Audrius Andrijauskas

The maintenance and monitoring of perioperative blood volume

The assessment and maintenance of perioperative blood volume is important because fluid therapy is a routine part of intraoperative care. In the past, patients undergoing major surgery were given large amounts of fluids because health-care providers were concerned about preoperative dehydration and intraoperative losses to a third space. In the last decade it has become clear that fluid therapy has to be more individualized. Because the exact determination of blood volume is not clinically possible at every timepoint, there have been different approaches to assess fluid requirements, such as goal-directed protocols guided by invasive and less invasive devices.This article focuses on laboratory volume determination, capillary dynamics, aspects of different fluids and how to clinically assess and monitor perioperative blood volume.

Evaluation of hydration status calculated from differences in venous and capillary plasma dilution during stepwise crystalloid infusions: A randomized crossover study in healthy volunteers

BACKGROUND AND OBJECTIVE A mini volume loading test (mVLT) was proposed for estimating hydration status and interstitial fluid accumulation during stepwise infusion of crystalloids. The method is based on both the transcapillary reflux model and the hypothesis that when subjects are dehydrated, venous plasma dilution induced by a fluid challenge is higher than in the capillaries, and that difference is diminished when the fluid challenge is given to more hydrated individuals. Our objective was to test that hypothesis by evaluating the veno-capillary dilution difference during mVLT in subjects with different hydration status. MATERIALS AND METHODS In a prospective randomized crossover study, three mini fluid challenges were given to 12 healthy volunteers on two occasions. The subjects were either dehydrated or hydrated before the experiments. RESULTS In dehydrated subjects only, capillary plasma dilution was significantly lower than venous (P=0.015, 0.005 and 0.006) after each mini fluid challenge. CONCLUSIONS Veno-capillary dilution difference during mVLT depends on the hydration status. The mVLT method could possibly discriminate between the different states of hydration.

Goal Directed Fluid Therapy Revised: Indirect Monitoring of Interstitial Fluid Accumulation During Mini Fluid Challenges with Crystalloids

Goal directed fluid therapy (GDT) implies administration of fluid boluses with the aim of optimizing cardiac performance. There is a major concern that maximization of cardiovascular performance can be achieved in expense of deterioration in body hydration processes. Also, these methods require semi invasive devices. However, monitoring of the whole body hydration status and interstitial fluid accumulation during fluid loading is not possible in everyday clinical practice. A new method, minimum Volume Loading Test (mVLT), uses evaluation of plasma dilution efficacy in small fluid boluses (2.5 - 5.0 ml kg -1 ) of isoosmotic crystalloid solutions followed by 5 min periods without fluids. The inva- sively measured arterial and venous hemoglobins, and simultaneous non-invasively measured hemoglobin (SpHb TM from Radical-7, Masimo inc., Irvine, USA) are used for estimation of plasma dilution which serves as an indication of plasma volume expansion. The objective of this paper was to discuss plasmadilution as a target parameter for goal directed therapy. Could plasma di- lution also indicate a degree of interstitial fluid accumulation?

A mini volume loading test for indication of preoperative dehydration in surgical patients.

BACKGROUND AND OBJECTIVE Previously, a mini volume loading test (mVLT) detected signs of dehydration in healthy volunteers after an overnight fast. Our objective was to investigate whether mVLT could indicate preoperative dehydration in patients after an overnight fast. MATERIALS AND METHODS The mVLT was performed in 36 elective primary total knee arthroplasty patients. Each subject received three fluid challenges before anesthesia induction. These consisted of 5 mL/kg boluses of Ringers acetate infused over 3-5 min and followed by a 5-min period without fluids. Invasive (arterial, venous) and noninvasive (capillary) measurements of hemoglobin concentration were performed before and after each fluid challenge, as well as after a 20-min period without fluids which followed the last bolus. Arterial, venous and capillary plasma dilutions were calculated in every data point. Dilution values were used to calculate the plasma dilution efficacy of each fluid challenge. RESULTS Venous dilution was higher than capillary after the first fluid challenge (P=0.030), but lower than capillary after 20 min period following the last bolus (P=0.009). Arterial dilution was lower than capillary (P=0.005) after 20 min following the last bolus. Veno-capillary and arterio-capillary plasma dilution efficacy differences decreased (P=0.004 and P=0.033, respectively) from positive to negative during mVLT. These are signs of re-hydration from pre-existing dehydration according to a transcapillary reflux model. CONCLUSIONS Signs of dehydration were observed during mVLT in patients after pre-operative overnight fast. A revised transcapillary reflux model was proposed to explain the results.

A mini volume loading test (mVLT) using 2.5-mL kg−1 boluses of crystalloid for indication of perioperative changes in hydration status

BACKGROUND AND OBJECTIVE A mini volume loading test (mVLT) evaluating hemodilution during step-wise crystalloid infusion has established that the arterio-capillary plasma dilution difference is inversely correlated to the body hydration level of subjects. This observational study aimed to test whether this can be replicated in a perioperative setting using a 2.5-mLkg-1 boluses. MATERIALS AND METHODS The mVLT was performed before induction of regional anesthesia and 24h later. Step-wise infusion implied six mini fluid challenges. These consisted of 2.5-mLkg-1 boluses of Ringers acetate infused during 2-3min and followed by 5-min periods with no fluids. Invasive (arterial) and noninvasive (capillary) measurements of hemoglobin were performed before and after each mini fluid challenge, as well as after a 20-min period without fluid following the last bolus. Hemoglobins were used to calculate the arterio-capillary plasma dilution difference which is used as an indication of changes in body hydration level. The 24-h fluid balance was calculated. RESULTS Subjects were 69.5 (6.0) years old, their height was 1.62m (1.56-1.65), weight was 87.0kg (75.5-97.5) and body mass index (BMI) was 33.5kg/m2 (31.0-35.1). Preoperative arterio-capillary plasma dilution difference was significantly higher than postoperative (0.085 [0.012-0.141] vs. 0.006 [-0.059 to 0.101], P=0.000). The perioperative 24-h fluid balance was 1976mL (870-2545). CONCLUSIONS The mVLT using 2.5-mLkg-1 boluses of crystalloid was able to detect the higher postoperative body hydration level in total knee arthroplasty patients.

Different Stabilization Techniques for Type 62B3 Acetabular Fractures in Combination With Primary Total Hip Arthroplasty in Elderly Patients: A Biomechanical Comparison

Introduction: The total hip arthroplasty (THA) as part of acute fracture management is used for acetabular fractures in elderly patients. Our objective was to assess the stability of osteosynthesis performed using 2 different techniques in combination with THA in an experimental model. Materials and Methods: We conducted 20 experiments using the left-side hemipelves composite bone models. There were 2 testing groups: 1- and 2-stage osteosynthesis. The acetabular fractures of the anterior column and posterior hemitransverse were simulated. The same THA technique was used in both groups. The stability of osteosynthesis was explored and compared between the groups by measuring the fracture displacement of anterior and posterior columns under the standardized test load (1187 N) protocol. Load distance diagrams were generated. Results: The 0.680-mm gap (0.518; 1.548) of the posterior column in the 1-stage group (n = 10) was higher than the 0.370-mm gap (0.255; 0.428) in the 2-stage group (n = 10; P = .002). There was no significant difference between the gap of the anterior column in the 1- and 2-stage groups (0.135 [0.078; 0.290] mm vs 0.160 [0.120; 0.210] mm; P = .579). Conclusion: The 2-stage osteosynthesis of the anterior and posterior columns in combination with THA provides better stability of posterior column when compared to 1-stage method in composite bone models.

Intra-articular morphine or neostigmine does not assure better pain relief

Background and ObjectivesChoice of optimal postoperative analgesia technique remains challenging. Our double — blind randomized prospective clinical study compares efficacy of end-of- surgery intra-articular application of morphine or neostigmine after anterior crutiate ligament repair.Methods60 adult ASA I–II patients were randomized into 3 groups: intra-articular morphine 6 mg, neostigmine 0.5 mg, placebo. All received femoral nerve block and spinal anesthesia. Numeric rating scale used for pain assessment at rest and motion during 48 postoperative hours, and 0–10 scale for evaluation of overall patient satisfaction. Adjunct analgesics were recorded.ResultsThe only significant difference between protocol groups was better pain relief at motion at the end of trial in neostigmine 0.5 mg group than in placebo (p=0.018). Consumption of adjuncts wasn’t different on day of surgery, postoperative Day 1 and Day 2 respectively - diclofenac (p=0.85, p=0.41, p=0.9) and tramadol (p=0.62, p=0.72, p=1). Patient satisfaction was similar (p=0.59) among groups.ConclusionsIntra-articular neostigmine provided similar pain control at motion as morphine during the trial, but it was better than placebo on the 2nd postoperative day. Similar pain control at rest, adjunct consumption and patient satisfaction recorded throughout the whole observation period in all groups.

Hipotenzinė anestezija atliekant klubo ir kelio sąnarių endoprotezavimą: į tikslą nukreiptas skysčių terapijos algoritmas

Audrius Andrijauskas 1 , Juozas Ivaskevicius 1 , Manvilius Kocius 2 , Narūnas Porvaneckas 2 , Darius Cincikas 1 , Jeugenija Olsevska 1 1 Vilniaus universiteto Anesteziologijos ir reanimatologijos klinika, Siltnamių g. 29 LT-04130 Vilnius 2 Vilniaus universiteto Reumatologijos, ortopedijos, traumatologijos, plastinės ir rekonstrukcinės chirurgijos klinika, Siltnamių g. 29 LT-04130 Vilnius El pastas: Audrius.Andrijauskas@mf.vu.lt Kontroliuojama hipotenzinė anestezija jau ilgą laiką taikoma siekiant sumažinti kraujo netektį ir kraujo perpylimo poreikį. Be to, sumažinus arterinį kraujo spaudimą, pagerėja operavimo sąlygos („sausas operacinis laukas“). Atsiranda galimybė sumažinti isorinį mechaninį spaudimą, taikomą operuojamos galūnės kraujotakai sustabdyti atliekant kelio sąnario endoprotezavimą, arba net visai jo netaikyti. Siuolaikiniai metodai grindžiami įvairiais valdomą hipotenziją sukelianciais veiksniais, kaip pavyzdžiui, tai gali būti (a) kraujagysles pleciantys vaistai, (b) centrinė simpatinė blokada ir (c) stiprų kardiodepresinį-vazopleginį poveikį turintys inhaliaciniai anestetikai. Taikant hipotenzine anesteziją, didžiausią rūpestį kelia paciento saugumo užtikrinimas. Ypatingą pavojų kelia „nebyli“ organų isemija dėl nepakankamo jų aprūpinimo krauju, nes ji gali sutrikdyti audinių ir organų funkciją ar net sukelti žūtį. Taigi, užtikrinant metodo saugumą lemiama reiksmė tenka efektyvaus cirkuliuojancio tūrio (normovolemijos) palaikymui arterinės hipotenzijos sąlygomis. Deja, iki siol nėra paprasto, patikimo ir veiksmingo metodo, kuris leistų užtikrinti sią ypac svarbią paciento saugumo sąlygą. Tradicinius kraujotakos optimizavimo metodus siuo metu keicia skyscių terapijos metodai, grindžiami į tikslą nukreiptų priemonių taikymo koncepcija. Remdamiesi sia koncepcija autoriai sukūrė klinikinį TNP algoritmą, kuris skirtas normovolemijai užtikrinti, atliekant kelio ir klubo sanario planinį endoprotezavimą hipotenzinės anestezijos sąlygomis. Algoritmas pateikiamas kartu su svarbiausių hemodinamikos parametrų taikymo ir klinikinio interpretavimo ypatumų apžvalga. Reiksminiai žodžiai: hemodinamika, į tikslą nukreipta skyscių terapija, skysciai, transfuzija, algoritmas Hypotensive anaesthesia in total hip and knee arthroplasty: algorithm for the goal-directed fluid management Audrius Andrijauskas 1 , Juozas Ivaskevicius 1 , Manvilius Kocius 2 , Narūnas Porvaneckas 2 , Darius Cincikas 1 , Jeugenija Olsevska 1 1 Vilnius University Clinic of Anaesthesiology and Intensive Care, Siltnamių str. 29 LT-04130 Vilnius, Lithuania 2 Vilnius University Clinic of Rheumatology, Orthopaedics, Traumatology, Plastic and Reconstructive Surgery, Siltnamių str. 29, LT-04130 Vilnius, Lithuania E-mail: Audrius.Andrijauskas@mf.vu.lt Hypotensive anaesthesia is a technique that deploys the controlled reduction of mean arterial pressure. It has been used for decades to reduce intraoperative blood loss and related blood transfusions, also to ensure the ‘dry operating field’ and minimize the tourniquet inflation pressure in patients undergoing total hip (THA) and knee (TKA) arthroplasty. Hypotensive anesthesia can be achieved in different ways such as (a) by decreasing cardiac output with vasodilatory agents, (b) inducing the sympathetic block by spinal and/or epidural anaesthesia, and/or (c) by using potent anesthetic gases in general anaesthesia. The major concern in the method’s clinical applicability is the patient’s safety. Inherent risks related to hypotensive anaesthesia are mainly associated with the concern of occult tissue hypoperfusion resulting from inadequately compensated relative hypovolemia. Therefore, maintaining an effective circulating volume (normovolemia) is crucial for the safe management of controlled arterial hypotension. However, the lack of a simple, reliable and effective method for the guidance of appropriate measures is an ongoing deficiency. Conventional strategies aiming to establish, monitor and maintain normovolemia are currently replaced by the goal-directed management (GDM) in fluid therapy. It has already become a standard of care in selected patients such as those undergoing major abdominal surgery. On the basis of goal-directed fluid management, authors have developed a GDM algorithm for the optimization of fluid status, aiming to secure normovolemia during hypotensive anaesthesia. The new algorithm is highlighted along with a review of related issues of its clinical application. Key words: hemodynamics, goal-directed-management, fluid, transfusion, algorithm