One-lung ventilation with fixed and variable tidal volumes on oxygenation and pulmonary outcomes: A randomized trial

OBJECTIVE

Test the hypothesis that one-lung ventilation with variable tidal volume improves intraoperative oxygenation and reduces postoperative pulmonary complications after lung resection.

BACKGROUND

Constant tidal volume and respiratory rate ventilation can lead to atelectasis. Animal and human ARDS studies indicate that oxygenation improves with variable tidal volumes. Since one-lung ventilation shares characteristics with ARDS, we tested the hypothesis that one-lung ventilation with variable tidal volume improves intraoperative oxygenation and reduces postoperative pulmonary complications after lung resection.

DESIGN

Randomized trial.

SETTING

Operating rooms and a post-anesthesia care unit.

PATIENTS

Adults having elective open or video-assisted thoracoscopic lung resection surgery with general anesthesia were randomly assigned to intraoperative ventilation with fixed (n = 70) or with variable (n = 70) tidal volumes.

INTERVENTIONS

Patients assigned to fixed ventilation had a tidal volume of 6 ml/kgPBW, whereas those assigned to variable ventilation had tidal volumes ranging from 6 ml/kg PBW ± 33% which varied randomly at 5-min intervals.

MEASUREMENTS

The primary outcome was intraoperative oxygenation; secondary outcomes were postoperative pulmonary complications, mortality within 90 days of surgery, heart rate, and SpO2/FiO2 ratio.

RESULTS

Data from 128 patients were analyzed with 65 assigned to fixed-tidal volume ventilation and 63 to variable-tidal volume ventilation. The time-weighted average PaO2 during one-lung ventilation was 176 (86) mmHg in patients ventilated with fixed-tidal volume and 147 (72) mmHg in the patients ventilated with variable-tidal volume, a difference that was statistically significant (p < 0.01) but less than our pre-defined clinically meaningful threshold of 50 mmHg. At least one composite complication occurred in 11 (17%) of patients ventilated with variable-tidal volume and in 17 (26%) of patients assigned to fixed-tidal volume ventilation, with a relative risk of 0.67 (95% CI 0.34-1.31, p = 0.24). Atelectasis in the ventilated lung was less common with variable-tidal volumes (4.7%) than fixed-tidal volumes (20%) in the initial three postoperative days, with a relative risk of 0.24 (95% CI 0.01-0.8, p = 0.02), but there were no significant late postoperative differences. No other secondary outcomes were both statistically significant and clinically meaningful.

CONCLUSION

One-lung ventilation with variable tidal volume does not meaningfully improve intraoperative oxygenation, and does not reduce postoperative pulmonary complications.

Incomplete circle of Willis as a risk factor for intraoperative ischemic events during carotid endarterectomies performed under regional anesthesia - A prospective case-series

Background

The role of the willisian collaterals during carotid endarterectomies (CEAs) is a debated issue. The aim of the present work was to test whether an incomplete or non-functional circle of Willis (CoW) is a risk factor for ischemic events during CEA.

Patients and methods

CEAs were performed under local anesthesia. Patients were considered symptomatic (SY) if neurological signs appeared after the cross-clamping phase. In SY patients shunt insertion was performed. CoW on CT angiograms (CTa) were analyzed offline and categorized as non-functional (missing or hypoplastic collaterals) or functional collaterals by three neuroradiologists. Near-infrared spectroscopy (NIRS) was performed throughout the procedure.

Results

Based on CTa, 67 incomplete circles were found, 54 were asymptomatic (ASY) and 13 were SY. No complete CoW was found among the SY patients. Significant differences could be detected between incomplete and complete circles between ASY and SY groups (Chi-square: 6.08; p = 0.013). The anterior communicating artery was missing or hypoplastic in 5/13 SY cases. There were no cases of the non-functional anterior communicating arteries in the ASY group (Chi-square: 32.9; p = 10^-8). A missing or non-functional bilateral posterior communicating artery was observed in 9/13 SY and in 9/81 ASY patients (Chi-square: 24.4; p = 10^-7). NIRS had a sensitivity of 76.9% and a specificity of 74.5% in detecting neurological symptoms.

Conclusions

Collateral ability of the CoW may be a risk factor for ischemic events during CEAs. Further studies should delineate whether the preoperative assessment of collateral capacity may be useful in decision-making about shunt use during CEA.

The value of transcranial Doppler monitoring of cerebral blood flow changes during carotid endarterectomy performed under regional anesthesia - A case series

Recent evidence suggests no difference between patient outcomes when carotid endarterectomies (CEAs) are performed under general or regional anesthesia. However, for detecting the need for a shunt, general anesthesia has the drawback of monitoring needs in the intraoperative setting. In the present study, we attempted to perform intraoperative transcranial Doppler (TCD) monitoring for CEAs performed under intermediate plexus block to describe cerebral hemodynamic changes during different phases of the procedure.

Patients and methods

Patients with unilateral hemodynamically significant carotid stenosis scheduled for elective CEAs were included. Ultrasound-guided intermediate plexus block was used for regional anesthesia. TCD monitoring of the middle cerebral artery mean blood flow velocity (MCAV) was performed throughout the procedure. MCAVs were offline analyzed during different phases of CEA: (1) resting state, before regional block, (2) after block, before incision, (3) before cross-clamp, (4) after cross-clamp, (5) 5 min after cross-clamp, (6) 10 min after cross-clamp, (7) after declamping, and (8) during the postoperative period (4-6 h).

Results

Shunt insertion based on the deterioration of neurological symptoms after cross-clamping was necessary for 11/66 patients (16.6%). In these symptomatic patients, the ipsilateral percent decrease of the MCAV was more than 70% in 8 out of 11 cases (72.7%). In asymptomatic patients, without shunt insertion, the average decrease of MCAV was less than 50%.

Conclusions

Neurological symptoms referring to cerebral ischemia may be superior to TCD monitoring of cerebral blood flow for detecting the necessity of a shunt. Regional anesthesia enables reliable, symptom-based monitoring of CEAs.

Korábban SARS-CoV-2-fertőzésen átesett betegek műtéti érzéstelenítése és perioperatív ellátása

Összefoglaló. A korábban SARS-CoV-2-vírusfertőzésen átesett betegeknél különösen fontos az elektív műtét időpontjának megválasztása. Egy több, mint százezer beteget felölelő tanulmány szerint átlagosan 7 hét szükséges az elektív műtétre bocsátáshoz. Sürgős műtétek esetében a beteg általános állapota és a műtéttől várt javulás alapján mérlegelendő a műtét időpontja. A vitális indikációjú műtétek képezik a legnagyobb rizikót, hiszen ezen esetekben igen csekély idő és lehetőség van a preoperatív betegelőkészítésre.

A SARS-CoV-2-vírusfertőzés nem minden esetben múlik el nyomtalanul. Szövődményeként felléphetnek cardiopulmonalis, véralvadási, központi idegrendszeri, mozgásszervi problémák, akut veseelégtelenség, ion- és vércukorháztartás felborulása, valamint gastrointestinalis eltérések is, melyek lehetnek rövid vagy hosszú távúak, illetve egyes esetekben maradandó károsodások is.

A preoperatív kivizsgálási stratégiát, a műtéti érzéstelenítés módszerét (általános vagy regionális), valamint az intraoperatív monitorozást ezen szövődmények súlyosságának, valamint a műtét típusához megfelelően kell megválasztani. A posztoperatív időszakban a SARS-CoV-2-vírusfertőzésen átesett betegek körében gyakrabban lehet szükség emelt szintű monitorozásra vagy intenzív osztályos megfigyelésre. Orv Hetil. 2022; 163(18): 695–701.

Summary. The timing of elective surgery is very important in patients, who suffered SARS-CoV-2 virus infection. According to a study of more than 100,000 patients, it takes approximately seven weeks to be safely admitted to elective surgery. In the case of emergency surgeries, the date of the surgery should be considered based on the patient’s general condition and the expected improvement from the surgery. Surgery with a vital indication takes the greatest risk, as there is very little time and opportunity for preoperative examination in these cases.

SARS-CoV-2 virus infection does not go away without a trace. Complications may include cardiopulmonary, coagulation, central nervous system, locomotor problems, acute renal failure, ionic and diabetic disorders, and gastrointestinal abnormalities, which may be short-term or long-term, and in some cases permanent.

The preoperative examination strategy, the method of anesthesia (general or regional) and the intraoperative monitoring should be chosen according to the severity of these complications and the type of surgery. In the postoperative period, patients suffered with SARS-CoV-2 virus infection may require more frequent monitoring or intensive ward monitoring. Orv Hetil. 2022; 163(18): 695–701.

Thoracic Anesthesia during the COVID-19 Pandemic: 2021 Updated Recommendations by the European Association of Cardiothoracic Anaesthesiology and Intensive Care (EACTAIC) Thoracic Subspecialty Committee

The novel coronavirus pandemic has radically changed the landscape of normal surgical practice. Lifesaving cancer surgery, however, remains a clinical priority, and there is an increasing need to fully define the optimal oncologic management of patients with varying stages of lung cancer, allowing prioritization of which thoracic procedures should be performed in the current era. Healthcare providers and managers should not ignore the risk of a bimodal peak of mortality in patients with lung cancer; an imminent spike due to mortality from acute coronavirus disease 2019 (COVID-19) infection, and a secondary peak reflecting an excess of cancer-related mortality among patients whose treatments were deemed less urgent, delayed, or cancelled.

The European Association of Cardiothoracic Anaesthesiology and Intensive Care Thoracic Anesthesia Subspecialty group has considered these challenges and developed an updated set of expert recommendations concerning the infectious period, timing of surgery, vaccination, preoperative screening and evaluation, airway management, and ventilation of thoracic surgical patients during the COVID-19 pandemic.

The effect of propofol-sufentanil intravenous anesthesia on systemic and cerebral circulation, cerebral autoregulation and CO2 reactivity: a case series

Background and objectives

The aim of our study was to assess systemic and cerebral hemodynamic changes as well as cerebral CO₂-reactivity during propofol anesthesia.

Methods

27 patients undergoing general anesthesia were enrolled. Anesthesia was maintained using the Target-Controlled Infusion (TCI) method according to the Schnider model, effect site propofol concentration of 4 μg.mL^-1. Ventilatory settings (respiratory rate and tidal volume) were adjusted to reach and maintain 40, 35, and 30 mmHg EtCO₂ for 5 minutes, respectively. At the end of each period, transcranial Doppler and hemodynamic parameters using applanation tonometry were recorded.

Results

Systemic mean arterial pressure significantly decreased during anesthetic induction and remained unchanged during the entire study period. Central aortic and peripherial pulse pressure did not change significantly during anesthetic induction and maintenance, whereas augmentation index as marker of arterial stiffness significantly decreased during the anesthetic induction and remained stable at the time points when target CO₂ levels were reached. Both cerebral autoregulation and cerebral CO₂-reactivity was maintained during propofol anesthesia.

Conclusions

Propofol at clinically administered doses using the Total Intravenous Anesthesia (TIVA/TCI) technique decreases systemic blood pressure, but does not affect static cerebral autoregulation, flow-metabolism coupling and cerebrovascular CO₂ reactivity. According to our measurements, propofol may exert its systemic hemodynamic effect through venodilation.

Trial registration

The study was registered at http://www.clinicaltrials.gov, identifier: NCT02203097, registration date: July 29, 2014.

Practical aspects of anesthetic and perioperative care for COVID-19 patients

Caring for those affected by the coronavirus outbreak of December 2019 imposed a heavy burden on healthcare systems. Not only because some patients require intensive care, but because patients with any form of the disease may need surgical intervention. Managing these cases is a major challenge for anesthesiologists. The purpose of this summary is to present the practical aspects of anesthetic and perioperative care for patients requiring surgical treatment. Orv Hetil. 2020; 161(17): 692–695.

A COVID–19-betegek kórházon belüli újraélesztésének speciális szempontjai

A koronavírus-pandémia számos kihívással szembesíti az egészségügyi ellátószemélyzetet. A vírus cseppfertőzéssel terjed, és magas a virulenciája, ezért minden olyan beavatkozás, mely légúti aeroszolképződéssel jár, potenciálisan veszélyezteti az ellátásban részt vevők egészségét. A koronavírus-fertőzés mortalitása akár 10% feletti lehet, ezért a COVID–19-betegek körében gyakori a reanimáció. A reanimáció során fokozott a légúti aeroszolképződés valószínűsége, így magas az ellátószemélyzet fertőződésének a veszélye. Cikkünk célja, hogy gyakorlatorientált áttekintést adjon a koronavírussal fertőzött betegek újraélesztésének specialitásairól. Orv Hetil. 2020; 161(17): 710–712.

Organ replacement therapy and life-supporting treatment modalities in critically ill COVID-19 patients

In critically ill COVID-19 patients, the failure of the cardiorespiratory system can be due to one of the following: (1) cytokine storm, haemophagocytosis – septic shock, (2) unmanageable hypoxemia, (3) isolated organ failure or as part of multi-organ failure. Herein we give an overview of the therapeutic options for treating or preventing these disease states. In recent years, CytoSorb-haemoperfusion to remove cytokines has shown promising results in the treatment of septic shock. Inhalational nitric oxide (iNO), inhalational epoprostenol and veno-venous extracorporeal membrane oxygenation (ECMO) are options in severe hypoxemia that is unresponsive to conventional mechanical ventilation. Renal failure is a frequent component of the multi-organ failure usually seen with disease progression and necessitates starting one of the available continuous renal replacement modalities. Orv Hetil. 2020; 161(17): 704–709.

Practical aspects of intensive care for critically ill COVID-19 patients requiring respiratory support

In December 2019, a novel outbreak of pneumonia was reported in Wuhan city, China. Initially, the zoonitic infection spread from human to human, causing a pandemic. This viral disease (COVID-19) can appear in a variety of forms, from asymptomatic through the spectrum of mild symptoms to severe respiratory failure, requiring intensive care. Caring for this latter group of patients puts a significant burden on health care. The purpose of this summary is to present the practical aspects of intensive care for patients requiring respiratory support and mechanical ventilation. Orv Hetil. 2020; 161(17): 678–684.

Farmakoterápiás lehetőségek SARS-CoV-2-fertőzés/COVID–19-betegség esetén

Jelenleg a COVID–19 kezelésére bizonyítottan hatékony terápia nem áll rendelkezésre. Az alábbiakban a teljesség igénye nélkül az ilyen vonatkozásban leginkább vizsgált gyógyszerek kerülnek bemutatásra. A felsorolt terápiás lehetőségek mindegyike kísérletinek tekintendő ebben a fázisban. Tekintettel a járvány súlyos népegészségügyi hatásaira, illetve az intenzív osztályon kezelt COVID–19-betegek potenciálisan fatális kimenetelére, ’off-label’ alkalmazásuk mégis megfontolandó. Orv Hetil. 2020; 161(17): 685–688.

Légútbiztosítás koronavírus-fertőzött betegekben

A világunkon végigvonuló koronavírus-járvány számos kihívással szembesíti az egészségügyben dolgozókat. A vírus cseppfertőzéssel terjed, és magas a virulenciája, ezért minden olyan beavatkozás, mely légúti aeroszolképződést generál, potenciálisan veszélyezteti az ellátásban részt vevők egészségét. A koronavírus-fertőzés súlyos formája progresszív légzési elégtelenséggel jár, melynek ellátásában a korai endotrachealis intubáció és invazív gépi lélegeztetés elengedhetetlen. Az intubáció során fokozott a légúti aeroszolképződés veszélye, így magas az ellátó személyzet fertőződésének veszélye. Az előzőeken túl ezen betegeknél relatíve gyakori a nehéz légútbiztosítás is. Cikkünk célja, hogy gyakorlatorientált áttekintést adjon a koronavírussal fertőzött betegek légútbiztosításának specialitásairól, különös tekintettel az infekciókontroll és a betegbiztonság szempontjaira. Orv Hetil. 2020; 161(17): 696–703.

Optimized angiotensin-converting enzyme activity assay for the accurate diagnosis of sarcoidosis

BACKGROUND

Serum angiotensin-converting enzyme (ACE) activity determination can aid the early diagnosis of sarcoidosis. We aimed to optimize a fluorescent kinetic assay for ACE activity by screening the confounding effects of endogenous ACE inhibitors and interfering factors. Genotype-dependent and genotype-independent reference values of ACE activity were established, and their diagnostic accuracies were validated in a clinical study.

METHODS

Internally quenched fluorescent substrate, Abz-FRK(Dnp)P-OH was used for ACE-activity measurements. A total of 201 healthy individuals and 59 presumably sarcoidotic patients were enrolled into this study. ACE activity and insertion/deletion (I/D) genotype of the ACE gene were determined.

RESULTS

Here we report that serum samples should be diluted at least 35-fold to eliminate the endogenous inhibitor effect of albumin. No significant interferences were detected: up to a triglyceride concentration of 16 mM, a hemoglobin concentration of 0.71 g/L and a bilirubin concentration of 150 μM. Genotype-dependent reference intervals were considered as 3.76-11.25 U/L, 5.22-11.59 U/L, 7.19-14.84 U/L for II, ID and DD genotypes, respectively. I/D genotype-independent reference interval was established as 4.85-13.79 U/L. An ACE activity value was considered positive for sarcoidosis when it exceeded the upper limit of the reference interval. The optimized assay with genotype-dependent reference ranges resulted in 42.5% sensitivity, 100% specificity, 100% positive predictive value and 32.4% negative predictive value in the clinical study, whereas the genotype-independent reference range proved to have inferior diagnostic efficiency.

CONCLUSIONS

An optimized fluorescent kinetic assay of serum ACE activity combined with ACE I/D genotype determination is an alternative to invasive biopsy for confirming the diagnosis of sarcoidosis in a significant percentage of patients.

Tüdőreszekciót követő tüdővérzés ritka esete

Abstract:

Enormous airway secretion after lung resection is common and can lead to dyspnea and radiological anomalies. Depending on the patient’s medical history, it can lead to heart failure, which appears in arrythmia or pulmonary edema. An inflammatory event with high level of proinflammatory cytokines can also lead to arrythmia. The stretch of the wall of vessels can also cause a cytokine release, and the thromboembolic event is a possible common cause of this stretch in the perioperative period. Orv Hetil. 2018; 159(28): 1158–1162.

Effects of different tidal volumes for one-lung ventilation on oxygenation with open chest condition and surgical manipulation: a randomised cross-over trial

BACKGROUND

The ideal tidal volume (TV) during one-lung ventilation (OLV) remains controversial. High TVs may increase the incidence of postoperative lung injury after thoracic surgery. There is nonetheless little evidence that the use of low TV during OLV will fail to provide adequate arterial oxygenation. We evaluated the influence of low (5 mL/kg-1) and high (10 mL/kg-1) TV on arterial oxygenation during one-lung ventilation in clinical conditions.

METHODS

A hundred patients scheduled for lung surgery were studied. Patients were randomly assigned to either 30 minutes of one-lung ventilation with a TV of 10 mL/kg-1 at a rate of 10 breaths/minute (Group 10, N.=50) or a TV of 5 mL/kg-1 with 5 cmH2O PEEP at a rate of 20 breaths/minute (Group 5, N.=50). According to the rules of crossover design during the subsequent 30 minutes, each patient received the alternative management. Arterial blood partial pressures, hemodynamic responses, and ventilatory parameters were recorded. Results are presented as means ± SDs; P<0.05 was considered statistically significant.

RESULTS

PaO2 was unaffected by TV (10 mL/kg-1: 218±106 versus 5 mL/kg-1: 211±119 mmHg, P=0.29). Calculated intrapulmonary shunt fraction was also similar with each TV during OLV (5 mL/kg-1: 25±9% versus 10 mL/kg-1: 24±8%, p=0.14). In contrast, low TV significantly increased PaCO2 (10 mL/kg-1: 39±6 versus 5 mL/kg-1: 44±8 mmHg, P<0.001). There were significant differences both in peak (10 mL/kg-1: 27±6 versus 5 mL/kg-1: 21±5 cmH2O, P<0.001) and plateau airway pressure values (10 mL/kg-1: 22±6 versus 5 mL/kg-1: 18±5 cmH2O, P<0.001) during OLV.

CONCLUSION

Low TV (5 mL/kg-1) accompanied by 5 cmH2O PEEP provides comparable arterial oxygenation and intrapulmonary shunt fraction during one-lung ventilation as higher TV (10 mL/kg-1) without PEEP.

Clinical experience with a new endobrochial blocker: the EZ-blocker

PURPOSE

In some thoracic surgical procedures, the insertion of a double-lumen tube (DLT) is not feasible, or the altered use of a DLT and a single-lumen tube (SLT) is justified during the surgery. In the present article we report our experience with a new bronchial blocker, the EZ-blocker, in clinical use.

METHODS

Data were obtained from ten patients undergoing thoracic surgery necessitating one-lung ventilation. For lung isolation, a combination of an SLT and an EZ-blocker was used. The time of insertion and positioning of the EZ-blocker, the lung deflation time with the EZ-blocker cuff inflated and deflated, and the cuff's minimal occlusion volume were recorded. Based on the CT scan, the diameter of the main bronchi and the angle of the bifurcation were measured offline.

RESULTS

The insertion duration of the EZ-blocker was 76 ± 15 s. Two malpositionings were caused by the too-deep positioning of the SLT used for introducing the EZ-blocker, which could be corrected within 65 ± 7 s. The use of the EZ-blocker allowed a short deflation time of the lung without (9.4 ± 0.7 s) and with (4.1 ± 0.7 s) administration of suctioning. The proper block was only dependent on the diameter of the main bronchi and was independent of the bifurcation angle.

CONCLUSIONS

Use of the EZ-blocker is easy and safe. The short insertion time and short lung deflation time through the lumen of the SLT allows its use in emergency situations or in cases of a difficult airway.

Reexpansion pulmonary edema

A reexpanziós tüdőödéma (RPE) egy ritkán előforduló kórállapot, amely rendszerint a krónikusan kollabált tüdő reexpanziója után jelentkezik. A klinikai manifesztáció széles skálán mozog a tünetmentes betegtől a halálos kimenetelig, amely utóbbi akár az esetek 20%-ában is előfordulhat. A patofiziológiai háttér komplex és máig nem teljesen tisztázott. Az ismert kockázati tényezők szem előtt tartásával és azok lehetőség szerinti kiküszöbölésével akár el is kerülhető az RPE kialakulása. Ez az összefoglaló megpróbál áttekintést adni a jelenlegi ismereteinkről, az RPE hátteréről, a terápiás lehetőségekről. Orv. Hetil., 2010,41,1708–1711.

Sepsis-associated encephalopathy

A szepszishez társuló encephalopathia a szisztémás gyulladásos reakció korai szakaszában jelentkező, gyakori, de klinikai szempontból elhanyagolt tünete. A szisztémás szepszis okozta diffúz agyi működészavar, újabb elnevezés szerint a szepszishez társuló encephalopathia (sepsis-associated encephalopathy – SAE) változatos megjelenésű lehet: az átmeneti, reverzíbilis encephalopathiával jellemezhető formától egészen a visszafordíthatatlan agyi károsodással járó súlyos formáig terjedhet a klinikai spektrum. A jelen közleményben a hazai és a nemzetközi szakirodalom áttekintése alapján össze kívántuk foglalni a kórkép kórélettani hátterét, a leggyakrabban előforduló klinikai tüneteket és a kezelés lehetséges módjait. Fel kívántuk hívni a figyelmet arra, hogy szepszisben a különböző súlyosságú tudatzavar az egyik legkorábbi figyelmeztető tünet, ezért a szepszis szempontjából veszélyeztetett betegekben felismerése nagy klinikai jelentőségű.

[A complicated case of spontaneous oesophageal rupture managed by transgastric drainage]

Spontaneous rupture of the oesophagus is an extremely serious condition with high morbidity and mortality. Primary surgical repair may be followed by numerous complications. A 29-year-old man had undergone primary surgical repair due to spontaneous rupture of the lower third of the oesophagus. After the operation he developed suture insufficiency, which could not have been stented, and transgastric drainage was performed therefore. After a slow healing of the fistula, we could avoid another operation and his oesophagus was preserved. Fortunately, a stricture did not develop either. Transgastric drainage of the oesophagus could be a good therapeutic choice in selective and complicated cases.

Impaired cerebrovascular reactivity in sepsis-associated encephalopathy studied by acetazolamide test

INTRODUCTION

The pathophysiology of sepsis-associated encephalopathy (SAE) is not entirely clear. One of the possible underlying mechanisms is the alteration of the cerebral microvascular function induced by the systemic inflammation. The aim of the present work was to test whether cerebral vasomotor-reactivity is impaired in patients with SAE.

METHODS

Patients fulfilling the criteria of clinical sepsis and showing disturbance of consciousness of any severity were included (n = 14). Non-septic persons without previous diseases affecting cerebral vasoreactivity served as controls (n = 20). Transcranial Doppler blood flow velocities were measured at rest and at 5, 10, 15 and 20 minutes after intravenous administration of 15 mg/kgBW acetazolamide. The time course of the acetazolamide effect on cerebral blood flow velocity (cerebrovascular reactivity, CVR) and the maximal vasodilatory effect of acetazolemide (cerebrovascular reserve capacity, CRC) were compared among the groups.

RESULTS

Absolute blood flow velocities after administration of the vasodilator drug were higher among control subjects than in SAE. Assessment of the time-course of the vasomotor reaction showed that patients with SAE reacted slower to the vasodilatory stimulus than control persons. When assessing the maximal vasodilatory ability of the cerebral arterioles to acetazolamide during vasomotor testing, we found that patients with SAE reacted to a lesser extent to the drug than did control subjects (CRC controls:46.2 +/- 15.9%, CRC SAE: 31,5 +/- 15.8%, P < 0.01).

CONCLUSIONS

We conclude that cerebrovascular reactivity is impaired in patients with SAE. The clinical significance of this pathophysiological finding has to be assessed in further studies.

Surgically treated Hashimoto's thyroiditis

The primary way to treat Hashimoto's thyroiditis is conservative. However, it has a relatively high occurrence in operated patients, up to 13% in the literature. Indications for surgery are suspicion of malignancy, and/or trachea/esophagus compression. 2818 thyroid operations were performed at our department between 1986 and 1995. 279 patients suffered from thyroid cancer and 2539 had benign disease. Histology revealed Hashimoto's thyroiditis in 118 cases. Coexisting malignant thyroid tumor was found in 14 cases (11.8%): 9 papillary, 2 follicular, 1 anaplastic cancer, and 2 non-Hodgkin lymphoma. Postoperative recurrent laryngeal nerve paralysis occurred in 8 cases, of which 6 remained permanent. This relatively high incidence supports the importance to identify the laryngeal nerve during every operation for Hashimoto's thyroiditis. Four patients had temporary and one had permanent hypoparathyroidism. Coexistence of Hashimoto's thyroiditis and thyroid carcinoma, the increased risk for the development of non-Hodgkin's lymphoma in chronic lymphocytic thyroiditis and the need for thyroxin supplementation in many cases justify a careful, long-term follow-up of patients with Hashimoto's disease.

[Quality control of dental radiography]

The quality assurance of dental X-ray films can be made by a simple device prepared by Crabtree. Using this tool it is possible to check-up dental films to assure consistent radiographic quality. The radiation done of patient will be "as low as reasonably achievable".