Anesthesia for outpatient female sterilization

This issue of the Bulletin deals with the principles of anesthesia for outpatient female sterilization with emphasis on techniques for laparoscopy and minilaparotomy. General anesthesia techniques provide analgesia, amnesia, and muscle relaxation and are particularly useful for managing the anxious patient. Disadvantages include increased expense, need for specialized equipment, and highly trained personnel, and delayed recovery. Complications, though relatively rare, can be life-threatening and include aspiration of stomach contents, hypoxia, hypercarbia, hypotension, hypertension, cardiac arrhythmias, cardiorespiratory arrest, and death. There is no single preferred technique of general anesthesia, athough most anesthetists employ methods that allow rapid recovery of faculties, enabling the patient to be discharged soon after surgery. To accomplish this end, light anesthesia with sodium thiopental induction and nitrous oxide maintenance is often used. Short duration muscle relaxation with an agent such as succinylcholine supplements this technique. Other techniques include light anesthesia with inhalational anesthetic agents and the use of intravenous ketamine. Local anesthesia augmented by systemic and/or inhalational analgesia is supplanting general anesthesia techniques for laparoscopy in many locales. This approach is also particularly well-suited for minilaparotomy in developing countries, where it has achieved its greatest popularity. The local technique carries with it reduced morbidity and mortality but may not entirely relieve discomfort. The primary danger of local anesthesia is respiratory depression due to excessive narcosis and sedation. The operator must be alert to the action of the drugs and should always use the minimal effective dose. Although toxicity due to overdosage with local anesthetic drugs is occasionally experienced, allergic reactions to the amide-linkage drugs such as lidocaine or bupivacaine are exceedingly rare. For outpatient laparoscopy or minilaparotomy, local anesthesia with proper preoperative counselling and premedication should provide adequate relief of pain and is the method of choice, unless the patient cannot be examined awake or is totally uncooperative. The decision to utilize either general or local anesthesia should be made by the patient after thorough counselling by the surgical team. In many cases, the circumstances of the surgical environment will dictate the choice, but patient comfort and safety should always be the goal.     

Simultaneous and direct determination of pyridoxal, pyridoxal-5'-phosphate, and pyridoxic acid in serum by derivative synchronous fluorescence spectroscopy

Simultaneous and direct assays of pyridoxal, pyridoxal-5'-phosphate, and pyridoxic acid in human serum are described. The method applied is based on the reaction of these compounds with beryllium in an ammoniacal medium to yield highly fluorescent derivatives. Overlapping of conventional fluorescence spectra is resolved by using second-derivative fluorescence spectroscopy, thus making the use of separation techniques unnecessary. The proposed method is simple (only beryllium and an ammoniacal buffer are needed to develop fluorescence), rapid (the derivative formation is instantaneous and serum treatment only requires deproteinization), and inexpensive (no sophisticated detection equipment is necessary, any conventional modern spectrofluorimeter being adequate for use). The analytical recovery achieved was of about 96% for pyridoxal, 97% for pyridoxal-5'-phosphate, and 100% for pyridoxic acid. Measurements were carried out in a single scan.     

PROBLEMS IN VENTILATION IN THE IMMEDIATE POSTOPERATIVE PERIOD

In the present day practice of surgical anesthesia, drugs and techniques are used which require or lead to cessation of voluntary respiration by the patient. Respiration is then controlled by the anesthesiologist. At the termination of operation many patients do not breathe adequately for variable periods of time. The causes include obstruction, excessive sedation, muscle relaxants, the effect of controlled respiration itself and various miscellaneous factors. A diagnosis is made by taking into consideration the drugs and techniques which have been used and the character of the patient''s respiratory efforts, if any. The cause may then be treated. In some cases antidotes are available. However, until truly adequate spontaneous respiration is observed for some time the patient must have his efforts assisted. High oxygen concentrations must not be substituted for adequate ventilation.     

I. P. Pavlov on vivisection and the modern ethical requirements for animal experiments]

It is shown that Pavlov's opinion is in agreement with the modern requirements for experiments in living animals: use of living animals in experiments is recommended only in the cases when there is no alternative and scientific-practical significance of the planned experiments is justified; minimization (as much as possible) of discomfort, distress and pain of animals under study without sacrifice of the quality of scientific research; use of appropriate number of animals necessary for obtaining reliable results which are adequate to a given experimental situation and general state of the animals inadmissibility of using extra number of animals; drawing up a protocol concerning the experimental procedure and results; reflection in the protocol the techniques of sedation, anesthesia, and euthanasia; constant care of the improvement of the theoretical and practical qualification of a researcher in the ethical questions and experimental technique. Pavlov's views led his time and at present they agree with modern concepts on the experimental ethics.     

The chemical restraint of apes and monkeys by means of phencyclidine or ketamine.

The anesthetic effects of two drugs, namely, Phencyclidine and Ketamine, used alone or in combination with atropine, were compared during clinical and experimental procedures on different primate species ranging from gorillas, orangutans, white-faced and dwarf chimpanzees, baboons, cercopithecus monkeys to new--world monkeys. It is concluded that both these anesthetics are very good and safe drugs for restraint and anesthesia. Ketamine appeared to be superior to Phencyclidine for use among apes and monkeys in so far as it is shorter acting, has wider safety margin and shorter recovery time, provides better muscle relaxation and is practically without side effects. But Phencyclidine has definite advantage in so far as it is needed is smaller quantity to produce comparable effect of anesthesia.     

A comparison of pentobarbital, fentanyl-droperidol, ketamine-xylazine and ketamine-diazepam anesthesia in adult male rats

Proper use of anesthetics is of paramount importance for humane animal care. Current research trends show a greater reliance on rats for laboratory investigations. This study compared several dosages for four different drugs, (pentobarbital, fentanyl-droperidol, ketamine-xylazine and ketamine-diazepam) for use in the laboratory rat. Each drug was evaluated in respect to its onset, duration of effect, recovery, adverse effects and mortality. A quantitative assessment of the depth of anesthesia also was obtained for all dosages of each drug. Results showed that all tested dosages of pentobarbital, ketamine-xylazine and ketamine-diazepam were suitable anesthetics for use in the laboratory rat. Low dosages of fentanyl-droperidol (Innovar-Vet), however, appeared to produce a state known as neuroleptanalgesia as opposed to anesthesia seen with the other agents.     

Viral Hepatitis: Problems of Incidence and Control in Military Personnel

(A) Hepatitis B virus (HBV) is now the major cause of infectious viral hepatitis in U.S. military personnel and probably also in the civilian population over 15 years of age. (B) The incidence of icteric, viral hepatitis is much higher in U.S. military personnel than in comparable age groups in the civilian population. The 17-to 20-year-old enlisted men show the highest rates. (C) In parts of the world (e.g., U.S.A., Germany) where most of the inapparent infection is caused by the adw subtype of HBV, most of the acute clinical disease is caused by the ayw subtype. In the U.S.A. and Germany, 95% or more of HB_s Ag isolates from U.S. military personnel with acute hepatitis is ayw. (D) It may be many years before one can expect to have sufficient data for a decision as to the possible availability of an effective HBV vaccine. Accordingly, a decision is urgently needed regarding either the immediate use of the best practically available hepatitis immune gamma globulin, that can be prepared by modern techniques, for the prevention of hepatitis in U.S. military personnel or postponement of such use until an adequate and properly controlled trial can be carried out in active duty military personnel in an area of high incidence.     

The Use of Positive Reinforcement Training Techniques to Enhance the Care,Management, and Welfare of Primates in the Laboratory

Handled frequently and subjected to a wide range of medical procedures that may be particularly invasive, nonhuman animals in a laboratory setting have unique needs. To produce the most reliable research results and to protect and enhance the well-being of the animals, it is desirable to perform these procedures with as little stress for the animals as possible. Positive reinforcement training can use targeted activities and procedures to achieve the voluntary cooperation of nonhuman primates. The benefits of such work include diminished stress on the animals, enhanced flexibility and reliability in data collection, and a reduction in the use of anesthesia. Training also provides the means to mitigate social problems, aid in introductions, reduce abnormal behavior, enhance enrichment programs, and increase the safety of attending personnel. This article describes the application of operant conditioning techniques to animal management.     

The use of positive reinforcement training techniques to enhance the care, management, and welfare of primates in the laboratory

Handled frequently and subjected to a wide range of medical procedures that may be particularly invasive, nonhuman animals in a laboratory setting have unique needs. To produce the most reliable research results and to protect and enhance the well-being of the animals, it is desirable to perform these procedures with as little stress for the animals as possible. Positive reinforcement training can use targeted activities and procedures to achieve the voluntary cooperation of nonhuman primates. The benefits of such work include diminished stress on the animals, enhanced flexibility and reliability in data collection, and a reduction in the use of anesthesia. Training also provides the means to mitigate social problems, aid in introductions, reduce abnormal behavior, enhance enrichment programs, and increase the safety of attending personnel. This article describes the application of operant conditioning techniques to animal management.     

Trifluoroethylvinyl ether (fluoromar); a preliminary report on clinical experience and animal experiment

In observations of 80 cases in which Fluoromar was used for inhalation anesthesia it was noted that induction was rapid; maintenance although labile, was usually smooth; and recovery of reflexes was rapid. Anesthetic complications were minimal, and postanesthetic complications were limited to nausea and vomiting in no greater incidence than that expected to follow the use of most inhalation anesthetic agents. Fluoromar produces rapid, and not particularly unpleasant, loss of consciousness, and will produce complete anesthesia without supplement. However, the muscular relaxation afforded by Fluoromar is not complete, and delayed recovery from anesthesia may follow attempts to produce relaxation by deepening too greatly the level of anesthesia. The inflammability of Fluoromar is less than that of other inhalation agents.     

TRIFLUOROETHYLVINYL ETHER (FLUOROMAR?)—A Preliminary Report on Clinical Experience and Animal Experiment

In observations of 80 cases in which Fluoromar was used for inhalation anesthesia it was noted that induction was rapid; maintenance although labile, was usually smooth; and recovery of reflexes was rapid. Anesthetic complications were minimal, and postanesthetic complications were limited to nausea and vomiting in no greater incidence than that expected to follow the use of most inhalation anesthetic agents.Fluoromar produces rapid, and not particularly unpleasant, loss of consciousness, and will produce complete anesthesia without supplement. However, the muscular relaxation afforded by Fluoromar is not complete, and delayed recovery from anesthesia may follow attempts to produce relaxation by deepening too greatly the level of anesthesia.The inflammability of Fluoromar is less than that of other inhalation agents.     

Cardiopulmonary,hematological, serum biochemical and behavioral effects of sevoflurane compared with isoflurane or halothane in spontaneously ventilating goats

This study compares cardiopulmonary, hematological, serum biochemical and behavioral effects of sevoflurane, isoflurane or halothane anesthesia in spontaneously breathing, conventionally medicated goats. Six male adult goats were anesthetized repeatedly at 2-week intervals with three anesthetics. Goats were administered atropine (0.1 mg/kg) intramuscularly, and 10 min later, induced to anesthesia by an intravenous infusion of thiopental (mean 14.3 mg/kg). After intubation, goats were anesthetized with halothane, isoflurane or sevoflurane in oxygen and maintained at surgical depth of anesthesia for 3 h. Recovery from anesthesia with sevoflurane was more rapid than that with isoflurane or halothane. Time-related hypercapnia and acidosis were observed during halothane anesthesia, but not observed during sevoflurane or isoflurane anesthesia. Both hypercapnia and acidosis during sevoflurane anesthesia did not differ from isoflurane anesthesia, but were less during halothane anesthesia, especially at prolonged maintenance period. There were no significant differences between anesthetics in respiration and heart rates, arterial pressures, hematological and serum biochemical values. It was concluded that sevoflurane is an effective inhalant for use in goats showing the most rapid recovery from anesthesia, and that cardiopulmonary effects of sevoflurane are similar to isoflurane than halothane.     

OPERATING ROOM DEATHS—An Analysis of Mortality in a Veterans Administration Hospital Over a Ten-Year Period

A study of operating room and recovery room deaths which occurred during a ten-year period from 1948 through 1957 at one hospital revealed that there were 59 deaths associated with 57,132 surgical procedures.Factors which directly influenced the rate of operating room and recovery room death were the age of the patient and the length of operating time. Seventy-five per cent of the deaths occurred in cases in which the operation took longer than one hour. Combined anesthesia techniques may have indirectly contributed to death in some cases.Complications of operation requiring another surgical procedure sometimes occur. In this series, reoperation proved to be more hazardous in terms of mortality rate than did single operations. This is not surprising for most complications occur in the poorer risk patients.The operating room death rate steadily increased during the ten-year period studied. This increasing death rate can largely be attributed to the more intricate operations which are being done on poorer risk patients. The use of the curariform drugs had no influence on the increasing death rate.     

Operating room deaths; an analysis of mortality in a Veterans Administration hospital over a ten-year period

A study of operating room and recovery room deaths which occurred during a ten-year period from 1948 through 1957 at one hospital revealed that there were 59 deaths associated with 57,132 surgical procedures. Factors which directly influenced the rate of operating room and recovery room death were the age of the patient and the length of operating time. Seventy-five per cent of the deaths occurred in cases in which the operation took longer than one hour. Combined anesthesia techniques may have indirectly contributed to death in some cases. Complications of operation requiring another surgical procedure sometimes occur. In this series, reoperation proved to be more hazardous in terms of mortality rate than did single operations. This is not surprising for most complications occur in the poorer risk patients. The operating room death rate steadily increased during the ten-year period studied. This increasing death rate can largely be attributed to the more intricate operations which are being done on poorer risk patients. The use of the curariform drugs had no influence on the increasing death rate.     

Detection and determination of antimalarial drugs and their metabolites in body fluids

This review of methods for determining antimalarial drugs in biological fluids has focused on the various analytical techniques for the assay of chloroquine, quinine, amodiaquine, mefloquine, proguanil, pyrimethamine, sulphadoxine, primaquine and some of their metabolites. The methods for determining antimalarials and their metabolites in biological samples have changed rapidly during the last eight to ten years with the increased use of chromatographic techniques. Chloroquine is still the most used antimalarial drug, and various methods of different complexity exist for the determination of chloroquine and its metabolites in biological fluids. The pharmacokinetics of chloroquine and other antimalarials have been updated using these new methods.The various analytical techniques have been discussed, from simple colorimetric methods of intermediate selectivity and sensitivity to highly sophisticated, selective and sensitive chromatographic methods applied in a modern analytical laboratory. Knowledge concerning the method for a particular study is determined by the type of application and the facilities, equipment and personnel available. Often is it useful to apply various methods when conducting a clinical study in malaria-endemic areas. Field-adapted methods for the analysis of urine samples can be applied at the study site for screening, and corresponding blood samples can be preserved for subsequent analysis in the laboratory. Selecting samples for laboratory analysis is based on clinical, parasitological and field-assay data. The wide array of methods available for chloroquine permit carefully tailored approaches to acquire the necessary analytical information in clinical field studied concerning the use of this drug. The development of additional field-adapted and field-interfaced methods for other commonly used antimalarials will provide similar flexibility in field studies of these drugs.     

Artificial Respiration and Artificial Circulation: Training Experiences—Principles and Practice of Emergency Resuscitation and Post-Resuscitation Care

A training program in the newer methods of treatment of acute cardiopulmonary emergencies which was developed at the University Hospital, University of Saskatchewan, is reported. Artificial respiration by the chance rescuer, primary and secondary resuscitation, and post-resuscitation measures involving the use of special drugs and equipment by trained personnel are described. Figures and tables designed for wall-mounting and ready reference in an emergency situation are presented. Firstaid ventilatory adjuncts for use by trained personnel are classified and critically appraised, and the propriety of their use is emphasized. A plea is made to the medical profession and allied agencies to assume the responsibility of spreading knowledge of the new techniques more widely. Unless effective treatment is instituted early enough to prevent death or permanent anoxic damage to heart and brain, follow-through therapy will often be fruitless.     

Insect natural products and processes: new treatments for human disease

In this overview, some of the more significant recent developments in bioengineering natural products from insects with use or potential use in modern medicine are described, as well as in utilisation of insects as models for studying essential mammalian processes such as immune responses to pathogens. To date, insects have been relatively neglected as sources of modern drugs although they have provided valuable natural products, including honey and silk, for at least 4-7000 years, and have featured in folklore medicine for thousands of years. Particular examples of Insect Folk Medicines will briefly be described which have subsequently led through the application of molecular and bioengineering techniques to the development of bioactive compounds with great potential as pharmaceuticals in modern medicine. Insect products reviewed have been derived from honey, venom, silk, cantharidin, whole insect extracts, maggots, and blood-sucking arthropods. Drug activities detected include powerful antimicrobials against antibiotic-resistant bacteria and HIV, as well as anti-cancer, anti-angiogenesis and anti-coagulant factors and wound healing agents. Finally, the many problems in developing these insect products as human therapeutic drugs are considered and the possible solutions emerging to these problems are described.     

Propofol anesthesia in loggerhead (Caretta caretta) sea turtles

Rapid, safe, and effective methods of anesthetic induction and recovery are needed for sea turtles, especially in cases eligible for immediate release. This study demonstrates that intravenous propofol provides a rapid induction of anesthesia in loggerhead (Caretta caretta) sea turtles and results in rapid recovery, allowing safe return to water shortly after the procedure. Forty-nine loggerhead sea turtles were recovered as local fishery by-catch in pound nets and transported to a surgical suite for laparoscopic sex determination. Treatment animals (n = 32) received 5 mg/kg propofol intravenously (i.v.) as a rapid bolus, whereas control animals (n = 17) received no propofol. For analgesia, all animals received a 4 ml infusion of 1% lidocaine, locally, as well as 2 mg/kg ketoprofen intramuscularly (i.m.). Physiologic data included heart and respiratory rate, temperature, and a single blood gas sample collected upon termination of the laparoscopy. Subjective data included jaw tone and ocular reflex: 3 (vigorous) to 0 (none detected). Anesthetic depth was scored from 1, no anesthesia, to 3, surgical anesthesia. Turtles receiving propofol became apneic for a minimum of 5 min with a mean time of 13.7 +/- 8.3 min to the first respiration. Limb movement returned at a mean time of 21.1 +/- 16.8 min. The treatment animals were judged to be sedated for approximately 30 min (mean anesthetic depth score > or = 1.5) when compared to controls. Median respiratory rates for treatment animals were slower compared to controls for the first 15 min, then after 35 min, they became significantly faster than the controls. Median heart rates of control animals became significantly slower than treatment animals between 40 and 45 min. Physiologic differences between groups persisted a minimum of 55 min. Possible explanations for heart rate and respiratory rate differences later in the monitoring period include a compensatory recovery of treatment animals from anesthesia-induced hypoxia and hypercapnia or, alternatively, an induced response of the nonsedated control animals. The animals induced with propofol were easier to secure to the restraint device and moved less during laparoscopy. In conclusion, propofol is a safe and effective injectable anesthetic for use in free-ranging loggerhead sea turtles that provides rapid induction and recovery.