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Biomedical subjects

R A Lawson

Publications and source records attributed to R A Lawson.

At least 19 recordsLinked to original sources
PubMed2005

The use of iloprost in early pregnancy in patients with pulmonary arterial hypertension.

In patients with pulmonary hypertension, pregnancy is associated with a high risk of maternal death. Such patients are counselled to avoid pregnancy, or if it occurs, are offered early interruption. Some patients, however, decide to continue with their pregnancy and others may present with symptoms for the first time whilst pregnant. Pulmonary vasodilator therapy provides a treatment option for these high-risk patients. The present study describes three patients with pulmonary arterial hypertension of various aetiologies who were treated with the prostacyclin analogue iloprost during pregnancy, and the post-partum period. Nebulised iloprost commenced as early as 8 weeks of gestation and patients were admitted to hospital between 24-36 weeks of gestation. All pregnancies were completed with a duration of between 25-36 weeks and all deliveries were by caesarean section under local anaesthetic. All patients delivered children free from congenital abnormalities, and there was no post-partum maternal or infant mortality. In conclusion, although pregnancy is strongly advised against in those with pulmonary hypertension, the current authors have achieved a successful outcome for mother and foetus with a multidisciplinary approach and targeted pulmonary vascular therapy.

Administration, Inhalation↗
PubMed2004

Anaesthetic management of the newborn with multiple congenital epulides.

Epulis of the newborn is a granular cell tumour that originates from the dental alveolar mucosa. We report a case of a neonate with multiple congenital masses of the alveolar mucosa who presented for surgery with a potential airway problem. Intubation was achieved uneventfully using a gaseous induction with a large facemask and displacement of the epulides to allow cautious laryngoscopy.

Anesthesia, Inhalation↗
PubMed2003

The role of neutrophil apoptosis in the resolution of acute lung injury in newborn infants.

BACKGROUND: The persistent airway neutrophilia observed in chronic lung disease of prematurity (CLD) may reflect inappropriate suppression of neutrophil apoptosis. METHODS: 134 bronchoalveolar lavage (BAL) samples were obtained from 32 infants requiring mechanical ventilation for respiratory distress syndrome (RDS): 13 infants (median gestation 26 weeks, range 23 to 28) subsequently developed CLD (CLD group), and 19 infants (gestation 31 weeks, range 25 to 39) recovered fully (RDS group). A further 73 BAL samples were obtained from 20 infants (median age 2 days, range 1 to 402) receiving extracorporeal membrane oxygenation (ECMO) for severe respiratory failure. RESULTS: Neutrophil apoptosis was increased in the RDS group (mean (SEM) neutrophil apoptosis on day 7 BAL: RDS 17.0 (8.6)% v CLD 0.7 (0.2)% (p<0.05)). BAL fluid obtained from RDS but not CLD patients was proapoptotic to neutrophils (apoptosis ratio BAL fluid/saline control: day 1, RDS 9.8 (5.5) v CLD 1.2 (0.1) (p<0.05); day 2, RDS 4.32 (2.8) v CLD 0.5 (0.4) (p<0.05)). There were similar findings in the ECMO group: survivors had proapoptotic BAL fluid compared with non-survivors (apoptosis ratio day 1, survivors 7.9 (2.1) v non-survivors 2.1 (0.7) (p<0.05)). CONCLUSIONS: Inappropriate suppression of neutrophil apoptosis may be associated with a poor outcome in newborn infants with respiratory failure.

Apoptosis↗
PubMed2000

Monthly haemoptysis in a woman with platelet storage pool disease.

A 26-year-old female with known platelet storage pool disease presented with a short history of recurrent haemoptysis. Initial investigations were unhelpful until the cyclical nature of the symptoms became apparent prompting the unusual diagnosis of pulmonary endometriosis to be made. This was subsequently confirmed on premenstrual CT scanning. The introduction of a specific hormonal therapy and multidisciplinary input was ultimately successful.

Adult↗
PubMed2000

Intracellular trafficking and killing of Streptococcus pneumoniae by human alveolar macrophages are influenced by opsonins.

Human alveolar macrophages (HAM) are the major resident phagocytic cells of the gas-exchanging areas of the lung. Following contact with macrophages, bacteria enter phagosomes, which gradually acquire the characteristics of terminal phagolysosomes, with incorporation of lysosome-associated membrane protein (LAMP). We measured the binding of type 1 Streptococcus pneumoniae to the surface of HAM and then measured subsequent internalization and phagosomal incorporation of LAMP-1 under various opsonic conditions. Opsonization with serum containing immunoglobulin resulted in significantly greater binding of pneumococci to HAM compared with opsonization with immunoglobulin G (IgG)-depleted serum containing complement, which in turn resulted in marginally increased binding over that observed in the absence of opsonization. Internalization of opsonized S. pneumoniae gradually increased to a maximum of 20% of bound bacteria by 120 min of warm incubation, with 20% of internalized pneumococci being localized within LAMP-containing compartments by 80 min. Internalization of opsonized S. pneumoniae by HAM correlated with a reduction of bacterial viability. When inocula were adjusted so that pneumococcal binding under different conditions was equalized, subsequent internalization, trafficking to LAMP-containing compartments, and reduction of bacterial viability were less efficient in the absence of opsonization than that observed following opsonization with adsorbed or IgG-replete adsorbed serum. Once bound to the surface of HAM, pneumococci opsonized with adsorbed serum with or without IgG were internalized, processed, and killed equally well. In conclusion, binding, intracellular trafficking, and killing of S. pneumoniae by HAM are each significantly increased by opsonization with serum containing immunogloblin and/or complement.

Antigens, CD↗
PubMed1998

Treatment of mediastinitis: early modified Robicsek closure and pectoralis major advancement flaps.

BACKGROUND: The treatment of sternal wound complications is controversial. It is our practice to combine early aggressive debridement, a modified Robicsek sternal closure, and bilateral pectoralis major advancement flaps with or without closed irrigation in a single procedure. We reviewed our experience to determine the efficacy of this approach. METHODS: Grade II to IV mediastinitis (dehiscence and infection) developed in 47 patients 3 to 14 days after routine open heart operations between 1990 and 1995. Culture-positive infection was identified in 60% (n = 28); 62% (n = 29) had septicemia. Thirty patients underwent incision, drainage, and surgical assessment of the wound. Once systemic signs of infection were under control (no pyrexia, normal white blood cell count), formal single-stage debridement of all infected soft tissues and bones was performed. Sternal stability was achieved using a modified Robicsek closure and bilateral pectoralis major advancement flaps. Seventeen patients were treated with staged procedures. RESULTS: Early sternal closure and coverage with pectoralis major advancement flaps can be associated with a low mortality (0%), low morbidity (13%; n = 4: three superficial wound infections, one seroma), and shortened hospital stay (median, 22 days, compared with a median of 82 days in patients managed with conservative staged treatment; p < 0.05). Sternal stability with excellent functional and aesthetic results has been achieved in all patients. CONCLUSIONS: The combination of aggressive early surgical debridement, sternal closure, and the placement of bilateral pectoralis major advancement flaps is a simple procedure associated with a low mortality and morbidity and a short hospital stay.

Adult↗
PubMed1998

Amethocaine gel for percutaneous local anaesthesia.

Amethocaine gel is a recently developed formulation of amethocaine, designed to provide percutaneous local anaesthesia. Its pharmacological characteristics coupled with a phase-change gel formulation may confer therapeutic advantages over existing preparations. Percutaneous local anaesthesia has increasing relevance in analgesia for paediatric procedures and superficial surgical operations.

Administration, Cutaneous↗
PubMed1997

Endobronchial inflammatory pseudotumour exacerbating asthma.

Primary pulmonary tumours are rare in the paediatric population. Of the benign tumours, the most common is the inflammatory pseudotumour (plasma cell granuloma). It can present as a variety of non-specific symptoms which may delay diagnosis. It usually occupies a peripheral pulmonary location and gives rise to symptoms due to its local mass effect and destructive invasion. We report the case of an endobronchial inflammatory pseudotumour presenting as an exacerbation of asthma in a 10-year-old girl. Appropriate investigation lead to pre-operative diagnosis and early complete surgical resection. A good prognosis is anticipated.

Asthma↗
PubMed1997

Diclofenac vs oxybuprocaine eyedrops for analgesia in paediatric strabismus surgery.

Forty children undergoing strabismus surgery as day patients were randomly allocated to receive oxybuprocaine 0.4% eyedrops or 0.1% diclofenac eyedrops for perioperative analgesia. A non-invasive anaesthetic technique using the reinforced laryngeal mask airway was used. The study demonstrated that both topical analgesics provided good to excellent analgesia and the anaesthetic technique was associated with a relatively low incidence of nausea and vomiting. Complications were limited to two children who were admitted with persistent postoperative nausea and vomiting.

Ambulatory Surgical Procedures↗
PubMed1996

Recovery after desflurane anaesthesia in the infant: comparison with isoflurane.

We have studied 20 infants, aged 2.5-8 weeks, undergoing general anaesthesia for pyloromyotomy with either desflurane or isoflurane. Patients were anaesthetized with equivalent 1 MAC values for age and agent. A blinded observer recorded times to breathing, swallowing, movement, extubation and side effects after discontinuation of the agent. Recovery times in the desflurane group were significantly shorter than in the isoflurane group. The times to swallowing, movement and extubation in the desflurane group were 3.89 (SD 2.4) min, 5.33 (4.95) min, 7.5 (4.53) min, respectively, and 8.82 (2.40) min, 10.73 (3.93) min, 13.45 (4.20) in the isoflurane group. In addition, postoperative apnoea was documented in the isoflurane group but not in those infants receiving desflurane. There was no laryngospasm after extubation in either group. We conclude that desflurane possesses useful characteristics for recovery conditions in the infant and may be particularly useful in the ex-premature infant prone to apnoea and ventilatory depression.

Anesthesia Recovery Period↗
PubMed1995

Evaluation of an amethocaine gel preparation for percutaneous analgesia before venous cannulation in children.

We have evaluated the efficacy and safety of a preparation of 4% amethocaine gel in alleviating the pain of venous cannulation in children. In an initial open study of 148 children, clinically acceptable anaesthesia was achieved in 92% of cases. The preparation was then compared with 5% EMLA cream in a single-blind study in 94 patients using an application time of 40 min. We found clinically acceptable conditions in 85% of patients receiving amethocaine gel compared with 66% in the EMLA group. There were no significant adverse effects noted in each group, although 37% of those children treated with amethocaine gel showed localized erythema at the application site. The results suggest that amethocaine gel has greater efficacy and a faster onset time than EMLA cream when used for this purpose in children.

Administration, Cutaneous↗
PubMed1995

Ventilatory arrest after a fluid challenge in a neonate receiving s.c. morphine.

S.c. infusions of morphine have been advocated for postoperative analgesia in children, but experience with this technique is limited. We report a case in which an s.c. infusion of morphine given after operation to a neonate failed to provide acceptable analgesia until the child had been adequately rehydrated. However, restoration of peripheral perfusion with a fluid challenge was followed by sudden ventilatory arrest which required resuscitation and naloxone infusion. This report emphasizes the dangers of giving morphine by a peripheral route in the dehydrated or hypovolaemic infant.

Analgesics, Opioid↗
PubMed1994

Effects of antiplatelet therapy with indobufen or aspirin-dipyridamole on graft patency one year after coronary artery bypass grafting.

Saphenous vein coronary artery bypass graft patency can be increased by antiplatelet therapy. Aspirin plus dipyridamole are effective but are associated with tolerability problems. Indobufen is a possible alternative antiplatelet agent that may be better tolerated. A prospective, randomized, double-blind, parallel-group study was undertaken to compare the efficacy and safety of indobufen 200 mg twice daily with aspirin 300 mg thrice daily plus dipyridamole 75 mg thrice daily in preventing occlusion of autologous saphenous vein coronary artery bypass grafts. A total of 803 patients were randomized in the study, of whom 552 had a follow-up coronary angiogram approximately 1 year after operation. All anastomoses were patent in 56% of indobufen-treated patients and 59% of aspirin-dipyridamole recipients (p = 0.384). The percentage of all anastomoses patent was 82% in the indobufen group and 83% in the aspirin-dipyridamole group (p = 0.297). Mean postoperative blood loss was significantly less in the indobufen group (p = 0.043). Patients who received indobufen also had significantly fewer adverse events considered to be treatment-related compared with aspirin-dipyridamole recipients (p = 0.02). At the doses tested indobufen was as effective as aspirin plus dipyridamole in preventing occlusion of saphenous vein grafts and was better tolerated. Because indobufen was associated with less postoperative blood loss it may be used before operation in coronary artery bypass grafting.

Adolescent↗
PubMed1993

Haemodynamic effects of transurethral prostatectomy.

Thoracic bio-impedance cardiography was used to study the haemodynamic changes in 28 patients undergoing transurethral prostatectomy (TURP) under either general or spinal anaesthesia. Cardiac output and mean arterial pressure fell with induction of general anaesthesia, whilst mean arterial pressure and systemic vascular resistance fell with induction of spinal anaesthesia. The transthoracic fluid index fell during resection under general anaesthesia, but no significant haemodynamic changes were seen during resection under either anaesthetic. This study suggests that resection has no specific adverse haemodynamic consequences. Spinal anaesthesia may produce less haemodynamic disturbance than general anaesthesia in patients undergoing TURP and formal comparison of the 2 techniques seems necessary.

Aged↗
PubMed1992

Finger blood content, light transmission, and pulse oximetry errors.

The changes in light emitting diode current necessary to maintain a constant level of light incident upon a photodetector were measured in 20 volunteers at the two wavelengths employed by pulse oximeters. Three states of finger blood content were assessed; exsanguinated, hyperaemic, and normal. The changes in light emitting diode current with changes in finger blood content were small and are not thought to represent a significant source of error in saturation as measured by pulse oximetry.

Anemia↗
PubMed1992

Vascular invasion in non-small cell lung carcinoma.

AIMS: To determine if there is any correlation between vascular invasion and prognosis in non-small cell carcinoma of the lung; and to look specifically at invasion of vascular channels by tumour cells. METHODS: Eighty seven patients undergoing lobectomy or pneumonectomy for adenocarcinoma or squamous carcinoma were followed up for five years. The histological sections were studied for evidence of vascular invasion using an elastic van Gieson stain. The incidence of intimal fibrosis in arteries and veins was noted and the proportion with vascular invasion evaluated using a scoring system. The presence or absence of lymphatic permeation and tumour necrosis were noted. Survival data were analysed using the log rank test. RESULTS: The overall five year survival was 32%. There were 64 squamous cell carcinomas and 23 adenocarcinomas. Vascular invasion was seen in 77% of patients and lymphatic invasion in 44%. Neither the presence nor absence nor the proportion of blood vessels showing vascular invasion showed any relation to prognosis. Intimal fibrosis and tumour necrosis were unrelated to prognosis. Patients with lymphatic permeation had recurrence and died earlier than those without. CONCLUSION: The presence of arterial or venous invasion by adenocarcinoma or squamous carcinoma of the lung was unrelated to survival; lymphatic permeation was associated with poor prognosis. The two common non-small cell lung cancers behaved differently from other solid tumours, where vascular invasion was a significant factor in determination of prognosis. The presence of intimal fibrosis was unrelated to prognosis.

Adenocarcinoma↗