Ingrid Venneman

Effects of training on exercise-induced muscle damage and interleukin 6 production

To address the question of whether the increased plasma concentration of interleukin 6 (IL‐6) following strenuous muscular work could be related to exercise‐induced muscle damage, 5 moderately active male volunteers underwent two isokinetic exercise sessions in the eccentric mode, separated by a period of 3 weeks during which the subjects underwent five training sessions. Before training, exercise was followed by severe muscle pain (delayed‐onset muscle soreness; DOMS), and by significant increases in plasma IL‐6 level and serum myoglobin concentration (SMb) (P < 0.001). After training, postexercise DOMS and SMb values were significantly lower than those measured before training. There was no significant difference between plasma IL‐6 levels measured at the same time points before and after training. We conclude that the hypothetical relationship between exercise‐induced muscle damage and increased postexercise levels of circulating IL‐6 is not substantiated by the present results.

Endotoxaemia, production of tumour necrosis factor α and polymorphonuclear neutrophil activation following strenuous exercise in humans

Abstract To examine whether endotoxaemia accompanying long-term, strenuous physical exercise is involved in exercise-induced increase in plasma tumour necrosis factor alpha (TNF-α) concentration and polymorphonuclear neutrophil (PMN) activation, 14 male recreational athletes [mean age 28 (SEM 1) years] were studied. Exercise consisted of a 1.5-km river swim, a 40-km bicycle race, and a 10-km road race. Mean time to complete the race was 149.8 (SEM 4.8) min. The plasma concentrations of granulocyte myeloperoxidase (MPO) and TNF-α were significantly higher than baseline values immediately and 1 h after exercise (P < 0.001). Both variables returned to pre-race levels the day after exercise. Marked, transient decreases in plasma concentrations of anti-lipopolysaccharide (LPS) immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies directed against a panel of selected smooth gram-negative LPS were observed after the race, reaching in most cases minimal values in the blood sample drawn immediately following the completion of the triathlon. There was no significant correlation between the magnitude of PMN activation, as assessed by the increase in plasma concentrations of MPO, and the humoral markers of endotoxaemia and TNF-α. An inverse, highly significant relationship between the increase in plasma TNF-α concentrations and the changes in circulating anti-LPS IgM antibodies concentrations was observed (r = −0.7; P < 0.01). These findings suggest that exercise-induced endotoxaemia was involved in the release of TNF-α, that the magnitude of the TNF-α response to exercise was down-regulated by anti-LPS antibodies of the IgM class, and that the production of TNF-α and endotoxaemia did not seem to play a role in the activation of circulating PMN in the exercising subjects.

Intravenous magnesium re-establishes neuromuscular block after spontaneous recovery from an intubating dose of rocuronium: a randomised controlled trial

Context Intravenous magnesium deepens non-depolarising neuromuscular block. Objective To assess whether intravenous magnesium has the potential to re-establish paralysis in patients who have just recovered from a non-depolarising neuromuscular block. Design Prospective randomised double-blind controlled study. Patients Twenty non-obese patients ranging in age from 18 to 80 years were enrolled. Exclusion criteria were a history of liver, kidney or neuromuscular disease and intake of medications interacting with neuromuscular blocking agents. Intervention After spontaneous recovery from an intubating dose of rocuronium had been achieved (train-of-four ratio ≥0.9), patients were given either a bolus dose of magnesium 50 mg kg−1 intravenously or an equivalent volume of isotonic saline over 5 min. Main outcome measures The train-of-four ratio was measured every minute until the end of surgery. The primary endpoint was the proportion of patients who experienced a decrease in train-of-four ratio following administration of magnesium or saline. Results Following infusion of the study solution, the train-of-four ratio decreased in all patients in the magnesium group in contrast to none in the saline group (P < 0.001). On average, magnesium-induced train-of-four ratio depression reached a nadir of 0.49 after 10 min and lasted for 45 min. Conclusion A bolus dose of intravenous magnesium 50 mg kg−1 re-establishes a clinically relevant degree of muscle paralysis in patients who have just recovered from a non-depolarising neuromuscular block. Trial registration EudraCT.ema.europa.eu 2009-017372-24.

Possible in vivo tolerance of human polymorphonuclear neutrophil to low-grade exercise-induced endotoxaemia

To address the question of whether translocation of bacterial lipopolysaccharide (LPS) into the blood could be involved in the process of exercise-induced polymorphonuclear neutrophil (PMN) activation, 12 healthy male subjects who took part in a sprint triathlon (1.5 km river swim, 40 km bicycle race, 10 km road race) were studied. While there was no detectable amount of endotoxin in the blood samples drawn at rest, exercise was followed by the appearance of circulating endotoxin molecules at the end of competition in four subjects, and after one and 24 h recovery in three and seven athletes, respectively. The concentrations of plasma granulocyte myeloperoxidase ([MPO]), were significantly higher immediately after exercise and one hour later-than baseline values (P<0.001). This variable returned to pre-race levels the day after exercise, despite the presence of detectable amounts of LPS, at that time, in seven athletes. The absence of significant correlation (r=0.26; P=0.383) and temporal association between [MPO] and plasma endotoxin levels led us to conclude that endotoxaemia was not involved in the process of exercise-induced PMN degranulation observed in our subjects.

Pancreatic cellular injury after cardiac surgery with cardiopulmonary bypass: frequency, time course and risk factors.

Although often clinically silent, pancreatic cellular injury (PCI) is relatively frequent after cardiac surgery with cardiopulmonary bypass; and its etiology and time course are largely unknown. We defined PCI as the simultaneous presence of abnormal values of pancreatic isoamylase and immunoreactive trypsin (IRT). The frequency and time evolution of PCI were assessed in this condition using assays for specific exocrine pancreatic enzymes. Correlations with inflammatory markers were searched for preoperative risk factors. One hundred ninety-three patients submitted to cardiac surgery were enrolled prospectively. Blood IRT, amylase, pancreatic isoamylase, lipase, and markers of inflammation (&agr;1-protease inhibitor, &agr;2-macroglobulin, myeloperoxidase) were measured preoperatively and postoperatively until day 8. The postoperative increase in plasma levels of pancreatic enzymes and urinary IRT was biphasic in all patients: early after surgery and later (from day 4 to 8 after surgery). One hundred thirty-three patients (69%) experienced PCI, with mean IRT, isoamylase, and &agr;1-protease inhibitor values higher for each sample than that in patients without PCI. By multiple regression analysis, we found preoperative values of plasma IRT ≥40 ng/mL, amylase ≥42 IU/mL, and pancreatic isoamylase ≥20 IU/L associated with a higher incidence of postsurgery PCI (P < 0.005). In the PCI patients, a significant correlation was found between the 4 pancreatic enzymes and urinary IRT, total calcium, myeloperoxidase, &agr;1-protease inhibitor, and &agr;2-macroglobulin. These data support a high prevalence of postoperative PCI after cardiac surgery with cardiopulmonary bypass, typically biphasic and clinically silent, especially when pancreatic enzymes were elevated preoperatively.

Pancreatic cellular injury after cardiopulmonary bypass

The pancreas is both an endocrine and exocrine gland, but it is its exocrine portion which is more easily described as the target of cellular alterations in shock and other pathological situations [1]. This exocrine pancreatic injury is often characterized by an increase in the blood levels of pancreatic enzymes such as the P-type amylase, the lipase and the trypsinogen, precursor of the proteolytic enzyme trypsin.

Transversus abdominis plane block or intravenous lignocaine in open prostate surgery: a randomized controlled trial.

Transversus abdominis plane block (TAP) and intravenous lignocaine are two analgesic techniques frequently used after abdominal surgery. We hypothesized that these two techniques improve post‐operative analgesia after open prostate surgery and sought to compare their efficacy on immediate post‐operative outcome after open prostate surgery.