Impaired utilization of exogenous amino acids after surgery for subarachnoid haemorrhage

Plasma Amino Acids May Improve Prediction Accuracy of Cerebral Vasospasm after Aneurysmal Subarachnoid Haemorrhage

Aneurysmal subarachnoid haemorrhages (aSAH) account for 5% of strokes and continues to place a great burden on patients and their families. Cerebral vasospasm (CVS) is one of the main causes of death after aSAH, and is usually diagnosed between day 3 and 14 after bleeding. Its pathogenesis remains poorly understood. To verify whether plasma concentration of amino acids have prognostic value in predicting CVS, we analysed data from 35 patients after aSAH (median age 55 years, IQR 39-62; 20 females, 57.1%), and 37 healthy volunteers (median age 50 years, IQR 38-56; 19 females, 51.4%). Fasting peripheral blood samples were collected on postoperative day one and seven. High performance liquid chromatography-mass spectrometry (HPLC-MS) analysis was performed. The results showed that plasma from patients after aSAH featured a distinctive amino acids concentration which was presented in both principal component analysis and direct comparison. No significant differences were noted between postoperative day one and seven. A total of 18 patients from the study group (51.4%) developed CVS. Hydroxyproline (AUC = 0.7042, 95%CI 0.5259-0.8826, p = 0.0248) and phenylalanine (AUC = 0.6944, 95%CI 0.5119-0.877, p = 0.0368) presented significant CVS prediction potential. Combining the Hunt-Hess Scale and plasma levels of hydroxyproline and phenylalanine provided the model with the best predictive performance and the lowest leave-one-out cross-validation of performance error. Our results suggest that plasma amino acids may improve sensitivity and specificity of Hunt-Hess scale in predicting CVS.

Interventions for dysphagia and nutritional support in acute and subacute stroke

BACKGROUND

Dysphagia (swallowing problems) are common after stroke and can cause chest infection and malnutrition. Dysphagic, and malnourished, stroke patients have a poorer outcome.

OBJECTIVES

To assess the effectiveness of interventions for the treatment of dysphagia (swallowing therapy), and nutritional and fluid supplementation, in patients with acute and subacute (within six months from onset) stroke.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (February 2012), MEDLINE (1966 to July 2011), EMBASE (1980 to July 2011), CINAHL (1982 to July 2011) and Conference Proceedings Citation Index- Science (CPCI-S) (1990 to July 2011). We also searched the reference lists of relevant trials and review articles, searched Current Controlled Trials and contacted researchers (July 2011). For the previous version of this review we contacted the Royal College of Speech and Language Therapists and equipment manufacturers.

SELECTION CRITERIA

Randomised controlled trials (RCTs) in dysphagic stroke patients, and nutritional supplementation in all stroke patients, where the stroke occurred within six months of enrolment.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied the inclusion criteria, assessed trial quality, and extracted data, and resolved any disagreements through discussion with a third review author. We used random-effects models to calculate odds ratios (OR), 95% confidence intervals (95% CI), and mean differences (MD). The primary outcome was functional outcome (death or dependency, or death or disability) at the end of the trial.

MAIN RESULTS

We included 33 studies involving 6779 participants.Swallowing therapy: acupuncture, drug therapy, neuromuscular electrical stimulation, pharyngeal electrical stimulation, physical stimulation (thermal, tactile), transcranial direct current stimulation, and transcranial magnetic stimulation each had no significant effect on case fatality or combined death or dependency. Dysphagia at end-of-trial was reduced by acupuncture (number of studies (t) = 4, numbers of participants (n) = 256; OR 0.24; 95% CI 0.13 to 0.46; P < 0.0001; I(2) = 0%) and behavioural interventions (t = 5; n = 423; OR 0.52; 95% CI 0.30 to 0.88; P = 0.01; I(2) = 22%). Route of feeding: percutaneous endoscopic gastrostomy (PEG) and nasogastric tube (NGT) feeding did not differ for case fatality or the composite outcome of death or dependency, but PEG was associated with fewer treatment failures (t = 3; n = 72; OR 0.09; 95% CI 0.01 to 0.51; P = 0.007; I(2) = 0%) and gastrointestinal bleeding (t = 1; n = 321; OR 0.25; 95% CI 0.09 to 0.69; P = 0.007), and higher feed delivery (t = 1; n = 30; MD 22.00; 95% CI 16.15 to 27.85; P < 0.00001) and albumin concentration (t = 3; n = 63; MD 4.92 g/L; 95% CI 0.19 to 9.65; P = 0.04; I(2) = 58%). Although looped NGT versus conventional NGT feeding did not differ for end-of-trial case fatality or death or dependency, feed delivery was higher with looped NGT (t = 1; n = 104; MD 18.00%; 95% CI 6.66 to 29.34; P = 0.002). Timing of feeding: there was no difference for case fatality, or death or dependency, with early feeding as compared to late feeding. Fluid supplementation: there was no difference for case fatality, or death or dependency, with fluid supplementation. Nutritional supplementation: there was no difference for case fatality, or death or dependency, with nutritional supplementation. However, nutritional supplementation was associated with reduced pressure sores (t = 2; n = 4125; OR 0.56; 95% CI 0.32 to 0.96; P = 0.03; I(2) = 0%), and, by definition, increased energy intake (t = 3; n = 174; MD 430.18 kcal/day; 95% CI 141.61 to 718.75; P = 0.003; I(2) = 91%) and protein intake (t = 3; n = 174; MD 17.28 g/day; 95% CI 1.99 to 32.56; P = 0.03; I(2) = 92%).

AUTHORS' CONCLUSIONS

There remains insufficient data on the effect of swallowing therapy, feeding, and nutritional and fluid supplementation on functional outcome and death in dysphagic patients with acute or subacute stroke. Behavioural interventions and acupuncture reduced dysphagia, and pharyngeal electrical stimulation reduced pharyngeal transit time. Compared with NGT feeding, PEG reduced treatment failures and gastrointestinal bleeding, and had higher feed delivery and albumin concentration. Nutritional supplementation was associated with reduced pressure sores, and increased energy and protein intake.

Supplementation of essential amino acids may reduce the occurrence of infections in rehabilitation patients with brain injury

BACKGROUND

To investigate whether supplementation with oral essential amino acids (EAAs) may reduce the occurrence of nosocomial infection among patients with brain injury (BI: stroke, trauma, anoxic coma).

METHODS

Patients (n = 125; 77 men, 48 women; mean age 63 ± 15 years) with stroke (68.8%), subarachnoid hemorrhage (17.6%), traumatic BI (7.2%), and anoxic BI (6.4%) 88 ± 15 days after the index event. Patients were randomly assigned to 2 months of oral EAAs (n = 63; 8 g/d) or placebo (n = 62).

RESULTS

Over the first month of rehabilitation, there were 60 infections in the whole population of 125 patients (48%); however, the rate was 23.2% lower in the EAA group (23 episodes/63 patients; 36.5%) than in the placebo group (37 episodes/62 patients; 59.7%) (P < .01). The types of infection were similarly distributed between the 2 groups. Serum levels of prealbumin <20 mg/dL and C-reactive protein (CRP) >0.3 mg/dL were the best predictors of future infection (prealbumin: odds ratio [OR] = 4.17, confidence interval [CI] 1.84-9.45, P < .001; CRP: OR = 3.8, CI 1.71-8.44, P < .001).

CONCLUSION

Supplementary EAAs may reduce the occurrence of nosocomial infections in rehabilitation patients with BI. Prealbumin and CRP are the best predictors of future infections.

Metabolic profiles of patients with subarachnoid hemorrhage treated by early surgery

OBJECTIVE

This study was conducted to evaluate the metabolic response of patients with subarachnoid hemorrhage (SAH) and to determine whether the severity of hemorrhage influenced the response.

METHODS

Resting energy expenditure, nitrogen balance, and serum rapid-turnover proteins were studied for 3-day periods at Day 4, Day 10, and before discharge in patients with SAH who underwent surgical clipping within 2 days after the onset. The patients were divided into two groups according to the Hunt and Hess classification system; there were 17 patients with Grade I or II (mild group) and 19 patients with Grade III, IV, or V (severe group).

RESULTS

The mean resting energy expenditures (mean+/-standard deviation) were highest on Day 10, which were 146+/-24% and 198+/-78% of basal energy expenditure in the mild and severe groups, respectively. The nitrogen balance levels of the mild group on Days 4 and 10 were -3.0+/-3.5 g per day and -4.5+/-2.9 g per day, and those of the severe group were -7.5+/-3.2 g per day and -9.2+/-4.1 g per day, respectively. There was a significant difference in the nitrogen balance over time between the two groups (P=0.0037). Serum transferrin, prealbumin, and retinol-binding protein levels were lowest on Day 4 and gradually increased. There were no significant differences in these parameters between the two groups.

CONCLUSION

SAH treated by surgery induces a profound stress response. A significant difference of increased catabolism but not decreased anabolism between the mild and severe groups was noted.