Severe shoulder dystocia leading to neonatal injury: a case control study.

BACKGROUND AND OBJECTIVES: Severe shoulder dystocia (SD) is associated with neonatal brachial plexus injuries and skeletal fractures, with the former being the commonest cause for litigation related to birth trauma. The aim of this case-control study was to evaluate risk factors for birth injuries in cases presenting with SD. METHODS: Between January 2000 and December 2006, 22 babies who sustained brachial nerve paralysis or skeletal fractures following severe SD and requiring admission to Special Care Baby Unit (SCBU) were identified. The control group (n = 22) comprised the next infant delivered who was deemed to have SD but did not suffer significant birth injuries. Antenatal, labour and postnatal data were collected and compared between the two groups. RESULTS: The study and control groups had similar median maternal age (28 vs. 26.5 years), gestational age at delivery (40 vs. 40 weeks) and estimated blood loss (300 vs. 225 ml) (both P > 0.05, Mann-Whitney test). Median 1 min Apgar scores (5.5 vs. 7), maternal BMI (31.34 vs. 27.19 kg/m(2)) and duration of second stages (53.8 vs. 49.2 min) were also statistically similar in both groups (P > 0.05). However, compared to controls, brachial nerve injuries and skeletal fractures were more likely to occur in mothers with gestational diabetes (5/22 vs. 1/22) or who had previous big babies (4/22 vs. 1/22) (both P < 0.05, Fisher's exact test). Babies who had birth injuries were also more likely to have greater median birth weights (4.3 vs. 3.8 kg) and postnatal anthropometric measurements such as head circumference (35 vs. 34 cm) and ponderal indices (81.9 vs. 74.3 kg/m(3)) compared to controls. CONCLUSION: In babies with SD, brachial nerve injuries and skeletal fractures are more likely to occur in those with greater birthweights but also larger length to weight ratios. In these babies, assessment of abdominal circumference and biacromial length by magnetic resonance imaging (MRI) may help predict the likelihood of severe SD, especially in mothers with identifiable risk factors. However, further research in larger controlled trials are still needed to determine their predictive value.

Weight changes after total hip arthroplasty.

A survey is presented that contradicts the often quoted teleologic argument that restricted mobility is the limiting factor in weight reduction in overweight patients needing a total hip arthroplasty. One hundred fifty patients were reviewed at 1 year after arthroplasty. All reported improved mobility, but there was no evidence of a trend toward weight loss. More complications with overweight patients were observed. This is useful information in encouraging overweight people to lose weight prior to hip arthroplasty, and could be extrapolated to other procedures.

Resolution of low-energy chlorophylls in Photosystem I of Synechocystis sp. PCC 6803 at 77 and 295 K through fluorescence excitation anisotropy.

Fluorescence excitation spectra of highly anisotropic emission from Photosystem I (PS I) were measured at 295 and 77 K on a PS II-less mutant of the cyanobacterium Synechocystis sp. PCC 6803 (S. 6803). When PS I was excited with light at wavelengths greater than 715 nm, fluorescence observed at 745 nm was highly polarized with anisotropies of 0.32 and 0.20 at 77 and 295 K, respectively. Upon excitation at shorter wavelengths, the 745-nm fluorescence had low anisotropy. The highly anisotropic emission observed at both 77 and 295 K is interpreted as evidence for low-energy chlorophylls (Chls) in cyanobacteria at room temperature. This indicates that low-energy Chls, defined as Chls with first excited singlet-state energy levels below or near that of the reaction center, P700, are not artifacts of low-temperature measurements.If the low-energy Chls are a distinct subset of Chls and a simple two-pool model describes the excitation transfer network adequately, one can take advantage of the low-energy Chls' high anisotropy to approximate their fluorescence excitation spectra. Maxima at 703 and 708 nm were calculated from 295 and 77 K data, respectively. Upper limits for the number of low-energy Chls per P700 in PS I from S. 6803 were calculated to be 8 (295 K) and 11 (77 K).

Case report: bilateral carpal and tarsal synostoses.

Carpal and tarsal synostoses are uncommon. We report a rare combination of bilateral carpal and tarsal synostoses, including fusion across the carpal and tarsal rows, and review the literature.

Limb exsanguination. II. The leg: effect of angle of elevation.

Although limb exsanguination prior to tourniquet inflation is usually accomplished using mechanical devices, elevation alone may still be employed under circumstances where mechanical means are contraindicated. The rather confusing advice within the literature as to duration of elevation, stimulated a study in the arm which revealed the optimal duration of elevation to be 5 min, a period somewhat longer than generally advised. Because the pattern of venous drainage within the leg is slightly different to that of the arm, we undertook a similar study to ascertain if our findings for the arm also held true for the leg. Volume changes in the calves of seven male volunteers during elevation at 45 degrees and 90 degrees were assessed using strain gauge plethysmography. To achieve maximal exsanguination it is recommended that the leg should be elevated at an angle of 45 degrees for 5 min. Higher angles of elevation produce slower and less complete exsanguination.

Limb exsanguination. I. The arm: effect of angle of elevation and arterial compression.

Limb exsanguination before tourniquet inflation is usually accomplished using mechanical devices although, where their use is contraindicated, exsanguination by elevation alone may be employed. Advice regarding duration of elevation within the literature is a little confusing with recommendations ranging from 20 s to 5 min. Volume changes, during elevation at 45 degrees and 90 degrees, were measured using strain gauge plethysmography in seven male volunteers. In addition, the superimposed effect of brachial arterial compression on elevation at 90 degrees was investigated. To achieve maximal exsanguination it is recommended that the arm should be elevated for 5 min at 90 degrees before tourniquet inflation. Supplementary brachial arterial compression is not recommended as this tends to attenuate changes in volume.

Temperature dependence and polarization of fluorescence from Photosystem I in the cyanobacterium Synechocystis sp. PCC 6803.

To determine the fluorescence properties of cyanobacterial Photosystem I (PS I) in relatively intact systems, fluorescence emission from 20 to 295 K and polarization at 77 K have been measured from phycobilisomes-less thylakoids of Synechocystis sp. PCC 6803 and a mutant strain lacking Photosystem II (PS II). At 295 K, the fluorescence maxima are 686 nm in the wild type from PS I and PS II and at 688 nm from PS I in the mutant. This emission is characteristic of bulk antenna chlorophylls (Chls). The 690-nm fluorescence component of PS I is temperature independent. For wild-type and mutant, 725-nm fluorescence increases by a factor of at least 40 from 295 to 20 K. We model this temperature dependence assuming a small number of Chls within PS I, emitting at 725 nm, with an energy level below that of the reaction center, P700. Their excitation transfer rate to P700 decreases with decreasing temperature increasing the yield of 725-nm fluorescence.Fluorescence excitation spectra of polarized emission from low-energy Chls were measured at 77 and 295 K on the mutant lacking PS II. At excitation wavelengths longer than 715 nm, 760-nm emission is highly polarized indicating either direct excitation of the emitting Chls with no participation in excitation transfer or total alignment of the chromophores. Fluorescence at 760 nm is unpolarized for excitation wavelengths shorter than 690 nm, inferring excitation transfer between Chls before 760-nm fluorescence occurs.Our measurements illustrate that: 1) a single group of low-energy Chls (F725) of the core-like PS I complex in cyanobacteria shows a strongly temperature-dependent fluorescence and, when directly excited, nearly complete fluorescence polarization, 2) these properties are not the result of detergent-induced artifacts as we are examining intact PS I within the thylakoid membrane of S. 6803, and 3) the activation energy for excitation transfer from F725 Chls to P700 is less than that of F735 Chls in green plants; F725 Chls may act as a sink to locate excitations near P700 in PS I.