Medical Management and Risk Reduction of the Cardiovascular Effects of Underwater Diving.

Undersea diving is a sport and commercial industry. Knowledge of potential problems began with Caisson disease or "the bends", first identified with compressed air in the construction of tunnels under rivers in the 19th century. Subsequently, there was the commercially used old-fashioned diving helmet attached to a suit, with compressed air pumped down from the surface. Breathhold diving, with no supplementary source of air or other breathing mixture, is also a sport as well as a commercial fishing tool in some parts of the world. There has been an evolution to self-contained underwater breathing apparatus (SCUBA) diving with major involvement as a recreational sport but also of major commercial importance. Knowledge of the physiology and cardiovascular plus other medical problems associated with the various forms of diving have evolved extensively. The major medical catastrophes of SCUBA diving are air embolism and decompression sickness (DCS). Understanding of the essential referral to a hyperbaric recompression chamber for these problems is critical, as well as immediate measures until that recompression is achieved. These include the administration of 100% oxygen and rehydration with intravenous normal saline. Undersea diving continues to expand, especially as a sport, and a basic understanding of the associated preventive and emergency medicine will decrease complications and save lives.

In a time of cholera.

INTRODUCTION: Dr. Nathaniel Alcock in his book A treatise on cholera described 22 cases of cholera that he treated in 1832. Blood-letting, either by leeches or venesection, was an essential part of the treatment. RATIONALE: The belief was that reducing the blood volume would relieve stress on the heart and lungs allowing for better function. The receipts of the Townsend Street Cholera Hospital where Dr. Alcock worked show how extensive the practice was. Outside Dublin, local Boards of Health dealt with the cholera epidemic. Various public measures such as street cleaning and removal of patients to temporary hospitals were undertaken and various cures were tried. OUTCOME: The overall mortality rate from cholera in Ireland during the epidemic was 38 %, but in some areas much higher. CONCLUSION: Even as cholera was spreading in the 1830s, a number of doctors were showing that intravenous fluids could dramatically alter the course of the disease. Unfortunately, their work was ignored and blood-letting continued to be a major component of the treatment of cholera for another 55 years.

Historical perspectives in critical care medicine: blood transfusion, intravenous fluids, inotropes/vasopressors, and antibiotics.

Significant progress in critical care medicine has been the result of tireless observation, dedicated research, and well-timed serendipity. This article provides a historical perspective for four meaningful therapies in critical care medicine: blood transfusion, fluid resuscitation, vasopressor/inotropic support, and antibiotics. For each therapy, key discoveries and events that have shaped medical history and helped define current practice are discussed. Prominent medical and social pressures that have catalyzed research and innovation in each domain are also addressed, as well as current and future challenges.

The early history of the treatment for dehydration.

The difficulties of managing dehydration in infants, along with the special problems of infant feeding in the wake of the industrial revolution, led to the specialty of pediatrics. The scientific and clinical beginnings that preceded the specialty are reviewed; much that came later can be credited to pediatric scientists.

History of the development of oral rehydration therapy.

Humans have often used oral fluids to replace perceived losses of water, either instinctively or with a therapeutic orientation in the form of folk remedies. Replacement therapy with intravenous (IV) fluids was formally introduced in the last century for the treatment of patients with cholera. The modern implementation of oral replacement therapy was begun by pediatricians in the 1940s who used electrolyte solutions as maintenance therapy in mildly purging children with diarrhea. However, the scientific development of oral rehydration therapy (ORT) has occurred only in the last 30 years. Basic physiologic research in the 1950s demonstrated the cotransport mechanism of sodium and organic solutes (sugars and amino acids) in the intestinal cells, thereby establishing the scientific basis for ORT. The use of ORT based on scientific observations was first reported in 1964 from the Philippines by Phillips and coworkers. Research laboratories in Dhaka and Calcutta subsequently demonstrated that the mechanism of sodium and glucose cotransport remains intact in cholera patients and that oral solutions can successfully rehydrate and maintain hydration in these patients. Clinical studies carried out in Dhaka and Calcutta confirmed the efficacy of oral rehydration solutions (ORS) and showed that nearly 80% of IV fluid could be saved if patients were hydrated by the oral route. Further studies demonstrated the safety and efficacy of ORT in patients of all ages suffering from acute diarrhea of any cause. The use of ORT has substantially reduced morbidity and mortality from acute diarrhea, particularly after the World Health Organization adopted and promoted ORT on a worldwide scale. Researchers continue to search for better ORS formulations in terms of safety, efficacy, availability, and cost. Food-based ORS are a promising area of research. The use of a sound scientific method, the establishment of a close link between basic and clinical science, and the use of field studies have proved to be major assets in the development of ORT.