Non-freezing cold injury (NFCI) is the Cinderella of thermal injuries and is a clinical syndrome that occurs when tissues are exposed to cold temperatures close to freezing point for sustained periods. NFCI is insidious in onset, often difficult to recognize and problematic to treat, and yet the condition accounts for significant morbidity in both military and civilians who work in cold conditions. Consequently recognition of those at risk, limiting their exposure and the appropriate and timely use of suitable protective equipment are essential steps in trying to reduce the impact of the condition. This review addresses the issues surrounding NFCI.

Frostbite is a thermal injury that can occur when temperatures drop low enough for tissue to freeze. On rewarming the tissues, an inflammatory process develops which is often associated with tissue loss. The extent of the tissue loss reflects the severity of the cold exposure and includes factors such as temperature, duration, wind chill, altitude, and systemic hypothermia. This review discusses the epidemiology, the pathophysiological processes involved, and the clinical management of frostbite injuries. Practical advice is given on both the field and hospital management and how to seek expert advice from remote situations. The review also discusses newer developments in frostbite treatment such as intra-vascular thrombolysis and adjunctive treatments such as the use of intravenous vasodilators.

pH and K+ from the extracellular space, PO2, and CBF have been measured in the same region during progressive ischaemia of primate cerebral cortex. As blood flow was reduced, the other changes had the following sequence. PO2 fell rapidly to 30% of control levels at regional CBF (rCBF) of 30 ml 100 g−1 min−1. As CBF was further reduced, PO2 continued to fall. pH remained stable until around 20 ml 100 g−1 min−1, below which pH fell rapidly, with an exponential increase in H+ concentration. K+ showed the well-known relationship to CBF, remaining normal until around 10 ml 100 g−1 min−1, below which K+ rose rapidly. pHe and log K+ were linearly related and confirmed that pH fell by 0.3 U before K+ rose significantly, and fell by 0.6 U before the massive rise in K+. The mechanisms involved in this sequence of events and the role of pH changes in the development of the so-called “ischaemic penumbra” are discussed.

SUMMARY Three cases of stable fractures of the atlas and axis in children are presented. All patients presented with pain, spasm of neck musculature and head tilt along with a neurological deficit. All fractures were apparently stable; with conservative treatment all symptoms and signs resolved.Fractures of the atlas and axis without dislocation are rare, being particularly rare in children. Three cases are presented here along with discussion of their diagnosis and management. Case reportsCase I A 7-year-old girl was knocked down by a motorcycle in October 1981. She was unconscious for five minutes and suffered a simple, undisplaced fracture of the left ulna and a compound fracture of the left tibia. On recovering consciousness she complained of pain in the neck which was associated with spasm of the cervical muscles giving head tilt to the right. There was a grade 4 (MRC Scale) global weakness of the left arm with absent biceps and supinator reflexes, but no sensory loss. Standard antero-posterior and lateral cervical radiographs were reported as showing no abnormality. The symptoms and signs persisted for six weeks which led to investigation. Radiographs were repeated along with A-P and lateral tomography. These revealeil an abnormally high odontoid peg with tilting to the left, separation of the lateral masses of the atlas and a possible crush fracture of the right lateral mass of the axis (Fig). It was concluded that she had suffered a forced flexion injury on the right side, fracturing the anterior arch of the atlas and the right lateral mass of the axis. These injuries were thought to be associated with a mild traction injury of the left brachial plexus. She had been wearing a soft cervical collar from the time of injury which was replaced by a firm collar. She began to show signs of recovery of neck movements 8 weeks after injury. After supporting her neck in the firm collar for a further 3 weeks she was pain free with full neck mobility. During this period her arm weakness recovered completely. Examination revealed tendemess of the left upper cervical region with spasm of the cervical muscles and head tilt to the right. There was a grade 4+ (MRC Scale) right hemiparesis with normal reflexes and sensation. Cervical spine radiographs showed a compression fracture of the left lateral mass of the atlas with separation of the lateral masses. The odontoid was tilted to the right. As in case 1 it was felt that he had fractured the lateral mass and the anterior arch of the atlas. The hemiparesis was thought to be due to a mild cord contusion. He was placed in a firm cervical collar which was changed several days later to a plaster-of-Paris Minerva jacket. His hemiparesis rapidly recovered. The Minerva jacket was removed 6 weeks after injury and he was found to be pain free with no limitation of neck movement and no neurological signs.Case 3 A 4-year-old girl was knocked down by a car in May 1983. She was unconscious for a few minutes after impact but on admission to hospital was found to be fully alert with a l...

The scanning electron microscope reveals that the egg of Pollenia rudis (Fabricius) is structurally suitable for a plastron method of respiration.