The tracheas of 12 patients who had undergone autopsies after percutaneous dilatational tracheotomy (PDT) were analyzed macroscopically and microscopically. The puncture site of the trachea varied from just below the cricoid cartilage (two patients) to below the third ring (three patients). A fracture of one or more tracheal rings was present in 11 patients, of whom 2 had a fractured cricoid. Destruction of one or more tracheal rings was present in all eight patients cannulated for more than 10 days and was related to duration of cannulation (p<0.005). Protrusion of the anterior wall into the tracheal lumen with tracheal stenosis was seen in two patients. Improvements to the PDT technique are discussed to avoid complications.

Aged↗

PubMed1996

Late complications of percutaneous dilatational tracheotomy.

STUDY OBJECTIVE: To assess the late complications of percutaneous dilatational tracheotomy, particularly the incidence of tracheal stenosis and voice changes. DESIGN: Prospective descriptive clinical study. SETTING: Teaching hospital, the Netherlands. PATIENTS: Eighty consecutive patients who were successfully decannulated after percutaneous tracheotomy. MEASUREMENTS AND RESULTS: Fourteen patients died after decannulation, of tracheotomy-unrelated causes. Sixty-six patients were followed up 3 to 39 months after decannulation (mean, 16 months). Fifty-four patients underwent tomography of the trachea. In 14 patients (26%), there was tracheal narrowing of more than 10%. Data analysis showed that these stenoses were operator dependent (p = 0.03). Voice changes, found in 13 (21%) of 61 patients, were major in 1 and minor in 12. Scars were generally cosmetically acceptable. Retraction of the scar, seen in 13 (19%) of 66 patients, was related to the duration of cannulation (p = 0.002). A persistent tracheocutaneous fistula was present in two patients. CONCLUSIONS: The incidence of tracheal stenosis after percutaneous dilatational tracheotomy is low compared with conventional tracheotomy. Experience with the technique is important to avoid late complications.

Adolescent↗

PubMed1995

Natural cytokine antagonists and endogenous antiendotoxin core antibodies in sepsis syndrome. The Sepsis Intervention Group.

OBJECTIVE: To assess the value of measuring circulating concentrations of mediators (endotoxin, tumor necrosis factor-alpha [TNF-alpha], interleukin-1 beta [IL-1 beta], and interleukin-6[IL-6]) and their endogenous antagonists (antiendotoxin core antibody [EndoCAb], interleukin-1 receptor antagonist [IL-1ra], and soluble TNF receptors [sTNF-R]) in predicting mortality and organ failure in sepsis syndrome. DESIGN: Cohort study with a follow-up period of 30 days. SETTING: Intensive therapy units of five tertiary referral centers in Scotland. SUBJECTS: A total of 146 intensive therapy unit patients with sepsis syndrome underwent repeated sampling during a 10-day period following admission to an intensive therapy unit. MAIN OUTCOME MEASURES: Circulating concentrations of mediators and antagonists were compared in survivors and nonsurvivors. RESULTS: Median Acute Physiology and Chronic Health Evaluation II score was 23 (range, 8 to 40). Mortality at 30 days was 49%. On entry to the study, circulating endotoxin was detected in 66% of patients, TNF-alpha in 14%, and IL-1 beta in 29%. Levels did not predict mortality or organ failure. Patients with IL-6 concentrations in excess of 3000 pg/mL had an increased mortality rate (64% vs 40%, P = .02). The incidence of IgG EndoCAb depletion on entry to the study was 26% in nonsurvivors and 10% in survivors (P = .02). Initial concentrations of both type I and type II sTNF-R were significantly higher in nonsurvivors (P < .01). Initial circulating IL-1ra concentrations were not of value in predicting mortality. Cytokine antagonists were present in concentrations 30- to 100,000-fold greater than their corresponding cytokine. CONCLUSION: The observed high circulating levels of the cytokine antagonists IL-1ra and sTNF-R and the relatively small proportion of patients developing EndoCAb depletion may contribute to the limitations of therapies that aim to augment natural defenses against endotoxin or the proinflammatory cytokines.

APACHE↗

PubMed1995

Modified spectrophotometer for multi-dimensional circular dichroism/fluorescence data acquisition in titration experiments: application to the pH and guanidine-HCI induced unfolding of apomyoglobin.

In a previous paper (Ramsay and Eftink, Biophys. J. 66:516-523) we reported the development of a modified spectrophotometer that can make nearly simultaneous circular dichroism (CD) and fluorescence measurements. This arrangement allows multiple data sets to be collected during a single experiment, resulting in a saving of time and material, and improved correlation between the different types of measurements. The usefulness of the instrument was shown by thermal melting experiments on several different protein systems. This CD/fluorometer spectrophotometer has been further modified by interfacing with a syringe pump and a pH meter. This arrangement allows ligand, pH, and chemical denaturation titration experiments to be performed while monitoring changes in the sample's CD, absorbance, fluorescence, and light scattering properties. Our data acquisition program also has an ability to check whether the signals have approached equilibrium before the data is recorded. For performing pH titrations we have developed a procedure which uses the signal from a pH meter in a feedback circuit in order to collect data at evenly spaced pH intervals. We demonstrate the use of this instrument with studies of the unfolding of sperm whale apomyoglobin, as induced by acid pH and by the addition of guanidine-HCI.

Animals↗

PubMed1995

Comparison of the effects of four i.v. anaesthetic agents on polymorphonuclear leucocyte function.

Initial resistance of bacterial infection is mediated primarily by polymorphonuclear leucocytes (PMN). Anaesthetic agents have been reported to impair various aspects of PMN function. It is possible that the use of these agents to sedate critically ill patients may further compromise an already depressed host defence mechanism. A flow cytometric technique with fresh whole blood from 10 healthy volunteers was used. Phagocytic and respiratory burst activity of PMN incubated for 1 h with either propofol, thiopentone, midazolam or ketamine at both clinical plasma concentrations and 100 times this concentration were determined. Thiopentone at the higher concentration reduced both respiratory burst activity (mean peak channel 50.7 compared with control value of 77.6 (P < 0.0001)) and phagocytosis (mean peak channel 47.5 compared with 79.9 (P < 0.0001)). Ketamine at 100 times the clinical plasma concentration also reduced respiratory burst and phagocytosis, but this failed to reach statistical significance (P = 0.10 and P = 0.053, respectively). No significant depression occurred in the other groups. The results suggest that these i.v. anaesthetic agents, at clinically relevant concentrations, have minimal effects on PMN phagocytosis and oxygen free radical production. At higher concentrations thiopentone and ketamine may affect phagocytic function and thiopentone may impair intracellular cytolysis.

Anesthetics, Dissociative↗

PubMed1995

Lipopolysaccharide toxicity-regulating proteins in bacteremia.

The toxicity of lipopolysaccharide (LPS) is modified by several proteins, such as bactericidal/permeability-increasing protein (BPI) and LPS-binding protein (LBP). BPI and LBP plasma levels were measured in patients with gram-negative (n = 36) or gram-positive (n = 28) bacteremia. Levels of BPI and LBP, which are proteins that neutralize and enhance LPS effects, respectively, were increased before bacteremia was first detected. The BPI/neutrophil ratio, reflecting neutrophil activation, was significantly associated with the presence of sepsis syndrome and death in bacteremic patients: 1.06 (0.11-6.49) versus 0.57 (0.06-3.82) in patients with and without sepsis syndrome (P < .01), respectively, and 0.64 (0.06-3.82) versus 1.02 (0.12-6.49) in survivors and nonsurvivors (P < .05), respectively (ratio in nanograms of BPI per 10(6) neutrophils). High LBP peak levels were significantly associated with the presence of sepsis syndrome (P < .01). No differences in BPI and LBP levels were observed in patients with gram-negative versus gram-positive bacteremia. BPI/neutrophil ratio, as a parameter of neutrophil activation, may be useful in monitoring infectious disease.

Acute-Phase Proteins↗

PubMed1994

Laparoscopic versus minilaparotomy cholecystectomy: a randomised trial.

Although laparoscopic cholecystectomy has rapidly become routine practice in the UK, there has been no rigorous comparison of it with open cholecystectomy. In our trial, 302 patients were randomised to laparoscopic or minilaparotomy cholecystectomy. Recovery after surgery was assessed by length of hospital stay, outpatient review at 10 days and 4 weeks, and patient questionnaires 1, 4, and 12 weeks after surgery. The mean operation time was 14 min shorter for minilaparotomy, while median post-operative hospital stay was 2 days shorter after laparoscopic cholecystectomy. The hospital costs were about 400 pounds greater for the laparoscopic procedure. Laparoscopic patients returned to work in the home sooner; at 1 week, they had better physical and social functioning, were less limited by physical problems, and had less pain and depression. At 4 weeks, only physical functioning and depression scores were better in the laparoscopic group, and by 3 months there were no differences. Laparoscopic patients were more satisfied with the appearance of their scars. The incidence of complications after both procedures was 20%. Compared to minilaparotomy cholecystectomy, laparoscopic cholecystectomy results in shorter hospital stay, less postoperative dysfunction, and quicker return to normal activities, but is more costly.

Activities of Daily Living↗

PubMed1994

Breast-conserving surgery and tumour bed positivity in patients with breast cancer.

Between March 1988 and April 1992, in 264 patients undergoing breast-conserving surgery for stage I and II cancer, the tumour bed was analysed for residual disease. After a conventional breast-conserving operation the entire wall of the cavity from which the lumpectomy specimen had been taken was excised. This was involved with disease in 38 per cent of patients. Additional random biopsies of the secondary cavity were performed in 130 patients and were involved with disease in 13 per cent. Residual disease was detected in the tumour bed of 37 per cent of patients with screen-detected tumours.

Adult↗

PubMed1994

A multidimensional spectrophotometer for monitoring thermal unfolding transitions of macromolecules.

We describe a multidimensional spectrometer that is capable of (nearly) simultaneous measurement of circular dichroism, steady-state fluorescence, and absorbance values on the same sample in a standard 1 x 1 cm cuvette. With a computer controlled thermoelectric cell holder, this instrument is capable of measuring the above types of spectral data at various wavelengths as a function of temperature. We have developed software to control the various acquisition functions and to convert the data files to a format appropriate for use with the nonlinear least squares program, NONLIN (Johnson and Frasier, 1985). We have tested various features of this instrument and we have applied this instrument and data analysis procedure to study the thermal unfolding of ribonuclease A, under conditions were the unfolding of this protein involves an intermediate state.

Biophysical Phenomena↗

PubMed1994

Laparoscopic and minilaparotomy cholecystectomy: a randomized trial comparing postoperative pain and pulmonary function.

BACKGROUND: Upper abdominal surgery is associated with severe postoperative pain and a concomitant reduction in pulmonary function and oxygen saturation. Laparoscopic cholecystectomy is said to result in less postoperative pain compared with open cholecystectomy. METHODS: In a pragmatic, randomized trial, postoperative pain, opiate analgesic consumption, oxygen saturation, and pulmonary function (forced vital capacity, forced expiratory volume in 1 second, and peak expiratory flow rate) were assessed after laparoscopic (n = 67) and minilaparotomy (n = 65) cholecystectomy. RESULTS: Compared with minilaparotomy cholecystectomy, laparoscopic cholecystectomy was associated with lower linear analogue pain scores (median 40 vs 59, p < 0.001), lower patient-controlled morphine consumption (median 22 vs 40 mg, p < 0.001), a smaller reduction in postoperative pulmonary function (mean peak expiratory flow rate 64% of preoperative value vs 49%, p < 0.001), and better oxygen saturation (mean 92.9% vs 91.2%, p = 0.008). CONCLUSIONS: This study confirms that the postoperative pain and pulmonary changes associated with upper abdominal surgery are significantly reduced by the laparoscopic technique. These findings suggest that laparoscopic cholecystectomy may result in a reduced risk of postoperative pulmonary complications.

Adult↗