The use of massive transfusion protocol for trauma and non-trauma patients in a civilian setting: what can be done better?

<p><b>INTRODUCTION</b>Massive transfusion protocol (MTP) is increasingly used in civilian trauma cases to achieve better haemostatic resuscitation in patients requiring massive blood transfusions (MTs), with improved survival outcomes. However, in non-trauma patients, evidence for MTP is lacking. This study aims to assess the outcomes of a newly established MTP in a civilian setting, for both trauma and non-trauma patients, in an acute surgical care unit.</p><p><b>METHODS</b>A retrospective cohort analysis was performed on 46 patients for whom MTP was activated in Changi General Hospital, Singapore. The patients were categorised into trauma and non-trauma groups. Assessment of Blood Consumption (ABC) score was used to identify MTP trauma patients and analyse over-activation rates.</p><p><b>RESULTS</b>Only 39.1% of all cases with MTP activation eventually received MTs; 39.8% of the MTs were for non-trauma patients. Mean fresh frozen plasma to packed red blood cells (pRBC) ratio achieved with MTP was 0.741, while mean platelet to pRBC ratio was 0.213. The 24-hour mortality rate for all patients who received an MT upon MTP activation was 33.3% (trauma vs. non-trauma group: 45.5% vs. 14.3%). The ABC scoring system used for trauma patients had a sensitivity and specificity of 81.8% and 41.2%, respectively.</p><p><b>CONCLUSION</b>MTP may be used for both trauma and non-trauma patients in acute care surgery. Scoring systems to predict the need for an MT, improved compliance to predefined transfusion ratios and regular reviews of the MTP are necessary to optimise MTPs and to improve the outcomes of patients receiving MTs.</p>

Importance of Residual Water Permeability on the Excretion of Water during Water Diuresis in Rats

When the concentration of sodium (Na+) in arterial plasma (P(Na)) declines sufficiently to inhibit the release of vasopressin, water will be excreted promptly when the vast majority of aquaporin 2 water channels (AQP2) have been removed from luminal membranes of late distal nephron segments. In this setting, the volume of filtrate delivered distally sets the upper limit on the magnitude of the water diuresis. Since there is an unknown volume of water reabsorbed in the late distal nephron, our objective was to provide a quantitative assessment of this parameter. Accordingly, rats were given a large oral water load, while minimizing non-osmotic stimuli for the release of vasopressin. The composition of plasma and urine were measured. The renal papilla was excised during the water diuresis to assess the osmotic driving force for water reabsorption in the inner medullary collecting duct. During water diuresis, the concentration of creatinine in the urine was 13-fold higher than in plasma, which implies that ~8% of filtered water was excreted. The papillary interstitial osmolality was 600 mOsm/L > the urine osmolality. Since 17% of filtered water is delivered to the earliest distal convoluted tubule micropuncture site, we conclude that half of the water delivered to the late distal nephron is reabsorbed downstream during water diuresis. The enormous osmotic driving force for the reabsorption of water in the inner medullary collecting duct may play a role in this reabsorption of water. Possible clinical implications are illustrated in the discussion of a case example.

Is There Escape from Renal Actions of Vasopressin in Rats with a Hyponatremia for Greater than 48 Hours?

Escape from the renal actions of vasopressin is said to occur in rats with chronic hyponatremia. Our objective was to provide specific evidence to test this hypothesis. Hence the osmolality in the excised renal papilla and in simultaneously voided urine (U(Osm)) was measured in rats with and without hyponatremia. To induce hyponatremia, rats were fed low-electrolyte chow for 6 days. In the first 3 days, water was provided ad lib. On days 4 to 6, a long acting vasopressin preparation (dDAVP) was given every 8 hours to induce water retention. The hyponatremic rats drank 21 mL 5% sucrose on day 4 and 6 mL on day 5. On the morning of day 6, these rats were given 10 mL of 5% glucose in water (D5W) by the intraperitoneal route at 09:00 hour and at 11:00 hour. Analyses were performed in blood, urine, and the excised renal papilla at 13:00 hour on day 6. The concentration of Na+ in plasma (P(Na)) in rats without intraperitoneal D5W was 140+/-1 mEq/L (n=7) whereas it was 112+/-3 mEq/L in the hyponatremic group (n=12). The hyponatremic rats had a higher osmolality in the excised papillary (1,915+/-117 mOsm/kg H2O) than the U(Osm) (1,528+/-176 mOsm/kg H2O, P<0.05). One explanation for this difference is that the rats escaped from the renal action of vasopressin. Nevertheless, based on a quantitative analysis, other possibilities will be considered.

A review of fatal road traffic accidents in Singapore from 2000 to 2004

<p><b>INTRODUCTION</b>This retrospective study aims to assess the epidemiology of road traffic accident (RTA) fatalities in Singapore, other causes of death besides trauma in a RTA, and identify the groups at risk.</p><p><b>MATERIALS AND METHODS</b>Data of 1038 RTA fatalities were reported between 2000 and 2004. Analyses using the Fisher's exact test for discrete variables and multivariate Cox regression analysis were performed to identify groups at risk. The risk of fatality was measured using the prevalence rate ratio (PRR).</p><p><b>RESULTS</b>The median age of victims in the sample was 36 years (interquartile range 24 to 55). Eight hundred and thirty six cases (78%) were in the economically productive age range of 15 to 65 years. Over the 5-year period, there was a preponderance of males. Majority of fatalities involved multiple injuries. There were also 64 (6.2%) and 25 (2.4%) cases of RTA fatalities from infective and cardiovascular (CVS) causes, respectively. Multivariate analyses showed that those > or = 60 years were 4 (95% CI of PRR, 3.04 to 5.43) times as likely to be pedestrian fatalities. Conversely, the risk of fatalities involving pedestrians and cyclists was reduced for males (PRR = 0.58; 95% CI, 0.46 to 0.73). However, males were at increased risk of fatalities involving motorcyclists, scooter and pillion riders (PRR = 1.96; 95% CI, 1.43 to 2.70), whereas such risk was reduced for those aged 30 to 59 (PRR = 0.70; 95% CI, 0.58 to 0.85) or > or = 60 years (PRR = 0.30; 95% CI, 0.21 to 0.42), respectively.</p><p><b>CONCLUSION</b>As such, it appears that the groups at-risk had varying demographic characteristics. Public education could be modified to target these different groups to reduce the number of fatalities.</p>