Accuracy of conventional digital palpation and ultrasound of the cricothyroid membrane in obese women in labour

Success of cricothyroidotomy depends on accurate identification of anatomical neck landmarks. Anaesthetists palpated the cricothyroid membrane of 28 obese and 28 non‐obese women in labour (cut‐off BMI 30 kg.m^?2) and marked the entry point for device insertion with an ultraviolet invisible pen. Ultrasonography was used to mark the midpoint of the cricothyroid membrane and the distance between the two marks was measured. The median (IQR [range]) distance between the two marks was significantly greater in the obese than the non‐obese patients (5 (2–9.5 [0–34]) mm vs 1.8 (0.1–6 [0–15]) mm, respectively; p = 0.02). The cricothyroid membrane was accurately identified with digital palpation in only 39% (11/28) of obese compared with 71% (20/28) of non‐obese patients (p = 0.03). Increased neck circumference in obese patients was significantly associated with inaccuracy in locating the cricothyroid membrane. Percutaneous identification of the cricothyroid membrane in obese women in labour was poor. Pre‐procedural ultrasound may help improved the identification of neck landmarks for cricothyroidotomy.     

End of life in the intensive care unit: knowledge and practice of clinicians from Karachi, Pakistan

Background:  With improvements in the care of critically ill, physicians are faced with obligations to provide quality end-of-life care. Barriers to this include inadequate understanding of the dying patient and withdrawal or limitation of care. The objectives of this study were to document the comprehensions of physicians and nurses regarding the recognition and practice of end-of-life care for critically ill patients placed on life support in the intensive care unit.
Methods:  This was a cross-sectional study carried out at three hospitals in Karachi. Chi-squared analysis and one-way anova were used to compare differences in response between the groups.
Results:  One hundred and thirty-seven physicians and critical care nurses completed the survey. 'Brain death' was defined as an ' irreversible cessation of brainstem function' by 85% respondents, with 50% relying on specialty consultation. Withdrawal of life support is practised by 83.2%; physicians are more likely (Chi square test P -value < 0.001) to withdraw mechanical ventilation, compared with nurses who would withdraw vasopressors ( P -value 0.006). In a do not resuscitate patient, 72.3% use vasopressors, 83% initiate haemodialysis and 17.5% use non-invasive ventilation; 72.6% consult Hospital Ethics Committees; 16% respondents never withdraw life support; 28.3% considered it their responsibility to 'sustain life at all costs' and only 8% gave religious beliefs as a reason.
Conclusions:  There are confusions in the definition of brain death, end-of-life recognition and indications and processes of withdrawal of life support. There are discrepancies between physicians' and nurses' perceptions and attitudes. Clearly, teaching programmes will need to incorporate cultural and religious differences in their ethics curricula.     

Inferior glenohumeral joint dislocation with greater tuberosity avulsion

Inferior glenohumeral dislocation is the least common type of glenohumeral dislocations. It may be associated with fractures of the adjacent bones and neurovascular compromise. It should be treated immediately by close reduction. The associated neuropraxia usually recovers with time. Traction-counter traction method is commonly used for reduction followed by immobilization of the shoulder for three weeks. Here, we report a case of inferior glenohumeral joint dislocation with greater tuberosity fracture with transient neurovascular compromise and present a brief review of the literature.     

Photochemotherapeutic Strategy against Acanthamoeba Infections

Acanthamoeba is a protist pathogen that can cause serious human infections, including blinding keratitis and a granulomatous amoebic encephalitis that almost always results in death. The current treatment for these infections includes a mixture of drugs, and even then, a recurrence can occur. Photochemotherapy has shown promise in the treatment of Acanthamoeba infections; however, the selective targeting of pathogenic Acanthamoeba has remained a major concern. The mannose-binding protein is an important adhesin expressed on the surface membranes of pathogenic Acanthamoeba organisms. To specifically target Acanthamoeba, the overall aim of this study was to synthesize a photosensitizing compound (porphyrin) conjugated with mannose and test its efficacy in vitro. The synthesis of mannose-conjugated porphyrin was achieved by mixing benzaldehyde and pyrrole, yielding tetraphenylporphyrin. Tetraphenylporphyrin was then converted into mono-nitrophenylporphyrin by selectively nitrating the para position of the phenyl rings, as confirmed by nuclear magnetic resonance (NMR) spectroscopy. The mono-nitrophenylporphyrin was reduced to mono-aminophenylporphyrin in the presence of tin dichloride and confirmed by a peak at m/z 629. Finally, mono-aminoporphyrin was conjugated with mannose, resulting in the formation of an imine bond. Mannose-conjugated porphyrin was confirmed through spectroscopic analysis and showed that it absorbed light of wavelengths ranging from 425 to 475 nm. To determine the antiacanthamoebic effects of the derived product, amoebae were incubated with mannose-conjugated porphyrin for 1 h and washed 3 times to remove extracellular compound. Next, the amoebae were exposed to light of the appropriate wavelength for 1 h. The results revealed that mannose-conjugated porphyrin produced potent trophicidal effects and blocked excystation. In contrast, Acanthamoeba castellanii incubated with mannose alone and porphyrin alone did not exhibit an antiamoebic effect. Consistently, pretreatment with mannose-conjugated porphyrin reduced the A. castellanii-mediated host cell cytotoxicity from 97% to 4.9%. In contrast, treatment with porphyrin, mannose, or solvent alone had no protective effects on the host cells. These data suggest that mannose-conjugated porphyrin has application for the targeted photodynamic therapy of Acanthamoeba infections and may serve as a model in the development of therapeutic interventions against other eukaryotic infections.