The UK defence anaesthesia experience with the Zambia Anaesthesia Development Programme.

For 18 months UK military anaesthetic trainees have been travelling to Zambia for a 3-month fellowship under the auspices of the Zambia Anaesthesia Development Programme. In this article we will discuss the history, current state and future intent of the fellowship in order to better inform the anaesthetic cadre and wider UK Defence Medical Services.

Comparison of two methods of assessing total body water at sea level and increasing high altitude.

Fluid retention is a recognized feature of acute mountain sickness. However, accurate assessment of hydration, including the quantification of body water, has traditionally relied on expensive and non-portable equipment limiting its utility in the field setting. We compared the assessment of total body water (TBW) and their relationship to total body weight using two non-invasive methods using the NICas single-frequency bioimpedance analysis (SF-BIA) system and the BodyStat QuadScan 4000 multifrequency BIA system (MF-BIA). TBW measurements were performed at rest at sea level and at high altitude (HA) at 3833 m postexercise and at rest and thereafter at rest at 4450 m and 5129 m on 47 subjects. The average age was 34.5 ± 9.3 years with an age range of 21-54 years (70.2% male). There were strong correlations between TBW assessment with both methods at sea level (r = 0.90; 95% CI 0.78-0.95: P<0.0001) and at HA (r = 0.92; 0.89-0.94: P<0.0001), however, TBW readings were 0.2 l and 1.91 l lower, respectively, with the NICaS. There was a stronger correlation between TBW and body weight with the QuadScan (r = 0.91; P<0.0001) than with the NICaS (r = 0.83; P<0.0001). The overall agreement between the two TBW methods was good, but the 95% confidence intervals around these agreements were relatively wide. We conclude that there was reasonable agreement between the two methods of BIA for TBW, but this agreement was lower at HA.

Factors associated with prophylactic plasma transfusion before vascular catheterization in non-bleeding critically ill adults with prolonged prothrombin time: a case-control study.

BACKGROUND: Fresh-frozen plasma (FFP) is widely used in critically ill patients, despite a weak evidence base. Factors that influence the decision to transfuse FFP before intravascular catheter insertion are poorly described. METHODS: We undertook a case-controlled study based on a prospective cohort study of 1923 admissions to 29 intensive care units in the UK. Non-bleeding patients with an international normalized ratio (INR) ≥1.5 who underwent intravascular catheterization, but no other invasive procedure, were identified. We compared patient characteristics, illness-related factors, and biochemical and haematological variables between patients who did or did not receive pre-procedural FFP. RESULTS: One hundred and eighty-six patients fulfilled the criteria; 26 received FFP during the 24 h before line insertion (cases) and 160 did not (controls). Factors associated with greater use of prophylactic FFP by clinicians were pre-existing chronic liver disease (P=0.01), higher serum bilirubin before procedure (P=0.01), lower platelet count (P=0.01), higher activated partial thromboplastin time (P=0.001), lower fibrinogen (P=0.01), and concurrent red cell transfusion despite the absence of bleeding (P=0.001). There was no difference in pre-procedural INR [median (1st, 3rd quartile) cases: 1.95 (1.85, 2.6); controls 1.8 (1.6, 2.3); P=0.19]. The mean FFP dose was 11.1 ml kg(-1) (sd 5.7 ml kg(-1)); 53.8% of cases were transfused <10 ml kg(-1). CONCLUSIONS: Chronic liver disease and more abnormal coagulation tests were associated with greater probability of pre-procedural FFP administration before vascular catheterization, whereas the severity of prothrombin time prolongation alone was not. FFP was more likely to be administered when red cells were also transfused, even in the absence of bleeding.

High altitude pulmonary oedema.

High altitude pulmonary oedema (HAPE) is an important and preventable cause of death at high altitudes. However, little is known about the global incidence of HAPE, in part because most cases occur in remote environments where no records are kept. Furthermore, despite international efforts to achieve consensus, there is wide disparity in the diagnostic criteria in clinical and research use. We have reviewed the literature on the incidence and epidemiology of HAPE. There is broad agreement between studies that HAPE incidence at 2500m is around 0.01%, and increases to 1.9% at 3600m and 2.5-5% at 4300m. Risk factors for HAPE include rate of ascent, intensity of exercise and absolute altitude attained, although an individual pre-disposition to developing the condition is also well described and suggests an underlying genetic susceptibility. It is increasingly recognised that clinically-detectable HAPE is an extreme of a continuous spectrum of excess pulmonary fluid accumulation, which has been demonstrated in asymptomatic individuals. There is a continued need to ensure awareness of the diagnosis and treatment of HAPE among visitors to high altitude. It is likely that HAPE is preventable in all cases by progressive acclimatisation, and we advocate a pragmatic "golden rules" approach. Our understanding of the epidemiology and underlying genetic susceptibility to HAPE may be advanced if susceptible individuals register with the International HAPE Database: http://www.altitude.org/hape.php. HAPE has direct relevance to military training and operations and is likely to be the leading cause of death at high altitude.

Cuspal movement and microleakage in premolar teeth restored with posterior filling materials of varying reported volumetric shrinkage values.

OBJECTIVES: To investigate the effect of polymerisation shrinkage stress of various aesthetic posterior filling materials on cuspal movement and cervical gingival microleakage of mesio-occlusal-distal (MOD) restorations placed in increments in extracted maxillary premolar teeth. METHODS: Forty sound extracted upper premolar teeth were subjected to standardised preparation of a large MOD cavity. One curing regimen was used and each posterior filling material was placed in eight increments with the appropriate bonding system. A twin channel deflection-measuring gauge allowed a measurement of individual cusp deflections at each stage of polymerisation. Restored teeth were thermocycled before immersion in 0.2% basic fuchsin dye for 24h. After sagittal sectioning of the restored teeth in a mesio-distal plane, the sectioned restorations were examined to assess cervical gingival microleakage. RESULTS: In general, cuspal deflection measurements were dependent upon the constituent monomers and the associated shrinkage on curing, with significantly increased cuspal movement (P<0.05) being recorded for Z100 (20.03+/-2.92 microm) compared with Filtek Z250 (12.34+/-2.18 microm), P60 (13.41+/-4.43 microm) and Admira (11.2+/-2.58 microm). No significant differences were identified between the posterior filling materials when the cervical gingival microleakage scores were examined. CONCLUSIONS: It would appear that a reduction in the manufacturers' reported volumetric polymerisation shrinkage for Z100 (4.0%) to below 3% for Filtek Z250, P60 and Admira, resulted in a significant reduction in the associated cuspal strain on the MOD cavity. The diluent triethyleneglycol dimethacrylate (TEGDMA) increases the polymerisation shrinkage of Z100 resin-based composite due to an increased concentration of carbon-to-carbon double bonds (CC). The replacement of TEGDMA with urethane dimethacrylate (UDMA) and Bis-EMA in Filtek Z250 and P60, decreases the polymerisation shrinkage stress by increasing the cross-linking of polymer networks. However, no group was identified as producing less gingival microleakage at the cervical dentine cavosurface margin when the cavities were sectioned and examined, regardless of the reported variations in cuspal strain and the associated volumetric polymerisation shrinkage values.

Preventive mental health interventions in peacekeeping missions to Somalia and Haiti.

Mental health interventions of the 528th Combat Stress Control unit to limit the numbers of psychiatric casualties on recent peacekeeping missions are discussed. Similarities and differences in the mental health support of Operation Restore Hope (Somalia) and Operation Uphold Democracy (Haiti) are reviewed. The mission to Somalia was marked by unexpected combat casualties. The mission to Haiti was marked by unexpected self-inflected casualties. Lessons learned by mental health officers serving on these missions are discussed. Recommendations for prevention of psychiatric casualties on future missions are presented.

Stress, suicide, and military service during Operation Uphold Democracy.

The initial weeks of Operation Uphold Democracy were marked by a high rate of major axis I disorders among soldiers presenting for treatment at the 528th Combat Stress Center. The mission to Haiti was also marked by three suicides during the first 30 days. The author explores psychodynamic sources of stress that may have contributed to the high level of psychiatric acuity observed during that first month. Then, distinctions are made between psychiatric conditions that present in combat and those that occur on peacekeeping missions.

Stress and arousal in deployment of a combat support hospital.

Two hundred thirty-nine soldiers from the 28th Combat Support Hospital were evaluated for stress and arousal during deployment preparations for Operation Uphold Democracy. We measured stress and arousal using the Stress Arousal Checklist and found increased levels of arousal in officers and older soldiers. We also found higher levels of arousal in soldiers reporting a greater number of hours of sleep during the preceding 24 hours. We found no significant difference in stress scores for several demographic and coping behavior groups. Based on lower arousal scores, younger, sleep-deprived, and enlisted soldiers may be at the highest risk for accidents during deployment preparations.

Helping the helper: 528th Combat Stress Center in Somalia.

Seventy-three Rangers were injured and 18 were killed after an ambush in Somalia. Members of the 46th Combat Support Hospital provided nearly continuous care to the wounded soldiers over the subsequent 36 hours. Members of the 528th Combat Stress Center provided psychological support to hospital personnel. Those who provide emergency services to trauma victims are often neglected in terms of the emotional trauma they experience in caring for the injured. This article describes the use of critical incident stress debriefings as a means to reduce distress in the wake of mass-casualty care.

Frontal lobe cerebral aneurysm rupture presenting as psychosis.

A 23 year old male with acute onset of blunted affect, looseness of associations and auditory hallucinations presented to a tertiary care hospital 10 days after development of symptoms. Before transfer, the patient received a diagnosis of schizophreniform disorder and treatment with haloperidol was started which resulted in moderate improvement. Examination led to detection of a ruptured cerebral aneurysm in the left frontal lobe. Evacuation of the haematoma and repair of the aneurysm resulted in nearly complete resolution of symptoms. The rare incidence of acute aneurysm rupture, presenting in the case described, demonstrates the importance of a complete neurological examination in the evaluation of acute mental status changes.

Identification and characterization of greater mood variance in depression.

OBJECTIVE: The authors sought to assess the quantity and quality of mood variation in depressed persons. METHOD: Using a visual analogue scale, they compared variation of mood in a group of patients (N = 9) with a DSM-III-R diagnosis of depressive disorder and in a group of nondepressed subjects (N = 9) over 12 consecutive hours. To quantify mood variation for each subject, the authors computed the standard deviation of each subject's 13 mood ratings on the visual analogue scale. To characterize the quality of mood variation within each subject, they plotted each subject's mood ratings as a function of time and applied complex demodulation to confirm cyclical patterns of mood variability (ultradian cycles). RESULTS: The depressed group demonstrated greater mood score variability over the course of the day. Both groups demonstrated ultradian cycles and circadian trends; however, the depressed group demonstrated ultradian cycles of significantly greater amplitude than the nondepressed group. CONCLUSIONS: Repeated assessments of mood at different times of the day may be necessary to obtain an accurate impression of a patient's mood state. Further, the mechanism of depressive disorders may include a deregulation of a normal oscillatory mood variation pattern.

Exposure to nicotine enhances the behavioral stimulant effect of nicotine and increases binding of [3H]acetylcholine to nicotinic receptors.

Rats were given daily injections of nicotine sulfate in doses ranging from 0.1 to 0.4 mg/kg. The behavioral effect of these injections was measured as locomotor activity in photocell cages. Repeated administration of the same dose to each rat resulted in an enhancement of the stimulant effect of nicotine. This enhanced behavioral effect was quite pronounced within 5 days of repeated injection. Tissue from the cerebral cortex of these rats, exposed to nicotine for 5 days, was assayed for binding of [3H]acetylcholine to nicotinic receptors. These relatively small doses of nicotine resulted in 18-26% increases in cortical nicotinic receptors, compared to saline-treated rats. Rats exposed to 0.2 mg/kg of nicotine for 5 days and then given saline for 7 days still showed an enhanced behavioral response to nicotine on the eighth day after exposure, and nicotinic binding in the cortex was still elevated. However, 21 days after exposure to nicotine both the behavioral response to nicotine and the binding values had returned to the same values as those of saline-treated rats. These data imply that increased binding of [3H]acetylcholine to nicotinic sites and the enhanced behavioral effect of nicotine are functionally linked.