Biomedical subjects

W M Morgan

Publications and source records attributed to W M Morgan.

At least 19 recordsLinked to original sources

PubMed1997

Hyperthermia during repair of pectus excavatum.

We have observed an elevation of body temperature during surgical repair of pectus excavatum. To document this phenomenon and attempt to prevent it, we undertook a combination retrospective-prospective study. The retrospective arm included an analysis of the anesthetic records of patients undergoing repair of pectus excavatum during the past 5 years and included 22 boys and 3 girls. Body temperature increased in all 25 patients, from a starting temperature of 36.1 degrees C +/- 0.5 degree C to 38.0 degrees C +/- 0.6 degree C. The maximum temperature exceeded 38 degrees C in 12 patients and 39 degrees C in 3 patients. An additional retrospective review of the anesthetic records of 15 children undergoing another type of thoracic procedure (thoracotomy) for noninfectious problems revealed only a modest, statistically nonsignificant rise in temperature from a starting point of 35.9 degrees C +/- 0.7 degree C to a maximum of 36.3 degrees C +/- 1.2 degrees C. The maximum temperature was greater than 38 degrees C in one of these 15 patients. The prospective arm of the study included a standardized anesthetic technique in 10 patients. Neither a heated humidifier nor a warming blanket were used, and the ambient temperature of the room was maintained at 70 degrees F. Core body temperature increased from a starting temperature of 36.1 degrees C +/- 0.6 degree C to 36.8 degrees C +/- 0.8 degree C. A significant elevation of body temperature occurs in children during repair of pectus excavatum that may be avoided by eliminating the use of exogenous methods to prevent hypothermia (e.g., heated humidifier, warming blanket).

Adolescent↗

PubMed1996

Continuous caudal anaesthesia with chloroprocaine as an adjunct to general anaesthesia in neonates.

PURPOSE: The authors prospectively evaluated the use of a continuous caudal epidural infusion of chloroprocaine as an adjunct to general anaesthesia during intra-abdominal surgery in neonates. CLINICAL FEATURES: The technique was used in 25 neonates ranging in age from 1 to 28 days and in weight from 2.2 to 4.9 kg. Following anaesthetic induction and tracheal intubation, an initial bolus dose of chloroprocaine 3% (1 or 1.5 ml.kg-1) was followed by a continuous infusion of 1 or 1.5 ml.kg-1.hr-1 administered through a caudal epidural catheter. No parenteral opioids were administered. The duration of the surgical procedures varied from one hour five minutes to three hours 15 min. The first three neonates received a bolus dose of 1.0 ml.kg-1 followed by an infusion of 1.0 ml.kg-1.hr-1 chloroprocaine 3%. These three neonates required an additional bolus dose followed by an increase in the infusion to 1.5 ml.kg-1.hr-1 to provide surgical anaesthesia. Adequate intraoperative anaesthesia was achieved in all 25 neonates with an infusion of 1.5 ml.kg-1.hr-1 of chloroprocaine 3%. This was evidenced by a lack of haemodynamic response to surgical manipulation. No neonate required more than 0.2% isoflurane or 70% nitrous oxide in oxygen. No episodes of haemodynamic instability (decreased blood pressure/bradycardia) related to the caudal epidural anaesthesia were noted. Twenty-three of 25 of the neonates' tracheas were extubated immediately (within 10 minutes) following the surgical procedure. CONCLUSIONS: Caudal anaesthesia with a continuous infusion of chloroprocaine can be used as an adjunct to general anaesthesia during abdominal surgery in neonates. Our initial experience suggests that the combined technique may eliminate the need for parenteral opioids and limit the intraoperative requirements for inhalational anaesthetic agents.

Anesthesia, Caudal↗

PubMed1996

Laparoscopic evaluation for contralateral patent processus vaginalis: Part II.

Between May 1,1992 and August 1, 1995, 599 consecutively treated children under 10 years of age evaluated by the authors for a known inguinal hernia were involved in a prospective protocol to determine whether diagnostic laparoscopy has a place for evaluation of the contralateral inguinal region. The experience with the first 221 patients was reported at the 1993 AAP meeting. In this total experience, 81 patients had known bilateral inguinal hernias and did not require diagnostic laparoscopy. Five hundred eighteen patients had a unilateral inguinal hernia with the status of the contralateral region being unknown. Between May 1, 1992 and May 1, 1994, 368 children underwent evaluation using an umbilical approach. However, for the past 14 months, 150 patients have undergone the diagnostic laparoscopy through the ipsilateral hernia sac. Among the children under 1 year of age, 98 were found to have a unilateral hernia and also a contralateral patent processus vaginalis (CPPV) and 110 had a unilateral hernia. Of the children older than age 1,116 had a unilateral hernia and CPPV and 194 had only a single hernia. After induction of anesthesia, it was suspected on clinical examination that 195 of the 518 patients had a CPPV. However, laparoscopy showed that only 94 (48%) had a CPPV. In the remaining 323 patients, the surgeon believed that a CPPV was not present based on the examination. This negative finding was verified in only 198 patients (81%), but a surprising 125 (39%) did have CPPV documented at the time of endoscopy. Insufflation alone was very unrellable for documenting the presence of CPPV. Of the 214 patients for whom CPPV on the contralateral side was documented during laparoscopy, only 41 (19%) had a positive finding on insufflation. This experience has convinced the authors that diagnostic laparoscopy is the most accurate means to ascertain whether a patient should undergo contralateral inguinal exploration. In addition, laparoscopy through the ipsilateral inguinal sac is now the preferred approach.

Female↗

PubMed1996

Recurrent necrotizing jejunitis in a child.

We report the case of a 5-year-old boy with segmental necrotizing jejunitis, present a review of the literature including a single previously described North American child, and give evidence to document disease recurrence. This uncommon disease must be differentiated from Crohn disease because the treatment and prognosis are different.

Biopsy↗

PubMed1996

General anesthesia using the laryngeal mask airway during brief, laparoscopic inspection of the peritoneum in children.

The authors prospectively examined the cardiorespiratory changes seen with general anesthesia using the laryngeal mask with spontaneous ventilation during brief laparoscopic inspection of the peritoneum in children. Anesthesia consisted of halothane in 50% oxygen/air and a caudal epidural block. The patient was allowed to ventilate spontaneously without assistance. Baseline measurements of heart rate, systolic blood pressure (SBP), end-tidal CO2 (ETCO2), tidal volume, respiratory rate, and oxygen saturation were recorded every 1 min for 5 min prior to the start of laparoscopy and every minute during the laparoscopic procedure. A total of 15 patients were enrolled in the study ranging in age from 15 to 90 months (35.5 +/- 23.8 months) and in weight from 10 to 26.4 kg (14.9 +/- 4.9 kg). The length of the laparoscopy varied from 3 to 9 min (6.1 +/- 2.1 min). Although clinically insignificant, there was an increase in the heart rate from a baseline value of 141 +/- 9 to 148 +/- 9 beats/min (p = 0.0016) and in the SBP from a baseline value of 97 +/- 6 mm Hg to 101 +/- 7 mm Hg (p = 0.0087). The baseline tidal volume prior to the start of laparoscopy was 5.2 +/- 1.1 mL/kg and increased to 6.4 +/- 1.4 mL/kg during laparoscopy (p < 0.0001) while the respiratory rate increased from 32 +/- 4 to 40 +/- 6 breaths/min (p < 0.0001). ETCO2 increased from a baseline value of 47 +/- 6 to 53 +/- 6 torr (p = 0.0059). The maximum value of the ETCO2 was 55 torr or greater in 6 patients, exceeded 60 torr in 3 patients, with a maximum value of 63 torr. The increased ETCO2 returned to baseline within 2 to 7 min (4.7 +/- 1.5 min) following completion of the laparoscopy. There was no significant change in oxygen saturation. Our initial experience suggests that general anesthesia may be provided using the laryngeal mask during brief laparoscopic inspection of the peritoneum.

Anesthesia, General↗

PubMed1996

The use of laparoscopy in the management of the nonpalpable testis.

Fifty-eight children with a nonpalpable testis have been evaluated at our institution between 1988 and 1994. Laparoscopy was performed in these children to effect a treatment plan. The children range in age from 10 months to 14 years. Thirty patients had a nonpalpable left testis, 18 had a nonpalpable right testis, and 10 had bilateral nonpalpable testes. In 28 children, a testis was visualized. Two underwent laparoscopic orchiectomy and 26 underwent either a standard single stage procedure (11), a staged open procedure (3), or a laparoscopically assisted staged procedure (12). Attenuated vessels were seen in 26 patients and inguinal exploration revealed a viable testis in 6 patients and a testis remnant, which was removed, in 20 patients. Four patients had laparoscopic blind-ending vessels. Diagnostic laparoscopy affords the surgeon not only the ability to localize the testis with virtual certainty, but also the advantage of planning a highly successful treatment program. The position of the testis intra-abdominally and the length of the spermatic vessels can be easily evaluated to decide whether a staged approach versus a single stage procedure can be performed. The use of the KTP laser has made the two staged procedure quite easy with only one Trocar site necessary. This experience has allowed us to develop and modify an algorithm for the effective management of the nonpalpable testis.

Adolescent↗

PubMed1995

Prevalence, incidence, and risks for HIV-1 infection in female sex workers in Miami, Florida.

Annual cross-sectional prevalence, incidence of new infection, and risks for human immunodeficiency virus type 1 (HIV-1) infection were studied in 607 women convicted of prostitution between October 1987 and December 1990 and tested for HIV under court order. Cross-sectional prevalence was stable for 4 years (23-24% positivity in 1987-1991, p = 0.6). However, the incidence of new infections (rate of seroconversion) in 264 women tested more than once increased significantly each year from 12 per 100 person-years in 1987-1988 to 19 per 100 person-years in 1991 (p < 0.03). Seroconverters were more likely to be young black women with a prior history of syphilis or gonorrhea. A new episode of syphilis or rectal gonorrhea during the follow-up period predicted HIV seroconversion in a survival analysis model. Female sex workers are at great risk of acquiring HIV infection. Although HIV prevalence in cross-sectional samples was stable, incidence was increasing. Interpretation of prevalence trends from convenience samples, such as screening programs, may be difficult because changes in incidence may not be detected.

Adult↗

PubMed1995

Cardiorespiratory changes in children during laparoscopy.

The authors prospectively examined the cardiorespiratory changes during brief laparoscopy (less than 15 minutes) in children. Intraoperative ventilatory management included a tidal volume of 12 mL/kg, with the rate adjusted to achieve an end-tidal CO2 (PETCO2) of 30 to 35 mm Hg. The initial rate and tidal volume were not changed during the procedure. Baseline measurements of heart rate, blood pressure, peak inflating pressure (PIP), PETCO2, and oxygen saturation were recorded every minute for 5 minutes before the start of the laparoscopic procedure, and every minute during the laparoscopic procedure. Fifty-five patients were enrolled in the study (age range, 1 month to 7 years; weight range, 5.2 to 31 kg). PIP increased from the baseline value of 20 +/- 2.5 to 23 +/- 3.2 cm H2O (P < .01) during laparoscopy. The increase in PIP was 5 or more in six patients, with a maximum of 7. PETCO2 increased from the baseline value of 32 +/- 3.1 to 35 +/- 4.8 mm Hg (P < .01). The PETCO2 returned to baseline within 10 minutes after completion of the laparoscopy. No increase in ventilatory parameters was required during the brief laparoscopic procedure.

Blood Pressure↗

PubMed1995

Ureterosigmoidostomy: is it a viable procedure in the age of continent urinary diversion and bladder substitution?

Between January 1977 and June 1985, 63 patients requiring supravesical diversion underwent ureterosigmoidostomy with an antireflux technique. Of the patients 49 had bladder cancer and 14 had other conditions. Two patients died in the postoperative period. Postoperatively, all patients were instructed to empty the rectum frequently, and received bicarbonate and potassium supplementation. Median followup was 41 months (range 3 to 70). Renal function remained stable in 92% of the patients. Radiographic deterioration occurred in 23% of the renal units, which was severe in 7%. These results indicate that the short and intermediate followup results with ureterosigmoidostomy are comparable to those of an ileal conduit. The method has the added advantage of being a form of continent diversion. We believe that ureterosigmoidostomy remains a viable and convenient alternative in select patients with bladder cancer who are not suitable for other forms of continent diversion or bladder substitution.

Adolescent↗

PubMed1994

Transmission of Mycobacterium tuberculosis associated with air travel.

OBJECTIVE: To investigate potential transmission of Mycobacterium tuberculosis in aircraft from a crew member with tuberculosis. DESIGN: Retrospective cohort study and survey. SETTING: A large US airline carrier. PARTICIPANTS: A total of 212 crew members and 59 passengers who were exposed to a crew member with tuberculosis during a potentially infectious period (May through October 1992). Comparison volunteer sample of 247 unexposed crew members. MAIN OUTCOME MEASURES: Positive tuberculin skin test (TST) result or tuberculosis. RESULTS: Rates of positive TST results were higher among foreign-born persons in all study groups. Among US-born comparisons and contacts, rates of positive TST results did not differ between comparisons and contacts exposed from May through July (5.3% vs 5.9%, respectively). However, contacts exposed from August through October had significantly higher rates of positive TST results than did contacts exposed from May through July (30% vs 5.8%, respectively; P < .001); two had documented TST conversions between September 1992 and February 1993. The risk of infection increased with increasing hours of exposure to the index case. Four (6.7%) of 59 frequent flyers were TST-positive; all flew in October. CONCLUSIONS: Data support the conclusion that M tuberculosis was transmitted from an infectious crew member to other crew members on an aircraft. Because of the clustering of TST-positive frequent flyers in October when the index patient was most infectious, transmission of M tuberculosis to passengers cannot be excluded.

Air Pollution, Indoor↗

PubMed1994

Laparoscopic cholecystectomy in infants and children: modifications and cost analysis.

Between June 1990 and February 1993, 26 children underwent laparoscopic cholecystectomy. Their ages ranged from 25 months to 19 years (mean, 12.3 years; median, 13 years). Only six of them had hemolytic diseases associated with gallstones. Five presented with acute cholecystitis. Laparoscopic cholecystectomy was performed on these five, within 5 days of admission; the mean postoperative hospital stay was 2.5 days. The other 21 patients underwent elective cholecystectomy; their mean postoperative stay was 1 day. Several modifications have been made in our technique. Three 5-mm ports and one 10-mm umbilical port are used. In addition, direct incision of the umbilical fascia is performed with insertion of a blunt trocar and cannula rather than using the Veress needle for insufflation. The importance of positioning the epigastric cannula in the left upper quadrant in small children cannot be overemphasized. Cholangiography is now attempted in all patients and is easier with the Kumar cholangioclamp and sclerotherapy needle, under fluoroscopy. The total hospital charges for the patients who underwent elective laparoscopic cholecystectomy are compared retrospectively with those of seven children who had elective open cholecystectomy during the same period. In addition, a comparison is made between the two groups with respect to the costs of operating room equipment and postoperative pain control.

Child↗

PubMed1994

Laparoscopic evaluation for a contralateral patent processus vaginalis.

Between May 1, 1992 and March 1, 1993, 221 consecutively treated children under 10 years of age evaluated by the authors for a known inguinal hernia were involved in a prospective protocol to determine whether diagnostic laparoscopy has a place for evaluation of the contralateral inguinal region. Twenty-six had known bilateral inguinal hernias and did not require diagnostic laparoscopy. Of the other 195 children who underwent laparoscopy before hernia repair, 86 had a unilateral hernia with a contralateral patent processus vaginalis (CPPV), and 109 had only a unilateral hernia. After anesthesia, it was suspected on prelaparoscopic clinical examination that 55 patients had a CPPV. During laparoscopy, it was noted that 31 (56%) had patent processus vaginalis and 24 (44%) did not. Of the 140 patients believed to have a CPPV on prelaparoscopic clinical examination, 60 (43%) did and 80 (57%) did not. Insufflation alone was not diagnostic of CPPV; of the 195 patients undergoing laparoscopy, insufflation resulted in a positive finding on the known side in only 129 (66%) and on the contralateral side in 23 of the 86 patients (27%) found to have a CPPV. There were no complications related to the laparoscopy or the hernia repair.

Child↗

PubMed1994

HIV-1 incidence determined retrospectively among drug users in Bangkok, Thailand.

OBJECTIVE: To measure trends in the incidence of HIV-1 infection among drug users in treatment at Thailand's largest drug detoxification unit. DESIGN: A retrospective cohort was established using computed, existing HIV-1 test results of 26,396 inpatients and outpatients admitted for 47,907 drug detoxification treatment courses from August 1987 to August 1992. METHODS: Matching of patient record numbers showed that 10,050 (38.1%) patients had been admitted two or more times during the period. From these, we selected a cohort of 7807 initially HIV-negative patients. Subsequent seroconversions among them were assumed to have occurred with uniform probability throughout the interval between the last HIV-negative and the first HIV-positive tests. RESULTS: There were 2311 (29.6%) seroconversions in the cohort. HIV-1 incidence among the 5974 (76.5%) who were injecting drug users (IDU) escalated from 20 new infections per 100 person-years (PY) of observation in 1987 to a peak of 57 per 100 PY in 1988, then gradually declining to a stable rate of about 11 per 100 PY during 1991 and 1992. Non-IDU (smokers, inhalers) constituted 683 (8.8%) of the cohort patients, and had HIV-1 incidence rates varying from 0.2 to five per 100 PY. 'Mixed' drug users, defined as individuals reporting different routes of drug administration on different admissions, composed 1150 (14.7%) of cohort patients and had an HIV-1 incidence rate between that of IDU and non-IDU. Prevalence of HIV-1 seropositivity among all IDU increased rapidly, from about 1% in early 1988 to a peak of about 40% by early 1989, and has remained stable through 1992. CONCLUSIONS: Prevention efforts must continue for IDU, since recent annual HIV-1 incidence remains high at > 10 per 100 PY. Such a high rate suggests that this group should be considered for HIV-1 vaccine efficacy trials. Stable HIV-1 prevalence can mask substantial incidence in a population with high turnover.

Acquired Immunodeficiency Syndrome↗

PubMed1994

Laparoscopy for the nonpalpable testis.

Between 1988 and 1992, 287 infants and children have been evaluated for an undescended testis. In 35, the testis was not palpable. These 35 patients ranged in age between 10 months and 14 years, with a mean of 44 months and a median of 15 months. Thirteen patients had a nonpalpable right testis, 18 had a nonpalpable left testis, and four had bilateral nonpalpable testes. Diagnostic laparoscopy was performed in these 35 boys with a nonpalpable testis to allow a planned approach to management of this condition. In 11 children, a testis was visualized. The testis was in an inguinal hernia sac in seven, and single stage conventional orchiopexy was performed. In four children an intra-abdominal testis was seen, and three infants underwent laparoscopic clip ligation of the testicular vessels. One teenager underwent orchiectomy. In 21 of the remaining 24 boys, small, attenuated testicular vessels were noted to pass into the inguinal canal and inguinal exploration was required. A small testicular remnant was excised in 15 patients, but orchiopexy was possible in six boys. Diagnostic laparoscopy takes 7 to 10 minutes and enables the surgeon to develop a planned approach to this condition. With the information gathered at laparoscopy, the surgeon is best able to decide if an inguinal exploration is necessary or if a single-stage orchiopexy is possible. If a two-stage orchiopexy is required for an intra-abdominal testis, then clip ligation of the testicular vessels can be performed laparoscopically as the first stage, followed by Fowler-Stephens orchiopexy 6 to 9 months later.

Adolescent↗

PubMed1990

The changing incidence of Kaposi's sarcoma among patients with AIDS.

Kaposi's sarcoma (KS), the most common cancer in patients with acquired immunodeficiency syndrome (AIDS), occurs predominantly in homosexual men. However, the percentage of homosexual AIDS patients with KS has declined during the past 6 years. This and other findings suggest that one or more cofactors associated with the homosexual lifestyle, rather than a special viral strain, probably influence the development of KS in patients infected with the human immunodeficiency virus (HIV). Possible reasons for the decline include changes in homosexual behaviors, leading to the practice of safer sexual techniques, and a decrease in use of nitrite inhalants. Identification of the KS-AIDS cofactor(s) could be invaluable to developing prevention and treatment strategies.

Acquired Immunodeficiency Syndrome↗

PubMed1990

Kaposi's sarcoma in patients with AIDS: sex, transmission mode, and race.

We review epidemiologic studies aimed at identifying the cause(s) or cofactors for AIDS-related Kaposi's sarcoma (KS). The epidemiology of AIDS-related KS in the United States differs from that of other forms of KS. One important feature of the epidemiology of AIDS-related KS is that its occurrence by race is strikingly disproportional. We believe this maldistribution can shed light on recent discussions concerning the cause of AIDS-related KS, and we propose further studies to elucidate the etiology of AIDS-related KS.

Acquired Immunodeficiency Syndrome↗

PubMed1988

Epidemiology of HIV infection and AIDS in the United States.

By the end of 1987, nearly 50,000 cases of acquired immunodeficiency syndrome (AIDS) had been reported since 1981, 20,745 in the past year alone. Black and Hispanic adults and children have reported rates 3 to 12 times as high as whites. This can be largely attributed to higher reported rates in black and Hispanic intravenous (IV) drug abusers, their sex partners, and infants. In 1986, reported AIDS deaths increased adult male and female mortality in the United States by an estimated 0.7 and 0.07%, respectively, with much greater increases in selected age groups or areas of the country. The greatest variation in infection with the human immunodeficiency virus (HIV) (0 to 70%) has been found in surveys of IV drug abusers, while surveys of homosexual men reveal infection rates of 20 to 50%. Infection with HIV ranged from 0 to 2.6% in limited sexually transmitted disease clinic surveys of heterosexual men and women without a history of IV drug abuse or known sexual contact with persons at increased risk. The modes of HIV transmission are now well understood, but a large amount of biologic variability in efficiency of transmission remains to be explained. The period between initial infection with HIV and the development of AIDS is variable, but the risk for disease progression increases with duration of infection.

Acquired Immunodeficiency Syndrome↗

PubMed1988

Estimating AIDS infection rates in the San Francisco cohort.

Between 1978 and 1980 a cohort of approximately 6700 homosexual and bisexual men were recruited from the San Francisco City Clinic to participate in studies of sexually transmitted hepatitis B. Testing frozen blood specimens collected at intervals from these patients provides a means of tracking the spread of the AIDS virus since 1978. The rate of spread of HIV was estimated by fitting different survival curves to interval-censored serological data using maximum likelihood techniques. The curves were compared using the Akaike Information Criterion (AIC) to select that which best describes the data. The best was found to be a log-logistic model, which suggested that between 1978 and 1981 the virus spread rapidly, infecting 44% of the then uninfected cohort members. More recently the rate of spread has declined, with an additional 32% of the cohort becoming infected between 1981 and 1987.

Acquired Immunodeficiency Syndrome↗