RADON INHALATION EXPERIMENTS TO TEST RADON EXHALATION KINETICS.

Three experiments were conducted with a volunteer to test the kinetics of the 222Rn exhalation after a short-time exposure to an elevated 222Rn air concentration. Radon concentration in an exhaled air was measured, complemented by whole body counting of 222Rn decay products in a body. Exhaled activities are compared with the prediction of the recent ICRP biokinetic model for radon. While a rapid equilibration of the exhaled radon activity concentration with that in the air inhaled corresponded with the model, the measured 222Rn exhalation rate was significantly less than modelled. Five hours after termination of the inhalation phase, the radon concentration in the exhaled air decreased to levels expected for non-elevated indoor radon activity concentration. Whole body activities of the 222Rn decay products were found higher than expected. Inhalation of the unattached fraction or residual activity of decay products in the air inhaled may be the explanation.

Trophoblast antigenicity demonstrated by altered challenge graft survival.

Adult C57BL/6J male mice received either a primary ectopic transplant or a primary and a challenge ectopic transplant of trophoblast tissue obtained from the ectoplacental cones of 7(1/2)-day-old C3H/HeJ x C3H/HeJ embryos. Gross and histologic examinations of these grafts at 5, 7, and 12 days of growth indicated that the challenge grafts were inhibited in growth; there were a smaller percentage of grossly successful grafts, smaller hemorrhagic reactions, fewer viable cells at all stages of growth, and better host containment of the colony. The evidence indicates that exposure to pure trophoblast alters an animal's subsequent reaction to grafts syngeneic with the original trophoblast and can best be explained as evidence of immunologic sensitization of the host.

Radon in context of natural radiation exposure: the Czech experience.

Radon issue should be seen in the context of other human exposures and harms. The range of doses from the internal (inhalation and ingestion) and external exposure pathways is presented. Indoor radon regulation is compared with regulation of other natural exposures.

Radon programme: presence and future.

An overview of radon programme experience is presented. The paper summarises broad topics concerning radon issue: philosophy of radon policy, radon measurements strategies with respect to indoor radon variation, progress in radon measurement of an individual house (radon diagnosis), national programmes, the role of preventive measures and interventions with respect to existing and future exposure and knowledge of radon risk, problems of remediation strategies, radon mapping process and sense of delineation of radon prone areas, public awareness on radon issue and publicity campaign. Some research activities are proposed aiming at effective solutions for radon issues in the future.

A simple irrigator-aspirator cannula for laparoscopy: the Stewart system.

An irrigator-aspirator cannula (Stewart system) that may be assembled from common operating room supplies is described for use during operative laparoscopy. The unit consists of a disposable three-way stopcock inserted into a standard 5-mm suction probe. One stopcock port is connected to an irrigation fluid source and pressurized with an inflatable cuff; the other stopcock port is attached to wall suction. Flow rates were determined comparing two types of influx tubing, two different heights of the fluid source, and a range of inflatable cuff pressures. The flow rate of this system with urologic irrigation tubing at pressures of 150 mmHg was comparable to that of a commercially available irrigator-aspirator system. The instrument has been used in 15 routine and emergency operative laparoscopy cases and provides adequate aquadissection, rapid and easy maintenance of a clean operative field, smoke evacuation during laser vaporization, and atraumatic suction traction of tissues.

Vaginal prostaglandin E1 analogue (ONO-802) to soften the cervix in first trimester abortion.

Cervical softening by vaginal administration of a prostaglandin E1 analogue (ONO-802) was studied in a double-blind, placebo-controlled study using an objective measure of cervical resistance in 121 women undergoing first trimester induced abortion. Three hours after administration, cervical resistance in control and treated patients did not differ significantly in nulliparous women but did in parous women.

Direct trocar insertion at laparoscopy: an evaluation.

The need for pneumoperitoneum before trocar entry in laparoscopy is evaluated. In over 2000 unselected cases performed in a residency training program from January 1979 to December 1982, three complications of bowel perforation and peritonitis occurred, one despite needle induction of pneumoperitoneum. In entering the abdomen directly with a trocar, critical surgical points are emphasized: adequate relaxation, sharp trocars, adequate skin incision, elevation of the abdominal wall, and insertion of the trocar into the true pelvis. For most patients with no previous abdominal surgery, the authors suggest that this technique offers more clinical security because it does not place reliance on secondary tests but emphasizes concentration entirely upon surgical skill and anatomic knowledge during entry.

Pulse oximetry: a review of the theory, accuracy, and clinical applications.

Pulse oximetry has emerged as a clinical tool in anesthesia and newborn monitoring within the last 7 years as a result of recent technological and theoretical advances. Oximeters measure the different absorption spectra of oxygenated and deoxygenated hemoglobin. Electronic measures of oxygenation at the peak of the pulse allow computation and display of oxygen saturation of the arterial blood almost instantly. Correlation coefficients between pulse oximetry and direct blood oxygen saturation measurement range from 0.77-0.99 when oxygen saturation is greater than 60%. The method is noninvasive (a clip or tape on a finger), simple to operate, and adaptable to various patient populations. Pulse oximetry monitors continuously and instantaneously, is responsive to change, and is accurate. Factors adversely affecting the accuracy of pulse oximeter output include transducer movement, peripheral vasoconstriction, a nonpulsating vascular bed, hypotension, anemia, changes in systemic vascular resistance, hypothermia, presence of intravascular dyes, and nail polish. Pulse oximetry has been used to monitor oxygen saturation intraoperatively in the adult and neonatal intensive care units and to monitor pregnant patients and their infants at delivery. Once the advantages and limitations of pulse oximetry are recognized, this monitoring technique can play an important role in the care of patients with cardiovascular and respiratory compromise.

Modified endometrial ablation: electrocoagulation with vasopressin and suction curettage preparation.

Patient preparation and a modified operative technique are described for electrocoagulation ablation of the endometrium using a roller-bar electrode. No preoperative or postoperative endometrial suppression was used. Rather, the endometrial cavity was denuded by suction curettage just before ablation, which was performed in the early proliferative phase of the menstrual cycle. Lidocaine paracervical block containing vasopressin was injected at the start of the procedure to control pain and to minimize bleeding and irrigation fluid absorption. Pulsed irrigation of the uterus was used to improve visibility through uterine debris and the bubbles generated by the electrical current. The first 20 patients who had electrocoagulation ablation of the endometrium with these modifications were compared with the first 18 patients who had laser coagulation ablation using standard technique and preoperative endometrial suppression. Compared with the laser method, the modified coagulation method resulted in a comparable rate of satisfactory bleeding decrease at 6 months (90 versus 94%), but involved a clinically significant reduction in total anesthesia time (66.8 versus 117.3 minutes) and volume of irrigation fluid used (5.7 versus 15.9 L).

Effects of carbon dioxide-saturated normal saline and Ringer's lactate on postsurgical adhesion formation in the rabbit.

OBJECTIVE: To evaluate the effect of combining carbon dioxide gas (CO2) with normal saline versus CO2 with lactated Ringer's solution on adhesion formation in the rabbit model. METHODS: Sixty New Zealand white rabbits underwent surgery based on a proven experimental adhesion model. Following abdominal closure, the animals were randomly assigned to three groups: Group 1 underwent abdominal CO2 insufflation only; group 2 underwent abdominal irrigation with CO2-saturated normal saline; group 3 underwent abdominal irrigation with CO2-saturated lactated Ringer's solution. Three weeks later, the rabbits were sacrificed and the adhesions were scored in a blinded fashion based on the extent, type, and tenacity, with a maximum possible score of 11. RESULTS: The mean (+/- standard deviation) adhesion scores were 7.75 +/- 2.82 in group 1, 7.85 +/- 2.58 in group 2, and 4.75 +/- 2.95 in group 3. There was no difference in severity of adhesions between groups 1 and 2. However, the mean adhesion score was significantly lower in group 3 (lactated Ringer's with CO2) than in either group 1 (CO2) or group 2 (normal saline with CO2) (P = .004 and P = .002, respectively). CONCLUSION: It appears that when CO2 is the insufflating gas, lactated Ringer's solution has a protective effect against adhesion formation in the rabbit model.

Spontaneous vaginal expulsion of Hulka clips.

BACKGROUND: Laparoscopic Hulka clip application is a common method of outpatient sterilization in women. We present a patient who experienced spontaneous expulsion of two Hulka clips. CASE: A 21-year-old woman was seen 17 months after sterilization because of spontaneous, asymptomatic passage of two Hulka clips into the vagina. The passage of one clip went unnoticed by the patient. Radiographic studies confirmed the migration and absence of two Hulka clips previously placed on the left fallopian tube. CONCLUSION: In rare circumstances, Hulka clips can migrate from the abdominal cavity and be expelled spontaneously, possibly by transuterine passage. This migration may occur without the patient's knowledge.

Local versus general anesthesia for laparoscopic sterilization: a randomized study.

Despite the contention by some that local anesthesia is a preferred alternative to general anesthesia for laparoscopic sterilization, there have been no randomized studies comparing these techniques. To better characterize the relative safety and acceptability of these techniques for laparoscopic sterilization, we randomly assigned 100 women undergoing bipolar electrocoagulation or spring clip application to either local or general anesthesia. Of the 53 women assigned local anesthesia, four had their procedures completed using another technique because of technical problems related to obesity. Thirteen other obese women, however, underwent successful surgery with local anesthesia. Women undergoing local anesthesia had a slightly shorter anesthesia time (30 versus 36 minutes) and recovery room stay (65 versus 78 minutes). Women having general anesthesia were 2.3 and 1.5 times more likely to have maximum systolic and diastolic blood pressures above 160 and 90 mmHg, respectively. They were also 5.7 times more likely to have a maximum heart rate 110 or higher. Patient movement was reported to be a concern in five women undergoing general anesthesia, but in none having local anesthesia. An equal percentage (80%) of women in each group expressed satisfaction with their anesthetic technique.

Retrograde menstruation in healthy women and in patients with endometriosis.

Blood was found in the peritoneal fluid in 90% of women with patent tubes at laparoscopy during perimenstrual time. If the fallopian tubes were occluded, then only 15% of patients had evidence of blood in the pelvis. Also, 90% of patients with endometriosis and eight of nine women on oral contraceptives had bloody fluid during the menstrual period. The present observations indicate that retrograde menstruation through the fallopian tubes into the peritoneal cavity is a very common physiologic event in all menstruating women with patent tubes.

Outpatient laparoscopic sterilization with therapeutic abortion versus abortion alone.

Records of 108 patients undergoing combined vacuum aspiration and laparoscopic sterilization in an outpatient surgical program were reviewed and compared with those of 195 patients who underwent abortion only in the same outpatient program. Mean operating time for the combined procedure was 30 minutes; total mean hospitalization time was 5 hours and 7 minutes. Complication rates for the combined procedure and for abortion alone were 9.2 and 7.2 per cent, respectively. Subsequent hospitalization was necessary for 4.7 per cent of patients undergoing the combined procedure and 3.1 per cent of those having abortion only. Laparoscopic sterilization has been found to add no significant morbidity but has markedly reduced cost and hospitalization for the patient desiring permanent contraception following first trimester abortion.

An outpatient program for laparoscopic sterilization.

PIP: This is a report of a pilot program for laparoscopic sterilization with emphasis on surgical and anesthetic technics. In 1971 the program was developed at the North Carolina Memorial Hospital. Subjects were 129 private patients, mostly white, of middle income with 2 or more children, and from 19 to 47 years of age. Follow up of over 90% indicated high patient satisfaction. Complications were few but may occasionally require surgical management and the method should not be considered a minor procedure. At first patients were handled as inpatients for 1 day preceding surgery. Later an outpatient status was adopted. At an earlier visit a history is taken, instructions given by a nurse, the assigned physician (who may be a physician in training) reviews the history, performs a physical examination, and explains the operation to both the patient and her husband. Laboratory work is performed, operative permits are signed, and patients are asked at this time to agree to sterilization by laparotomy if the laparoscopic approach proves infeasible. On the morning of surgery suitable intravenous medication (Valium 5 mg), fentanyl, and atropine are given and followed by pure oxygen inhalation for 3-5 minutes. Pentothal followed by succinylcholine are given and the patient intubated. Anesthesia is maintained by succinylcholine drip and inhalation of nitrous oxide and oxygen. After surgical preparation with Betadine solution, a combination tenaculum-sound is placed in the cervical canal. Pneumoperitoneum is established with carbon dioxide gas through a Verres needle inserted through a small subumbilical incision. The laparoscopic trocar is introduced by enlarging the same incision. After inspection a second 6 mm trocar is inserted just about the tubes and biopsy forceps introduced. The tenaculum in the cervix is used to position the uterus and tubes. After cauterization tubes are divided with the biopsy forceps and a biopsy specimen obtained if possible without undue action on the tube. After inspection for bleeding or injury to other viscera, the instruments are withdrawn. The procedure can be completed in 15 minutes. After recovery from the anesthesia the patient is removed to the recovery area and then the holding area. After 2 or 3 hours she is seen by a physician and discharged if vital signs are stable. Oral and written instructions for her convalescence are given. Patients are requested to return in 2 weeks or to consult a physician in their home area. 30 patients required postoperative hospital admissions: 15 for non-medical reasons (i.e., distance to travel home) and 15 for observation at the physicians' request. These stayed 14 to 24 hours. Nausea and vomiting were indications in 5. :In one case nosebleed following intubation combined with slight elevation of temperature caused a stay of 48 hours. Retrospectively, only 8 of the 15 hospitalized or 6% of all cases required this extra service. In the initial series there was 1 technical failure due to obesity. The average time to resume normal activities was 3 1/2 days. 115 patients (97.4%) of those responding to a questionnaire stated they would recommend the procedure to a friend. The 3 dissatisfied respondents gave no specific reason. Thorough training of the physicians is urged. Use as an office procedure with local anesthesia is not recommended. Single-puncture technic is being tried. Subsequently over 100 additional procedures have been performed.^ieng

Luteinized unruptured follicle syndrome: a subtle cause of infertility.

A clinical description of luteinized unruptured follicles is presented. This abnormality in ovulation is characterized by normal endocrinologic presumptive signs of ovulation: biphasic basal body temperature curves, secretory endometrium, and laboratory evidence of progesterone production by elevated urinary pregnanediol or plasma progesterone levels. In a group of 102 such infertile women, laparoscopy performed 3 to 5 days after apparent ovulation revealed the absence of a corpus hemorrhagicum in 30 women, and the absence of a sigma on a corpus hemorrhagicum in an additional 32 women. These findings were evidence that a follicle had not ruptured and an ovum had not escaped. Of 28 patients undergoing follicular stimulation with clomiphene citrate or human menopausal gonadotropin after this diagnosis, 15 conceived.

Current status of elective sterilization in the United States.

PIP: The desire for smaller families has brought about a change in obstetrics and gynecology with more and more women asking for contraception and elective sterilization. Surveys conducted in 1970 and 1973 found couples choosing sterilization increased from 16.3% to 23.5%. In 1973, 33.7% of couples with wives over age 30 had chosen sterilization. In 1975, 174 sterilizations were performed for every 1000 births, 105 of these postpartum and 69 laparoscopic. The average physician performing laparoscopic sterilization does 62 per year or a little more than 1 per week. Attempts to perform them in clinics or doctors' offices have not proved satisfactory because of the potential major complications. However, they are commonly performed in the hospital on an outpatient basis. Major complication rate in the U.S. (complication requiring laparotomy) is 3.7/1000 cases and the death rate is 2.5/100,000. Compared with the recurrent annual risks of pills and IUDs, which are in the same range as this 1-time only procedure, it is easy to understand why more than 200,000 chose laparoscopic sterilization in 1975. Increasingly younger women are asking for sterilization but the physician is warned to use his common sense and make sure informed consent is obtained. Both the Association for Voluntary Sterilization and the Planned Parenthood Federation of America have patient instruction materials available. Reversibility is still questionable. Reversal of the most popular U.S. procedure, some form of Pomeroy postpartum sterilization, requires laparotomy with isthmic-ampullary anastomosis and has a 20-40% pregnancy rate and an increased risk of ectopic pregnancy. Electrocoagulation as performed in the U.S. destroys the entire isthmic portion of the tube and may require ampullary implantation for reversal. Relatively few have been performed. Microsurgery holds promise although to date fewer than 50 cases have been reported in the literature. Use of clips and bands may improve reversibility. Comparative techniques are briefly summarized. The most popular in the U.S. is postpartum Pomeroy, the 2nd laparoscopic sterilization with a 2-hole technique. Hysterectomy is popular, especially when other gynecological conditions are present; its use is falling with increase in availability of laparoscopy. Colpotomy, culdoscopy, and fimbriectomy are not greatly popular. Studies have given conflicting results for subsequent gynecologic symptoms after sterilization, 1 in Britian suggesting a higher incidence and 1 showing less. The effect on incidence of ectopic pregnancy has not been shown either, although with increased use of sterilization, figures should begin to be available. The Food and Drug Administration is regulating introduction of new devices in this rapidly growing field.^ieng

Reversibility of clip sterilization.

A spring clip designed to be applied to the fallopian tube for sterilization without electrocoagulation was applied to 10 pigs. After documenting the prevention of pregnancy for 3 months, the clips were removed and successful reanastomosis was performed on eight pigs. Six of these pigs became pregnant within 2 months of the reanastomosis. This paper describes the technique of the reanastomosis and documents the potential reversibility of spring clip sterilization.

Second-look laparoscopy in infertility surgery: therapeutic and prognostic value.

Sixty infertile women underwent infertility surgery followed by "second-look laparoscopy" (SLL). All these women had undergone detailed fertility workups, including a diagnostic laparoscopy prior to surgery. The tuboovarian adhesive disease was staged according to the severity of the disease and compared with findings at SLL. Sixty percent of adnexa showed improvement at SLL. During SLL, newly formed adhesions were lysed and stenotic fimbrial ostia dilated. Optimal time for SLL was 4 to 8 weeks after surgery. From these observations, we suggest that SLL provides further opportunity to lyse re-formed adhesions and may have prognostic and therapeutic benefits after laparotomy for lysis of adhesions.

Classification of adnexal adhesions: a proposal and evaluation of its prognostic value.

A system of classification of adnexal disease is proposed. Hysterosalpingography is important to determine tubal patency (stage I) and to distinguish between the presence of rugae in early fillage of the ampullae (stage II) and their absence (stage III or IV). Diagnostic laparoscopy under general anesthesia with the double-puncture technique is recommended to inspect the ovaries thoroughly and to put adhesions on a stretch for evaluation of thin, avascular adhesions (A) and thick, vascularized adhesions (B). The extent of adnexal disease can be classified as stage I minimal if most or all of the ovarian surface is visible; stage II, over 50% of the ovary is visible; stage III, less than 50% of the ovary is visible; Stage IV, no ovarian surface is visible. Each adnexum should be described separately. The worst aspect of each adnexum should be described. The best adnexal classification should be used in describing the patient for purposes of comparing surgical treatments. Using this approach, the authors describe a gradient from stage I (best prognosis) to stage IV (poorest) in a personal series of 99 tuboplasties over a 10-year period.