Implementation of Ultrasound-Guided Infraclavicular Subclavian Venous Catheterization During Anesthesia and Elective Surgery: A Prospective Observational Study at a Single Center in Lithuania.

BACKGROUND Ultrasound-guided procedures have become more reliable and efficient in daily anesthesiology practice, with increased patient comfort, better antimicrobial pattern, and easer care, and can be used in routine central vein catheterization practice. The infraclavicular subclavian vein approach provides all these advandages and in some clinical scenarios ensures the only appropriate route to central vein access. Therefore, this study of 105 patients aimed to implement and evaluate the use of ultrasound-guided infraclavicular subclavian venous catheterization. MATERIAL AND METHODS We enrolled 108 patients who were scheduled for elective major abdominal surgery and had an indication for central venous access. Catheterization was done according to the developed protocol. Anesthesiologists with at least 1 year of experience in regional ultrasound-guided anesthesia participated in this study. Data were collected and compared with the existing literature. RESULTS Out of 108 patients enrolled, 3 were excluded due to unfulfilled protocol. The successful catheterization rate was 98.1%. A significant relationship with deeper and narrower vein and failure was noted. On average, the distance between the vein entry point and acoustic shadow of the clavicle was 10.45 mm, at this point the depth was 22.01 mm and the diameter of the vein was 10.74 mm. The length of catheter intratissue passage was 42.06 mm. The angle between the skin and catheter passage was 31.58°. The malposition rate was 8.7%, and no predictive factors were identified. Equations to predict vein diameter and depth were generated. Patient weight more than 119.5 kg predicted procedure failure. There were no complications. CONCLUSIONS Ultrasound-guided infraclavicular subclavian vein catheterization can be easily and safely integrated into daily clinical practice, with high success rates and low complication rates.

Precise Terminology and Specified Catheter Insertion Length in Ultrasound-Guided Infraclavicular Central Vein Catheterization.

Background and Objectives: As the latest research encourages the ultrasound-guided infraclavicular central venous approach, due to the lateral puncture site displacement, in comparison to the anatomical landmark technique based on subclavian vein catheterization, the need to re-calculate the optimal catheter insertion length and possibly to rename the punctuated vessel emerges. Although naming a particular anatomical structure is a nomenclature issue, a suboptimal catheter position can be associated with multiple life-threatening complications and must be avoided. The main study objective is to determine the optimal catheter insertion length by the most proximal ultrasound-guided, in-plane infraclavicular central vein approach, to compare results with the anatomical landmark technique based on subclavian vein catheterization and to clarify the punctuated anatomical structure. Materials and Methods: 109 patients were enrolled in this study. All procedures were performed according to the same catheterization protocol. In order to determine optimal insertion length, chest X-ray scans with an existing catheter were performed. The definition of punctuated vessel was based on computer tomography and evaluated by radiologists. Independent predictors for optimal insertion length were identified, prediction equations were generated. Results: The optimal catheter insertion length is approximately 1.5 cm longer than estimated by Pere's formula and can be accurately calculated based on anthropometric data. Computed tomography revealed: five cases with subclavian vein puncture and three cases with axillary vein puncture. Conclusions: Even the most proximal ultrasound-guided infraclavicular central vein access does not guarantee subclavian vein catheterization. A more accurate term could be infraclavicular central venous access, with the implication that the entry point could be through either subclavian or axillary veins. The optimal insertion length is approximately 1.5 cm deeper than the length determined for the anatomical landmark technique based on subclavian vein catheterization.

Thromboelastographic changes during laparoscopic fundoplication.

INTRODUCTION: Thromboelastography (TEG) is a technique that measures coagulation processes and surveys the properties of a viscoelastic blood clot, from its formation to lysis. AIM: To determine the possible hypercoagulability state and the effect of antithrombotic prophylaxis on thromboelastogram results and development of venous thrombosis during laparoscopic fundoplication. MATERIAL AND METHODS: The study was performed on 106 patients who were randomized into two groups. The first group received low-molecular-weight heparin (LMWH) 12 h before the operation, and 6 and 30 h after it. The second group received LMWH only 1 h before the laparoscopic fundoplication. The TEG profile was collected before LMWH injection, 1 h after the introduction of the laparoscope and 15 min after the surgery was completed. RESULTS: There was no significant difference in thromboelastography R-time between the groups before low-molecular-weight heparin injection. In group I preoperative R-values significantly decreased 1 h after the introduction of the laparoscope, after the end of surgery and on the third postoperative day. K-time values decreased significantly on the third postoperative day compared with the results before low-molecular-weight heparin injection, and after the operation. In group II, preoperative R-values significantly decreased 1 h after the introduction of the laparoscope, and after surgery. K-time values did not change significantly during or after the laparoscopic operation. CONCLUSIONS: Our study results demonstrated that the hypercoagulation state (according to the TEG results) was observed during and after laparoscopic fundoplication in patients when LMWH was administered 12 h before the operation together with intraoperative intermittent pneumatic compression. The optimal anticoagulation was obtained when LMWH was administered 1 h before fundoplication.

Monitoring of Hypercoagulability by Thromboelastography in Bariatric Surgery.

BACKGROUND Obesity is known as a major risk factor for postoperative vein thrombosis. Thromboelastography (TEG) is used to monitor viscoelastic features of blood clots. The aim of this study was to determine hypercoagulable states in patients undergoing bariatric surgery and to assess dynamics of coagulation parameters in the perioperative setting using TEG. MATERIAL AND METHODS We included 60 consecutive patients undergoing bariatric surgery. TEG alterations were assessed at 4 time points: at baseline, after the surgery, and on postoperative day 1 (POD1) and 2 (POD2). Hypercoagulable state was defined when patients showed clot strength (G) of ≥11 dynes/cm² or maximum amplitude (MA) ≥68 mm. RESULTS Fourteen patients (23.3%) out of 60 showed hypercoagulability prior to surgery on TEG. Fibrinogen levels were significantly higher in the G ≥11 group compared to the G <11 group, at 4.2 and 3.8 g/l, respectively (p=0.02). Seventeen patients (28.3%) had MA ≥68 mm at baseline. Fibrinogen levels increased significantly from 3.90 at baseline to 4.16 g/l in POD2 (p<0.001). There was an increase in mean reaction time from baseline (6.74 s) to POD2 (7.43 s, p=0.022). We found a correlation between baseline fibrinogen levels and MA (R=0.431, p=0.001) or G (R=0.387, p=0.003). ROC curve analysis showed that fibrinogen levels can predict clot strength (G) ≥11 dynes/cm² with AUC=0.680 (p=0.044). CONCLUSIONS A considerable proportion of patients referred to bariatric surgery show a trend towards hypercoagulability on TEG. This study shows the potential of hypercoagulation monitoring by TEG in the perioperative setting of bariatric surgery.

Thrombosis Related ABO, F5, MTHFR, and FGG Gene Polymorphisms in Morbidly Obese Patients.

Objective. Obesity is a well-known risk factor for thrombotic complications. The aim of the present study was to determine the frequency of thrombosis related ABO, F5, MTHFR, and FGG gene polymorphisms in morbidly obese patients and compare them with the group of nonobese individuals. Methods. Gene polymorphisms were analyzed in 320 morbidly obese patients (BMI > 40 kg/m2) and 303 control individuals (BMI < 30 kg/m2) of European descent. ABO C>T (rs505922), F5 C>G (rs6427196), MTHFR C>T (rs1801133), and FGG C>T (rs6536024) SNPs were genotyped by RT-PCR. Results. We observed a tendency for MTHFR rs1801133 TT genotype to be linked with morbid obesity when compared to CC genotype; however, the difference did not reach the significant P value (OR 1.84, 95% CI 0.83-4.05, P = 0.129). Overall, the genotypes and alleles of rs505922, rs6427196, rs1801133, and rs6536024 SNPs had similar distribution between morbidly obese and nonobese control individuals. Distribution of height and weight means among individuals carrying different rs505922, rs6427196, rs1801133, and rs6536024 genotypes did not differ significantly. Conclusions. Gene polymorphisms ABO C>T (rs505922), F5 C>G (rs6427196), MTHFR C>T (rs1801133), and FGG C>T (rs6536024) were not associated with height, weight, or morbid obesity among European subjects.

An evaluation of the effectiveness and safety of midazolam in children undergoing dental surgery.

OBJECTIVE: The aim of this study was to evaluate the effectiveness and safety of oral midazolam in children undergoing dental surgery. MATERIALS AND METHODS: A prospective, randomized, controlled trial was conducted to assess the effectiveness and safety of midazolam in children. Patients aged 2-9 years who underwent dental surgery under general anesthesia were randomly allocated into one of the four groups: midazolam 0.2mg/kg dose group (n=30); midazolam 0.21-0.4mg/kg dose group (n=15); midazolam more than 0.41mg/kg dose group (n=15) or the placebo group (n=31). The effectiveness of midazolam on sedation was assessed by the evaluation of vital signs, such as the respiratory and heart rate, oxygen saturation and the patients' reactive behaviors, in comparison with the placebo. RESULTS: The scores of the ratings for sleep, movement and crying, as well as patients' reactions at the moment of separation from their parents and their collaboration with the staff were statistically significantly better among patients who received oral midazolam compared with the placebo. There were statistically significant direct correlations between the doses of midazolam and higher sleep, movement, crying and reaction scores 30min after premedication as well as higher scores of patients upon separation from their parents. There were only a few clinically insignificant side effects. CONCLUSIONS: Oral midazolam, at a single dose from 0.2 to 0.6mg/kg, is effective and safe, and provides the expected sedative effects in children required by premedication for dental surgery.

Single shot intercostal block for pain management in pediatric patients undergoing the Nuss procedure: a double-blind, randomized, controlled study.

PURPOSE: The aim of this study was to investigate the efficacy of a single shot intercostal block for pain control in pediatric patients undergoing the Nuss procedure. METHODS: A double-blind, randomized, controlled study was performed. Thirty patients received a single shot bilateral intercostal block with levobupivacaine (L group) and 30 patients with 0.9 % saline (S group). Standardized baseline analgesia was applied for all patients. Morphine consumption, pain scores, respiratory depression, nausea and vomiting, and urinary retention were recorded every 3h for 48h after surgery. RESULTS: The loading dose of morphine was lower (p<0.00001) in the L group. There were significantly lower morphine doses up to 6h after surgery and VAS scores up to 3h after surgery in the L group (p<0.001 and p=0.0003, respectively). The incidence of nausea and vomiting was lower in the L group (<0.00001). The incidence of urinary retention was lower in the L group (p=0.019). CONCLUSIONS: A single shot IB is an effective additional treatment for pediatric patients undergoing the Nuss procedure and results in the reduced consumption of morphine, less postoperative pain, and fewer opioid-related adverse effects.

The influence of thoracic epidural anesthesia on liver hemodynamics in patients under general anesthesia.

BACKGROUND AND OBJECTIVE: Hepatic hypoperfusion is regarded as an important factor in the pathophysiology of perioperative liver injury. Although thoracic epidural anesthesia is a widely used technique, limited data are available about the effects on hepatic blood flow with blockade restricted to thoracic segments in humans. The main objective of the present study was to investigate the effects of thoracic epidural anesthesia on hepatic blood flow under general anesthesia in humans. MATERIAL AND METHODS: In 40 patients under general anesthesia, we assessed hepatic blood flow using plasma disappearance rate of indocyanine green (PDRICG) as a simple noninvasive method before and after induction of thoracic epidural anesthesia. The epidural catheter was inserted at the Th7/8 or Th8/9, and 1% lidocaine at a mean (range) dose of 8 (6-10) mL was injected. Ephedrine bolus was given to patients who demonstrated a decrease in mean arterial blood pressure below 60 mm Hg after induction of thoracic epidural anesthesia (TEA-E group). Other patients did not receive any catecholamines during the study period (TEA group). Ten patients who did not undergo TEA served as controls (control group). RESULTS: In 7 patients, administration of ephedrine was necessary to avoid a decrease in mean arterial blood pressure below 60 mm Hg. Thus, the TEA-E group consisted of 7 patients and TEA group of 33. In the TEA group, thoracic epidural anesthesia was associated with a mean 2.3% min(-1) decrease in PDRICG (P<0.05). In the TEA-E group, all seven patients showed a 2.2% min(-1) decrease in PDRICG (P<0.05). Patients in the control group showed a mean 1.1% min(-1) increase in PDRICG (P<0.05). In contrast to hepatic blood flow, cardiac output was not affected by thoracic epidural anesthesia. CONCLUSIONS: In humans, thoracic epidural anesthesia is associated with a decrease in hepatic blood flow. Thoracic epidural anesthesia combined with ephedrine bolus was found to result in further decrease in hepatic blood flow.