ABSTRACT
INTRODUCTION: Blood loss and red blood cell (RBC) transfusion in liver surgery are areas of concern for surgeons, anesthesiologists, and patients alike. While various methods are employed to reduce surgical blood loss, the evidence base surrounding each intervention is limited. Hypovolemic phlebotomy, the removal of whole blood from the patient without volume replacement during liver transection, has been strongly associated with decreased bleeding and RBC transfusion in observational studies. This trial aims to investigate whether hypovolemic phlebotomy is superior to usual care in reducing RBC transfusions in liver resection. METHODS: This study is a double-blind multicenter randomized controlled trial. Adult patients undergoing major hepatic resections for any indication will be randomly allocated in a 1:1 ratio to either hypovolemic phlebotomy and usual care or usual care alone. Exclusion criteria will be minor resections, preoperative hemoglobin <100g/L, renal insufficiency, and other contraindication to hypovolemic phlebotomy. The primary outcome will be the proportion of patients receiving at least one allogeneic RBC transfusion unit within 30 days of the onset of surgery. Secondary outcomes will include transfusion of other allogeneic blood products, blood loss, morbidity, mortality, and intraoperative physiologic parameters. The surgical team will be blinded to the intervention. Randomization will occur on the morning of surgery. The sample size will comprise 440 patients. Enrolment will occur at four Canadian academic liver surgery centers over a 4-year period. Ethics approval will be obtained at participating sites before enrolment. DISCUSSION: The results of this randomized control trial will provide high-quality evidence regarding the use of hypovolemic phlebotomy in major liver resection and its effects on RBC transfusion. If proven to be effective, this intervention could become standard of care in liver operations internationally and become incorporated within perioperative patient blood management programs. TRIAL REGISTRATION: ClinicalTrials.gov NCT03651154 . Registered on August 29 2018.
Subject(s)
Hypovolemia , Phlebotomy , Adult , Humans , Hypovolemia/diagnosis , Hypovolemia/etiology , Hypovolemia/prevention & control , Phlebotomy/adverse effects , Phlebotomy/methods , Canada , Blood Transfusion , Liver , Randomized Controlled Trials as Topic , Multicenter Studies as Topic , Clinical Trials, Phase III as TopicABSTRACT
Intravascular fluid administration belongs to the cornerstones of perioperative treatment with a substantial impact on surgical outcome especially with respect to major abdominal surgery. By avoidance of hypovolemia and hypervolemia, adequate perioperative fluid management significantly contributes to the reduction of insufficient tissue perfusion as a determinant of postoperative morbidity and mortality. The effective use of intravascular fluids requires detailed knowledge of the substances as well as measures to guide fluid therapy. Fluid management already starts preoperatively and should be continued in the postoperative setting (recovery room, peripheral ward) considering a patient-adjusted and surgery-adjusted hemodynamic monitoring. Communication between all team members participating in perioperative care is essential to optimize fluid management.
Subject(s)
Fluid Therapy , Hemodynamic Monitoring , Abdomen/surgery , Humans , Hypovolemia/prevention & control , Perioperative CareABSTRACT
Fluid intake is an essential innate behaviour that is mainly caused by two distinct types of thirst1-3. Increased blood osmolality induces osmotic thirst that drives animals to consume pure water. Conversely, the loss of body fluid induces hypovolaemic thirst, in which animals seek both water and minerals (salts) to recover blood volume. Circumventricular organs in the lamina terminalis are critical sites for sensing both types of thirst-inducing stimulus4-6. However, how different thirst modalities are encoded in the brain remains unknown. Here we employed stimulus-to-cell-type mapping using single-cell RNA sequencing to identify the cellular substrates that underlie distinct types of thirst. These studies revealed diverse types of excitatory and inhibitory neuron in each circumventricular organ structure. We show that unique combinations of these neuron types are activated under osmotic and hypovolaemic stresses. These results elucidate the cellular logic that underlies distinct thirst modalities. Furthermore, optogenetic gain of function in thirst-modality-specific cell types recapitulated water-specific and non-specific fluid appetite caused by the two distinct dipsogenic stimuli. Together, these results show that thirst is a multimodal physiological state, and that different thirst states are mediated by specific neuron types in the mammalian brain.
Subject(s)
Neurons/classification , Neurons/physiology , Thirst/physiology , Animals , Base Sequence , Drinking/physiology , Female , Hypovolemia/prevention & control , Male , Mice , Mice, Inbred C57BL , Models, Animal , Organum Vasculosum/cytology , Organum Vasculosum/physiology , Osmotic Pressure , Single-Cell Analysis , Subfornical Organ/cytology , Subfornical Organ/physiology , Water DeprivationABSTRACT
Pulse transit time (PTT) is a hemodynamic indicator that may be obtained non-invasively using photoplethysmogram (PPG) signals for continuous blood pressure (BP) monitoring. Among the most promising applications of this technology are military and civilian trauma cases, where reduced blood volume due to hemorrhage, or absolute hypovolemia, is the leading preventable cause of death. However, the drawback of this method is that it requires calibration for each patient; additionally, changes in physiological state may affect PTT calibration. In this work, a porcine model (n = 6) was used to demonstrate that changes in blood volume lead to miscalibration of PTT for BP estimation. To mitigate hypovolemia-induced miscalibration, this work first defines a template-based signal quality index (SQI) for characterizing the morphology of PPG signals; it is then shown that the subject-specific calibration of SQI to BP is more robust to changes in blood volume than PTT. Though changes in PPG signal quality are not necessarily specific to changes in BP, these results suggest that PPG-based monitoring systems may benefit from incorporating morphological information for cuffless BP estimation in trauma settings.
Subject(s)
Hypovolemia , Photoplethysmography , Animals , Blood Pressure , Blood Pressure Determination , Humans , Hypovolemia/prevention & control , Pulse Wave Analysis , SwineABSTRACT
Introducción: Los protocolos ERAS de cirugía colorrectal son programas multimodales cuyo objetivo es minimizar la respuesta al estrés quirúrgico y acelerar así la recuperación del paciente. Un aspecto fundamental es el manejo intraoperatorio de fluidos, ya que tanto la hipovolemia como la hipervolemia se han relacionado con complicaciones. Los protocolos de fluidoterapia guiada por objetivos se basan en la monitorización de parámetros hemodinámicos para guiar la administración de fluidos y optimizar la perfusión tisular. Objetivo: Comparar la aplicación de 2regímenes de fluidoterapia (balance cero vs. optimización hemodinámica) en pacientes intervenidos mediante cirugía colorrectal laparoscópica ERAS, en cuanto a la aparición de infección del sitio quirúrgico, dehiscencia anastomótica, íleo, náuseas y vómitos postoperatorios y cambios en la función renal. Materiales y métodos: Estudio observacional retrospectivo, para comparar la aplicación de 2regímenes de fluidoterapia en pacientes intervenidos mediante cirugía colorrectal laparoscópica ERAS y estudiar la tasa de complicaciones postoperatorias?. Resultados: Recogimos datos de 128 pacientes, en 43 (33,6%) se empleó la fluidoterapia intraoperatoria habitual o balance cero, y en 85 (66,4%) la fluidoterapia guiada por objetivos. El total de fluidos administrados fue menor en el grupo de optimización. La tasa de complicaciones sépticas postoperatorias (infección del sitio quirúrgico o dehiscencia anastomótica) e íleo fue mayor en el grupo balance cero, y la aparición de náuseas y vómitos postoperatorios fue menor en el grupo de optimización; todos estos resultados fueron estadísticamente significativos. No observamos diferencias en la estancia hospitalaria, diuresis intraoperatoria ni en el filtrado glomerular estimado. Conclusión: La aplicación de un algoritmo de fluidoterapia guiada por objetivos puede conseguir una reducción en la cantidad de fluidos administrada, con una menor incidencia en las complicaciones analizadas, sin afectar a la función renal
Introduction: Enhanced recovery after surgery protocols (ERAS) are used in peri-operative care to reduce the stress response to surgical aggression. As fluid overload has been associated with increased morbidity and delayed hospital discharge, a major aspect of this is fluid management. Intra-operative goal-directed fluid protocols have been shown to reduce post-operative complications, particularly in high risk patients.?. Objective: To compare 2fluid therapy models (zero-balance versus goal-directed fluid therapy) in patients who were scheduled for laparoscopic colorectal surgery within an ERAS program, recording the rate of complications such as surgical site infection, ileus, post-operative náusea and vomiting, and variability of the estimated glomerular filtration rate (eGFR). Materials and methods: An observational, retrospective study was conducted including adults who were scheduled for elective laparoscopic colorectal surgery within an ERAS program, and to investigate the postoperative complication rate. Results: A total of 128 patients were included in this study; 43 (33.6%) in the zero-balance group and 85 (66.4%) in the goal-directed fluid therapy group. The total fluids administered was lower in the goal-directed fluid therapy group, as well as the incidence of post-operative complications (surgical site infection, anastomotic leak, ileus, and postoperative náusea and vomiting). No significant differences were found for length of stay, intra-operative urine output, and variability of the eGFR?. Conclusion: The results of this study show that by using a goal-directed fluid therapy algorithm, the total amount of fluids administered can be reduced, as well as obtaining a lower incidence of post-operative complications
Subject(s)
Humans , Male , Female , Middle Aged , Aged , Fluid Therapy/methods , Rehydration Solutions/administration & dosage , Colorectal Neoplasms/surgery , Laparoscopy/methods , Combined Modality Therapy/methods , Postoperative Complications/epidemiology , Hypovolemia/prevention & control , Retrospective Studies , Treatment OutcomeABSTRACT
BACKGROUND: Pulse pressure variation (PPV) and stroke volume variation (SVV) can predict fluid responsiveness effectively. However, high Body Mass Index (BMI) can restrict their use due to changes in respiratory system compliance (CS), intra-abdominal pressure, and stroke volume (SV) in the prone position. Therefore, we aimed to investigate the effectiveness of mini-fluid challenge (MFC) in predicting fluid responsiveness in obese (BMI ≥30 kg/m2) patients in the prone position. METHODS: A total of 33 patients undergoing neurosurgery were included. After standardized anesthesia induction, patients' PPV, SVV, stroke volume index (SVI) and CS values were recorded in the prone position (T1), after the infusion of 100 mL of crystalloid named as MFC (T2) and after fluid loading was completed with additional 400 mL of crystalloid. Patients whose SVI increased more than 15% after the fluid loading were defined as volume responders. RESULTS: Fifteen (45%) patients were responders to 500 mL fluid loading. After the 100 mL fluid load, a higher percentage increase in SVI was observed among responders (P<0.001), with values of 6.6% (6.2-8.6%) and 3.5% (1.7-4.8%) in responders and non-responders, respectively. Areas under the receiver operating characteristic curves of MFC, PPV, and SVV were 0.967 (95% CI: 0.838-0.999), 0.683 (95% CI: 0.499-0.834), and 0.709 (95% CI: 0.526-0.853), respectively. The area under the curve of MFC was significantly higher than that of PPV (P=0.003) and SVV (P=0.005). CONCLUSIONS: The increase in SVI after a rapid infusion of 100 mL crystalloid could predict fluid responsiveness in patients with BMI ≥30 kg/m2 in the prone position.
Subject(s)
Blood Pressure/drug effects , Crystalloid Solutions/pharmacology , Fluid Therapy/methods , Intraoperative Care/methods , Monitoring, Intraoperative/methods , Neurosurgical Procedures , Obesity/physiopathology , Patient Positioning , Prone Position/physiology , Stroke Volume/drug effects , Adult , Area Under Curve , Body Mass Index , Crystalloid Solutions/administration & dosage , Female , Humans , Hypovolemia/prevention & control , Intraoperative Complications/prevention & control , Male , Middle Aged , Prospective Studies , ROC CurveABSTRACT
BACKGROUND: Pulse pressure variation (PPV) and stroke volume variation (SVV) do not predict fluid responsiveness when using a protective ventilation strategy: the use of functional haemodynamic tests can be useful to overcome this limitation. OBJECTIVES: We tested the use of a tidal volume challenge (VTC), during 6âmlâkg [predicted body weight (PBW)] ventilation, and the end-expiratory occlusion test (EEOT) for prediction of fluid responsiveness. DESIGN: An interventional prospective study. SETTING: Supine elective neurosurgical patients. INTERVENTIONS: The study protocol was, first, the initial EEOT test was performed during baseline 6âmlâkg PBW ventilation; second, VTC was performed by increasing the VT up to 8âmlâkg PBW and PPV and SVV changes were recorded after 1âmin; third, a second EEOT was performed during 8âmlâkg PBW ventilation; and VT was reduced back to 6âmlâkg PBW and a third EEOT was performed. Finally, a 250âml fluid challenge was administered over 10âmin to identify fluid responders (increase in stroke volume index ≥10%). RESULTS: In the 40 patients analysed, PPV and SVV values at baseline and EEOT performed at 6âmlâkg PBW did not predict fluid responsiveness. A 13.3% increase in PPV after VTC predicted fluid responsiveness with a sensitivity of 94.7% and a specificity of 76.1%, while a 12.1% increase in SVV after VTC predicted fluid responsiveness with a sensitivity of 78.9% and a specificity of 95.2%. After EEOT performed at 8âmlâkg PBW, a 3.6% increase in cardiac index predicted fluid responsiveness with a sensitivity of 89.4% and a specificity of 85.7%, while a 4.7% increase in stroke volume index (SVI) with a sensitivity of 89.4% and a specificity of 85.7%. CONCLUSION: The changes in PPV and SVV obtained after VTC are reliable and comparable to the changes in CI and SVI obtained after EEOT performed at 8âmlâkg PBW in predicting fluid responsiveness in neurosurgical patients. TRIAL REGISTRATION: ACTRN12618000351213.
Subject(s)
Elective Surgical Procedures/adverse effects , Fluid Therapy/methods , Hypovolemia/prevention & control , Monitoring, Intraoperative/methods , Neurosurgical Procedures/adverse effects , Aged , Blood Pressure/physiology , Female , Fluid Therapy/adverse effects , Humans , Hypovolemia/etiology , Hypovolemia/physiopathology , Male , Middle Aged , Operating Rooms , Predictive Value of Tests , Prospective Studies , ROC Curve , Reproducibility of Results , Respiration, Artificial/adverse effects , Respiration, Artificial/methods , Stroke Volume/physiology , Tidal Volume/physiology , Treatment OutcomeABSTRACT
BACKGROUND: Volume overload and depletion both lead to high morbidity and mortality. Achieving euvolemia is a challenge in patients with end stage kidney disease on hemodialysis (HD). Blood volume analysis (BVA) uses radiolabeled albumin to determine intravascular blood volume (BV). The measured BV is compared to an ideal BV (validated in healthy controls). We hypothesized that BVA could be used in HD to evaluate the adequacy of the current clinically prescribed "estimated dry weight" (EDW) and to titrate EDW in order to improve overall volume status. We were also interested in the reproducibility of BVA results in end stage kidney disease. METHODS: Twelve adults on chronic HD were recruited; 10 completed the study. BVA (Daxor, New York, NY, USA) was used to measure BV at baseline. EDW was kept the same if the patient was deemed to be euvolemic by BVA otherwise, the prescribed EDW was changed with the aim that measured BV would match ideal BV. A second BVA measurement was done 1-3 months later in order to measure BV again. RESULTS: Based on BVA, 6/10 patients were euvolemic at baseline and 5/10 were euvolemic at the second measurement. When comparing patients who had their prescribed EDW changed after the initial BVA to those who did not, both groups had similar differences between measured and ideal BV (P = 0.75). BV values were unchanged at the second measurement (P = 0.34) and there was no linear correlation between BV change and weight change (r2 = 0.08). CONCLUSIONS: This pilot study is the first longitudinal measurement of BVA in HD patients. It revealed that changing weight did not proportionally change intravascular BV. BV remained stable for 1-3 months. BVA may not be helpful in clinically stable HD patients but studies on patients with hemodynamic instability and uncertain volume status are needed. TRIAL REGISTRATION: ClinicalTrials.gov (NCT02717533), first registered February 4, 2015.
Subject(s)
Blood Volume , Body Weight , Hypovolemia/prevention & control , Kidney Failure, Chronic/therapy , Renal Dialysis , Water-Electrolyte Imbalance/prevention & control , Adult , Anthropometry , Cross-Over Studies , Female , Humans , Indicator Dilution Techniques , Iodine Radioisotopes/pharmacokinetics , Male , Middle Aged , Renal Dialysis/adverse effects , Reproducibility of Results , UltrafiltrationABSTRACT
Hypervolemic (dilutional) hyponatremia is the most common dysnatremia in cirrhosis, with a prevalence close to 50% in patients with ascites, while hypovolemic hyponatremia occurs in a minority of cases. Hyponatremia carries a poor prognosis, being associated with increased mortality and reduced survival after liver transplantation. Hypernatremia is rarer and is also associated with an adverse prognosis. Increased non-osmotic secretion of arginine vasopressin and altered renal tubular sodium handling due to impaired free water generation are the mechanisms leading to hypervolemic hyponatremia, while diuretic-induced fluid loss is the main cause of hypovolemic hyponatremia. Hypernatremia usually follows hypotonic fluid losses due to osmotic diuresis (glycosuria) or lactulose-induced diarrhea. The main clinical manifestations of dysnatremias are due to their effects on the central nervous system: astroglial cell hyperhydration follows hyponatremia-an abnormality that exacerbates ammonia neurotoxicity-while the opposite abnormality occurs with hypernatremia. Asymptomatic or mildly symptomatic hypervolemic hyponatremia is mainly managed by correcting of precipitating factors and non-osmotic fluid restriction. Severe, life-threatening hyponatremia requires hypertonic saline infusion, avoiding rapid and complete correction of serum sodium concentration to prevent neurological sequelae such as osmotic demyelination. V2 receptor blockade by vaptans may be considered in patients with sustained hyponatremia waitlisted for liver transplantation. Diuretic withdrawal and plasma volume expansion are required in hypovolemic hypernatremia. Prompt recognition, removal of the precipitating factor(s) and non-osmotic fluid administration represent the mainstays of hypernatremia management. Rapid correction of long-standing hypernatremia can lead to cerebral edema and has to be avoided.
Subject(s)
Central Nervous System Diseases/etiology , Hyponatremia/physiopathology , Hyponatremia/therapy , Liver Cirrhosis/complications , Humans , Hypernatremia/etiology , Hypernatremia/physiopathology , Hypernatremia/therapy , Hyponatremia/etiology , Hyponatremia/prevention & control , Hypovolemia/complications , Hypovolemia/prevention & controlABSTRACT
INTRODUCTION: In peritoneal dialysis (PD) patients, volume overload is related to cardiac dysfunction and mortality, while intravascular volume depletion is associated with a rapid decline in the residual renal function (RRF). This study sought to determine the clinical usefulness of bioimpedance spectroscopy (BIS)-guided fluid management for preserving RRF and cardiac function in PD patients. SUBJECTS AND METHODS: This is a multicenter, prospective, open-label study that was conducted over a 1-year period (NCT01887262). Non-anuric (urine volume > 500 mL/day) subjects on PD were enrolled. Subjects in the control group received fluid management based on the clinical information alone. Those in the BIS group received BIS-guided fluid management along with clinical information. RESULTS: The subjects (N = 137, mean age 51.3 ± 12.8 years, 54% male) were randomly assigned to the BIS group (n = 67) or to the control group (n = 70). There were no significant differences between the 2 groups with regard to age, sex ratio, cause of kidney failure, duration of PD, baseline comorbidity, RRF, PD method, or peritoneal transport type. At baseline, the 2 groups were not different in terms of RRF (glomerular filtration rate [GFR], 5.1 ± 2.9 vs 5.5 ± 3.7 mL/min/1.73 m2). After follow-up, changes in the GFR between the 2 groups were not different (-1.5 ± 2.4 vs -1.3 ± 2.6 mL/min/1.73 m2, p = 0.593). Over the 1-year study period, both groups maintained stability of various fluid status parameters. Between the 2 groups, there were no differences in the net change of various fluid status parameters such as overhydration (OH) and extracellular water/total body water (ECW/TBW). A net change in ECW over 1 year was slightly but significantly higher in the control group (net increase, 0.57 ± 1.27 vs 0.05 ± 1.63 L, p = 0.047). However, this difference was not translated into an improvement in RRF in the BIS group. There were no differences in echocardiographic parameters or arterial stiffness at the end of follow-up. CONCLUSION: Routine BIS-guided fluid management in non-anuric PD patients did not provide additional benefit in volume control, RRF preservation, or cardiovascular (CV) parameters. However, our study cannot be generalized to the whole PD population. Further research is warranted in order to investigate the subpopulation of PD patients who may benefit from routine BIS-guided fluid management.
Subject(s)
Dielectric Spectroscopy , Fluid Therapy/methods , Hypovolemia/prevention & control , Kidney Failure, Chronic/therapy , Peritoneal Dialysis/methods , Water-Electrolyte Imbalance/prevention & control , Adult , Aged , Female , Glomerular Filtration Rate , Humans , Hypovolemia/diagnosis , Hypovolemia/etiology , Kidney Failure, Chronic/complications , Male , Middle Aged , Peritoneal Dialysis/adverse effects , Prospective Studies , Water-Electrolyte Imbalance/diagnosis , Water-Electrolyte Imbalance/etiologyABSTRACT
Massive hemorrhage causes instant and early deaths because of hypovolemia. However, even if the victim makes it to the hospital, hypothermia, metabolic acidosis, and coagulation impairments caused by bleeding pose a great risk for survival. Many topical hemostatic agents are developed for neck, armpit, or groin injuries that are not amenable to tourniquet application and for extremity wounds to be used in conjunction with tourniquets. This paper focuses on those hemostatics that differ based on the action mechanism and are suitable for pre-hospital setting and summarizes the latest recommendations regarding their usage.
Subject(s)
Hemorrhage/therapy , Hemostatics , Administration, Topical , Hemostatics/administration & dosage , Hemostatics/therapeutic use , Humans , Hypovolemia/prevention & controlABSTRACT
Initiation or continuation of artificial hydration (AH) at the end of life requires unique considerations. A combination of ethical precedents and medical literature may provide clinical guidance on how to use AH at the end of life. The purpose of this review is to describe the ethical framework for and review current literature relating to the indications, benefits, and risks of AH at the end of life. Provider, patient, and family perspectives will also be discussed.
Subject(s)
Fluid Therapy , Palliative Care , Quality of Life , Terminal Care , Attitude of Health Personnel , Attitude to Death , Dehydration/prevention & control , Dehydration/psychology , Dehydration/therapy , Family/psychology , Fluid Therapy/adverse effects , Fluid Therapy/ethics , Fluid Therapy/psychology , Fluid Therapy/trends , Hospice Care/ethics , Hospice Care/psychology , Hospice Care/trends , Humans , Hypovolemia/prevention & control , Hypovolemia/psychology , Hypovolemia/therapy , Palliative Care/ethics , Palliative Care/psychology , Palliative Care/trends , Practice Guidelines as Topic , Stress, Psychological/etiology , Stress, Psychological/prevention & control , Terminal Care/ethics , Terminal Care/psychology , Terminal Care/trendsABSTRACT
For patients who survive the initial bleeding event of a ruptured brain aneurysm, delayed cerebral ischemia (DCI) is one of the most important causes of mortality and poor neurological outcome. New insights in the last decade have led to an important paradigm shift in the understanding of DCI pathogenesis. Large-vessel cerebral vasospasm has been challenged as the sole causal mechanism; new hypotheses now focus on the early brain injury, microcirculatory dysfunction, impaired autoregulation, and spreading depolarization. Prevention of DCI primarily relies on nimodipine administration and optimization of blood volume and cardiac performance. Neurological monitoring is essential for early DCI detection and intervention. Serial clinical examination combined with intermittent transcranial Doppler ultrasonography and CT angiography (with or without perfusion) is the most commonly used monitoring paradigm, and usually suffices in good grade patients. By contrast, poor grade patients (WFNS grades 4 and 5) require more advanced monitoring because stupor and coma reduce sensitivity to the effects of ischemia. Greater reliance on CT perfusion imaging, continuous electroencephalography, and invasive brain multimodality monitoring are potential strategies to improve situational awareness as it relates to detecting DCI. Pharmacologically-induced hypertension combined with volume is the established first-line therapy for DCI; a good clinical response with reversal of the presenting deficit occurs in 70 % of patients. Medically refractory DCI, defined as failure to respond adequately to these measures, should trigger step-wise escalation of rescue therapy. Level 1 rescue therapy consists of cardiac output optimization, hemoglobin optimization, and endovascular intervention, including angioplasty and intra-arterial vasodilator infusion. In highly refractory cases, level 2 rescue therapies are also considered, none of which have been validated. This review provides an overview of current state-of-the-art care for DCI management.
Subject(s)
Brain Ischemia/etiology , Disease Management , Subarachnoid Hemorrhage/complications , Time Factors , Brain Ischemia/complications , Brain Ischemia/physiopathology , Calcium Channel Blockers/pharmacology , Humans , Hyponatremia/etiology , Hyponatremia/prevention & control , Hypotension/drug therapy , Hypovolemia/etiology , Hypovolemia/prevention & control , Microcirculation/physiology , Nimodipine/pharmacology , Nimodipine/therapeutic use , Subarachnoid Hemorrhage/surgery , Tomography, X-Ray Computed/methods , Ultrasonography, Doppler, Transcranial/methods , Vasoconstrictor Agents/pharmacokinetics , Vasoconstrictor Agents/pharmacology , Vasoconstrictor Agents/therapeutic use , Vasospasm, Intracranial/complications , Vasospasm, Intracranial/etiologyABSTRACT
BACKGROUND: Scoliosis surgery is often associated with substantial blood loss, requiring fluid resuscitation and blood transfusions. In adults, dynamic preload indices have been shown to be more reliable for guiding fluid resuscitation, but these indices have not been useful in children undergoing surgery. The aim of this study was to introduce frequency-analyzed photoplethysmogram (PPG) and arterial pressure waveform variables and to study the ability of these parameters to detect early bleeding in children during surgery. METHODS: We studied 20 children undergoing spinal fusion. Electrocardiogram, arterial pressure, finger pulse oximetry (finger PPG), and airway pressure waveforms were analyzed using time domain and frequency domain methods of analysis. Frequency domain analysis consisted of calculating the amplitude density of PPG and arterial pressure waveforms at the respiratory and cardiac frequencies using Fourier analysis. This generated 2 measurements: The first is related to slow mean arterial pressure modulation induced by ventilation (also known as DC modulation when referring to the PPG), and the second corresponds to pulse pressure modulation (AC modulation or changes in the amplitude of pulse oximeter plethysmograph when referring to the PPG). Both PPG and arterial pressure measurements were divided by their respective cardiac pulse amplitude to generate DC% and AC% (normalized values). Standard hemodynamic data were also recorded. Data at baseline and after bleeding (estimated blood loss about 9% of blood volume) were presented as median and interquartile range and compared using Wilcoxon signed-rank tests; a Bonferroni-corrected P value <0.05 was considered statistically significant. RESULTS: There were significant increases in PPG DC% (median [interquartile range] = 359% [210 to 541], P = 0.002), PPG AC% (160% [87 to 251], P = 0.003), and arterial DC% (44% [19 to 84], P = 0.012) modulations, respectively, whereas arterial AC% modulations showed nonsignificant increase (41% [1 to 85], P = 0.12). The change in PPG DC% was significantly higher than that in PPG AC%, arterial DC%, arterial AC%, and systolic blood pressure with P values of 0.008, 0.002, 0.003, and 0.002, respectively. Only systolic blood pressure showed significant changes (11% [4 to 21], P = 0.003) between bleeding phase and baseline. CONCLUSIONS: Finger PPG and arterial waveform parameters (using frequency analysis) can track changes in blood volume during the bleeding phase, suggesting the potential for a noninvasive monitor for tracking changes in blood volume in pediatric patients. PPG waveform baseline modulation (PPG DC%) was more sensitive to changes in venous blood volume when compared with respiration-induced modulation seen in the arterial pressure waveform.
Subject(s)
Blood Volume , Monitoring, Intraoperative/methods , Oximetry , Oxygen/blood , Photoplethysmography , Respiration, Artificial , Scoliosis/surgery , Spinal Fusion , Adolescent , Age Factors , Arterial Pressure , Biomarkers/blood , Blood Loss, Surgical/prevention & control , Female , Fourier Analysis , Humans , Hypovolemia/etiology , Hypovolemia/physiopathology , Hypovolemia/prevention & control , Male , Predictive Value of Tests , Scoliosis/diagnosis , Spinal Fusion/adverse effects , Time FactorsABSTRACT
BACKGROUND: Induction of general anaesthesia has been shown to cause haemodilution and an increase in plasma volume. The aim of this study was to evaluate whether prevention of hypotension during anaesthesia induction could avoid haemodilution. METHODS: Twenty-four cardiac surgery patients, 66 ± 10 years, were randomised to receive either norepinephrine in a dose needed to maintain mean arterial blood pressure (MAP) at pre-anaesthesia levels after induction or to a control group that received vasopressor if MAP decreased below 60 mmHg. No fluids were infused. Changes in plasma volume were calculated with standard formula: 100 × (Hct(pre)/Hct(post) - 1)/(1 - Hct(pre)). Arterial blood gas was analysed every 10 minutes and non-invasive continuous haemoglobin (SpHb) was continuously measured. RESULTS: Pre-anaesthesia MAP was 98 ± 7 mmHg. Ten minutes after anaesthesia induction, the haematocrit decreased by 5.0 ± 2.5% in the control group compared with 1.2 ± 1.4% in the intervention group, which corresponds to increases in plasma volume by 310 ml and 85 ml respectively. MAP decreased to 69 ± 15 mmHg compared to 92 ± 10 mmHg in the intervention group. The difference maintained throughout the 70 min intervention period. The change in haemoglobin level measured by blood gas analysis could not be detected by SpHb measurement. The mean bias between the SpHb and blood gas haemoglobin was 15 g/l. CONCLUSION: During anaesthesia induction, haematocrit decreases and plasma volume increases early and parallel to a decrease in blood pressure. This autotransfusion is blunted when blood pressure is maintained at pre-induction levels with norepinephrine.
Subject(s)
Anesthesia , Arterial Pressure , Hematocrit , Plasma Volume , Aged , Aged, 80 and over , Cardiac Surgical Procedures , Female , Hemodilution , Humans , Hypotension/chemically induced , Hypotension/prevention & control , Hypovolemia/prevention & control , Male , Middle Aged , Norepinephrine/therapeutic use , Vasoconstrictor Agents/therapeutic useABSTRACT
The use of human albumin is common in hepatology since international scientific societies support its administration to treat or prevent severe complications of cirrhosis, such as the prevention of post-paracentesis circulatory dysfunction after large-volume paracentesis and renal failure induced by spontaneous bacterial peritonitis, and the treatment of hepatorenal syndrome in association with vasoconstrictors. However, these indications are often disregarded, mainly because the high cost of human albumin leads health authorities and hospital administrations to restrict its use. On the other hand, physicians often prescribe human albumin in patients with advanced cirrhosis for indications that are not supported by solid scientific evidence and/or are still under investigation in clinical trials. In order to implement appropriate prescription of human albumin and to avoid its futile use, the Italian Association for the Study of the Liver (AISF) and the Italian Society of Transfusion Medicine and Immunohaematology (SIMTI) nominated a panel of experts, who reviewed the available clinical literature and produced practical clinical recommendations for the use of human albumin in patients with cirrhosis.
Subject(s)
Acute Kidney Injury/prevention & control , Albumins/therapeutic use , Hepatorenal Syndrome/prevention & control , Hypovolemia/prevention & control , Liver Cirrhosis/complications , Shock/prevention & control , Acute Kidney Injury/microbiology , Ascites/drug therapy , Ascites/etiology , Evidence-Based Medicine , Hepatic Encephalopathy/drug therapy , Hepatorenal Syndrome/diagnosis , Humans , Hyponatremia/drug therapy , Hypovolemia/etiology , Italy , Liver Cirrhosis/therapy , Paracentesis/adverse effects , Peritonitis/complications , Peritonitis/microbiology , Shock/etiologyABSTRACT
We described our experience in using the new noninvasive hemodynamic monitoring (esCCO), which allowed recording most important parameters of heart capacity. Infusion therapy during laparoscopic operations might be based on dynamic of systolic blood volume. This functional approach can be used for evaluation of heart reaction on bolus fluid load, to optimike volemic status in situations associated with dynamical blood circulation changes. We compared intraoperative infused fluid volumes, calculated by traditional approach and by target approach. The obtained results had significant differences among groups, and didn't correspond with "liberal" and "restrictive" strategy for infusion therapy.
Subject(s)
Fluid Therapy/methods , Heart/physiology , Hemodynamics/physiology , Isotonic Solutions/administration & dosage , Laparoscopy/methods , Monitoring, Intraoperative/methods , Adult , Crystalloid Solutions , Electrocardiography , Female , Head-Down Tilt , Humans , Hypovolemia/prevention & control , Male , Middle AgedSubject(s)
Exercise/physiology , Hyponatremia/prevention & control , Forecasting , Hospitalization , Humans , Hyponatremia/diagnosis , Hyponatremia/etiology , Hypovolemia/diagnosis , Hypovolemia/etiology , Hypovolemia/prevention & control , Information Dissemination , Patient Education as Topic/methods , Risk Factors , Sports Medicine/education , Thirst/physiology , Water-Electrolyte Imbalance/diagnosis , Water-Electrolyte Imbalance/etiology , Water-Electrolyte Imbalance/prevention & controlABSTRACT
BACKGROUND: The use of artificial colloids is currently controversial, especially in Central Europe Several studies demonstrated a worse outcome in intensive care unit patients with the use of hydroxyethyl starch. This recently even led to a drug warning about use of hydroxyethyl starch products in patients admitted to the intensive care unit. The data on hydroxyethyl starch in non-critically ill patients are insufficient to support perioperative use. METHODS/DESIGN: We are conducting a single-center, open-label, randomized, comparative trial with two parallel patient groups to compare human albumin 5% (test drug) with hydroxyethyl starch 6% 130/0.4 (comparator). The primary endpoint is cystatin C ratio, calculated as the ratio of the cystatin value at day 90 after surgery relative to the preoperative value. Secondary objectives are inter alia the evaluation of the influence of human albumin and hydroxyethyl starch on further laboratory chemical and clinical parameters, glycocalyx shedding, intensive care unit and hospital stay and acute kidney injury as defined by RIFLE criteria (risk of renal dysfunction, injury to the kidney, failure of kidney function, loss of kidney function, and end-stage kidney disease) criteria. DISCUSSION: There is a general lack of evidence on the relative safety and effects of hydroxyethyl starch compared with human albumin for volume replacement in a perioperative setting. Previously conducted studies of surgical patients in which researchers have compared different hydroxyethyl starch products included too few patients to properly evaluate clinical important outcomes such as renal function. In the present study in a high-risk patient population undergoing a major surgical intervention, we will determine if perioperative fluid replacement with human albumin 5% will have a long-term advantage over a third-generation hydroxyethyl starch 130/0.4 on the progression of renal dysfunction until 90 days after surgery. TRIAL REGISTRATION: EudraCT number 2010-018343-34. Registered on 11 January 2010.