Evaluation of efficacy and indications of surgical fixation for multiple rib fractures: a propensity-score matched analysis.

PURPOSE: The purpose of this study was to assess the effects of recent surgical rib fixation and establish its indications not only for flail chest but also for multiple rib fractures. METHODS: Between 2007 and 2015, 187 patients were diagnosed as having multiple rib fractures in our institution. After the propensity score matching was performed, ten patients who had performed surgical rib fixation and ten patients who had treated with non-operative management were included. Categorical variables were analyzed with Fischer's exact test and non-parametric numerical data were compared using the Mann-Whitney U test. Wilcoxon signed-rank test was performed for comparison of pre- and postoperative variables. All statistical data are presented as median (25-75 % interquartile range [IQR]) or number. RESULTS: The surgically treated patients extubated significantly earlier than non-operative management patients (5.5 [1-8] vs 9 [7-12] days: p = 0.019). The duration of continuous intravenous narcotic agents infusion days (4.5 [3-6] vs 12 [9-14] days: p = 0.002) and the duration of intensive care unit stay (6.5 [3-9] vs 12 [8-14] days: p = 0.008) were also significantly shorter in surgically treated patients. Under the same ventilating conditions, the postoperative values of tidal volume and respiratory rate improved significantly compared to those values measured just before the surgery. The incidence of pneumonia as a complication was significantly higher in non-operative management group (p = 0.05). CONCLUSIONS: From the viewpoints of early respiratory stabilization and intensive care unit disposition without any complications, surgical rib fixation is a sufficiently acceptable procedure not only for flail chest but also for repair of severe multiple rib fractures.

Oxidation of D(-)3-hydroxybutyrate administered to rats with extensive burns.

Although the suppressive effect of 3-hydroxybutyrate (3-OHB) on post-traumatic protein catabolism in traumatized patients is well documented, the oxidation of exogenously administered 3-OHB during catabolic stress has not been investigated. The present study was designed to evaluate, using radioactive isotopes, total body oxidation in rats with and without burn stress to which 3-OHB had been exogenously administered, in comparison with total body oxidation in such rats that had received glucose. The rats were divided into four groups, based on whether or not a 30% full-thickness burn was inflicted, and the type of infusate they received after the burn, namely, 3-OHB or glucose. The total exhaled CO2 was collected for 6h after the infusion was commenced, and 14CO2 was assayed in a liquid scintillation spectrometer. Oxidation of the infusate was calculated from the percentage of exhaled 14CO2 derived from the infused substrates. The plasma concentration of 3-OHB was significantly increased after the infusion in both the burned and non-burned rats. The total exhaled 14CO2 from the rats infused with glucose decreased from 48.2 +/- 2.4% to 40.8 +/- 3.7% (means +/- SD, P < 0.001) after thermal injury. However, the total exhaled 14CO2 from the rats infused with 3-OHB appeared sooner, and there was no difference in the total expired 14CO2 derived from 3-OHB between the burned and non-burned rats, at 68.1 +/- 2.7% vs 66.4 +/- 3.4%, respectively. These findings suggest that even under conditions of burn stress, 3-OHB can be oxidized normally if the plasma concentration of 3-OHB is elevated by exogenous administration.

The duration of infection modifies mitochondrial oxidative capacity in rat skeletal muscle.

Sepsis increases phosphocreatine (PCr) breakdown and reduces PCr stores in skeletal muscle. To determine if systemic infection impairs mitochondrial function, in vivo 13P magnetic resonance spectroscopy (31P MRS) studies of the gastrocnemius muscle were performed in virus-free male Wistar rats 24 or 48 hr after cecal ligation and 18-gauge needle single puncture (24 degrees CLP, n = 16; 48 degrees CLP, n = 15) or sham operation (24 degrees SHAM, n = 18; 48 degrees SHAM, n = 13). Physiologic saline (6 ml/100 g body wt) was injected intraperitoneally for fluid resuscitation. Water but no food was allowed in all animals. High resolution (8.45 Tesla) 31P MRS spectra, obtained at rest and during exercise using a 1.4-cm surface coil, were used to calculate PCr/ATP, PCr/P(i) ratios, and intracellular pH. Steady-state muscle exercise was induced by supramaximal sciatic nerve stimulation at 10 Hz for 10 min. Recovery of PCr/(PCr + P(i)) ratios after exercise was fitted to a monoexponential curve. The resultant function was used to calculate the half time for PCr recovery, the initial PCr resynthesis rate, and the maximal oxidative ATP synthesis rate, which reflect the rephosphorylation of ADP and are therefore measures of mitochondrial oxidative capacity. PCr/ATP ratios decreased by 12 and 11%, 24 and 48 hr after CLP, respectively. The PCr/P(i) ratios decreased incrementally (7% in 24 degrees CLP vs 23% in 48 degrees CLP animals). Twenty-four hours after operation the half time for PCr recovery was shortened while the initial PCr resynthesis rate and maximal oxidative ATP synthesis rate were accelerated in CLP animals compared to controls.(ABSTRACT TRUNCATED AT 250 WORDS)

31P magnetic resonance spectroscopy demonstrates expansion of the extracellular space in the skeletal muscle of starved rats.

Starvation significantly alters the distribution of body water. To study the effects of starvation on cellular energetics and water distribution in skeletal muscle, a novel 31P magnetic resonance technique (31P MRS) was developed to measure water compartments. After 31P MRS-visible water space markers which distribute in total body water (dimethyl methylphosphonate, DMMP) and extracellular water (phenylphosphonate, PPA) were infused intravenously, 31P MRS spectra were obtained from the gastrocnemius muscle of male virus-free Wistar rats at baseline and after starvation or ad libitum feeding for 4 days. Muscle water spaces were also measured using the chloride method and Nernst's equation. Muscle water contents as determined by drying were equivalent in the two groups. In vivo measurements of changes in DMMP relative to all of the MRS visible phosphates also demonstrated that the total water space was similar in control and starved rats. However, starvation significantly increased the ratio of PPA/DMMP (0.67 +/- 0.05 vs 0.87 +/- 0.04, Control vs Starvation; P < 0.001), and therefore the ratio of extracellular water to total water in the gastrocnemius. Furthermore, because muscle water contents were comparable between the groups, this expansion of the extracellular space was accompanied by contraction of the intracellular compartment in starved animals. Equivalent changes were detected in vitro using the chloride method. Lastly, phosphocreatine/ATP ratios, which measured changes in high-energy phosphate stores, decreased after starvation (4.09 +/- 0.06 vs 3.61 +/- 0.06; P < 0.001) and were inversely related to changes in PPA/DMMP (r = -0.61; P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)