectomy.
 Methods: A total of 120 patients (18-65 years old) undergoing laparoscopic precision hepatectomy were randomly divided into the fluid therapy group (group S) guided by SVV and the fluid therapy group (group C) guided by central venous pressure group (CVP), with 60 cases in each group. Mean arterial pressure (MAP) and heart rate (HR) were recorded at the following time: at home calm (T0), the operation started (T1), began to cut the liver (T2), the hepatectomy was acheived (T3), and in the end (T4). The lactic acid was measured at T0 to T4 and 1 day after surgery (T5). The amount of blood loss, urine output and fluid supplement, the incidence of intraoperative hypotension, and the use of neophryn were recorded. The recovery of liver function, Hb, and so on were also recorded.
 Results: Compared with the group C, the number of hypotension cases, the amount of blood loss and the amount of neophryn in the group S were decreased during the operation (P<0.05), while the lactic acid values in the group S were not significantly increased than those in the group C at T3 and T4 (P<0.05) and the elevation of AST, ALT, DBIL and TBIL in the group S was significantly decreased than those in the group C at 1 and 2 d after the operation (P<0.05). Hb and Hct in the group S were higher than those in the group C at 1 d after the surgery (P<0.05). Compared with the group C, the postoperative exhaust time and hospitalization time were shortened in the group S (P<0.05), and the infection rate and ICU admission rate were decreased in the group S (P<0.05).
 Conclusion: SVV-guided GDFT in laparoscopic precise hepatectomy is safe and effective. It reduces intraoperative blood loss and benefits the short-term prognosis of patients after operations. High SVV value (13%-17%) is adopted at the liver resection stage, and SVV value with 8%-12% at the end of trans-section may be used as one of intraoperative liquid therapy in laparoscopic precise hepatectomy.
Adolescent ; Adult ; Aged ; Central Venous Pressure ; Fluid Therapy ; Hepatectomy ; Humans ; Laparoscopy ; Middle Aged ; Stroke Volume ; Young Adult

Enhanced recovery after surgery (ERAS) attenuates the stress response to surgery in the perioperative period and hastens recovery. Liver resection is a complex surgical procedure where the enhanced recovery program has been shown to be safe and effective in terms of postoperative outcomes. ERAS programs have been shown to be associated with lower morbidity, shortened postoperative stay, and reduced cost with no difference in mortality and readmission rates. However, there are challenges that are unique to hepatic resection such as safety after epidural catheterization and postoperative coagulopathy, intraoperative fluids and postoperative organ dysfunction, need for low central venous pressure to reduce blood loss, and non-lactate containing intravenous fluids. This narrative review briefly discusses these concerns and controversies and suggests revisiting some of the strong recommendations made by the ERAS society in light of the recent evidence.
Analgesia, Epidural ; Catheterization ; Catheters ; Central Venous Pressure ; Liver ; Mortality ; Perioperative Period

This is a report of a 58-year-old female with Cushing syndrome who underwent posterior lumbar fusion and lost both her vision completely. She was diagnosed with posterior ischemic optic neuropathy. Cushingoid features such as buffalo hump and central obesity might have attributed in triggering posterior ischemic optic neuropathy. When laid prone for surgery, perioperative high abdominal pressure causes venous hypertension leading to increase amount of blood loss. To compensate, infusion of large quantities of intravenous fluids is necessary which leads to hemodilution which decreases ocular perfusion pressure. Hypercoagulability of Cushing syndrome is also potentially a risk factor of this condition which increases the incidence of venous thromboembolism. For there is no known effective treatment for posterior ischemic optic neuropathy, means to prevent this complication must be strategically reviewed. When performing long spine surgery on patient who has Cushing syndrome or cushingoid features, caution must be taken to avoid this devastating complication.
Buffaloes ; Cushing Syndrome ; Female ; Hemodilution ; Humans ; Hypertension ; Incidence ; Intraocular Pressure ; Middle Aged ; Obesity, Abdominal ; Optic Neuropathy, Ischemic ; Perfusion ; Risk Factors ; Spinal Fusion ; Spine ; Thrombophilia ; Venous Thromboembolism

PURPOSE: To investigate the outflow characteristics of silicone tubes with intraluminal stents used in membrane-tube (MT) type glaucoma shunt devices. METHODS: The silicone tubes used in MicroMT (internal diameter of 100 µm with a 7-0 nylon intraluminal stent) and Finetube MT (internal diameter of 200 µm with a 5-0 nylon intraluminal stent) were connected to a syringe-pump that delivered a continuous flow of distilled water at flow rates of 2, 5, 10, and 25 µL/min. The pressures and resistances of tubes were measured at a steady flow rate with full-length, half-length, and absence of intraluminal stents. RESULTS: The mean outflow resistance of the two types of tubes ranged from 3.0 ± 1.9 to 3.8 ± 1.7 mmHg/µL/min with a full-length intraluminal stent, 1.8 ± 1.1 to 2.2 ± 1.1 mmHg/µL/min with a half-length intraluminal stent, and 0.1 ± 0.0 to 0.2 ± 0.0 mmHg/µL/min without an intraluminal stent. Theoretically, for a physiologic state with a flow rate of 2 µL/min and episcleral venous pressure of 6 mmHg, the mean pressures of tubes were expected to be 13.2 ± 3.0, 10.5 ± 2.4, and 6.4 ± 0.2 mmHg in MicroMT with full-length, half-length, and absence of intraluminal stents, respectively, and 12.5 ± 3.9, 9.6 ± 2.4, and 6.2 ± 0.2 mmHg in Finetube MT with full-length, half-length, and absence of intraluminal stents, respectively. The pressure variance also decreased with intraluminal stent retraction (p < 0.01). CONCLUSIONS: The small diameter tubes of 100 and 200 µm internal diameters, with 7-0 and 5-0 nylon intraluminal stents, respectively, used in the MT-type glaucoma shunt device showed safe and effective outflow characteristics.
Glaucoma ; Hydrodynamics ; Intraocular Pressure ; Nylons ; Silicon ; Silicones ; Stents ; Venous Pressure ; Water

PURPOSE: To evaluate clinical characteristics of pediatric nontraumaitc chylothorax and to suggest appropriate therapeutic managements. METHODS: We retrospectively reviewed medical records of 22 patients with nontraumatic chylothorax from January 2005 to December 2018 in the Children's Hospital of Seoul National University. We analyze their etiology, treatment, complications and outcome. RESULTS: Of the 22 patients, 16 were diagnosed before 1 year old and 6 after 1 year old. The causes of chylothorax under 1-year-old children were related to congenital factors (n=9), unknown causes (n=5), and high central venous pressure (n=2). The causes of chylothorax over 1-year-old children were related to congenital factors (n=3), unknown causes (n=1), high venous pressure (n=1), and lymphoma (n=1). All patients had dietary modification. Eight of them were cured by dietary modification, but there was no improvement in over 1-year-old children. Medication was added to patients refractory to dietary modification. Four patients with medication were improved and 5 were improved by surgical management. Nutritional, immunological and other complications occurred in many patients. Five death cases were reported. Four patients were under 1 year old and 1 was over 1 year old. The causes of nontraumatic chylothorax in dead patients were high central venous pressure (n=3), congenital (n=1), and unknown (n=1). CONCLUSION: Nontraumatic chylothorax more frequently occurs in under 1-year-old children. The most common cause is congenital factors. Stepwise management is effective in many patients, but specific treatment is needed in some cases. The prognosis is related to the onset of age and underlying diseases.
Central Venous Pressure ; Child ; Chylothorax ; Diet ; Food Habits ; Humans ; Lymphoma ; Medical Records ; Pediatrics ; Prognosis ; Retrospective Studies ; Seoul ; Venous Pressure

BACKGROUND: Static parameters such as central venous pressure and pulmonary artery occlusion pressure, have limitation in evaluation of patients' volume status. Dynamic parameters such as stroke volume variation (SVV), have been used to evaluate intraoperative hemodynamic volume status, in various operations. We examined if SVV is also effective for patients undergoing operation with prone position for fluid management. METHODS: Eighteen patients that received spinal surgery under prone position November 2015 to May 2016, were enrolled. Patients were kept at an SVV value less than 14% during surgery. Changes of pre-, post-operative volume status were evaluated, using transthoracic echocardiography. RESULTS: Mean fluid administered was 1,731.97 ± 792.38 ml. Left ventricular end-diastolic volume was 72.85 ± 13.50 ml before surgery, and 70.84 ± 15.00 ml after surgery (P value = 0.594). Right ventricular end-diastolic area was 15.56 ± 1.71 cm² before surgery, and 13.52 ± 2.65 cm² after surgery (P value = 0.110). Inferior vena cava diameter was 14.99 ± 1.74 mm before surgery, and 13.57 ± 2.83 mm after surgery (P value = 0.080). CONCLUSIONS: We can confirm that fluid management based on SVV is effective, even in prone position surgery. So, SVV, that can be measured by continuous arterial pressure, can be considered a guideline for effective fluid management in spinal surgery.
Arterial Pressure ; Central Venous Pressure ; Echocardiography ; Fluid Therapy ; Hemodynamics ; Humans ; Prone Position ; Pulmonary Artery ; Stroke Volume ; Stroke ; Vena Cava, Inferior

OBJECTIVE: To assess segmental liver stiffness (LS) with MRI before and after endovascular intervention in patients with Budd-Chiari syndrome (BCS). MATERIALS AND METHODS: Twenty-three patients (13 males and 10 females; mean age, 42.6 ± 12.6 years; age range, 31–56 years) with BCS as a primary liver disease were recruited for this study. Two consecutive magnetic resonance elastography (MRE) examinations were performed before the endovascular treatment. Fifteen patients who underwent endovascular intervention treatment also had follow-up MRE scans within three days after the procedure. LS was measured in three liver segments: the right posterior, right anterior, and left medial segments. Inter-reader and inter-exam repeatability were analyzed with intraclass correlation coefficients (ICCs) and Bland-Altman analysis. Segmental LS and clinical characteristics before and after the intervention were also compared. RESULTS: Within three days of the endovascular intervention, all three segmental LS values decreased: LS of the right posterior segment = 7.23 ± 0.88 kPa (before) vs. 4.94 ± 0.84 kPa (after), LS of the right anterior segment = 7.30 ± 1.06 kPa (before) vs. 4.77 ± 0.85 kPa (after), and LS of the left medial segment = 7.22 ± 0.87 kPa (before) vs. 4.87 ± 0.72 kPa (after) (all p = 0.001). There was a significant correlation between LS changes and venous pressure gradient changes before and after treatments (r = 0.651, p = 0.009). The clinical manifestations of all 15 patients significantly improved after therapy. The MRE repeatability was excellent, with insignificant variations (inter-reader, ICC = 0.839–0.943: inter-examination, ICC = 0.765–0.869). Bland-Altman analysis confirmed excellent agreement (limits of agreement, 13.4–19.4%). CONCLUSION: Segmental LS measured by MRE is a promising repeatable quantitative biomarker for monitoring the treatment response to minimally invasive endovascular intervention in patients with BCS.
Budd-Chiari Syndrome ; Elasticity Imaging Techniques ; Female ; Follow-Up Studies ; Humans ; Liver Diseases ; Liver ; Magnetic Resonance Imaging ; Male ; Venous Pressure