Management of Vascular Injuries in a Forward Hospital

Background

Management of vascular injuries poses a challenging problem under warlike conditions. Several authorities recommend limb revascularisation only within first 6-8 hours, as the outcome after delayed revascularisation is poor.

Methods

A retrospective analysis of 61 consecutive patients with vascular injury in a forward hospital over a 25- month period was carried out.

Results

Vascular injuries constituted 3.1% of all injuries. The mean injury to treatment delay (lag time) was 11 hours, and 10 patients received treatment after 12 hours. The overall amputation rate was 15%, but only 6.5% for those revascularised within 12 hours and 44% for those undergoing surgery after 12 hours (Chi-square 4.59, p < 0.05). Presence of associated fractures was associated with an adverse outcome (Chi-square 4.24, p < 0.05), as was ligation in comparison to revascularisation (Chi-square 7.86, p < 0.005). Popliteal injuries were associated with a high amputation rate.

Conclusions

Failure to revascularise (ligation of artery), presence of associated fracture, and restoration of circulation beyond 12 hours are associated with a high amputation rate.Key Words: Vascular injuries, trauma, amputation     

Identification of biliary metabolites of ifosfamide using 31P magnetic resonance spectroscopy and mass spectrometry

Biliary excretion is a significant component in the metabolism of many drugs, but remains difficult to detect and characterise non-invasively. A previous publication recently described the detection of metabolites of ifosfamide in gall bladder in a guinea pig model using in vivo ¹H-decoupled ³¹P 3-D magnetic resonance spectroscopic imaging and a clinical 1.5 T MR scanner.. Here high-resolution ³¹P magnetic resonance spectroscopy (MRS) of extracted bile identifies peaks as parent ifosfamide (1.19±1.47 mM; mean ± sd), carboxyifosfamide (2.04±1.04 mM) and a major contribution from a previously unreported peak at 16.0 ppm (4.05±2.38 mM). The unknown resonance was identified using liquid chromatography - mass spectrometry (LCMS) as the glutathione conjugate of ifosfamide (MW = 531). This was confirmed by analysing products from the reaction of glutathione with ifosfamide using LCMS and MRS. These results demonstrate how combined in vivo and analytical MRS, together with mass spectrometry, can help identify visceral routes of drug metabolism, thereby aiding understanding of ±drug disposition and mechanisms of action and toxicity. In particular, the distribution of ifosfamide and its metabolites into bile may be related to oxazophosphorine-related cholecystitis reported in patients.     

Nucleotide oligomerization domain 1 is a dominant pathway for NOS2 induction in vascular smooth muscle cells: comparison with Toll-like receptor 4 responses in macrophages

Background and purpose:

Gram-negative bacteria contain ligands for Toll-like receptor (TLR) 4 and nucleotide oligomerization domain (NOD) 1 receptors. Lipopolysaccharide (LPS) activates TLR4, while peptidoglycan products activate NOD1. Activation of NOD1 by the specific agonist FK565 results in a profound vascular dysfunction and experimental shock in vivo.

Experimental approach:

Here, we have analysed a number of pharmacological inhibitors to characterize the role of key signalling pathways in the induction of NOS2 following TLR4 or NOD1 activation.

Key results:

Vascular smooth muscle (VSM) cells expressed NOD1 mRNA and protein, and, after challenge with Escherichia coli or FK565, NOS2 protein and activity were induced. Macrophages had negligible levels of NOD1 and were unaffected by FK565, but responded to E. coli and LPS by releasing increased NO and expression of NOS2 protein. Classic pharmacological inhibitors for NF-κB (SC-514) and mitogen-activated protein kinase (SB203580, PD98059) signalling pathways inhibited responses in both cell types regardless of agonist. While TLR4-mediated responses in macrophages were specifically inhibited by the pan-caspase inhibitor z-VAD-fmk and the PKC inhibitor Gö6976, NOD1-mediated responses in VSM cells were inhibited by the Rip2 inhibitor PP2.

Conclusions and implications:

Our findings suggest a selective role for NOD1 in VSM cells, and highlight NOD1 as a potential novel therapeutic target for the treatment of vascular inflammation.     

Use of femur length/abdominal circumference ratio in detecting the macrosomic fetus

The femur length/abdominal circumference ratio, expressed as FL/AC X 100, was determined in 156 fetuses and evaluated as a predictor of fetal macrosomia within one week prior to delivery. The normal range (mean +/- 2 SD) in the 105 normal-weight fetuses was 22.0 +/- 2, while the normal range in the 51 macrosomic fetuses was 20.5 +/- 2; these differences were highly significant (P = less than .0001). The predictive power of a positive ratio was 68%, with a sensitivity of 63%. This ratio was particularly useful in the subset (n = 9) of macrosomic fetuses whose mothers were diabetic, correctly identifying 89% of this group. Because it is age independent, this ratio should prove most helpful in identifying fetuses at risk for macrosomia in patients whose dates are not known, since it may become abnormal before the fetal weight falls above the 90th percentile at term (3,900 g). In patients whose dates are known, early fetal macrosomia is best predicted by evaluating the abdominal circumference against normal standards for age.     

PHONOSURGERY AND OTHER VOICE IMPROVEMENT TECHNIQUES

This paper records our experience in dealing with 432 patients where phonosurgery was done. The cadaver study of the larynx confirms the basic principles on which the techniques are based. Our experience with Type 1 thyroplasty is that it gives better results than Teflon paste injection. Use of the microscope during laryngeal surgery has given us greater precision in dealing with mucosal and submucosal pathology. The results of surgery are excellent but require to be followed up with vocal rest, hygiene and rehabilitation to prevent recurrence and get good long-term results of voice improvement.KEY WORDS: Largngeal surgery, Laryngeal mucosa, Vocal cords, Voice training, Voice disorder     

CHANGES IN PULMONARY VASCULATURE IN LUNG DISEASES WHICH LEAD TO PULMONARY HYPERTENSION

The pulmonary vasculature was studied in lung biopsy/autopsy specimens of 20 cases, in conditions likely to lead to pulmonary hypertension. The changes were classified as per Edward and Heath classification and morphometric measurements to gauge medial and intimai hypertrophy were done. Medial hypertrophy was found to be the earliest and commonest change in all cases, irrespective of the pathogenic mechanism of pulmonary hypertension. Variable changes specific to various arteriopathies/vasculopathies were noted.KEYWORDS: Hypertension pulmonary, Pulmonary artery