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A F Nimmo

Publications and source records attributed to A F Nimmo.

8 recordsLinked to original sources
PubMed2006

Relationship between perioperative troponin elevation and other indicators of myocardial injury in vascular surgery patients.

BACKGROUND: In 2000 the European Society of Cardiology and the American College of Cardiology published a consensus document revising the definition of myocardial infarction. The usefulness of this revised definition has been challenged. It has been suggested that, rather than any release of cardiac troponin being potentially diagnostic of myocardial infarction, a diagnostic threshold consistent with significant myocardial injury should be defined. METHODS: We studied 65 patients undergoing elective major vascular surgery to examine the relationship between the magnitude of cardiac troponin I (cTnI) and creatine kinase MB fraction (CK-MB) release and clinical signs or symptoms of myocardial injury. cTnI and CK-MB concentrations were measured preoperatively and on the first 4 postoperative days using the ACCESS assay (Beckmann). Patients were considered to have suffered a perioperative myocardial infarction if they had either symptoms or ECG changes consistent with this diagnosis, together with cTnI release. RESULTS: Peak postoperative cTnI concentrations above the lower detection limit of the ACCESS assay (0.06 microg litre(-1)) occurred in 26 patients. Eight of these patients displayed symptoms or ECG changes consistent with myocardial injury. A cTnI level greater than 0.68 microg litre(-1) was found to be consistent with the clinical diagnosis of myocardial infarction. The optimal cut-off for the diagnosis of MI using CK-MB was 40.4 microg litre(-1). CONCLUSIONS: These data suggest that further studies are required to define the optimal cardiac troponin diagnostic threshold for the diagnosis of myocardial infarction in the non-cardiac surgery population.

Aged↗
PubMed2006

Regional versus general anaesthesia for carotid endarterectomy: impact of change in practice.

BACKGROUND: Local anaesthesia (LA) for carotid endarterectomy (CEA) may offer advantages over general anaesthesia (GA). AIM: Our aim was to compare outcome from CEA before and after changing our anaesthetic technique from GA to LA. METHODS: Sequential patients who underwent CEA between January 1997 and December 2001 were identified from a prospectively collected database. GA was used during the first two years of this period and LA was used exclusively over the last three years. Differences in the incidence of intraoperative shunting, perioperative stroke and transient ischaemic attack (TIA), cranial nerve injury, neck haematoma, perioperative death and duration of hospital stay were assessed. RESULTS: Three hundred and seventy one CEAs were carried out in 363 patients, 179 under GA and 192 under LA. Indications were TIAs (140), stroke with recovery (134), amaurosis fugax (85) and asymptomatic high-grade stenosis (12). Intraoperative shunting was used in 66 (37%) GA operations and 36 (18.8%) LA operations (p<0.01). There were nine strokes and four transient neurological events; 10 (5.5%) patients developed such problems with GA and three (1.6%) with LA (p<0.05). There were four deaths, three (1.7%) after GA and one (0.5%) after LA (p=NS). Duration of hospital stay was less in the LA group at a median (range) of three days (2-10) compared with 4.5 (3-14) days in the GA group (p<0.001). CONCLUSION: Employing LA rather than GA for CEA has been associated with a reduction in intraoperative shunting and perioperative stroke, and the duration of hospital stay. LA appears to offer clinical and possible cost advantages over GA.

Adult↗
PubMed2006

A simple presurgical necrotizing enterocolitis-mortality scoring system.

OBJECTIVE: To assess the relationship between early laboratory parameters, disease severity, type of management (surgical or conservative) and outcome in necrotizing enterocolitis (NEC). STUDY DESIGN: Retrospective collection and analysis of data from infants treated in a single tertiary care center (1980 to 2002). Data were collected on disease severity (Bell stage), birth weight (BW), gestational age (GA) and pre-intervention laboratory parameters (leukocyte and platelet counts, hemoglobin, lactate, C-reactive protein). RESULTS: Data from 128 infants were sufficient for analysis. Factors significantly associated with survival were Bell stage (P<0.05), lactate (P<0.05), BW and GA (P<0.01, P<0.001, respectively). From receiver operating characteristics curves, the highest predictive value resulted from a score with 0 to 8 points combining BW, Bell stage, lactate and platelet count (P<0.001). At a cutoff level of 4.5 sensitivity and specificity for predicting survival were 0.71 and 0.72, respectively. CONCLUSION: Some single parameters were associated with poor outcome in NEC. Optimal risk stratification was achieved by combining several parameters in a score.

Birth Weight↗
PubMed1998

Anesthesiology.

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Anesthesiology↗
PubMed1996

Respiratory mechanics after abdominal surgery measured with continuous analysis of pressure, flow and volume signals.

We studied 10 patients during the first night after upper abdominal surgery to assess the effect of airway obstruction on chest wall mechanics, by recording nasal gas flow and carbon dioxide concentration, rib cage and abdominal dimensions, abdominal muscle activity, and oesophageal and gastric pressures. The mean duration of study of each subject was 5.8 h, and 5.2 h were analysed. The median proportion of time spent breathing with normal mechanics was 29% (interquartile values 0-57%). Abnormal abdominal mechanical events were common and associated with airway obstruction (P < 0.001). Two common patterns of abnormal pressure and movement were found. In the first, abdominal pressure decreased at the onset of inspiration and there was a phase lag in abdominal movement. The incidence was 33 (14-50)%. In the second pattern, abdominal pressure decreased and in addition the abdominal wall moved inwards at the onset of inspiration. This occurred for 34 (0-52)% of the time. Both patterns were associated with evidence of increased activation of the abdominal muscles during expiration, changing the relationship of abdominal and pleural pressure changes and chest wall movements. Such changes have been interpreted previously as evidence of diaphragm dysfunction.

Abdomen↗
PubMed1996

Thoracic impedance used for measuring chest wall movement in postoperative patients.

Thoracic impedance (TTI) and rib cage inductance band (IB) signals were measured in 10 patients during the first night after abdominal surgery, and compared by successive correlation of the change in each signal. Poor matching of the signals occurred, on average, for 94 min either because of movement of differences in the waveform. There were frequent episodes of transient poor correlation, generally associated with transient respiratory disturbance, predominantly airway obstruction (58%). Thoracic impedance measurements are simpler than inductance band methods for detecting rib cage movement and may be useful for large studies of respiratory abnormalities in patients after operation.

Abdomen↗
PubMed1993

Pethidine has a local anaesthetic action on peripheral nerves in vivo. Addition to prilocaine 0.25% for intravenous regional anaesthesia in volunteers.

In a double-blind, randomised study, we have examined the effects of the addition of pethidine 100 mg to 40 ml prilocaine 0.25% for intravenous regional anaesthesia in healthy volunteers. During intravenous regional anaesthesia the hand and forearm are isolated from the rest of the circulation and pethidine interaction with central opiate receptors does not occur. Pethidine increased the speed of onset and extent of sensory and motor block, reduced tourniquet and forearm pain, and subjectively improved the quality of the block. Pethidine has local anaesthetic action on peripheral nerves in vivo.

Adult↗