Acute non-traumatic pain increases the hepatic amino- to urea-N conversion in normal man

Multidisciplinary, early mobility approach to enhance functional independence in patients admitted to a cardiothoracic intensive care unit: a quality improvement programme

Early mobilisation following cardiac surgery is vital for improved patient outcomes, as it has a positive effect on a patient's physical and psychological recovery following surgery. We observed that patients admitted to the cardiothoracic intensive care unit (CTICU) following cardiac surgery had only bed exercises and were confined to bed until the chest tubes were removed, which may have delayed patients achieving functional independence. Therefore, the CTICU team implemented a quality improvement (QI) project aimed at the early mobilisation of patients after cardiac surgery.A retrospective analysis was undertaken to define the current mobilisation practices in the CTICU. The multidisciplinary team identified various practice gaps and tested several changes that led to the implementation of a successful early mobility programme. The tests were carried out and reported using rapid cycle changes. A model for improvement methodology was used to run the project. The outcomes of the project were analysed using standard 'run chart rules' to detect changes in outcomes over time and Welch's t-test to assess the significance of these outcomes.This project was implemented in 2015. Patient compliance with early activity and mobilisation gradually reached 95% in 2016 and was sustained over the next 3 years. After the programme was implemented, the mean hours required for initiating out-of-bed-mobilisation was reduced from 22.77 hours to 11.74 hours. Similarly, functional independence measures and intensive care unit mobility scores also showed a statistically significant (p<0.005) improvement in patient transfers out of the CTICU.Implementing an early mobility programme for post-cardiac surgery patients is both safe and feasible. This QI project allowed for early activity and mobilisation, a substantial reduction in the number of hours required for initiating out-of-bed mobilisation following cardiac surgery, and facilitated the achievement of early ambulation and functional milestones in our patients.

Multidisciplinary, early mobility approach to enhance functional independence in patients admitted to a cardiothoracic intensive care unit: a quality improvement programme

Early mobilisation following cardiac surgery is vital for improved patient outcomes, as it has a positive effect on a patient's physical and psychological recovery following surgery. We observed that patients admitted to the cardiothoracic intensive care unit (CTICU) following cardiac surgery had only bed exercises and were confined to bed until the chest tubes were removed, which may have delayed patients achieving functional independence. Therefore, the CTICU team implemented a quality improvement (QI) project aimed at the early mobilisation of patients after cardiac surgery.A retrospective analysis was undertaken to define the current mobilisation practices in the CTICU. The multidisciplinary team identified various practice gaps and tested several changes that led to the implementation of a successful early mobility programme. The tests were carried out and reported using rapid cycle changes. A model for improvement methodology was used to run the project. The outcomes of the project were analysed using standard 'run chart rules' to detect changes in outcomes over time and Welch's t-test to assess the significance of these outcomes.This project was implemented in 2015. Patient compliance with early activity and mobilisation gradually reached 95% in 2016 and was sustained over the next 3 years. After the programme was implemented, the mean hours required for initiating out-of-bed-mobilisation was reduced from 22.77 hours to 11.74 hours. Similarly, functional independence measures and intensive care unit mobility scores also showed a statistically significant (p<0.005) improvement in patient transfers out of the CTICU.Implementing an early mobility programme for post-cardiac surgery patients is both safe and feasible. This QI project allowed for early activity and mobilisation, a substantial reduction in the number of hours required for initiating out-of-bed mobilisation following cardiac surgery, and facilitated the achievement of early ambulation and functional milestones in our patients.

Optimising pain management protocols following cardiac surgery: A protocol for a national quality improvement study

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Severe pain is associated with tachyarrhythmias, shallow breathing and poor recovery.

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Our protocol was effective at reducing post-cardiac surgery pain in a single centre.

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It consists of pre-operative gabapentin and dividing patients based on risk of pain.

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High-risk group receive PCA along with paracetamol and codeine given to all patients.

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Centres will undertake a baseline audit, then implement a protocol and re-audit pain.

Pain following cardiac surgery is a multifaceted phenomenon resulting from a number of mechanisms. High-levels of post-operative pain are associated with cardiovascular and respiratory complications and adequate pain management is crucial for enabling fast recovery. However, adequate pain control is complex, a challenge that stems from a combination of poor reporting of pain, significant variation amongst patients and the side-effects of strong, particularly opioid, analgesics. An initial audit at our hospital demonstrated high-levels of post-operative pain following cardiac surgery and a protocol was therefore devised by the anaesthetic department for cardiac surgical pain management. The protocol stratified patients into high- or low-risk of pain based on the presence of risk factors for pain and utilised a combination of pre-operative one-off dose of gabapentin, intra-operative opioid infusion and post-operative multimodal analgesia with paracetamol, weak and strong opioids. Additionally, patients at high-risk of pain also received patient controlled analgesia. Use of this protocol was associated with improved pain scores on the first three post-operative days. We have devised this study to test for reproducibility of the benefit experienced at our hospital at a larger multicentre level. After acquiring pre-existing post-operative pain management strategies through an initial survey, local study leads will undertake a baseline audit. Local study leads will then lead a 4-week period of protocol implementation. Trusts with official pain management protocols will be given the option to re-circulate their pre-existing protocols. Subsequently, pain scores during post-operative days 1–3 will be re-audited.

Alcoholic Hepatitis Markedly Decreases the Capacity for Urea Synthesis

Background and Aim

Data on quantitative metabolic liver functions in the life-threatening disease alcoholic hepatitis are scarce. Urea synthesis is an essential metabolic liver function that plays a key regulatory role in nitrogen homeostasis. The urea synthesis capacity decreases in patients with compromised liver function, whereas it increases in patients with inflammation. Alcoholic hepatitis involves both mechanisms, but how these opposite effects are balanced remains unclear. Our aim was to investigate how alcoholic hepatitis affects the capacity for urea synthesis. We related these findings to another measure of metabolic liver function, the galactose elimination capacity (GEC), as well as to clinical disease severity.

Methods

We included 20 patients with alcoholic hepatitis and 7 healthy controls. The urea synthesis capacity was quantified by the functional hepatic nitrogen clearance (FHNC), i.e., the slope of the linear relationship between the blood α-amino nitrogen concentration and urea nitrogen synthesis rate during alanine infusion. The GEC was determined using blood concentration decay curves after intravenous bolus injection of galactose. Clinical disease severity was assessed by the Glasgow Alcoholic Hepatitis Score and Model for End-Stage Liver Disease (MELD) score.

Results

The FHNC was markedly decreased in the alcoholic hepatitis patients compared with the healthy controls (7.2±4.9 L/h vs. 37.4±6.8 L/h, P<0.01), and the largest decrease was observed in those with severe alcoholic hepatitis (4.9±3.6 L/h vs. 9.9±4.9 L/h, P<0.05). The GEC was less markedly reduced than the FHNC. A negative correlation was detected between the FHNC and MELD score (rho = -0.49, P<0.05).

Conclusions

Alcoholic hepatitis markedly decreases the urea synthesis capacity. This decrease is associated with an increase in clinical disease severity. Thus, the metabolic failure in alcoholic hepatitis prevails such that the liver cannot adequately perform the metabolic up-regulation observed in other stressful states, including extrahepatic inflammation, which may contribute to the patients’ poor prognosis.

Urea

Urea is generated by the urea cycle enzymes, which are mainly in the liver but are also ubiquitously expressed at low levels in other tissues. The metabolic process is altered in several conditions such as by diets, hormones, and diseases. Urea is then eliminated through fluids, especially urine. Blood urea nitrogen (BUN) has been utilized to evaluate renal function for decades. New roles for urea in the urinary system, circulation system, respiratory system, digestive system, nervous system, etc., were reported lately, which suggests clinical significance of urea.

Prednisolone but not infliximab aggravates the upregulated hepatic nitrogen elimination in patients with active inflammatory bowel disease

BACKGROUND

Catabolism and weight loss are serious problems in patients with active inflammatory bowel disease (IBD). The body nitrogen (N) depletion is partly related to increased hepatic capacity for the elimination of N through urea synthesis. This is probably caused by the inflammation per se, and the treatment with prednisolone may aggravate the problem, whereas the effect of biological therapy is unknown. Therefore, we examined the effects of prednisolone or infliximab on the regulation of urea synthesis in patients with active IBD.

METHODS

Urea synthesis was quantified by the functional hepatic nitrogen clearance (FHNC), i.e., the slope of the linear relationship between the urea nitrogen synthesis rate and the blood α-amino nitrogen concentration during alanine infusion. Thirty-seven patients with active IBD treated with either prednisolone or infliximab were examined before and after 7 days of treatment.

RESULTS

At baseline, the FHNC was similar in the 2 treatment groups (36 L/h). After 7 days, prednisolone increased the FHNC by 40% (55 L/h) (P = 0.03), whereas infliximab tended to reduce the FHNC by 15% (30 L/h) (P = 0.09). The changes in the FHNC differed significantly between the 2 treatment groups (P < 0.01).

CONCLUSIONS

Prednisolone treatment further upregulated urea synthesis, which increases the hepatic loss of nitrogen and promotes body catabolism. In contrast, infliximab treatment caused no such aggravation and likely reduced the N loss. These results may argue in favor of infliximab therapy for IBD and add to the pathophysiological understanding of the interplay between inflammation, catabolism, and anti-inflammatory treatment.

Increased energy expenditure and glucose oxidation during acute nontraumatic skin pain in humans

BACKGROUND AND OBJECTIVE

Tissue injury is accompanied by pain and results in increased energy expenditure, which may promote catabolism. The extent to which pain contributes to this sequence of events is not known.

METHODS

In a cross-over design, 10 healthy volunteers were examined on three occasions; first, during self-controlled nontraumatic electrical painful stimulus to the abdominal skin, maintaining an intensity of 8 on the visual analogue scale (0-10). Next, the electrical stimulus was reproduced during local analgesia and, finally, there was a control session without stimulus. Indirect calorimetry and blood and urine sampling was done in order to calculate energy expenditure and substrate utilization.

RESULTS

During pain stimulus, energy expenditure increased acutely and reversibly by 62% (95% confidence interval, 43-83), which was abolished by local analgesia. Energy expenditure paralleled both heart rate and blood catecholamine levels. The energy expenditure increase was fuelled by all energy sources, with the largest increase in glucose utilization.

CONCLUSION

The pain-related increase in energy expenditure was possibly mediated by adrenergic activity and was probably to a large extent due to increased muscle tone. These effects may be enhanced by cortical events related to the pain. The increase in glucose consumption favours catabolism. Our findings emphasize the clinical importance of pain management.

Neural and muscular factors associated with motor impairment in neck pain

Clinical neck pain is associated with impairment of muscle performance, assessable at a functional level. Functional deficiencies reflect altered mechanisms of muscle control and changed muscle properties. The basic physiologic mechanisms of pain have been extensively investigated, and the functional impairments associated with neck pain are well documented. However, the cause-effect relationships between neck pain and motor control are poorly understood, due to difficulty translating basic physiologic findings into the complex scenario of clinical pain conditions. This article reviews current evidence of disturbances in neural control and muscle properties associated with neck pain and discusses their interrelationships. Although the links among pain, motor control, and muscle properties have been established, their relative significance for the perpetuation and recurrence of neck pain remains largely unexplored. Rehabilitation programs that include interventions for neuromuscular changes seem beneficial for restoring motor function and may prove effective for reducing neck pain recurrence.

Opposite effects on regulation of urea synthesis by early and late uraemia in rats

BACKGROUND & AIMS

Acute and chronic kidney failure lead to catabolism with loss of lean body mass. Up-regulation of hepatic urea synthesis may play a role for the loss of body nitrogen and for the level of uraemia. The aims were to investigate the effects of early and late experimental renal failure on the regulation of hepatic urea synthesis and the expression of urea cycle enzyme genes in the liver.

METHODS

We examined the in vivo capacity of urea nitrogen synthesis, mRNA levels of urea cycle enzyme genes, and N-balances 6 days and 21 days after 5/6th partial nephrectomy in rats, and compared these data with pair- and free-fed control animals.

RESULTS

Compared with pair-fed animals, early uraemia halved the in vivo urea synthesis capacity and decreased urea gene expressions (P<0.05). In contrast, late uraemia up-regulated in vivo urea synthesis and expression of all urea genes (P<0.05), save that of the flux-generating enzyme carbamoyl phosphate synthetase. The N-balance in rats with early uraemia was markedly negative (P<0.05) and near zero in late uraemia.

CONCLUSIONS

Early uraemia down-regulated urea synthesis, so hepatic ureagenesis was not in itself involved in the negative N-balance. In contrast, late uraemia up-regulated urea synthesis, which probably contributed towards the reduced N-balance of this condition. These time-dependent, opposite effects on the uraemia-induced regulation of urea synthesis in vivo were not related to food restriction and probably mostly reflected regulation on gene level.

Effect of lipopolysaccharide on in vivo and genetic regulation of rat urea synthesis

BACKGROUND

The acute phase response causes a negative nitrogen balance. It is unknown whether this involves regulation of hepatic urea synthesis.

METHODS

We examined the in vivo capacity of urea nitrogen synthesis (CUNS), mRNA levels of urea cycle enzyme genes and galactose elimination capacity (GEC) during moderate and severe acute phase response induced by low- and high-dose lipopolysaccharide (LPS) in rats.

RESULTS

Low-dose LPS doubled CUNS (P<0.05), decreased the mRNA level of the rate-limiting urea cycle enzyme (arginino succinate synthetase (ASS) by 26% (P<0.05) and did not change GEC. High-dose LPS did not change CUNS, decreased the mRNA level of the flux-generating enzyme carbamoyl phosphate synthetase (CPS) by 11% (P<0.05) and the rate-limiting urea cycle enzyme (ASS) by 27% (P<0.05) and almost halved GEC (P<0.05).

CONCLUSION

The moderate acute phase response up-regulated in vivo urea synthesis but had the opposite effect on gene level. The severe acute phase response decreased the functional liver mass that attenuated the increase in urea synthesis.

Possible beneficial role of exercise in modulating low-grade inflammation in the elderly

Aging is associated with increased levels of tumor necrosis factor-alpha (TNF) and interleukin (IL)-6. These two cytokines are tightly linked in that TNF induces production of IL-6, which again inhibits TNF gene expression. In epidemiological studies, both cytokines have been associated with obesity, insulin resistance and atherosclerosis. However, based on basal studies, we suggest that TNF (and not IL-6) is the driver behind insulin resistancy. Thus, it is possible that selective enhancement of the IL-6 level may inhibit TNF-induced insulin resistance. Muscle contractions induce production and release of IL-6, but not TNF, into the circulation, in both young and elderly humans. We suggest that muscle-derived IL-6 contributes to mediate the beneficial metabolic effects of exercise and may contribute to inhibit TNF-production and thereby insulin resistance.

Amino acid kinetics in patients with sepsis

BACKGROUND

In patients with sepsis and systemic inflammatory response syndrome, amino acid extraction by the liver is enhanced, resulting in decreased plasma amino acid concentrations. Systematic investigations of the elimination of intravenously infused amino acids have not been performed.

OBJECTIVE

The objective of this study was to compare the elimination of 17 amino acids in patients with sepsis and in healthy control subjects.

DESIGN

Elimination of amino acids was evaluated in 9 patients with sepsis and in 8 healthy control subjects by using a combined loading and maintenance infusion of 375 mg amino acids/kg body wt for 60 min. Pharmacokinetic variables were analyzed from plasma curves.

RESULTS

With the exception of lysine, methionine, glutamate, ornithine, phenylalanine, and tyrosine, plasma concentrations of amino acids were lower in the patients with sepsis than in the control subjects; phenylalanine was the only amino acid whose plasma concentration increased (P < 0.001). In patients with sepsis, whole-body clearance (Cl(tot)) of total amino acids was 74% higher than in control subjects (x +/- SEM: 13,161 +/- 1659 and 7566 +/- 91 mL/min, respectively; P < 0.01), the Cl(tot) of essential amino acids was 64% higher (P < 0.02), that of nonessential amino acids was 82% higher (P < 0.01), and that of both branched-chain amino acids and glucogenic amino acids was 97% higher (P < 0.001). With the exception of phenylalanine, ornithine, proline, and glutamate, the Cl(tot) of all amino acids was elevated. The Cl(tot) of phenylalanine and ornithine decreased slightly (NS).

CONCLUSIONS

In patients with sepsis, plasma concentrations of most amino acids are greatly decreased and the elimination of amino acids from the intravascular space during intravenous infusion is greatly enhanced.