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Biomedical subjects

G N Russell

Publications and source records attributed to G N Russell.

18 recordsLinked to original sources
PubMed1998

A survey of the practice of thoracic epidural analgesia in the United Kingdom.

A postal survey of the practice of thoracic epidural analgesia was sent to 275 hospitals in the United Kingdom. Responses were received from 70% of hospitals. Informed consent is rarely adequately obtained, with only 28% of respondents mentioning even the most common complications. Epidural cannulation is most often (60%) performed following induction of general anaesthesia, rather than in the awake patient. A test dose of local anaesthetic without adrenaline is usual. Neither aspirin nor low-dose heparin are considered a contraindication. The majority of respondents used a combination of bupivacaine with fentanyl (51%) or diamorphine (40%), usually administered by continuous infusion. Drugs were frequently prepared and adjusted by anaesthetic staff. The majority of epidurals (63%) are nursed in intensive care units postoperatively. Properly funded pain management teams, at present unusual, would facilitate ward-based epidural management and release intensive care resource. A central register of epidural complications is required to provide valuable evidence for the optimum practice of thoracic epidural analgesia.

Analgesia, Epidural↗
PubMed1998

Myocardial ischaemia after coronary artery bypass grafting: early vs late extubation.

The technique of early extubation after coronary artery bypass grafting is increasing in popularity, but its safety and effect on myocardial ischaemia remain to be established. In a randomized, prospective study, patients undergoing routine elective coronary artery bypass grafting were managed with either early or late tracheal extubation. The incidence and severity of electrocardiographic myocardial ischaemia were compared. Data were analysed from 85 patients (43 early extubation; 42 late extubation). Median time to extubation was 110 min in the early extubation patients and 757 min in the late extubation patients. After correction for randomization bias, there were no significant differences between groups in ischaemic burden, maximal ST-segment deviation, incidence of ischaemia and area under the ST deviation-time curve (integral of ST deviation and time). Similarly, there were no differences between groups in postoperative creatine kinase MB-isoenzyme concentrations and duration of stay in the ICU or hospital. Therefore, this study provides evidence for the safety of early extubation after routine coronary artery bypass grafting.

Adult↗
PubMed1996

Gastroesophageal reflux and tracheobronchial contamination after cardiac surgery: should a nasogastric tube be routine?

Nasogastric (NG) tubes are routinely used in patients undergoing cardiac surgery. This randomized study was designed to assess gastroesophageal reflux (GER) without a NG tube (control) compared with a NG tube managed either by gravity drainage (gravity) or continuous low-grade suction (suction). Antimony pH probes were placed in the lower esophagus and trachea after induction of anesthesia in 51 patients, and pH was recorded every 5 s until the time of tracheal extubation. GER was defined as reversible decrease in esophageal pH to less than 4.0. No significant difference was found between groups in age, weight, gender, duration of postoperative ventilation, morphine use, or antiemetic use. All indicators of GER were seen more frequently in the gravity group compared with the two other groups (P < 0.001). One episode of sudden decrease in tracheal pH was observed in a patient in the gravity group, indicating tracheal aspiration, which was associated with delayed extubation and postoperative pneumonia. The absence of a NG tube is not associated with reflux, probably since the gastroesophageal sphincter remains competent. NG tubes are not routinely necessary for cardiac surgery in patients without risk factors for GER, and increase reflux risk if managed without low-grade suction.

Aged↗
PubMed1995

Is this patient fit for thoracotomy and resection of lung tissue?

Central to risk assessment for lung resection is the fact that surgery offers the only chance of long-term survival and cure in non-small carcinoma of the lung. The challenge is, therefore, to offer surgery to as many patients as possible, whilst avoiding the risk of death from postoperative respiratory failure. Risk assessment is based on careful evaluation of the patient's existing cardiac and respiratory disease. The use of a cardiac risk index, such as that described by Detsky, will ensure that cardiac risk factors are recognised and, where possible, ameliorated prior to surgery. Pre-existing respiratory disease may be assessed by arterial blood gas analysis, exercise testing, whole and regional lung function tests. Criteria based on these tests have been proposed to aid patient selection prior to lung resection. However, these criteria take no account of the beneficial influence on outcome of modern anaesthesia and postoperative care. The elimination of postoperative pain, along with techniques such as minitracheostomy and incentive spirometry have allowed surgery to be offered to many patients who would have been deemed unsuitable by standard criteria. Patients with potentially resectable lung cancer must never be arbitrarily excluded from surgery on the basis of any single criteria or test. Referral for assessment by an experienced team consisting of a thoracic physician, surgeon and anaesthetist will maximise the number of patients offered surgery for this otherwise incurable disease.

Carcinoma, Non-Small-Cell Lung↗
PubMed1994

Variation in the arterial to end-tidal PCO2 difference during one-lung thoracic anaesthesia.

We have measured the arterial to end-tidal PCO2 difference (PaCO2-PE'CO2) in 22 patients undergoing pulmonary resection in the lateral thoracotomy position during two-lung ventilation (TLV) and after transition to one-lung ventilation (OLV). With OLV for each patient, the practice of correcting the estimate by an initial measurement of (PaCO2-PE'CO2) was evaluated by subtracting the initial (PaCO2-PE'CO2) from subsequent values measured at 10-min intervals. Net (uncorrected) and corrected differences during OLV were analysed using ANOVA. (PaCO2-PE'CO2) values during TLV and OLV were similar: mean (SD) 1.3 (0.6) kPa and 1.2 (0.7) kPa, respectively (ns). Mean (PaCO2-PE'CO2) varied in the range 0.2-2.5 kPa, while maximum (PaCO2-PE'CO2) was 0.3-2.8 kPa. The mean (SD) of 133 pairs of measurements with OLV was 1.1 (0.7) kPa. Even after correction, mean (PaCO2-PE'CO2) varied in the range -0.7 to 0.8 kPa; individual extreme values were from -1.3 to 1.7 kPa. Variation between patients was found to be greater than variation within patients for both net and corrected differences (F ratio = 37.0 and 10.9, respectively), although calculating a corrected difference did reduce variation between patients from a mean square value of 2.44 to 0.61. The wide variation in (PaCO2-PE'CO2) suggests that the accuracy of estimation of PaCO2 by monitoring PE'CO2, although improved by the use of a corrected difference, remains questionable during OLV.

Adult↗
PubMed1994

Pancuronium or vecuronium for treatment of shivering after cardiac surgery.

This randomized double-blind study compared the hemodynamic and metabolic effects of pancuronium and vecuronium during treatment of shivering after cardiac surgery with hypothermic cardiopulmonary bypass. Thirty sedated and pain-free patients who shivered after cardiac surgery were treated with pancuronium (n = 15) or vecuronium (n = 15) 0.08 mg/kg. Baseline values of heart rate (HR), mean arterial pressure, arterial and venous blood gases, total body oxygen consumption indexed to body surface area (VO2-I), and pressure work index (PWI, an estimate of myocardial oxygen consumption) were measured on arrival in the intensive care unit, at onset of shivering, and repeatedly for 2 h after treatment. Continuous ST segment analysis of leads II and V5 were used for detection of myocardial ischemia. Treatment of shivering with pancuronium decreased VO2-I by 32% (P = 0.0001). This was accompanied by a 14% increase in HR (P = 0.001) and a 10% increase in PWI (P = 0.03). Vecuronium decreased VO2-I by 36% (P = 0.003) with a 4% decrease in HR (P = 0.04) and a 6% decrease in PWI (P = 0.06). Myocardial ischemia (n = 3) and ventricular arrhythmias (n = 3) occurred in five patients treated with pancuronium. Only one patient treated with vecuronium had ventricular arrhythmia (P = 0.08). Seven patients treated with pancuronium and eight treated with vecuronium were taking beta-adrenergic blockers preoperatively which was associated with lower HR (96 +/- 16 vs 109 +/- 15 bpm; P = 0.025) and lower PWI (8.8 +/- 1.2 vs 10.7 +/- 1.92 mL.min-1 x 100 g-1; P = 0.003) at onset of shivering. However, beta-adrenergic blockers did not attenuate the relative HR increase induced by pancuronium. No relationship was found between hypercapnia and tachycardia or hypertension. These results suggest that, when compared to pancuronium for treatment of postoperative shivering, vecuronium may be advantageous because it does not increase myocardial work. The disproportionate relationship between VO2-I and PWI after treatment with muscle relaxants indicates that increased VO2-I does not contribute significantly to the hemodynamic disturbances associated with shivering. These disturbances are more likely the results of increased adrenergic activity related to pain and recovery from anesthesia. Shivering and its associated hemodynamic disturbances appear to be concomitant but independent signs of awakening.

Acid-Base Equilibrium↗
PubMed1993

The effect of cardiopulmonary bypass on cholinesterase activity.

Cholinesterase activity was determined in 18 patients who had undergone either hypothermic (n = 9) or normothermic (n = 9) cardiopulmonary bypass. The anaesthetic technique was standardised to avoid agents known to affect cholinesterase. Activity was determined in blood samples taken before the induction of anaesthesia, during cardiopulmonary bypass and for at least 7 days postoperatively. In six patients cholinesterase activity was also measured at 6 weeks postoperatively. All the patients were of normal cholinesterase genotype. In both groups cholinesterase activity fell by approximately 60% coinciding with the start of cardiopulmonary bypass, from a mean of 5976 to 2636 IU.l-1 in the hypothermic group, and from 5901 to 2615 IU.l-1 in the normothermic group (p < 0.001 in both instances) (normal range 4300-10,500 IU.l-1). Cholinesterase activity remained at this reduced level for at least 7 days postoperatively. By 6 weeks, activity had returned to within 7% of pre-induction values. There were no differences in cholinesterase activity between the hypothermic and normothermic groups at any of the sampling times.

Body Temperature↗
PubMed1991

Pain following thoracotomy. A randomised, double-blind comparison of lumbar versus thoracic epidural fentanyl.

Fifty-eight patients scheduled for elective thoracotomy were randomly allocated to receive fentanyl by either the thoracic or the lumbar epidural route for postoperative analgesia. The infusion rate was adjusted to optimise analgesia. Dose adjustment, pain assessment and the incidence of side effects were monitored by a blinded observer at set times over the 24 hour study period. Similar pain scores were obtained in both groups at all assessment times. In addition, there was no significant difference in dose requirements or incidence of side effects between the two groups. There appears little justification for the use of the generally less familiar, and potentially more dangerous, thoracic approach when fentanyl alone is infused into the epidural space following thoracotomy.

Adolescent↗
PubMed1989

Hard-shell cardiotomy reservoir for reinfusion of shed mediastinal blood.

We conducted a prospective, randomized, controlled trial comparing homologous blood consumption between groups of patients receiving conventional mediastinal drainage (group 1) or reinfusion of shed mediastinal blood (group 2) using hard-shell cardiotomy reservoir. One hundred consecutive patients who had elective coronary artery or valvular operations were studied. The two groups were comparable with regard to age, sex, weight, preoperative and postoperative hemoglobin levels, and surgical procedure. Group 2 patients had their shed mediastinal blood reinfused for up to 18 hours postoperatively; otherwise, the two groups were treated identically. For groups 1 and 2, average mediastinal blood losses were 705 +/- 522 and 822 +/- 445 mL and homologous blood consumption was 3.83 +/- 2.58 and 3.15 +/- 2.05 U, respectively (neither measure was significantly different). However, if blood losses exceeded 500 mL, there was a statistically significant reduction in homologous blood requirements in group 2 as compared with matched controls in group 1. This difference was most significant in patients with the greatest mediastinal losses.

Blood Transfusion, Autologous↗
PubMed1989

Propofol-fentanyl anaesthesia for coronary artery surgery and cardiopulmonary bypass.

A two-stage propofol infusion combined with fentanyl was used to maintain anaesthesia during coronary artery surgery in patients with good ventricular function. Whole blood propofol concentrations were measured at frequent intervals; plasma protein binding was measured before, during and after cardiopulmonary bypass. An initial infusion rate of 10 mg/kg/hour provided good protection from the pressor response to sternotomy. A predictable steady state concentration was achieved in the prebypass period with a maintenance infusion rate of 3 mg/kg/hour. The onset of bypass resulted in a small decrease in propofol concentration as a result of haemodilution. Induced hypothermia resulted in an increase in propofol concentration which returned rapidly to the prebypass steady state value during rewarming. The free propofol fraction increased during cardiopulmonary bypass. No patient had any recall of operative events or required inotropic support during weaning from bypass.

Adult↗
PubMed1988

Homologous blood use and conservation techniques for cardiac surgery in the United Kingdom.

The transfusion laboratories of 32 cardiothoracic surgical centres for adults were surveyed to determine the donor blood requirement for open heart surgery in the United Kingdom. Details of the transfusion practice and the use of blood conservation techniques were sought from a representative senior cardiac anaesthetist at each centre. Suitable data were received from 24 transfusion laboratories (75%) and 29 anaesthetists (90%). The mean (SD) blood use was 5.07 (1.53) units per operation. Seven centres routinely transfused fresh frozen plasma to all patients postoperatively. Experience with autologous deposit (three centres), "cell separators" (four centres), and the reinfusion of shed mediastinal blood (four centres) was limited. Prebypass phlebotomy for postbypass reinfusion (14 centres) and the infusion of residual oxygenator blood (27 centres) were the conservation techniques most commonly applied. In only nine centres was a postoperative normovolaemic anaemia to a haemoglobin concentration of less than 100 g/l accepted. Applying blood conservation techniques more widely would help to maintain blood supplies and reduce morbidity and mortality related to transfusion.

Anemia↗
PubMed1987

Pre-oxygenation and the parturient patient.

The effects of pre-oxygenation were studied by continuous expired oxygen analysis in twenty pregnant patients and ten nonpregnant controls. The Magill system and a demand valve breathing system were both studied with tidal and vital capacity breathing. Rapid pre-oxygenation was possible with the demand valve system but the technique was associated with air leaks around the mask. Vital capacity breathing with the Magill system was inefficient in practice because of rebreathing and air leaks, and the recently proposed four vital capacity breath technique provided suboptimal alveolar oxygenation in pregnant subjects. Oxygenation in pregnant subjects was significantly faster than in nonpregnant controls and was achieved after just 2 minutes of tidal breathing from a standard Magill system with a prefilled reservoir. Care was necessary to ensure a gas-tight seal around the facemask.

Adult↗
PubMed1986

Medical gas probes.

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Equipment Safety↗