Total Amount Of Fluid Research Articles

The Effect of HES (130/0.4) Usage as the Priming Solution on Renal Function in Children Undergoing Cardiac Surgery

Background: Experience with hydroxyethyl starch (HES) in children is limited. This study was conducted to observe the effects of HES or Ringer’s lactate (RL) usage as the priming solution on renal functions in children undergoing cardiac surgery. Methods: After ethical committee approval and parent informed consent, 24 patients were included in this prospective, randomized study. During cardiopulmonary bypass (CPB), Group I received RL and Group II received HES (130/0.4) as priming solution. Serum creatinine, blood urea nitrogen (BUN), β2-microglobulin, cystatin C, and urinary albumin and creatinine, serum, and urine electrolytes were analyzed after the induction (T1), before CPB (T2), during CPB (T3), after CPB (T4), at the end of the operation (T5), on 24th hour (T6), and on 48th hour postoperatively (T7). Fractional sodium excretion (FENa), urinary albumin/creatinine ratio, and creatinine clearance were calculated. Drainage, urine output, inotropes, diuretics, and blood requirements were recorded. Results: In both the groups, β2-microglobulin was decreased during CPB and cystatin C was decreased at T3,T4, and T5 periods (p < 0.05) and the levels remained within the normal range. Creatinine clearance did not differ in the HES group, but increased in the RL group (p < 0.05). Urine albumin/creatinine ratio was increased (p < 0.05) after CPB in the HES group, and it increased at T3, T4, and T5 in the RL group (p < 0.05). There were no differences in cystatin C, β2-microglobulin, FENa, urine albumin/creatinine ratio, creatinine clearance, total fluid amount, urine output, drainage, and inotropic and diuretic requirements between the groups. Conclusion: We conclude that usage of HES (130/0.4) did not have negative effects on renal function, and it can be used as a priming solution in pediatric patients undergoing cardiac surgery.

New 6% hydroxyethyl starch 130/0.4 does not increase blood loss during major abdominal surgery—A randomized, controlled trial

Ideal fluid management during surgery still poses a clinical dilemma gauging the benefits and adverse effects. This randomized controlled trial compared the tissue perfusion and coagulation profiles under clinically equivalent hydroxyethyl starch (HES 130/0.4) and lactated Ringer's solution (LR). Eighty-four patients undergoing major abdominal surgery were randomized to receive either HES or LR. Tissue perfusion parameters using heart rate, arterial blood pressure, central venous pressure, cardiac index, stroke volume index, and central venous oxygen saturation were measured at T0 (baseline), T1 (start of surgery), T2 (1 hour after start of surgery), and T3 (end of surgery). Coagulation parameters using thrombelastography (TEG) were measured at T0 (baseline), T4 (after 15mL/kg fluid transfused), and T5 (24 hours after baseline). The total amount of fluid administrated was 1547.9±424.0mL in HES group and 2303.1±1033.7mL in LR group (p<0.001). The parameters of tissue perfusion and TEG did not differ significantly between groups at any time point except for a transient decrease in clot kinetic and clot strength at T4 for HES group. There was no significant difference in blood loss and consumption of blood products between the two fluids. HES 130/0.4 is a more efficient intravascular volume expander to maintain tissue perfusion than conventional crystalloid. Transient hypocoagulability induced by HES 130/0.4 does not warrant excessive blood loss and blood transfusion.

Fluid therapy and acute kidney injury in cardiogenic shock after cardiac arrest

Aim of the studyIt has recently been suggested that acute kidney injury (AKI) may strongly be influenced by post-resuscitation disease and cardiogenic shock (CS), and may not just be a consequence of cardiac arrest and time without spontaneous circulation. AKI also has been suggested as a strong independent predictor of in-hospital mortality. Therefore the present study aimed at investigating the effect of fluid management on the incidence of AKI in patients with cardiogenic shock after cardiac arrest treated by mild therapeutic hypothermia. MethodsFluid therapy and the incidence of acute kidney injury (AKI) was retrospectively reviewed in 51 patients with cardiogenic shock after cardiac arrest comparing patients with and without hemodynamic (PPV, SVV) and volumetric (ELWI, GEDI) monitoring. ResultsThere was no significant difference in baseline or cardiac arrest characteristics between hemodynamic monitored patients and conventional monitored patients. 28 patients were monitored by standard monitoring, in 23 patients monitoring was complemented by a PICCO system. In the first 24h of treatment the total amount of fluid was significantly higher in patients under PICCO monitoring compared to conventional monitoring (4375±1285ml vs. 5449±1438ml, p=0.007). This was associated with a significant reduction in the incidence of AKI (RIFLE ‘I’/‘F’: PICCO-group: 1 (4.3%) vs. conventional group 8 (28.6%), p=0.03). ConclusionThe presented data suggest that volume therapy guided by volumetric (ELWI, GEDI) and arterial waveform derived variables (PPV, SVV) can reduce the incidence of AKI in patients with cardiogenic shock after cardiac arrest treated with mild therapeutic hypothermia.

Effects Of Isobaric Bupivacaine In Endoscopic Urological Surgeries Under Spinal Anaethesia

Introduction: Isobaric bupivacaine is not routinely practiced as a subarachnoid block, though it may be used as an alternative to traditional hyperbaric solution with less complications and a good operative condition in endoscopic urologic surgery. Objective: This prospective randomized study was conducted over a period of 18 months to evaluate the effects of isobaric bupivacaine with low dose fentanyl in endoscopic urologic surgeries under spinal anaesthesia. Methods: Two equally sized groups (n=60) of male patients were randomly selected and studied for routine endo-urological surgeries under subarachnoid block. One group received 0.5% hyperbaric bupivacaine (HBF) and the other group received 0.5% isobaric bupivacaine (IBF). In both groups bupivacaine was mixed with low dose fentanyl (10 microgram) and 1 ml distilled water. Non-invasive blood pressure, heart rate, SpO2, levels of sensory and motor blockade were recorded frequently. Complications of intrathecal block (if developed) were also recorded and treated. Results: The mean operation time was 49.9±9.55 and 50.10.10±7.98 minutes in HBF and IBF groups respectively and the difference was not statistically significant (p&gt;0.05). The mean time to request for first analgesic was 402.50 ± 37.21 and 288.90±25.22 minutes in HBF and IBF groups respectively and the difference was statistically significant (p&lt;0.001). There was no difference in the level of sensory block and total amount of fluid infused (p&gt;0.05). Base line heart rate and blood pressure of the two studied groups were similar. After the subarachnoid block blood pressure reduced significantly in both the groups (p&lt;0.001) but remained within the acceptable level for the surgery. No significant differences in complications like shivering, nausea, vomiting, hypotension, bradycardia were observed in the groups. Conclusion: Intrathecal isobaric bupivacaine with low dose fentanyl may be used as an alternative to traditional hyperbaric bupivacaine for endoscopic urologic surgeries with less side effects related to intrathecal opioid. DOI: http://dx.doi.org/10.3329/jafmc.v7i2.10394 JAFMC 2011; 7(2): 33-36

Effect of viscoelasticity on liquid transfer during gravure printing

Roll-to-roll patterning of small-scale features on a rapidly moving web is an industrially important process with a wide array of commercial applications both old and new. Examples include magazine printing and more recently the pattering of flexible electronics. Among the many existing web coating techniques for large-scale fabrication, slit die and gravure coating are the most commonly used. In gravure coating, an engraved roller with a regular array of shallow cavities/cells is used to pick up fluid from a bath. It is then passed through a flexible doctoring blade in order to meter off excess fluid before printing the fluid onto a flexible substrate. Here we present an experimental investigation into the effect that viscoelasticity has on the dynamics of liquid transfer from an idealized gravure cell to a flat rigid substrate. Although the dynamics of the actual gravure coating process is quite complex, we chose to study a simplified process by imposing an extensional flow using a modified filament stretching rheometer in which one of the endplates is replaced by a cell containing a single truncated conical gravure cell. The deformation and stretching of the resulting liquid bridges, the motion of the contact line within the gravure cell and the total amount of fluid removed from the gravure cell are studied as a function of the imposed stretch rate, the fluid rheology, and the geometry of the gravure cell. Two different viscoelastic solutions of high molecular weight polyethylene oxide in water were studied and compared to a series of Newtonian fluids. The results show that the primary impact of viscoelasticity is the addition of an elastic stress which increases the tension along the liquid bridge and significantly increases the bridge lifetime. For stretches where the gravure cell was placed on the bottom and the top plate moved vertically, viscoelasticity was found to significantly reduce the amount of fluid transferred to the top plate. However, by placing the gravure cell on top and reversing the relative direction of the inertial and gravitational stresses, viscoelasticity was found to significantly increase the amount of fluid transferred. Increasing the stretch rate was found to amplify these observations. Finally, increasing the contact angle between the fluid and the gravure cell and decreasing the aspect ratio of the gravure cell were both found to increase the amount of fluid transferred.

The value of mastectomy flap fixation in reducing fluid drainage and seroma formation in breast cancer patients

BackgroundProlonged and excessive drainage of serous fluid and seroma formation constitute the most common complications after mastectomy for breast carcinoma. Seroma formation delays wound healing, increases susceptibility to infection, skin flap necrosis, persistent pain and prolongs convalescence. For this, several techniques have been investigated to improve primary healing and minimize seroma formation.Materials and methodsBetween June 2009 and July 2010 forty patients with breast carcinoma, scheduled for modified radical mastectomy, were randomly divided into 2 groups, the study group (20) and the control group (20). In the study group; the mastectomy flaps were fixed to the underlying muscles in raws, at various parts of the flap and at the wound edge using fine absorbable sutures. In the control group; the wound was closed in the conventional method at the edges. Closed suction drains were used in both groups. Patients, tumor characteristics and operative related factors were recorded. The amount and color of drained fluid were recorded daily. The drains were removed when the amount become less than 50 cc. The total amount and duration of drained fluid and the formation of seroma were recorded and the results were compared between the two groups.ResultsIn the flap fixation group, the drain was removed in significantly shorter time compared to the control group (p < 0.001). Also, the total amount of fluid drained was significantly lower in the flap fixation group (p < 0.001). The flap fixation group showed a significantly lower frequency of seroma formation compared to the control group, both clinically (p = 0.028) and ultrasonographically (p = 0.047).ConclusionsThe mastectomy flap fixation technique is a valuable procedure that significantly decreases the incidence of seroma formation, and reduces the duration and amount of drained fluid. However, it should be tried on a much wider scale to prove its validity.

Retrospective analysis on transient tachypnea of the newborn: is it associated with spinal anesthesia after cesarean section?

We investigated whether maternal gestation, newborn gender, delivery times and cord blood gas and pH might play a role in the increased risk of transient tachypnea of the newborn (TTN) after cesarean section (C/S). Data from 114 term parturients scheduled for elective C/S under spinal anesthesia were retrospectively analyzed according to having a newborn with TTN or not. Presence of TTN, neonatal Apgar scores, umbilical artery (UA) and umbilical venous (UV) blood gas analysis and pH, total amount of fluid and ephedrine administered, time intervals related to delivery were documented. TTN was observed in 15 out of 114 cases (13.2%). No significant differences were observed in gestation age, Apgar scores, newborn gender, amount of ephedrine and fluid administered between newborns with or without TTN. Mean UA PO2 tensions of TTNs were significantly lower than in newborns without TTN (p=0.043). Time interval from spinal block to skin incision was significantly longer in newborns with TTN than without TTN (p=0.046). In conclusion, TTN might be associated with spinal anesthesia for C/S. Therefore, reducing the time interval from spinal block to onset of surgery might be one of the important factors to decrease the incidence of TTN after elective C/S under spinal anesthesia.

Fluid overload and changes in serum creatinine after cardiac surgery: predictors of mortality and longer intensive care stay. A prospective cohort study

IntroductionFluid overload is a clinical problem frequently related to cardiac and renal dysfunction. The aim of this study was to evaluate fluid overload and changes in serum creatinine as predictors of cardiovascular mortality and morbidity after cardiac surgery.MethodsPatients submitted to heart surgery were prospectively enrolled in this study from September 2010 through August 2011. Clinical and laboratory data were collected from each patient at preoperative and trans-operative moments and fluid overload and creatinine levels were recorded daily after cardiac surgery during their ICU stay. Fluid overload was calculated according to the following formula: (Sum of daily fluid received (L) - total amount of fluid eliminated (L)/preoperative weight (kg) × 100). Preoperative demographic and risk indicators, intra-operative parameters and postoperative information were obtained from medical records. Patients were monitored from surgery until death or discharge from the ICU. We also evaluated the survival status at discharge from the ICU and the length of ICU stay (days) of each patient.ResultsA total of 502 patients were enrolled in this study. Both fluid overload and changes in serum creatinine correlated with mortality (odds ratio (OR) 1.59; confidence interval (CI): 95% 1.18 to 2.14, P = 0.002 and OR 2.91; CI: 95% 1.92 to 4.40, P <0.001, respectively). Fluid overload played a more important role in the length of intensive care stay than changes in serum creatinine. Fluid overload (%): b coefficient = 0.17; beta coefficient = 0.55, P <0.001); change in creatinine (mg/dL): b coefficient = 0.01; beta coefficient = 0.11, P = 0.003).ConclusionsAlthough both fluid overload and changes in serum creatinine are prognostic markers after cardiac surgery, it seems that progressive fluid overload may be an earlier and more sensitive marker of renal dysfunction affecting heart function and, as such, it would allow earlier intervention and more effective control in post cardiac surgery patients.

Optimal flow control in acyclic networks with uncontrollable routings and precedence constraints

This paper introduces a novel optimal flow control problem that seeks to convey a specified amount of fluid to each of the nodes of an acyclic digraph with a single source node, while minimizing the total amount of fluid inducted into the network. Two factors complicating the aforementioned task are (i) the presence of nodes with uncontrollable routing of the traversing flow and (ii) a set of precedence constraints regarding the satisfaction of the nodal fluid requirements. It is shown that the considered problem can be naturally formulated as a continuous-time optimal control problem that can be reduced to a hybrid optimal control problem with controlled switching. This property subsequently enables the solution of the considered problem through a Mixed Integer Programming formulation. Additional results in the paper establish the NP-hardness of the considered problem, highlight its affinity to some well known scheduling problems, and offer guidelines that can alleviate the increased problem complexity.

Performance of the On-Q Pain Infusion Device During Hyperbaric Therapy

There are reports in the literature regarding the effects of hyperbaric conditions on various medical devices. In the current study we evaluated the performance of an elastomeric infusion device during exposure to a hyperbaric environment. Nineteen disposable 400-mL On-Q pain ball infusion devices were filled with 0.2% ropivacaine and connected to an infusion catheter. The regulator of the device was set to deliver 14 mL/h. Hyperbaric oxygen therapy included 7 minutes to achieve the desired hyperbaric pressure level, 90 minutes at the specific pressure (atm), and 7 minutes to return to normal atmospheric pressure (1 atm), thereby resulting in a study interval or dive of 104 minutes. The trials were performed for the devices in the following sequence of dives with a return to 1 atm between: 1, 2, 2.4, 2.8, 3, and 1 atm. The fluid delivered during each dive was measured with a graduated column. Additionally, the collection device was weighed before and at the completion of each dive to determine the change in weight as a measure of the total amount of fluid infused. The output over 104 minutes was also studied in 5 infusion devices without hyperbaric pressure (control group). No difference in output of the devices was noted when comparing the study group and the control group. Although there was a decrease in the output of the devices over 8 to 9 hours, no difference between the 2 groups was noted. This preliminary investigation demonstrates no clinically significant change in the function of the On-Q pain device during exposure to a hyperbaric environment.

Estimating the Volume of Chronic Pleural Effusions Using Transesophageal Echocardiography

To develop a simple method of quantifying the volume of chronic pleural effusions caused by heart failure using transesophageal echocardiography measurement of the maximum cross-sectional area of the pleural effusion. A prospective observational case series. An operating room. Twenty-eight patients undergoing cardiac surgery known to have chronic pleural effusions caused by heart failure diagnosed preoperatively in whom surgical management included draining the effusion. Transesophageal echocardiography was in situ for clinical reasons. The drainage of all pleural effusions was performed according to clinical judgement. The maximum cross-sectional area (CSA(max)) in centimeters squared of the pleural effusion on transesophageal echocardiography was recorded. The chest and pleural cavity were opened, the pleural effusion was drained, and total amount of fluid drained was recorded. The data were analyzed on a log-log plot with the conclusion that volume (V) in milliliters could be estimated from the following formula: V = 4.5 · CSA(max)(3/2). This study showed a simple way of quantifying the volume of chronic pleural effusions from heart failure in patients undergoing cardiac surgery, with potential for clinical applications.

Faster Rate of Initial Fluid Resuscitation in Severe Acute Pancreatitis Diminishes In-Hospital Mortality

Background/Aims:We evaluated the impact of the initial intravenous fluid resuscitation rate within the first 24 h of presentation to the emergency room on important outcomes in severe acute pancreatitis. Methods: Patients presenting directly with a diagnosis of severe acute pancreatitis were identified retrospectively. Patients were divided into two groups — those who received ≥.33% (‘early resuscitation’) and <33% (‘late resuscitation’) of their cumulative 72-hour intravenous fluid volume within the first 24 h of presentation.The primary clinical outcomes were in-hospital mortality, development of persistent organ failure, and duration of hospitalization. Results: 17 patients were identified in the ‘early resuscitation’ group and 28 in the ‘late resuscitation’ group and there were no baseline differences in clinical characteristics between groups. Patients in the ‘late resuscitation’ group experienced greater mortality than those in the ‘early resuscitation’ group (18 vs. 0%,p<0.04) and demonstrated a trend toward greater rates of persistent organ failure (43 vs. 35%, p = 0.31). There was no difference in the total amount of fluid given during the first 72 h. Conclusions: Patients with severe acute pancreatitis who do not receive at least one third of their initial 72-hour cumulative intravenous fluid volume during the first 24 h are at riskfor greater mortality than those who are initially resuscitated more aggressively.

Application of numerical modelling to a case of compaction-driven dolomitization: a Jurassic palaeohigh in the Po Plain, Italy

Dolomitization of a carbonate platform can occur at different times and in different diagenetic environments, from synsedimentary to deep burial settings. Numerical simulations are valuable tools to test and select the model that, among different hypotheses compatible with field and geochemical data, best honour mass balance, kinetic and thermodynamic constraints. Moreover, the simulation can predict the distribution of the dolomitized bodies in the subsurface and evaluate porosity changes; valuable information for the oil industry. This study is the first attempt to reproduce and investigate the compaction dolomitization model. The diagenetic study of the Jurassic carbonate basin and palaeohigh system of the Po Plain indicates that the carbonates of the palaeohighs were dolomitized by basin compaction fluids. The main goal of the simulations is to evaluate the origin and evolution of the dolomitizing fluids and to provide insights regarding the distribution of the potential reservoir-dolomitized bodies in the Po Plain. The modelling process is subdivided into two steps: basin modelling and reactive transport modelling. The SEBE3 basin simulator (Eni proprietary) was used to create a three-dimensional model of the compacting system. The results include compaction fluid flow rate from the basin to the palaeohigh, compaction duration and a determination of the total amount of fluid introduced into the palaeohigh. These data are then used to perform reactive transport modelling with the TOUGHREACT code. Sensitivities on dolomite kinetic parameters suggest that dolomitization was an efficient process even at low temperatures, with differences mainly related to the dynamics of the process. Fluid composition is one of the main constraints, the sea water derived compaction fluid is proven to be efficient for dolomitization due to its relatively high Mg content. Simulations also confirmed that permeability is the most important factor influencing fluid flow and, consequently, the dolomite distribution in the formation. Permeable fractured zones have a strong influence, diverting the dolomitizing fluids from their normal path towards overlying or lateral zones. Moreover, the simulations showed that, after dolomite replacement is complete, the dolomitizing fluids can precipitate dolomite cement, causing over-dolomitization, with related localized plugging effects in the zone of influx. Mass balance calculations indicate that in the dolomitization compaction model, the amount of compaction water fluxed from the basin to the carbonate is the main constraint on dolomitization efficiency. This observation implies that the ratio between the volume of the basin undergoing compaction and the volume of the palaeohigh is a limiting factor on the final size of the dolomitized bodies. An isolated palaeohigh could be an ideal site for pervasive replacement dolomitization due to the large volume of compaction fluids available compared with the carbonate rock volume. In the case of large platforms, the more permeable margin lithofacies are the most likely sites for compaction model dolomitization. The combined use of a basin simulator and reactive transport modelling has proved to be a successful method to verify model reliability and it provides insights into the volumetric distribution of diagenetic products.

Fluid therapy for severe acute pancreatitis in acute response stage

Background Fluid therapy for severe acute pancreatitis (SAP) should not only resolve deficiency of blood volume, but also prevent fluid sequestration in acute response stage. Up to date, there has not a strategy for fluid therapy dedicated to SAP. So, this study was aimed to investigate the effects of fluid therapy treatment on prognosis of SAP. Methods Seventy-six patients were admitted prospectively according to the criteria within 72 hours of SAP onset. They were randomly assigned to a rapid fluid expansion group (Group I, n=36) and a controlled fluid expansion group (Group II, n=40). Hemodynamic disorders were either quickly (fluid infusion rate was 10-15 ml·kg-1·h-1, Group I) or gradually improved (fluid infusion rate was 5-10 ml·kg-1·h-1, Group II) through controlling the rate of fluid infusion. Parameters of fluid expansion, blood lactate concentration were obtained when meeting the criteria for fluid expansion. And APACHE II scores were obtained serially for 72 hours. Rate of mechanical ventilation, incidence of abdominal compartment syndrome (ACS), sepsis, and survival rate were obtained. Results The two groups had statistically different (P &lt;0.05) time intervals to meet fluid expansion criteria (Group I, 13.5±6.6 hours; Group II, (24.0±5.4) hours). Blood lactate concentrations were both remarkably lower as compared to the level upon admission (P &lt;0.05) and reached the normal level in both groups upon treatment. It was only at day 1 that hematocrit was significantly lower in Group I (35.6%±6.8%) than in Group II (38.5%±5.4%) (P&lt;0.01). Amount of crystalloid and colloid in group I ((4028±1980)ml and (1336±816)ml) on admission day was more than those of group II ((2472±1871)ml and (970±633)ml). No significant difference was found in the total amount of fluids within four days of admission between the two groups (P&gt;0.05). Total amount of fluid sequestration within 4 days was higher in Group I ((5378±2751)ml) than in Group II ((4215±1998)ml, P &lt;0.05). APACHE II scores were higher in Group I on days 1, 2, and 3 (P &lt;0.05). Rate of mechanical ventilation was higher in group I (94.4%) than in group II (65%, P &lt;0.05). The incidences of abdominal compartment syndrome (ACS) and sepsis were significantly lower in Group II (P &lt;0.05). Survival rate was remarkably lower in Group I (69.4%) than in Group II (90%, P &lt;0.05). Conclusions Controlled fluid resuscitation offers better prognosis in patients with severe volume deficit within 72 hours of SAP onset.

A prospective randomized trial: The influence of intraoperative application of fibrin glue after radical inguinal/iliacal lymph node dissection on postoperative morbidity

Background Effects of intraoperative application of fibrin glue following combined radical inguinal and iliacal lymph node dissection (RILND) on the amount of postoperative lymphatic secretion are discussed controversially. To detect whether fibrin glue application results in a decreased lymphatic secretion following RILND a randomized patient blinded clinical trial was conducted. Method Between September 2003 and September 2006 58 patients with stage IV melanoma underwent therapeutic RILND and were randomized into two groups. 29 Patients received 4 cc fibrin glue after RILND whereas 29 patients were only irrigated with saline 0.9 percent. Postoperatively all patients received two inguinal and one iliacal closed suction drain. The main outcome criteria were the duration of drain placement in the wound. Minor criteria were the total amount of secretion and the length of hospital stay. Results There was no difference between the treatment and the control group in the duration of drain placement (fibrin group: 4 days (1–27); control group 5 days (1–26); p = 0.64). The total amount of fluid was 310 cc (30–6005) in the fibrin group vs. 365 cc (30–3945 cc) in the control group ( p = 0.9) and the length of hospital stay 10 days (3–41) (group 1) compared to 11 days (3–41) ( p = 0.99) were not different between both groups either. Conclusion Intraoperative application of 4 cc fibrin glue does not reduce the length of drain placement, drain output or hospitalisation of patients undergoing RILND with melanoma metastasis to the lymph node basin.

Application of ultrasound-guided pigtail catheter for drainage of pleural effusions in the ICU

Little is known about the effectiveness of the pigtail catheter for drainage of pleural effusions in the intensive care unit (ICU). We conducted a retrospective review of adult patients (>/=18 years) who underwent ultrasound-guided pigtail catheter drainage of pleural effusions in the ICUs from January 2005 to July 2007 in a university hospital. Among the 133 enrolled patients, there were 93 (70%) males and 40 (30%) females, with a mean age of 63.7 +/- 15.4 years old. The reasons for pigtail drainage were as follows: thoracic empyema (n = 59, 44%), massive transudative pleural effusions (n = 33, 25%), postoperative pleural effusion (n = 29, 15%), malignant pleural effusion (n = 18, 14%) and traumatic hemothorax (n = 3, 2%). In comparing the total amount of fluids drained, the duration of drainage, success rate and complication rate among these different causes of pleural effusion, pigtail drainage for massive transudative pleural effusion yielded the largest amount of pleural fluids (5,382 +/- 4,844 ml), provided the longest duration of drainage (9 +/- 7 days), and had the highest complication rate (18%). The success rate was highest when used to treat traumatic hemothorax (100%) and postoperative pleural effusions (85%); drains inserted for empyema were more likely to fail (overall success rate, 42%). No significant insertion complications, such as hollow organ perforation, were caused by this procedure. The ultrasound-guided pigtail catheter inserted by intensivists is a well-tolerated and effective method of draining all kinds of pleural effusions in critically ill patients. We suggest that pigtail catheter drainage be considered as the initial treatment of choice in the ICU.

Steady states in granulation of pharmaceutical powders with application to scale-up

Theoretical and experimental evidence is given to show that steady states can be reached during agglomerate growth and break-up in high-shear granulation of fine powders. An earlier theoretical model [G.I. Tardos, I.M. Khan and P.R. Mort, Critical parameters and limiting conditions in binder granulation of fine powders, Powder Technology, 94, 245–258 (1997).], based on simple energy-dissipation considerations hinted at the existence of these states at the point where growth is counterbalanced by breakage. Further theoretical evidence is obtained from molecular dynamic simulations of wet and dry particles situated in a constant shear field [I. Talu, G.I. Tardos and M.I. Khan, Computer simulation of wet granulation, Powder Technology, 110, 59–75 (2000).], where the size distribution of initially identical particles, shifts in time to reach a dynamic steady state. Under the conditions of this steady state, the number of breaking agglomerates approximately equals the number of forming ones to yield a time independent final-size distribution. Experimental evidence to support the theoretical findings is obtained during the present research by measuring particle size distributions at line at crucial points during granulation of a typical pharmaceutical powder in a high-shear mixer. In order to reach a steady state, binder addition has to be slow enough and wet massing has to be long enough so that neither has an influence on the final properties of the granules. We show experimentally that if binder is spread properly and homogeneously in the powder and continuous shearing of the wet mass ensures homogeneous, equal growth of the granules, the steady state will only be a function of the total amount of fluid added provided that the shear forces in the machine are maintained constant. These findings are important in that they show that under carefully controlled conditions of binder addition and shear in the mixer, the granulation process is robust and controllable and can, in principle, be scaled up with ease once the powder ingredients and the total amount of binder are fixed.

Intraoperative Application of Fibrin Sealant does not Reduce the Duration of Closed Suction Drainage Following Radical Axillary Lymph Node Dissection in Melanoma Patients: A Prospective Randomized Trial in 58 Patients

Patients suffering from malignant melanoma often require radical lymph node dissection of the axillary nodal basin. The effects of intraoperative application of fibrin sealant following radical axillary lymph node dissection (RALND) on the incidence of postoperative lymphatic secretion are discussed. To study the effect of intraoperatively applied fibrin sealant following RALND a randomized patient-blinded trial was carried out. Fifty-eight patients with axillary lymph node metastases of malignant melanoma underwent therapeutic RALND and were randomized into two groups: 29 patients received 2 cc of fibrin glue intraoperatively and 29 patients were only irrigated with 0.9% saline. The amount of drainage was recorded every 24 h. The main outcome criterion was the duration of drain placement in the wound. Minor criteria were the total amount of fluid and the length of hospital stay. Statistical analysis was performed using Spearman's log-rank correlation and paired t-test. There was no significant difference between the nonfibrin group 5 days (range = 3.6-5.7 days) and the fibrin group 5 days (range = 4.1-8.5 days) (p = 0.701). The total amount of fluid for the nonfibrin group (410 cc, range = 362-727 cc) and that for the fibrin group (503 cc, range = 369-1098 cc) (p = 0.605) and the length of postoperative hospital stay of 6 days (range = 5.4-7) vs. 7 days (range = 5.9-10.7), respectively, were not different between both groups (p = 0.387). Considering our study results, we cannot recommend the use of 2 cc of fibrin glue intraoperatively in the prevention of lymphatic secretion in patients undergoing RALND for metastatic melanoma.

An artificial intelligence tool to predict fluid requirement in the intensive care unit: a proof-of-concept study

IntroductionThe goal of personalised medicine in the intensive care unit (ICU) is to predict which diagnostic tests, monitoring interventions and treatments translate to improved outcomes given the variation between patients. Unfortunately, processes such as gene transcription and drug metabolism are dynamic in the critically ill; that is, information obtained during static non-diseased conditions may have limited applicability. We propose an alternative way of personalising medicine in the ICU on a real-time basis using information derived from the application of artificial intelligence on a high-resolution database. Calculation of maintenance fluid requirement at the height of systemic inflammatory response was selected to investigate the feasibility of this approach.MethodsThe Multi-parameter Intelligent Monitoring for Intensive Care II (MIMIC II) is a database of patients admitted to the Beth Israel Deaconess Medical Center ICU in Boston. Patients who were on vasopressors for more than six hours during the first 24 hours of admission were identified from the database. Demographic and physiological variables that might affect fluid requirement or reflect the intravascular volume during the first 24 hours in the ICU were extracted from the database. The outcome to be predicted is the total amount of fluid given during the second 24 hours in the ICU, including all the fluid boluses administered.ResultsWe represented the variables by learning a Bayesian network from the underlying data. Using 10-fold cross-validation repeated 100 times, the accuracy of the model in predicting the outcome is 77.8%. The network generated has a threshold Bayes factor of seven representing the posterior probability of the model given the observed data. This Bayes factor translates into p < 0.05 assuming a Gaussian distribution of the variables.ConclusionsBased on the model, the probability that a patient would require a certain range of fluid on day two can be predicted. In the presence of a larger database, analysis may be limited to patients with identical clinical presentation, demographic factors, co-morbidities, current physiological data and those who did not develop complications as a result of fluid administration. By better predicting maintenance fluid requirements based on the previous day's physiological variables, one might be able to prevent hypotensive episodes requiring fluid boluses during the course of the following day.

Microstructural Characterization of Adsorption and Depletion Regimes of Supercritical Fluids in Nanopores

Fluid accommodation in porous media has been studied over a wide range of pressures at three supercritical temperatures by small-angle neutron scattering. A new formalism gives for the first time the mean density and volume of the adsorbed fluid phase formed in the pores from experimental data; thus, excess, absolute, and total adsorption become measurable quantities without the introduction of further assumptions. Results on propane adsorption to a silica aerogel show the formation of a thin adsorption layer of high density at low bulk fluid pressures and densities. In that region, the density of the adsorption layer increases with increasing fluid density while its volume remains approximately constant. Depletion of the fluid from the pore space is found near and above the critical density, which leads to negative values of the excess adsorption. At high fluid densities, the pores are evenly filled with fluid of lower density than the bulk fluid. The total amount of fluid confined in the pore spaces inc...