As with all drugs, fluid therapy must be regarded as context sensitive. If a drug is given in the wrong context to the wrong patient and without a proper indication, only the side-effects of the drug will be seen, with probable demonstrable harm. Fluids, as with all drugs, should only be administered in the proper context in which consideration is given to the pharmacological properties of the agent being administered, the condition for which the drug is being given, and the expected benefits and possible harm. Without clear consideration of the context, drug administration is negligent and harmful.
Hemopure (hemoglobin glutamer-250 [bovine]; HBOC-201) is a hemoglobin (Hb)-based oxygen carrier registered with the Medicines Control Council of South Africa. It is indicated for the treatment of adult patients who are acutely anemic, for the purpose of maintaining tissue oxygen delivery thus eliminating, delaying, or reducing the need for allogeneic red blood cells (RBCs). Hemopure is a volume expander, and circulatory volume must be carefully monitored for signs of fluid overload. Hemopure is not as effective as RBCs for restoring Hb content and concentration, but in cases of severe anemia where allogeneic blood is not an option or is unavailable, it may offer an immediate alternative for improving oxygen transport. This document provides clinical recommendations on the safe and effective use of Hemopure based on the postmarketing experience in South Africa as well as a better understanding of Hemopure properties reflected in recent publications.
Although there are data demonstrating reversal of cerebral vasospasm with magnesium sulfate, there is little information on the effects of magnesium on the normal intact cerebral vasculature. This study investigated the actions of magnesium on cerebral blood flow (CBF) velocity, cardiovascular variables, and arterial gas tensions. Magnesium sulfate was infused into awake, adult sheep at rates of 3 and 6 mmol/min to a total of 15 and 30 mmol, respectively. Direct arterial pressure, cardiac output, and CBF velocity were measured using chronically implanted catheters and a sagittal sinus Doppler flow probe. Arterial blood was sampled for magnesium concentrations and blood gas analysis. Infusion of both 15 and 30 mmol of magnesium increased CBF velocity by 14% (P = .056) and 24% (P = .023), respectively. These increases were accompanied by increases in arterial carbon dioxide tension (PaCO2) of 12% (P = .033) and 17% (P = .048). Multiple linear regression analysis revealed that both PaCO2 (P = .00037) and magnesium (P = .0012) were important predictors of CBF velocity.
The present review of fluid therapy studies using balanced solutions versus isotonic saline fluids (both crystalloids and colloids) aims to address recent controversy in this topic. The change to the acid-base equilibrium based on fluid selection is described. Key terms such as dilutional-hyperchloraemic acidosis (correctly used instead of dilutional acidosis or hyperchloraemic metabolic acidosis to account for both the Henderson-Hasselbalch and Stewart equations), isotonic saline and balanced solutions are defined. The review concludes that dilutional-hyperchloraemic acidosis is a side effect, mainly observed after the administration of large volumes of isotonic saline as a crystalloid. Its effect is moderate and relatively transient, and is minimised by limiting crystalloid administration through the use of colloids (in any carrier). Convincing evidence for clinically relevant adverse effects of dilutional-hyperchloraemic acidosis on renal function, coagulation, blood loss, the need for transfusion, gastrointestinal function or mortality cannot be found. In view of the long-term use of isotonic saline either as a crystalloid or as a colloid carrier, the paucity of data documenting detrimental effects of dilutional-hyperchloraemic acidosis and the limited published information on the effects of balanced solutions on outcome, we cannot currently recommend changing fluid therapy to the use of a balanced colloid preparation.
The recent tragic and widely publicised death of South African (SA) celebrity Gugu Zulu on Mount Kilimanjaro has drawn significant public interest and speculation about the risks of high-altitude trekking and climbing. It has also demonstrated numerous myths and misconceptions with regard to safe high-altitude ascents among not only the lay public, but also medical professionals. Kilimanjaro is of particular relevance, as it has a very high incidence of altitude-related illnesses. Regardless of the details of the Zulu tragedy, a great number of southern Africans undertake treks on Kilimanjaro each year. We have a responsibility to improve understanding and access to medically sound advice for prospective adventurers, and to encourage tour operators to plan and market adventure activities that mitigate the risks to participants.
'%3e%3cpath fill='%23001489' d='M0 0v6h9V0z'/%3e%3cpath fill='%23e03c31' d='M0 0v3h9V0z'/%3e%3cg stroke='%23fff' stroke-width='2'%3e%3cpath id='d' d='m0 0 4.5 3L0 6m4.5-3H9'/%3e%3cuse xlink:href='%23b' stroke='%23ffb81c' clip-path='url(%23c)'/%3e%3c/g%3e%3cuse xlink:href='%23d' fill='none' stroke='%23007749' stroke-width='1.2'/%3e%3c/g%3e%3c/svg%3e)
'/%3e%3c/defs%3e%3cpath fill='%23012169' d='M0 0h10080v5040H0z'/%3e%3cpath stroke='%23fff' stroke-width='.6' d='m0 0 6 3m0-3L0 3' clip-path='url(%23b)' transform='scale(840)'/%3e%3cpath stroke='%23e4002b' stroke-width='.4' d='m0 0 6 3m0-3L0 3' clip-path='url(%23c)' transform='scale(840)'/%3e%3cpath stroke='%23fff' stroke-width='840' d='M2520 0v2520M0 1260h5040'/%3e%3cpath stroke='%23e4002b' stroke-width='504' d='M2520 0v2520M0 1260h5040'/%3e%3cg fill='%23fff'%3e%3cuse xlink:href='%23d' x='2520' y='3780'/%3e%3cuse xlink:href='%23a' x='7560' y='4200'/%3e%3cuse xlink:href='%23a' x='6300' y='2205'/%3e%3cuse xlink:href='%23a' x='7560' y='840'/%3e%3cuse xlink:href='%23a' x='8680' y='1869'/%3e%3cuse xlink:href='%23e' x='8064' y='2730'/%3e%3c/g%3e%3c/svg%3e)