Prevalence and commonality of non-technical skills and human factors in airway management guidelines: a narrative review of the last 5 years.

The primary aim of this review was to identify, analyse and codify the prominence and nature of human factors and ergonomics within difficult airway management algorithms. A directed search across OVID Medline and PubMed databases was performed. All articles were screened for relevance to the research aims and according to predetermined exclusion criteria. We identified 26 published airway management algorithms. A coding framework was iteratively developed identifying human factors and ergonomic specific words and phrases based on the Systems Engineering Initiative for Patient Safety model. This framework was applied to the papers to delineate qualitative and quantitative results. Our results show that human factors are well represented within recent airway management guidelines. Human factors associated with work systems and processes featured more prominently than user and patient outcome measurement and adaption. Human factors are an evolving area in airway management and our results highlight that further considerations are necessary in further guideline development.

Difficult airway management algorithms: a directed review.

The primary aim of this study was to identify, describe and compare the content of existing difficult airway management algorithms. Secondly, we aimed to describe the literature reporting the implementation of these algorithms. A directed search across three databases (MEDLINE, Embase and Scopus) was performed. All articles were screened for relevance to the research aims and according to pre-determined exclusion criteria. We identified 38 published airway management algorithms. Our results show that most facemask employ a four-step process as represented by a flow chart, with progression from tracheal intubation, facemask ventilation and supraglottic airway device use, to a rescue emergency surgical airway. The identified algorithms are overwhelmingly similar, yet many use differing terminology. The frequency of algorithm publication has increased recently, yet adherence and implementation outcome data remain limited. Our results highlight the lack of a single algorithm that is universally endorsed, recognised and applicable to all difficult airway management situations.

Long-term treatment of hypercholesterolemia with dietary fiber.

PURPOSE: To evaluate the hypocholesterolemic effects of long-term treatment (36 to 51 weeks) with a mixture of dietary fibers (guar gum, pectin, soy, pea, corn bran) administered twice a day. PATIENTS AND METHODS: Fifty-nine subjects with moderate hypercholesterolemia who completed a 15-week, placebo-controlled study with the dietary fiber were treated for an additional 36 weeks with 20 g/day of fiber. Subjects were counseled and monitored on a National Cholesterol Education Program (NCEP) Step-One Diet before starting and during treatment. Analyses of changes in lipoprotein values during the additional 36 weeks of treatment took into account changes in weight, diet, and other variables that might have affected the response to treatment. RESULTS: There were no significant effects on the levels of either triglycerides or high-density lipoprotein cholesterol (HDL-C). Levels of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) and the LDL/HDL ratio were significantly reduced during treatment. The mean percentage reductions from baseline after 51 weeks of treatment were approximately 5% for TC, 9% for LDL-C, and 11% for the LDL/HDL ratio. Changes were apparent after 3 weeks of treatment, with the maximum reductions occurring by the 15th week of treatment. CONCLUSIONS: For subjects on a Step-One Diet who complied with the treatment regimen, the moderate cholesterol-lowering effects of the fiber persisted throughout the 36-to-51 week treatment period.

The accumulation of nickel in human lungs.

Using data from published studies, lung concentrations of nickel were compare for persons with and without occupational exposure to nickel. As expected, the concentrations were much higher for persons with occupational exposure. To estimate the effects of nickel-containing tobacco smoke and nickel in the ambient air on the amount of nickel accumulated in lungs over time, a model was derived that took into account various variables related to the deposition of nickel in lungs. The model predicted nickel concentrations that were in the range of those of persons without known nickel exposure. Nickel is a suspected carcinogen and has been associated with an increased risk of respiratory tract cancer among nickel workers. However, before the nickel content of cigarettes can be implicated in the etiology of lung cancer, further studies are needed to evaluate the independent effects of smoking and exposure to nickel.

Autoimmune disease following the use of silicone gel-filled breast implants: a review of the clinical literature.

The association between the use of silicone breast implants and the later development of connective tissue disease was reviewed. Data from case reports (only 40 in the world literature), case series, case-control studies, surveys of plastic surgeons, and cohort studies provided no evidence of an association. In many studies, the appropriate information was not collected to evaluate the association. The case-control and cohort studies were too small to detect even moderately increased risks should they exist. Further prospective studies are required to determine the risks of connective tissue disease associated with the use of silicone breast implants.

In utero exposure to DES. Evaluation and followup of 199 women.

Among 199 women from 12 to 30 years of age who had been exposed to DES in utero, the colposcopic evaluation of the vagina and cervix was considered normal for only 13.6%. The incidence of colposcopically detected lesions was not related to the trimester of DES exposure, the patient's age, use of oral contraceptives, or presenting symptoms. Areas of punctation, mosaic patterns, white epithelium, and keratosis were not considered areas of adenosis. Cervical bands, hoods, cock's combs, etc., were considered as part of the cervix. Under this definition adenosis of the vagina was diagnosed in only 14.1% of the patients. Eight (4.0%) women were found to have cervical intraepithelial neoplasia (CIN), Grade 3 lesions, and an additional 36 (14.1%) women were found to have CIN, Grade 1 lesions based on the light microscopy evaluation of directed biopsies. There were no cases of clear cell adenocarcinoma. It appears that women with in utero DES exposure may be at a higher risk of developing squamous neoplasia compared with non-DES-exposed women.

PIP: In 1972, the Gynecologic Oncology Division of the University of North Carolina started a program which would identify, evaluate and follow-up women with in utero DES (diethylstilbestrol). Visual, bimanual, digital and colposcopic examination were performed on 199 women with suspected DES exposure (mean age, 21.6 years). Depending on severity of findings, patients were followed up at intervals of 6 weeks to 6 months. The terms white "epithelium, mosaic pattern, punctuation, keratosis, cervical eversion, adenosis of vagina, and cock's combs were defined according to the FIGO classfication. 86.4% had abnormal colposcopic examination of vagina and/or cervix; 13.6% had normal colposcopic findings. Lesions of the cervix or vagina did not correlate with the trimester of DES exposure, patient's age, use of oral contraceptives, or symptoms at initial examination. Patients with abnormal colposcopic findings showed that 14.1% had CIN, Grade 1 lesions, and 4.0% had CIN, Grade 3 lesions based on the light microscopy evaluation of directed biopsies. No cases of clear cell adenocarcinoma were observed. The relative risk of developing squamous neoplasia in DES-exposed women was 4.4 to 13.3. Other therapeutic approaches for treating DES-exposed women were partial vaginectomy (Sherman et.al.), CO2 laser (Bellina), multiple punch biopsies (Scott) cryosurgery, and progesterone suppositories (Herbst et.al.). As not all risks associated with intrauterine DES exposure have been clearly defined, DES exposed women should have regular colposcopic examination and vaginal/cervical cytology (depending on the severity of the lesions in the lower vaginal tract).

Cryosurgical treatment of early cervical intraepithelial neoplasia.

Two hundred forty patients, ages 12 to 54 years, with biopsy-confirmed early cervical intraepithelial neoplasia (CIN I) treated by cryosurgery were reviewed. CIN I has been viewed historically as having high rates of remission or stabilization. The initial cure rate was 89%, with a 97% cure rate after retreatment of failures. All failures were confirmed histologically. The initial cure rates are no better than those for higher grades of CIN. Thus, CIN I should be viewed with the same seriousness as CIN II or CIN III.

Risks of cervical intraepithelial neoplasia among DES-exposed women.

The increased occurrence of cervical intraepithelial neoplasia (CIN) in women with in utero exposure to diethylstilbestrol (DES) is described. Among 335 self-referred women exposed to DES, 14.9% (50) had a least 1 cytologic smear interpreted as CIN, and 16.2% (54) had at least 1 biopsy interpreted as CIN. Excluding those with grade 1 CIN, 8.7% (29) had at least grade 2 CIN on biopsy and 4.2% (14) had biopsies interpreted as grade 3 CIN. No invasive lesions were detected. Because the problem of differentiating true intraepithelial neoplasia from morphologically indistinguishable but benign lesions in DES-exposed women remains unresolved, the authors believe a conservative approach to treatment is still indicated. This study supports the recommendation that DES-exposed women merit continued thorough gynecologic evaluation, including regular cytologic evaluation and colposcopy, with biopsies as indicated.

Cryosurgery for the treatment of cervical intraepithelial neoplasia during the reproductive years.

Cervical intraepithelial neoplasia (CIN) is so rampant that simpler, effective, and less costly methods of therapy are being evaluated to replace the aggressive surgical therapeutic measures of the past. Cryosurgery is one alternative method. A review is presented of 152 patients in the childbearing age group with biopsy confirmation of CIN II (moderate dysplasia) and CIN III (severe dysplasia and carcinoma in situ). The persistence of CIN 3 months after therapy was deemed a treatment failure. Initial failure rates (24.2% for CIN II and 31.6% for CIN III) were high by this stringent definition. However, follow-up smears, further treatment, and a review of the literature definition of "treatment failure" lowered the failure rate to acceptable levels such that cryosurgery should be utilized in the therapy of cervical intraepithelial neoplasia.

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.

Adenoid cystic carcinoma of the Cervix. Report of 9 cases and a reappraisal.

The clinical and pathologic findings of 9 patients with adenoid cystic carcinoma of the cervix are presented. A review of the literature identified an additional 29 cases. The tumor was usually associated with adenocarcinoma or squamous cell carcinoma of the cervix. Adenoid cystic carcinoma of the cervix appears to be an aggressive type of tumor; of the 38 cases reported in the literature lung metastases have occurred in 18 (47.4%), and of these, 14 patients are known to have died of the cancer.

Long-term blood cholesterol-lowering effects of a dietary fiber supplement.

BACKGROUND: The study evaluated the blood cholesterol-lowering effects of a dietary supplement of water-soluble fibers (guar gum, pectin) and mostly non-water-soluble fibers (soy fiber, pea fiber, corn bran) in subjects with mild to moderate hypercholesterolemia (LDL cholesterol, 3.37-4.92 mmol/L). METHODS: After stabilization for 9 weeks on a National Cholesterol Education Program Step 1 Diet, subjects were randomly assigned to receive 20 g/d of the fiber supplement (n = 87) or matching placebo (n = 82) for 15 weeks and then receive the fiber supplement for 36 weeks. The efficacy analyses included the 125 subjects (58 fiber; 67 placebo) who were treatment and diet compliant. One hundred two (52 fiber; 50 placebo) completed the 15-week comparative phase. Of these subjects 85 (45 fiber; 40 placebo) elected to continue in the 36-week noncomparative extension phase. RESULTS: The mean decreases during the 15-week period for LDL cholesterol (LDL-C), total cholesterol (TC), and LDL-C/HDL-C ratio were greater (P < 0.001) in the fiber group. The mean changes from pre-treatment values in LDL-C, TC, and LDL-C/HDL-C ratio for subjects in the fiber group were -0.51 mmol/L (-12.1%), -0.53 mmol/L (-8.5%), and -0.30 (-9.4%), respectively. The corresponding changes in the placebo group were -0.05 mmol/L (-1.3%), -0.05 mmol/L (-0.8%), and 0.05 (1.5%), respectively. The fiber supplement had no significant effects (P > 0.05) on HDL cholesterol (HDL-C), triglyceride, iron, ferritin, or vitamin A or E levels. Similar effects were seen over the subsequent 36-week noncomparative part of the study. CONCLUSIONS: The fiber supplement provided significant and sustained reductions in LDL-C without reducing HDL-C or increasing triglycerides over the 51-week treatment period.

Menstrual regulation in the United States: a preliminary report.

The efficacy and safety of vacuum aspiration on an outpatient basis without anesthesia or cervical dilatation within 14 days of a missed menstrual period was evaluated in 1,009 women. Among those patients in whom pregnancy could be documented (54.8%), 4.2% were still pregnant after the procedure. Potentially serious complications were pelvic infection (0.4%), bleeding requiring a repeat curettage (0.3%), and prolonged bleeding (0.7%). For comfort, 26.7% received local anesthesia or analgesia. To allow selection of a higher proportion of pregnant patients, the probability of pregnancy was derived for patients with either a positive or negative pregnancy test at each length of amenorrhea. To determine the best vacuum pressure and source, and the cannula size and type at each duration of pregnancy, a more extensive (large, controlled, comparative) study is required.

Laparoscopic sterilization with electrocautery, spring-loaded clips, and Silastic bands: technical problems and early complications.

Among 2283 patients, rates of technical failure, technical difficulty, and operative and early postoperative complications were evaluated for different methods of tubal occlusion at laparoscopy: electrocoagulation (980 cases), spring-loaded clip application (991 cases), and Silastic band application (312 cases). Rates of technical failure and technical difficulty at surgery were significantly higher (P less than 0.05) for the spring-loaded clip technique than for the electrocoagulation and Silastic band techniques. Mechanical and optical difficulties with the prototype spring clip applicator were the major sources of technical difficulties. Rates of operative (1.2%) and early postoperative (1.9%) complications were not significantly different for the three techniques of tubal occlusion. It is concluded that all three study techniques appear to be practical, and large, long-term, randomized, comparative studies to determine rates of failure and subsequent gynecologic problems are necessary to determine the best method of sterilization.

Long-term safety and use-effectiveness of intrauterine devices.

The long-term safety and effectiveness of Lippes Loops, A, C, and D, Dalkon Shields, Saf-T-Coils, and Cu 7-200 intrauterine devices (IUDs) were evaluated on the basis of 670 insertions in 588 women. Ten-year life-table rates for the Lippes Loops C (291 first insertions) and D (213 first insertions) were evaluated. The Loop C was consistently associated with a significantly higher expulsion rate but lower pregnancy rate as compared with the Loop D. Over-all, the removal rates for these two IUDs were similar. The incidence of pelvic infection and abnormal Papanicolaou smears, the time from IUD removal to conception, pregnancy outcome, and the need for any surgery post-IUD insertion were evaluated for all IUDs and all segments of use.

Laparoscopic tubal clip sterilization under local anesthesia.

PIP: Tubal anesthesia with lidocaine during laparoscopic tubal clip appli cation was evaluated in 149 women; 147 tubes received no lidocaine and 151 received 1 or 2 ml of 1% or 4% lidocaine. For unanesthetized tubes the mean pain rating depended on the dose of diazepam and fentanyl given to the patient (p less than .1); pain ratings were higher in women who received no drug. When any diazepam and/or fentanyl was given, the anesthetized tubes were given a significantly lower pain rating (p less than .01). 23.8% of unanesthetized tubes received a pain rating of 2, 12.9% a rating of 3 or 4, while no anesthetized tube received a 3 or 4 (on a scale of 0 to 4) and only 4% received a 2. 68.5% patients were their own control; 42% rated the pain equal in each tube (1 was anesthetized), while 58% rated the anesthetized tube less painful. 3.4% of the patients experienced vasovagal reflex stimulation. It is concluded that using a local anesthetic solution substantially reduces discomfort associated with fallopian tube manipulation during sterilization.^ieng

IUD complications in perspective.

All methods of contraception are associated with the risk of pregnancy and complications. Although there is extensive literature on complications associated with the use of IUD, there are some aspects of IUD use that require further study including pelvic actinomycosis, pelvic inflammatory disease, and tubal infertility. Each of these are reviewed briefly. Ways in which the use of currently available IUDs may be made safer are discussed.

The intrauterine device and ectopic pregnancy.

Based on data given by case-control and cohort studies the relationships between current and past IUD use, duration of IUD use and the type of IUD were evaluated to determine the risk of ectopic pregnancy among IUD users. The results of this review indicate that current and past IUD users do not have an increased risk of ectopic pregnancy. No relationship was found between the duration of IUD use, for either current or past IUD users, and the risk of ectopic pregnancy. Pooled data from clinical studies of different types of IUD showed that the lowest risk of ectopic pregnancy was for users of copper-bearing IUDs, and the highest risk was for users of progesterone-releasing IUDs. Further research is needed to evaluate the ectopic pregnancy risks to past IUD users, especially in view of recent studies which have shown that these women may be at a higher risk of infertility.

PIP: A review of existing case-control and cohort studies on the association between IUD use and ectopic pregnancy suggests 3 conclusions: 1) neither current nor past use of an IUD is associated with any increased risk of ectopic pregnancy; 2) the incidence of ectopic pregnancy seems to be similar for current users of all types of IUDs, except for the Progestasert; and 3) the duration of IUD use does not increase the risk of ectopic pregnancy. Pooled data from clinical studies of various types of IUDs indicate that the lowest risk for ectopic pregnancy is found in users of copper-bearing IUDs, while the highest risk occurs in users of progesterone-releasing devices. Although the incidence of ectopic pregnancy increased throughout the 1970s, when IUD use was also on the rise, there is no basis for assuming a cause and effect relationship. It is more plausible that the increase in ectopic pregnancy is related to the increase in various sexually transmitted diseases and the effects they have on the female genital tract. However, there is a need for further evaluation of the interrelationships between contraceptive use and predisposing factors such as pelvic inflammatory disease to tubal infertility and ectopic pregnancy.

The probability of side effects with ovral, norinyl 1/50 and norlestrin.

This report provides specific information on the prevalence rates of the most common side effects during the first 3 cycles of use of 3 combination oral contraceptives (OCs) containing 50 mcg estrogen. The probabilities of a symptom occurring for the first time, or persisting once present, during the initial cycles of OC use are given for each of the 3 combined OCs.

PIP: Prevalence rates of various side effects were studied comparatively among 3 oral contraceptive preparations containing 50 mcg of the estrogen component. Norinyl 1/50, Ovral, and Norlestrin 1 were each randomly assigned to groups of 160 healthy women who had consented to participate in the study designed to quantitate probabilities of experiencing specific side effects and of their continuing into the subsequent cycles. Acne, breast discomfort, nausea, abdominal bloating, headache, fatigue, depression, irritability, vaginal discharge, and breakthrough bleeding were the specific side effects studied; only breakthrough bleedings showed a statistical difference in prevalence. The rate of breakthrough bleeding associated with Ovral use in the 1st 3 cycles (16.6%) was significantly (P .05) lower than that associated with using either Norinyl or Norlestrin (46% and 51.7%, respectively). Norelestrin, aside from breakthrough bleeding, was reported as generally freer of side effects than the other 2 preparations. The probabilities of side effects being experienced in the 2nd or 3rd cycle after the effect(s) was experienced in the 1st cycle showed that overall, for all 3 combination pills, the probabilities significantly decreased from the 2nd to the 3rd cycle (P .05). Also examined was the probability that a side effect would occur in the 2nd or 3rd cycle if the user had not experienced such an effect in the 1st cycle. In each instance, the probabilities are significantly lower (P .05) than the corresponding probabilities where the symptom had been experienced in a previous cycle. These data support the contention that side effects experienced on inititation of oral contraceptives should not prohibit its continuation because the majority of symptoms will disappear as the patient becomes accustomed to the hormonal preparation.

Timing of the IUD insertion.

The relationship between the time in the menstrual cycle when a TCu-200 or Cu-7-200 is inserted and subsequent IUD-related events was evaluated. For women who had either TCus or Cu-7s inserted, the pregnancy, expulsion and medical removal rates were similar for insertions performed at any time of the menstrual cycle.

PIP: The study conducted in the School of Medicine, University of Chile, evaluated the relationship between timing of IUD insertion during menstrual cycle and subsequent IUD related events such as pregnancy, expulsion and medical removal rate. Cu-7 and Tcu were inserted in women of similar age, parity, gravidity, and previous contraceptive experience. IUDs were inserted at 4 insertion times eg. during menstruation; midcycle; proliferative phase; and secretory phase (post-midcycle). Lifetable rates showed that Tcu and Cu-7 IUDs can be inserted at any time during the menstrual cycle without any increased risk of termination. Peng and co-workers reported similar findings in an evaluation of women having Lippes Loop or Majzlin spring inserted. However Akinla et. al. found significantly higher 12-month expulsion rates with Tcu-200 inserted on 8-14 day of the menstrual cycle as compared to all other insertion times. Removal rates for all reasons were lowest for women who had insertion on the first three days of menstrual cycle which progressively increased when insertions were done on later days of the cycle; however, no such differences in pregnancy rate were observed. No pregnancy was reported in 2 studies when the IUD was inserted after unprotected coitus. Although there are several advantages for both the physician and patient to the IUD insertion during menstruation, there is no valid reason to delay insertion if the patient requests an IUD at any other time during her menstrual cycle.