Total Intravenous Anesthesia with Ketofol versus Combination of Ketofol and Lidocaine for Short-Term Anesthesia in Pediatric Patients; Double Blind, Randomized Clinical Trial of Effects on Recovery.

BACKGROUND: Ketofol admixture has been proposed to be useful for sedation and general anesthesia. The beneficial effect of the combination of ketofol with lidocaine may be a shortened time of anesthesia and recovery period. This study aimed to establish the effect of total intravenous anesthesia (TIVA) with ketofol and ketofol with lidocaine on recovery in children. METHODS: Two hundred children from the ages of 1-12 years who underwent short surgical procedures were randomly allocated into two groups. Propofol mixtures (ketofol) were prepared for group l. A ratio of 1:4 of ketofol was used for induction and for the maintenance of anesthesia a ratio of was used 1:7. For the induction and maintenance of anesthesia ketofol with lidocaine (lidoketofol) was used in group II. The McFarlan infusion regimen was used with reduction. The extubating time, anesthesia duration and the length of stay in the post-anesthesia care unit (PACU) were recorded. RESULTS: Extubation time showed to be considerably shorter in the lidoketofol group than in the ketofol group (120 s versus 240 s; p < 0.00001). The anesthesia duration was also significantly shorter in the lidoketofol group (35 min vs. 50 min; p < 0.00001). The lidoketofol group showed to have a lower length of stay in the post-anesthesia care unit (PACU) than the ketofol group (20 min vs. 35 min; p < 0.00001). The lidoketofol group showed lower fentanyl consumption per kg (2.1 µg per kg vs. 2.3 µg per kg; p < 0.056) and lower propofol consumption (6.6 mg per kg vs. 7.6 mg per kg; p < 0.032). CONCLUSION: The recovery in pediatric anesthesia can improve with usage of TIVA with ketofol plus lidocaine admixture with a reduced McFarlan dose regimen.

DOES THE ANESTHESIA TECHNIQUE AFFECT ARTERIAL PRESSURE AND REGIONAL CEREBRAL OXYGEN SATURATION DURING SHOULDER ARTHROSCOPY IN THE BEACH CHAIR POSITION?

- This study aimed to investigate the impact of posture and anesthesia techniques on blood pressure changes, heart rate and regional cerebral oxygen saturation during shoulder arthroscopy in the beach chair position (BCP). Sixty patients were included in this prospective cohort study: 30 patients mechanically ventilated and subjected to general anesthesia (GA) and 30 patients subjected to interscalene block (ISB) without mechanical ventilation. Noninvasive blood pressure, heart rate (HR), peripheral blood oxygen saturation and regional oxygen saturation of the brain were measured in twelve predefined points during perioperative period. The GA group patients had significantly lower mean arterial pressure and heart rate values compared to patients in ISB group during BCP (p<0.001). There was a significant difference in regional cerebral saturation between the groups measured only in points of induction and emergence from anesthesia in favor of GA group when receiving 100% oxygen (p<0.001). Changes in the mean arterial pressure and regional cerebral oxygen saturation for both brain hemispheres correlated only at the 10th minute after setting up BCP in GA patients (right, p=0.004 and left, p=0.003). This correlation did not exist in the ISB group patients at any of the points measured. Cerebral desaturation events recorded in both groups were not statistically significantly different. Results of this study demonstrated that GA preserved regional cerebral oxygenation in a safe range during BCP despite changes in the arterial blood pressure and heart rate in comparison to ISB.

Transcranial Cerebral Oxymetric Monitoring Reduces Brain Hypoxia in Obese and Elderly Patients Undergoing General Anesthesia for Laparoscopic Cholecystectomy.

The aims of this prospective, observational study were to evaluate the changes of the regional cerebral saturation (rSO2) measured by near-infrared spectroscopy during elective laparoscopic cholecystectomy under total intravenous anesthesia and the association between patient's characteristics and critical decline of rSO2. Hemodynamics, rSO2, and oxygen saturation were recorded in different time points: before the anesthesia (Tbas), 2 minutes after the induction (supine position) (Tind), 2 minutes after CO2 insufflation (supine) (TCO2), 10 minutes after CO2 insufflation (reverse Trendelenburg) (TrevT), and 2 minutes after deflation (supine) (Tpost). Average age was 53±13 (range: 22 to 79 y). In 12 of a total of 62 patients (19.4%) the rSO2 decreased >20% (20.5% to 28.4%) in TCO2 or TrevT times. Significantly higher decrease of the rSO2 was found in patients older than 65 years and those with body mass index >30 kg/m (P<0.05). Noninvasive monitoring of cerebral oxygenation could be an important part of perioperative care in obese and older patients.

Sevoflurane preserves regional cerebral oxygen saturation better than propofol: Randomized controlled trial.

STUDY OBJECTIVE: To investigate possible effects of volatile induction and maintenance anesthesia with sevoflurane (VIMA) and total intravenous anesthesia with propofol (TIVA) on regional cerebral oxygen saturation (rcSo2) during laparoscopic cholecystectomy. DESIGN: Randomized, prospective and single-blinded study. SETTING: Academic hospital. PATIENTS: ASA physical status of I and II surgical patients, scheduled for elective laparoscopic cholecystectomy from March 2013 to October 2014. MEASUREMENTS: Changes of regional cerebral oxygen saturation were measured by near-infrared spectroscopy on the left and right sides of forehead at different time points: before anesthesia induction (Tbas), immediately after induction (Tind), after applaying a pneumoperitoneum (TCo2), 10 minutes after positioning the patient into reverse Trendelenburg's position (TrtCo2), immediately after desufflation of gas (Tpost) and 30 (Trec30) and 60 (Trec60) minutes after emergence from anesthesia. MAIN RESULTS: Study population included 124 patients, 62 in each group. There was no significant difference between these groups according to demographic characteristics, surgery and anesthesia times as well as in the basal rcSo2 values. Statistically higher rSco2 values were noted in the VIMA group when compared to the TIVA group in all time points Tind, TCo2, TrtCo2, Tpost, Trec30 and Trec60 and incidence of critical rcSo2 decreases was statistically lower in VIMA group (P<.05). There were no serious perioperative complications. CONCLUSIONS: VIMA technique provides significantly (4%-11%) higher rcSO2 values during general anesthesia for laparoscopic cholecystectomy, when compared with TIVA and also provides significantly less number of critical rcSO2 decreases.

Factors associated with difficult neuraxial blockade.

Spinal and epidural blocks are common practice in anesthesia and are usually used for various surgical or endoscopic procedures. Correct identification and puncture of the epidural or subarachnoid space determine the success or failure of the technique. Multiple attempts and difficult access to the epidural or subarachnoid space is a frequent problem in operating theaters and may be hazardous due to a number of possible acute or long-term complications. In addition, multiple punctures are associated with increased pain and patient discomfort. The aim of this study was to determine the factors associated with a difficult spinal or epidural block, dependent on the patient (age, gender, height, weight, body mass index, and quality of anatomical landmarks), the technique (type of blockade, needle gauge, and patient positioning), and the provider (level of experience). The study was conducted at the Department of Anesthesiology, Resuscitation, and Intensive Care Unit of University Hospital Osijek (Osijek, Croatia) and it included 316 patients who underwent a range of different surgical procedures in neuraxial blocks. There were 219 cases of first puncture success, while the overall success of neuraxial blocks was 97.5%. Five patients (1.6%) were submitted to the alternative technique, ie, general anesthesia. In three patients (0.9%), neuraxial block was partial so they required supplementation of intravenous anesthetics and analgesics. Furthermore, it was found that first puncture success was associated with younger age (P=0.007), lower weight (P=0.032), and body mass index (P=0.020). Spine deformity (P=0.015), poor identification of interspinous space (P=0.005), recumbent patient position during the puncture (P=0.001), and use of a paramedian approach were associated with first puncture failure. Adequate preoperative prediction of difficulties can help to reduce the incidence of multiple attempts, rendering the technique more acceptable and less risky to the patient, and consequently leading to improvement of medical care quality. The attending anesthesiologist should consider an alternative technique (general anesthesia or peripheral nerve block) for a patient if certain difficulties can be predicted.

In-hospital cardiac arrest: can we change something?

Cardiac arrest is classified as 'in-hospital' if it occurs in a hospitalised patient who had a pulse at the time of admission. A probability of patient's survival until hospital discharge is very low. The reasons for this are old age, multiple co-morbidity of patients, late recognition of cardiac arrest, poor knowledge about basic life support algorithm, insufficient equipment, absence of qualified resuscitation teams (RTs) and poor organization.The aim of this study was to demonstrate characteristics of in-hospital cardiac arrests and resuscitation measures in University Hospital Osijek. We analysed retrospectively all resuscitation procedures data where anaesthesiology RTs provided cardiopulmonary resuscitation (CPR) during 5-year period.We analysed 309 in-hospital resuscitation attempts with complete documentation. Victims of cardiac arrest were principally elderly patients, neurological (30.4 %), surgical (25.24 %) and neurosurgical patients (15.2 %) with many associated severe diseases. In 85.6 % of the cases, resuscitation was initiated by ward personnel and RTs arrived within 5 min in 67 % of the cases. However, in 14.6 % of the cases resuscitation measures had not been started before RT arrival. We found statistical correlation between lower initial survival rates and length of hospital stay (p = 0.001), presence of cerebral ischemia (p = 0.026) or cardiomyopathy (p = 0.004) and duration of CPR (p = 0.041). Initial survival was very low (14.6 %), and full recovery was accomplished in only eight patients out of 309 (2.59 %).Identification of terminal chronic patients in which the CPR is not reasonable, a better organisation and ward personnel education can contribute to better overall success.

Integrity of gut mucosa during anaesthesia in major abdominal surgery.

The aim of the study was to examine a perfusion and integrity of small bowel in 60 subsequent patients during the major open abdominal surgery which lasted from 2 to 7 hours. Two samples of the intestinal mucosa were removed: at the beginning, and at the end of the surgical procedure in general anaesthesia. A mucosal injury was classified into 4 grades. pH, PCO2 and lactate level were measured in the blood samples from the arterial and mesenteric vein in one hour time intervals. The changes of intestinal mucosa were found in 31 patients (51.7%): in 19 patients (31.7%) grade 1 changes were recorded, in 10 patients (16.7%) grade 2, and in 2 patients (3.3%) grade 3. Grade 4 lesions were not recorded. There was a statistically significant correlation between grades of the mucosal damage and the surgery duration (p = 0.001). Analysis during the one hour intervals showed that there was no exact time point when the significant aggravation of the pathohistological changes in intestinal mucosa occurred. However, when patients were allocated into two subgroups with surgical procedures lasting less than 4 hours and more than 4 hours, there was a statistically significant difference in the grades of mucosal damage between subgroups (p < 0.05). More biopsies without pathohistological changes were observed in the patients whose procedure duration was < 4 hours. A significantly higher lactate concentrations in arterial and mesenteric venous blood were observed in the patients with pathohistological changes at 6 hours time point as compared to 2 hour time point in the patients without pathohistological changes (p < 0.05). During the open abdominal surgery in general anaesthesia, the length of the procedure influences the grade of the intestinal mucosa injury. Deterioration of the pathohistological findings in the intestinal mucosa correlates with high lactate blood level, suggesting that the cause of these changes may result from tissue hypoxia.

Model of pulmonary fluid traffic homeostasis based on respiratory cycle pressure, bidirectional bronchiolo-pulmonar shunting and water evaporation.

The main puzzle of the pulmonary circulation is how the alveolar spaces remain dry over a wide range of pulmonary vascular pressures and blood flows. Although normal hydrostatic pressure in pulmonary capillaries is probably always below 10 mmHg, well bellow plasma colloid pressure of 25 mmHg, most textbooks state that some fluid filtration through capillary walls does occur, while the increased lymph drainage prevents alveolar fluid accumulation. The lack of a measurable pressure drop along pulmonary capillaries makes the classic description of Starling forces unsuitable to the low pressure, low resistance pulmonary circulation. Here presented model of pulmonary fluid traffic describes lungs as a matrix of small vascular units, each consisting of alveoli whose capillaries are anastomotically linked to the bronchiolar capillaries perfused by a single bronchiolar arteriole. It proposes that filtration and absorption in pulmonary and in bronchiolar capillaries happen as alternating periods of low and of increased perfusion pressures. The model is based on three levels of filtration control: short filtration phases due to respiratory cycle of the whole lung are modulated by bidirectional bronchiolo-pulmonar shunting independently in each small vascular unit, while fluid evaporation from alveolar groups further tunes local filtration. These mechanisms are used to describe a self-sustaining regulator that allows optimal fluid traffic in different settings. The proposed concept is used to describe development of pulmonary edema in several clinical entities (exercise in wet or dry climate, left heart failure, people who rapidly move to high altitudes, acute cyanide and carbon monoxide poisoning, large pulmonary embolisms).

Mutations that modulate receptor-hormone congruency as a cause of the primate GH receptor species specificity.

Peptide hormones depend on reliable recognition by their receptors. Any mutation that compromises recognition of hormone and receptor molecules is dangerous, the carrier animal would not procreate and the mutation would be lost. Although, most of the hormones from one mammalian species are active when injected into another, the incompatibility of human GH receptor toward nonprimate GHs is a notable exception. It is reported that the coevolution of GH and GHR in primates includes two crucial steps (Mol. Biol. Evol. 18 (2001) 945). The first was mutation of GH His-->Asp at position 171 that happened before the split of Old world and New world monkeys. The second event was Leu-->Arg change at position 43 in the GH receptor molecule that happened in the ancestor of Old world monkeys. The proposed model is based on the possibility that certain mutations can modify the surface of one of interacting molecules to form a confined empty space, a niche in the otherwise congruent hormone/receptor interface. Altoough affinity between molecules is probably slightly reduced, recognition and function are not compromised in this special case. Further mutations of hormone and receptor molecules are allowed under the condition that they remain confined to the niche space. Mutations that do not compromise hormone function can be passed to offsprings. If the consequent mutation of one molecule change its shape to fill the niche space, further mutations without function loss will become less probable. Without the niche space, the phase of fast evolution is closed and both genes become conserved. In this setting, accumulated mutations before the niche closing mutation are the cause of species specificity. To become a dominant variety, carrier animals must possess survival advantage in comparison to the carriers of other less advantageous mutations.

Inertia of endocrine systems due to hormone binding to circulatory proteins.

It is often presumed that the main role of hormone binding to albumins and binding proteins (BPs) is to reduce oscillating levels of free hormone molecules and to transport steroid hormones. This paper is an attempt to define possible consequences of hormone molecules binding to carrier proteins in circulation. Binding to albumins and BPs prevents exact and quick control of hormone actions. Hormones without significant protein binding govern vital and fast acting regulatory mechanisms (blood glucose or calcium) in which any added inertia might be dangerous. In the presented model, the added inertia for a partially bound hormone (H) is defined as: H(bound)/H(free). Values, calculated from the reported data, range from 0.4 for GH to more than 2000 for T(4). In comparison to albumins, high-affinity BPs make more stable reserve that would cover periods of low or no hormone secretion. At the same time, hormone molecules are taken away from the blood level control and thus might be considered sequestrated. For hormones without protein binding, the well-perfused areas of the body, or the areas with increased capillary permeability, would be more exposed, making an uneven distribution among target tissues. For the hormone that binds blood proteins, places of secretion and tissue perfusion become unimportant, since the hormone is being liberated anywhere in the circulation (i.e., for strongly bound IGFs, IGF binding proteins do not just stabilize proinsulin actions of IGF-1, but also make all parts of body to be under the same exposure to liberated IGFs, an important feature to promote a symmetrical bone growth). Estrogens are known to stimulate liver secretion of different BPs. A possible explanation is that in the follicular phase there is a small initial mass of granulosa cells, and it takes time to saturate free estrogen carriers, before the normal free hormone level can be reached and FSH secretion inhibited. Less inert peptide inhibin might suppress FSH before free estrogens reach the required level. Without inhibin suppression, an increased FSH level with an increased number of growing follicles can be expected. Estrogens increased production of BPs augments inertia of the estrogen loop and possibly modulates the FSH/estrogen negative feedback.