In this study, the authors used a custom-designed clamping method and laser Doppler flowmetry to investigate the short-term autoregulatory patterns of blood flow (BF) in partially elevated pedicled epigastric flaps in rats (n=11). The femoral artery was clamped for 30, 60, 120 and 180 sec directly after flap elevation and 40 to 80 min after flap elevation. Changes during and after clamping indicate the functioning of autoregulatory factors in the vessels of the epigastric partially elevated flap. The longer the clamp ischemia is in a flap, the greater (p < 0.0001) is the need for a compensatory increase in BF and for a longer time (p < 0.0001) in the flap after clamp release. They compared the responses of BF directly after flap elevation with those 40 to 80 min after flap elevation. The results suggest a significant increase in the autoregulatory capacity of the pedicled partially elevated flap in measurements performed 40 to 80 min after flap elevation (p = 0.043). They conclude that the novel clamping method seems to be reliable when studying the short-term autoregulatory patterns of the epigastric partially elevated pedicled flap.
Acoustic rhinometry is a new method to measure the patency of the nasal airway. In this study the clinical measuring conditions were systematically evaluated. The test-retest validity was analysed by repeated measurements in ordinary, not specially trained patients and was found to be at the level of approximately 15%. The need for acclimatization before measurements was tested by making a series of measurements on two separate occasions: one after a rest period following the patient's arrival at the nose laboratory, and a second in another session where no rest was allowed for. Statistically, no significant differences between the repeated measurements in the two occasions were found. However, there was a tendency towards smaller nasal volumes in the measures of the repeated recordings made without an acclimatization period. Therefore, it seems to be advisable to have an acclimatization period before acoustic rhinometry measurements.
Preoperative and postoperative rhinomanometry was performed on 102 patients referred for septoplasty. Nasal resistance was calculated according to the Broms method at radius 200 and at 150 Pascal pressure gradient. Because the latter could be calculated in only 62% of the recordings during normal nasal breathing, the Broms method is used in the analysis and also recommended for clinical practice. Results show that in cases with airway obstruction as the cause for surgery, the increase of nasal patency achieved with the operation was larger than in cases with other indications. The level of subjective satisfaction was highest among those patients whose nasal resistance was changed to normal limits. Rhinomanometry gives valuable data in cases where the patient's symptom is obstruction, but its value is not as clear in other indication groups. Rhinomanometry clearly shows cases where surgery has failed to correct the nasal obstruction and is, therefore, a good method of quality control. Preoperative rhinomanometry helps to avoid unnecessary septal operations.
Lowering the water-soluble chromium content of cement to < 2 ppm has been suggested to diminish the risk of allergic hand dermatitis caused by chromium among construction workers. The prevalence of chromium dermatitis was determined for a representative sample of 913 house construction workers and 707 concrete element prefabrication workers, with a questionnaire and clinical examination, before the use of cement with such a low content of water-soluble chromium was started on Finnish construction sites in 1987. The prevalence of allergic contact dermatitis caused by water-soluble chromium, diagnoses confirmed with patch tests among the workers with hand dermatitis, was 9/117 (7.7%). 4 of them were new 4/105 (4%) and 5 had been diagnosed earlier. In 1987, the prevalence of work-related hand dermatitis (allergic and irritant together) was 6.8% among the construction workers and 8.9% among the concrete element prefabrication workers. The Finnish Register of Occupational Diseases was checked for reports of chromium dermatitis and other forms of hand dermatitis from 1978 to 1992. The results indicated that, after 1987, the occurrence of allergic contact dermatitis caused by chromium decreased to less than 1/3 the previous level, whereas the occurrence of irritant contact dermatitis remained stable throughout the observation period. Regardless of some potential confounders, the addition of ferrous sulfate to cement during the production process may have reduced the number of cases of allergic contact dermatitis among construction and concrete element prefabrication workers. Our results agree with the results of Danish studies and Swedish observations.
Correlation between active anterior rhinomanometry and subjective sensation of nasal obstruction was studied in three groups of patients. Group A included patients with marked septal deviation causing high nasal resistance. Group B represented cases where there was minor septal deviation, but normal resistance. Group C consisted of cases with chronic rhinitis causing nasal stuffiness, but normal septum and normal decongestion resistance. The patient's response as to the more obstructed side of the nose was correlated with the rhinomanometrically recorded less patent nostril. The results show that the correlation was good in Group A, but did not exist in the other groups. The reason for this is that, when the side difference of resistance between the two nasal cavities was less than 60–70%, it was very difficult for the patient to estimate the more obstructed side. This was especially the case in Group C, where mucosal swelling often changes sides. The conclusion is that patients’ capability to detect a minor side difference is poorer than rhinomanometry's. Furthermore, if rhinomanometry and subjective sensation do not agree, the reason may be that the patient's nasal complaint is dominated by the mucosal disease, rather than by a structural deformity and therefore, treatment other than surgery may be preferred.
Research in the field of microvascular surgery has shown that ischemic preconditioning (repeated brief episodes of feeding artery occlusions followed by reperfusion) improves flap survival. The authors used a custom-designed clamping method and laser Doppler flowmetry to investigate changes in blood flow (BF) responses, either with acute ischemic preconditioning or without it. The animal model used was the partially elevated epigastric flap of adult Sprague-Dawley rats. In the preconditioned group (n=12), the flaps underwent preconditioning with three cycles of 10-min of feeding artery clamping, followed by 10 min of reperfusion, for a total preconditioning period of 1 hr. In the control group (n=12), the flaps were perfused without clamping for 1 hr. All the flaps underwent occlusion of the feeding artery for 15, 30, 60, 120 and 180 sec to observe the changes in the BF responses, 60 min and 150 min after flap elevation. To compare the responses between preconditoned and control groups the BF responses were analyzed during the overshoot period (i.e., BF being above the baseline after different feeding artery occlusion periods). Statistical analysis of the responses showed that the magnitude of increase in BF after clamp release (p<0.001), the duration of overshoot (p=0.014), and the amplitude of overshoot after clamp release (p=0.002) were statistically significantly greater in the preconditioned group than in the control group. The results suggest that vessels and their responses to change in perfusion pressure are involved in the multifactorial process of the ischemia-protective effect caused by acute ischemic preconditioning. As far as is known, this is the first report showing changes in flap vascular responses after acute ischemic preconditioning.
We introduce a new sophisticated Finnish rhinomanometer in which the need for routine work has been minimized. Technical information about the instrument is given, recording procedure is described and a normal material and reproducibility test is analyzed.
A systematic evaluation of the most common parameters used in active anterior rhinomanometry was made with artificial tube and cadaver models and patient recordings. The clinical suitability of the parameters was judged on their calculability, reproducibility and power to separate the recordings into meaningful degrees of patency. It was shown that resistance at 150 Pa was not calculable in 30% of the measurements because such a high pressure gradient was not achieved during quiet breathing. The power to separate the grades of obstruction was good with all the models but in the test-retest analysis, it was shown that the power to detect ±20% variation in repeated measurement in the same person with a decongested nose was not sufficient with the resistance at 150 ml/s and at radius 100. The coefficient of resistance W=P/V2 at peak flow and resistance at radius 200 showed good capability to separate the grades of obstruction, they are measurable in all recordings, their reproducibility is good and thus, they are recommended for clinical practice.
