The synthesis rate of albumin decreases during laparoscopic surgery

Prognostic Implication of Preoperative Serum Albumin to Carcinoembryonic Antigen Ratio in Colorectal Cancer Patients

Background: Preoperative serum albumin (ALB) and carcinoembryonic antigen (CEA) were useful prognostic factors in colorectal cancer (CRC); however, the ALB to CEA ratio (ACR) and their individual prognostic efficacies have been less studied. Methods: A retrospective study with 156 CRC patients staged I to IV was performed. The prognostic efficacy of ACR was estimated and subsequently compared with ALB, CEA, and other systemic inflammation markers, including the neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), and platelet-to-lymphocyte ratio (PLR). Differences in progression-free survival (PFS) and overall survival (OS) were determined by Kaplan-Meier (K-M) analysis, and the risk factors for survival were calculated by the Cox proportional hazards model. Results: A total of 31.41% (49 of 156) of patients presented with ACR-low disease, and these patients had tumors with advanced T stages, larger tumor diameters and distant metastases, and a lower LMR. When 5.98 was used as the cut-off point, it had a sensitivity of 58.50% and 61.50% and a specificity of 83.50% and 80.50% for PFS and OS, respectively. ACR displayed a superior prognostic efficacy than individual ALB, CEA and NLR, LMR, and PLR for both PFS and OS (except LMR). Patients in the ACR-low group displayed significantly worse PFS and OS than those in the ACR-high group. Finally, ACR was an independent prognostic factor for both PFS (HR = 0.31, 95% CI: 0.17-0.56, P < .01) and OS (HR = 0.33, 95% CI: 0.16-0.66, P < .01). Conclusions: ACR was a robust prognostic factor in CRC, and patients with a relatively low preoperative ACR would have significantly worse survival.

Repeated quantitative measurements of De Novo synthesis of albumin and fibrinogen

The possibility of using two different isotopomers, for the incorporation of isotopically labeled amino acids, was explored to enable longitudinal studies of de novo synthesis of two export liver proteins, albumin and fibrinogen. The agreement of the synthesis rates between the two different labels was evaluated along with the reproducibility of repeated experiments using different time intervals. Healthy volunteers were studied in a standardized fed state. Protocol A (n = 10) involved two measurements 48 hours apart. Protocol B (n = 6) involved three measurements at baseline and five hours and then seven days after the initial measurement. De novo synthesis of albumin and fibrinogen by the incorporation of D5-phenylalanine or D8-phenylalanine were measured using the flooding dose technique. Albumin and fibrinogen were isolated from plasma using standard techniques. Fractional and absolute synthesis rates were calculated. Repeated measurements employing the two isotoptomers showed good agreement for albumin fractional synthesis rate after 48 hours (p = 0.92) and after 7 days (p = 0.99), with a coefficient of variation of 5.9% when using the same isotopic label. For fibrinogen, the coefficient of variation for the fractional synthesis rate employing the same isotopic label was 16.6%. Repeated measurements after 48 hours and seven days showed less agreement although there was no statistical difference (P = 0.32 and P = 0.30 respectively). Repeated measurement after five hours showed a statistical significant difference for the fractional synthesis rate of fibrinogen (p = 0.008) but not for albumin (p = 0.12). Repeated measurements of albumin de novo synthesis more than 48 hours apart show acceptable agreement using either one or two different isotopic labels. For fibrinogen the larger intra-individual scatter necessitates larger study groups to detect changes in longitudinal studies. Repeated measurements within 48 hours need to be validated further.

Simultaneous assessment of the synthesis rate and transcapillary escape rate of albumin in inflammation and surgery

Background

Better knowledge of albumin kinetics is needed to define the indications for albumin use in clinical practice. This study involved two approaches: the synthesis rate and transcapillary escape rate of albumin were measured simultaneously at different levels of plasma albumin concentration in relation to acute inflammation and surgery; and two different tracers were compared to determine plasma volume and the transcapillary escape rate.

Methods

Healthy volunteers (n = 10), patients with acute inflammatory abdominal disease (n = 10), and patients undergoing elective pancreatic resection (n = 10) were studied. The albumin synthesis rate was measured by the incorporation of deuterium-labeled phenylalanine. Plasma volume and the transcapillary escape rate were assessed using ¹²³I-labeled and ¹²⁵I-labeled albumin.

Results

A 50 % elevated de-novo albumin synthesis rate was seen in patients with acute inflammation and marked hypoalbuminemia, while patients with marginal hypoalbuminemia before the start of surgery had a normal albumin synthesis rate. The transcapillary escape rate was elevated intraoperatively during the reconstructive phase of pancreatic surgery, when plasma albumin was decreased but stable. In acute inflammation with marked hypoalbuminemia, the transcapillary escape rate was no different from normal. ¹²³I-labeled and ¹²⁵I-labeled albumin were found exchangeable for plasma volume determinations, but could be used only in groups of patients for the transcapillary escape rate.

Conclusions

This observational study illustrates the limited information contained in albumin plasma concentrations to reflect albumin kinetics. On the contrary, single measurements of the synthesis rate and/or transcapillary escape rate of albumin obviously cannot explain the plasma level of albumin or the changes seen in plasma albumin concentration.

Trial registration

www.clinicaltrials.gov, study number NCT01686776. Registered 13 September 2012.

Leakage of albumin in major abdominal surgery

Background

The time course of plasma albumin concentration (P-alb) and cumulative perioperative albumin shift as a measure of albumin extravasation in major abdominal surgery is not well described. Knowledge of these indices of the vascular barrier and vascular content are important for our understanding of fluid physiology during surgery and anesthesia.

Methods

Patients (n = 10) were studied during esophageal or pancreatic surgery. P-alb was repeatedly measured over 72 h, and the mass balance of albumin and hemoglobin were obtained from measures of P-alb, blood hemoglobin and hematocrit.

Results

P-alb decreased rapidly from baseline (32.8 ± 4.8 g/L) until the start of surgical reconstruction (18.7 ± 4.8 g/L; p < 0.001), and was thereafter stable until postoperative day 3. Cumulative perioperative albumin shift increased until 1 h after the end of surgery, when 24 ± 17 g (p < 0.001) had been lost from the circulation.

Conclusions

The rapid fall in P-alb of more than 40 % consistently occurred during the first part of the surgical procedure, but albumin leakage progressed until 1 h after the end of surgery. After the initial drop, P-alb was stable for 72 h.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-016-1283-8) contains supplementary material, which is available to authorized users.

Promoting Perioperative Metabolic and Nutritional Care

Surgery represents a major stressor that disrupts homeostasis and can lead to loss of body cell mass. Integrated, multidisciplinary medical strategies, including enhanced recovery programs and perioperative nutrition support, can mitigate the surgically induced metabolic response, promoting optimal patient recovery following major surgery. Clinical therapies should identify those who are poorly nourished before surgery and aim to attenuate catabolism while preserving the processes that promote recovery and immunoprotection after surgery. This review will address the impact of surgery on intermediary metabolism and describe the clinical consequences that ensue. It will also focus on the role of perioperative nutrition, including preoperative nutrition risk, carbohydrate loading, and early initiation of oral feeding (centered on macronutrients) in modulating surgical stress, as well as highlight the contribution of the anesthesiologist to nutritional care. Emerging therapeutic concepts such as preoperative glycemic control and prehabilitation will be discussed.

Albumin Kinetics in Patients Undergoing Major Abdominal Surgery

Background

The drop in plasma albumin concentration following surgical trauma is well known, but the temporal pattern of the detailed mechanisms behind are less well described. The aim of this explorative study was to assess changes in albumin synthesis and transcapillary escape rate (TER) following major surgical trauma, at the time of peak elevations in two well-recognized markers of inflammation.

Methods

This was a clinical trial of radiolabeled human serum albumin for the study of TER and plasma volume. Ten patients were studied immediately preoperatively and on the 2nd postoperative day after major pancreatic surgery. Albumin synthesis rate was measured by the flooding dose technique employing incorporation of isotopically labelled phenylalanine.

Results

Fractional synthesis rate of albumin increased from 11.7 (95% CI: 8.9, 14.5) to 15.0 (11.7, 18.4) %/day (p = 0.027), whereas the corresponding absolute synthesis rate was unchanged, 175 (138, 212) versus 150 (107, 192) mg/kg/day (p = 0.21). TER was unchanged, 4.9 (3.1, 6.8) %/hour versus 5.5 (3.9, 7.2) (p = 0.63). Plasma volume was unchanged but plasma albumin decreased from 33.5 (30.9, 36.2) to 22.1 (19.8, 24.3) g/L. (p<0.001).

Conclusion

Two days after major abdominal surgery, at the time-point when two biomarkers of generalised inflammation were at their peak and the plasma albumin concentration had decreased by 33%, we were unable to show any difference in the absolute synthesis rate of albumin, TER and plasma volume as compared with values obtained immediately pre-operatively. This suggests that capillary leakage, if elevated postoperatively, had ceased at that time-point. The temporal relations between albumin kinetics, capillary leakage and generalised inflammation need to be further explored.

Trial Registration

clinicaltrialsregister.eu: EudraCT 2010-08529-21 ClinicalTrials.gov NCT01194492

Influência do trauma cirúrgico no comportamento dos níveis séricos de albumina após cirurgia da coluna vertebral

OBJETIVO: avaliar a variação da concentração da albumina nas cirurgias de coluna vertebral e relacioná-la às repercussões clínicas no pós-operatório. MÉTODOS: estudo prospectivo observacional sobre os valores do nível sérico da albumina de 55 pacientes submetidos à cirurgia na coluna vertebral. As amostras de sangue foram coletadas um dia antes da cirurgia e 24 horas após o procedimento. Foi aplicado o teste t pareado na avaliação da variação (pré versus pós) nos parâmetros albumina, hemoglobina e hematócrito. A presença de associação entre grau de variação nos níveis de albumina (<1 g/dL ou >1 g/dL) e as variáveis de interesse: presença de complicações, necessidade de transfusão, procedimento realizado, idade e gênero do paciente e diagnóstico foram avaliadas pelo teste do χ2 de Pearson ou teste do χ2 da razão de verossimilhança quando apropriado. RESULTADOS: a redução média dessa proteína foi de 0,58 g/dL, variando de 0 a 1,8 g/dL. Dos pacientes, 78,2% apresentaram valores da albumina no período pós-operatório abaixo da faixa considerada normal. Somente dois pacientes da amostra apresentaram complicações durante os 30 dias de seguimento. O grupo com correção de deformidades apresentou 100% de pacientes com variação >1 g/dL. CONCLUSÃO: houve influência do trauma cirúrgico na redução sérica da albumina, em média, de 0,58 g/dL nas cirurgias da coluna vertebral. Não foi possível associar essa queda às complicações no período pós-operatório após seguimento de 30 dias desses pacientes.

Importance of the evaluation of serum albumin concentration in postoperative period of patients submitted to major surgeries

BACKGROUND: The prevalence of protein-energy malnutrition in surgical patients is high, ranging from 10% to 54%. The correct assessment of the nutritional status of such patients is crucial since malnourishment is a risk factor for morbidity and mortality. AIM: To assess the effect of surgical trauma in serum albumin concentration during the immediate postoperative period of major surgeries. METHODS: The study was conducted on 100 randomly chosen adult patients submitted to elective major surgeries, classified according to sex, age and skin color. Blood samples for the determination of serum albumin concentrations were obtained on the days before and after the surgical procedure. RESULTS: There was a reduction in serum albumin from 3.72 ± 0.47 to 2.83 ± 0.71 g/dL (P< 0.0001) with no difference in sex or skin color for major surgeries. With respect to age groups, a greater drop in albumin was observed among patients aged over 65 years, followed by younger patients (< 45 years), and finally by patients aged 45 to 65 years. CONCLUSION: Major operations lead to acute reduction in albumin concentration in the immediate postoperative period, and it was more intense in patients aged over 65 years.

Altered protein metabolism following coronary artery bypass graft (CABG) surgery

The aim of the present study was to investigate the acute effect of CABG (coronary artery bypass graft) surgery on the rates of synthesis of muscle protein, the positive acute-phase protein fibrinogen and the negative acute-phase protein albumin. Synthesis rates of muscle protein, fibrinogen and albumin were measured simultaneously before and 4 h after the end of surgery from the incorporation of L-[2H5]phenylalanine (given at 43 mg/kg of body weight) in 12 patients undergoing CABG surgery. Surgery was performed either with the use of extracorporeal circulation with cardiopulmonary bypass (on-pump; n=5) or with the beating heart procedure without cardiopulmonary bypass (off-pump; n=7). Post-surgical muscle protein fractional synthesis rates were decreased by 36±6.5% compared with pre-surgical values (1.59±0.10 compared with 0.97±0.08%/day respectively; P<0.001). In contrast, the synthesis rates of both fibrinogen (36±4 compared with 100±11 mg·day−1·kg−1 of body weight; P<0.0001) and albumin (123±12 compared with 178±19 mg·day−1·kg−1 of body weight; P<0.001) were both significantly increased after surgery. No significant differences were found between surgery performed with or without cardiopulmonary bypass. In conclusion, the results demonstrate that CABG surgery has a profound effect on protein metabolism, with a differential response of protein synthesis in muscle and liver.

Metabolism before, during and after anaesthesia in colic and healthy horses

BACKGROUND

Many colic horses are compromised due to the disease state and from hours of starvation and sometimes long trailer rides. This could influence their muscle energy reserves and affect the horses' ability to recover. The principal aim was to follow metabolic parameter before, during, and up to 7 days after anaesthesia in healthy horses and in horses undergoing abdominal surgery due to colic.

METHODS

20 healthy horses given anaesthesia alone and 20 colic horses subjected to emergency abdominal surgery were anaesthetised for a mean of 228 minutes and 183 minutes respectively. Blood for analysis of haematology, electrolytes, cortisol, creatine kinase (CK), free fatty acids (FFA), glycerol, glucose and lactate was sampled before, during, and up to 7 days after anaesthesia. Arterial and venous blood gases were obtained before, during and up to 8 hours after recovery. Gluteal muscle biopsy specimens for biochemical analysis of muscle metabolites were obtained at start and end of anaesthesia and 1 h and 1 day after recovery.

RESULTS

Plasma cortisol, FFA, glycerol, glucose, lactate and CK were elevated and serum phosphate and potassium were lower in colic horses before anaesthesia. Muscle adenosine triphosphate (ATP) content was low in several colic horses. Anaesthesia and surgery resulted in a decrease in plasma FFA and glycerol in colic horses whereas levels increased in healthy horses. During anaesthesia muscle and plasma lactate and plasma phosphate increased in both groups. In the colic horses plasma lactate increased further after recovery. Plasma FFA and glycerol increased 8 h after standing in the colic horses. In both groups, plasma concentrations of CK increased and serum phosphate decreased post-anaesthesia. On Day 7 most parameters were not different between groups. Colic horses lost on average 8% of their initial weight. Eleven colic horses completed the study.

CONCLUSION

Colic horses entered anaesthesia with altered metabolism and in a negative oxygen balance. Muscle oxygenation was insufficient during anaesthesia in both groups, although to a lesser extent in the healthy horses. The post-anaesthetic period was associated with increased lipolysis and weight loss in the colic horses, indicating a negative energy balance during the first week post-operatively.

Effect of carbon dioxide pneumoperitoneum on liver function following laparoscopic cholecystectomy

BACKGROUND

It has been noted that following a laparoscopic cholecystectomy (LC), liver function parameters were disturbed. The causes of this disturbance are still controversial.

PATIENTS AND METHODS

The serum levels of eight parameters of liver function were measured both before and 24 hours after surgery in 142 consecutive patients who underwent LC, 23 patients who underwent open cholecystectomy (OC), and in 25 patients who underwent a conventional hernial repair. The same anesthetic protocol was applied to all patients in the various groups and in the case of LC; the intra-abdominal pressure was maintained at 12 mmHg of CO2.

RESULTS

Twenty-four (24) hours after surgery, there was a statistically significant change of all the eight parameters studied, except alkaline phosphatase in patients who underwent LC, whereas there were only 3 patients from the OC group who had changes of alanine aminotransferase and aspartite aminotransferase and 2 patients who had raised levels of direct bilirubin, and no changes were observed among those who had conventional hernial repair. We found that 83% of the patients showed more than a 100% increase in at least one parameter, 43% showed an increase in two or more parameters, and 23% showed an increase in three or more parameters. We also observed a significant drop of total proteins and albumin levels in all patients who had LC.

CONCLUSIONS

It appears that the pneumoperitoneum plays a major role in these changes. Although these changes of liver function were of no clinical relevance in healthy patients, the safety of the procedure must nonetheless be assessed in those with underlying liver diseases.

Synthesis rates of total liver protein and albumin are both increased in patients with an acute inflammatory response

The general perception that catabolism and inflammation are associated with a high synthesis rate of total liver protein and a low albumin synthesis rate has been challenged in recent years by several studies in man, indicating that the synthesis rate of albumin in response to a catabolic insult is increased rather than decreased. Thus changes in liver protein synthesis rates in conjunction with catabolism and acute inflammation in man need to be characterized better. The aim of the present study was to measure protein synthesis rates of total liver protein and albumin during a state of acute inflammation. Patients (n = 10) undergoing acute laparoscopic cholecystectomy due to acute cholecystitis were investigated. FSRs (fractional synthesis rates) of total liver protein (liver biopsy specimens) and albumin (plasma samples) were investigated as early as possible during the surgical procedure, using a flooding dose of L-[2H5]phenylalanine. The results were compared with a reference group of patients without cholecystitis undergoing elective laparoscopic cholecystectomy (n = 17). FSR of total liver protein was 60% higher (P < 0.001) and the FSR of albumin was 45% higher (P < 0.01) in the cholecystitis patients compared with the control group. In conclusion, the synthesis rates of total liver protein and albumin are both increased in patients with an acute general inflammatory reaction undergoing laparoscopic cholecystectomy.