Evaluation of a model for induction of periodontal disease in dogs

There are several methods for inducing periodontal disease in animal models, being the bone defect one of the most reported. This study aimed to evaluate this model, through clinical, radiographic, tomographic and histological analyzes, thus providing standardized data for future regenerative works. Twelve dogs were subjected to the induction protocol. In a first surgical procedure, a mucoperiosteal flap was made on the buccal aspect of the right third and fourth premolars and a defect was produced exposing the furcation and mesial and distal roots, with dimensions: 5mm coronoapical, 5mm mesiodistal, and 3mm buccolingual. Periodontal ligament and cementum were curetted and the defect was filled with molding polyester, which was removed after 21 days on new surgical procedure. Clinical and radiographic examinations were performed after the two surgeries and before the collection of parts for dental tomography and histological analysis. All animals showed grade II furcation exposure in both teeth. Clinical attachment level increased after induction. Defect size did not change for coronoapical and buccolingual measurements, while mesiodistal size was significantly higher than at the time of defect production. Radiographic analysis showed decreased radiopacity and discontinuity of lamina dura in every tooth in the furcation area. The horizontal progression of the disease was evident in micro-computed tomography and defect content in the histological analysis. Therefore, it is concluded that this method promotes the induction of periodontal disease in dogs in a standardized way, thus being a good model for future work.

Anaesthesia and Pain Management for Use in Orthopaedic Day Surgery

Day surgery has gained a large popularity during the last decades. In Finland, 57% of the elective procedures, and 50% at Turku University Hospital, were already conducted on day basis during 2012. The steady growth of day surgery is mostly due to an increased safety in perioperative care and cost-effectiveness. The development of surgical techniques and anaesthetic methods has advanced the modern day surgery and extended the repertory of the procedures for use in day surgery operations. Day surgery also offers certain benefits like reduced risk for hospital-related infections, stress and confusion. Patient satisfaction, regarding several issues, is high. Most concerns and complaints are related to postoperative pain, nausea and vomiting pain and nausea. Pain can hamper recovery and pain management is a crucial factor for hospital discharge. Appropriate pain treatment is effective, safe, easy and economical. A procedure-specific approach and an individually planned, multimodal analgesia should be the basis of modern pain management. The main aim of this thesis was to evaluate the effectiveness and safety of anaesthetic technique and methods in pain treatment of orthopaedic day case surgery, and following conclusions were made. Unilateral spinal block was achieved using hyperbaric bupivacaine with a small dose of clonidine but clonidine prolonged the block. Continuous subacromial bupivacaine was found to be safe but conferring only moderate efficacy in pain care after shoulder arthroscopy. Transdermal fentanyl, 12 g/h, as part of multimodal analgesia, offered a safe and easy option to pain management in this patient group. However, after forefoot surgery, it did not reduce pain any further. In general, pain scores in all patient groups were low and the need for rescue opioid moderate.

The effects of surgery on gastrointestinal motor activity

Gastrointestinal surgical procedures have the potential to disrupt motor activity in various organs of the gastrointestinal tract or, indeed, throughout the entire alimentary canal. Several of these motor effects have important clinical consequences and have also served to advance our understanding of the regulation of gastrointestinal motor activity. This review will focus, in particular, on the effects of surgery on the small intestine, and will attempt to emphasize the implications of these studies for our understanding of small intestinal motility, in general.

Daily blood pressure profile in Cushing's syndrome before and after surgery

No significant difference has been demonstrated in the altered circadian blood pressure pattern between the pituitary-dependent and adrenal forms of Cushing's syndrome before surgery. The effect of therapy, however, proved to be different. The mesor was normalized in the pituitary-dependent Cushing's syndrome more conspicuously for systolic than for diastolic blood pressure. In Cushing's syndrome due to adrenal adenoma, systolic and diastolic blood pressure mesors have been even significantly "overnormalized" after treatment, being 11 to 27 and 2 to 13 mmHg (95% confidence) lower than corresponding mesors in controls. There was no difference between forms in the effect of treatment on blood pressure amplitudes, which remained significantly lower than in controls. Finally, acrophase patterns were partly normalized after treatment of the pituitary-dependent form only for diastolic blood pressure, while both systolic and diastolic blood pressure acrophases were normalized in the treated adrenal form. In conclusion, complete normalization of the pattern of daily blood pressure profile has not been achieved in either form of the syndrome. This may be one of the reasons for the reduced long-term survival after surgical cure of hypercortisolism, than expected.

The effects of positive end-expiratory pressure on respiratory system mechanics and hemodynamics in postoperative cardiac surgery patients

We prospectively evaluated the effects of positive end-expiratory pressure (PEEP) on the respiratory mechanical properties and hemodynamics of 10 postoperative adult cardiac patients undergoing mechanical ventilation while still anesthetized and paralyzed. The respiratory mechanics was evaluated by the inflation inspiratory occlusion method and hemodynamics by conventional methods. Each patient was randomized to a different level of PEEP (5, 10 and 15 cmH2O), while zero end-expiratory pressure (ZEEP) was established as control. PEEP of 15-min duration was applied at 20-min intervals. The frequency dependence of resistance and the viscoelastic properties and elastance of the respiratory system were evaluated together with hemodynamic and respiratory indexes. We observed a significant decrease in total airway resistance (13.12 ± 0.79 cmH2O l-1 s-1 at ZEEP, 11.94 ± 0.55 cmH2O l-1 s-1 (P<0.0197) at 5 cmH2O of PEEP, 11.42 ± 0.71 cmH2O l-1 s-1 (P<0.0255) at 10 cmH2O of PEEP, and 10.32 ± 0.57 cmH2O l-1 s-1 (P<0.0002) at 15 cmH2O of PEEP). The elastance (Ers; cmH2O/l) was not significantly modified by PEEP from zero (23.49 ± 1.21) to 5 cmH2O (21.89 ± 0.70). However, a significant decrease (P<0.0003) at 10 cmH2O PEEP (18.86 ± 1.13), as well as (P<0.0001) at 15 cmH2O (18.41 ± 0.82) was observed after PEEP application. Volume dependence of viscoelastic properties showed a slight but not significant tendency to increase with PEEP. The significant decreases in cardiac index (l min-1 m-2) due to PEEP increments (3.90 ± 0.22 at ZEEP, 3.43 ± 0.17 (P<0.0260) at 5 cmH2O of PEEP, 3.31 ± 0.22 (P<0.0260) at 10 cmH2O of PEEP, and 3.10 ± 0.22 (P<0.0113) at 15 cmH2O of PEEP) were compensated for by an increase in arterial oxygen content owing to shunt fraction reduction (%) from 22.26 ± 2.28 at ZEEP to 11.66 ± 1.24 at PEEP of 15 cmH2O (P<0.0007). We conclude that increments in PEEP resulted in a reduction of both airway resistance and respiratory elastance. These results could reflect improvement in respiratory mechanics. However, due to possible hemodynamic instability, PEEP should be carefully applied to postoperative cardiac patients.

Bariatric and Post-Bariatric Surgery: from Metabolic Surgery to Plastic Surgery Indications

Background: Controversy exists concerning indications and outcomes of major bariatric surgery procedures. Massive weight loss after bariatric surgery leads to excess skin with functional and aesthetic impairments. The aim of this study was to investigate the major bariatric surgery procedures and their outcomes in two specific subgroups of morbidly obese patients, ≥55-year-olds and the superobese. Further aims were to evaluate whether the preoperative weight loss correlates with laparoscopic gastric bypass complications. The prevalence and impact of excess skin and the desire for body contouring after bariatric surgery were also studied. Patients and Methods: Data from patients who underwent Laparoscopic Adjustable Gastric Banding (LAGB) and Laparoscopic Roux-en-Y Gastric Bypass (LRYGB) at Vaasa Central Hospital were collected and postoperative outcomes were evaluated according to the BMI, age and preoperative weight loss. Patients who had undergone bariatric surgery procedures were asked to complete a questionnaire to estimate any impairment due to redundant skin and to analyse each patient’s desire for body contouring by area. Results: No significant difference was found in operative time, hospital stay, or overall early postoperative morbidity between LAGB and LRYGB. Mean excess weight loss percents (EWL%) at 6 and 12 months after LRYGB were significantly higher. A significant difference was found in operative time favouring patients <55 years. Intraoperative complications were significantly more frequent in the group aged >55 years. No significant difference was detected in overall postoperative morbidity rates. A significant difference was found in operative time and hospital stay favouring all patients who lost weight preoperatively. Most patients reported problems with redundant skin, especially on the abdomen, upper arms and rear/buttocks, which impaired daily physical activity in half of them. Excess skin was significantly associated with female gender, weight loss and ΔBMI. Patients with a WL >20 kg, ΔBMI ≥10 kg/m2 and an EWL % > 50 showed a significantly surplus skin discomfort (p < 0.001). Most patients desired body contouring surgery, with high or very high desire for waist/abdomen (62.2%), upper arm (37.6%), chest/breast (28.3%), and rear/buttock (35.6%) contouring. Conclusions: LRYGB is effective and safe in superobese (BMI >50) and elderly (>55 years) patients. A preoperative weight loss >5% is recommended to improve the outcomes and reduce complications. A WL >20 kg, ΔBMI ≥10 kg/m2 and an EWL % > 50 are associated with a higher functional discomfort due to redundant skin and to a stronger desire for body contouring plastic surgery.

Effect of lung resection and sham surgery on the frequency of infection in alloxan-diabetic rats

The present study was carried out in order to determine the effect of lung resection on the frequency of infections in alloxan-diabetic rats. Adult female Wistar rats were injected with alloxan (40 mg/kg, iv) to induce diabetes mellitus (group D; N = 45) or with vehicle (1.0 ml/kg, iv) to be used as controls (group C; N = 45). Thirty-six days after receiving alloxan both groups were randomly divided into three subgroups: no operation (NO; N = 15), sham operation (SO; N = 15), and left pneumonectomy (PE; N = 15). The rats were sacrificed 36 days after surgery and their lungs were examined microscopically and macroscopically. The occurrence of thoracic wall infection, thoracic wall abscess, lung abscess and pleural empyema was similar in groups D and C. In contrast, the overall infection rate was higher (P<0.05) in the diabetic rats (SO-D and PE-D subgroups, but not in the NO-D subgroup). Considering that the overall infection rate was similar in the SO-D and PE-D subgroups, we suggest that surgery but not pneumonectomy was related to the higher prevalence of infection in diabetic rats.

Transitory increased blood pressure after upper airway surgery for snoring and sleep apnea correlates with the apnea-hypopnea respiratory disturbance index

A transitory increase in blood pressure (BP) is observed following upper airway surgery for obstructive sleep apnea syndrome but the mechanisms implicated are not yet well understood. The objective of the present study was to evaluate changes in BP and heart rate (HR) and putative factors after uvulopalatopharyngoplasty and septoplasty in normotensive snorers. Patients (N = 10) were instrumented for 24-h ambulatory BP monitoring, nocturnal respiratory monitoring and urinary catecholamine level evaluation one day before surgery and on the day of surgery. The influence of postsurgery pain was prevented by analgesic therapy as confirmed using a visual analog scale of pain. Compared with preoperative values, there was a significant (P < 0.05) increase in nighttime but not daytime systolic BP (119 ± 5 vs 107 ± 3 mmHg), diastolic BP (72 ± 4 vs 67 ± 2 mmHg), HR (67 ± 4 vs 57 ± 2 bpm), respiratory disturbance index (RDI) characterized by apnea-hypopnea (30 ± 10 vs 13 ± 4 events/h of sleep) and norepinephrine levels (22.0 ± 4.7 vs 11.0 ± 1.3 µg l-1 12 h-1) after surgery. A positive correlation was found between individual variations of BP and individual variations of RDI (r = 0.81, P < 0.01) but not between BP or RDI and catecholamines. The visual analog scale of pain showed similar stress levels on the day before and after surgery (6.0 ± 0.8 vs 5.0 ± 0.9 cm, respectively). These data strongly suggest that the cardiovascular changes observed in patients who underwent uvulopalatopharyngoplasty and septoplasty were due to the increased postoperative RDI.

Cardiopulmonary bypass alters the pharmacokinetics of propranolol in patients undergoing cardiac surgery

The pharmacokinetics of propranolol may be altered by hypothermic cardiopulmonary bypass (CPB), resulting in unpredictable postoperative hemodynamic responses to usual doses. The objective of the present study was to investigate the pharmacokinetics of propranolol in patients undergoing coronary artery bypass grafting (CABG) by CPB under moderate hypothermia. We evaluated 11 patients, 4 women and 7 men (mean age 57 ± 8 years, mean weight 75.4 ± 11.9 kg and mean body surface area 1.83 ± 0.19 m²), receiving propranolol before surgery (80-240 mg a day) and postoperatively (10 mg a day). Plasma propranolol levels were measured before and after CPB by high-performance liquid chromatography. Pharmacokinetic Solutions 2.0 software was used to estimate the pharmacokinetic parameters after administration of the drug pre- and postoperatively. There was an increase of biological half-life from 4.5 (95% CI = 3.9-6.9) to 10.6 h (95% CI = 8.2-14.7; P < 0.01) and an increase in volume of distribution from 4.9 (95% CI = 3.2-14.3) to 8.3 l/kg (95% CI = 6.5-32.1; P < 0.05), while total clearance remained unchanged 9.2 (95% CI = 7.7-24.6) vs 10.7 ml min-1 kg-1 (95% CI = 7.7-26.6; NS) after surgery. In conclusion, increases in drug distribution could be explained in part by hemodilution during CPB. On the other hand, the increase of biological half-life can be attributed to changes in hepatic metabolism induced by CPB under moderate hypothermia. These alterations in the pharmacokinetics of propranolol after CABG with hypothermic CPB might induce a greater myocardial depression in response to propranolol than would be expected with an equivalent dose during the postoperative period.

Oral triiodothyronine for the prevention of thyroid hormone reduction in adult valvular cardiac surgery

Treatment of non-thyroidal illness by intravenous triiodothyronine (T3) after cardiac surgery causes a disproportional elevation of hormone levels. The administration of oral T3, which has never been studied in this context, could cause physiological hormone levels. The aim of this study was to test oral T3 for the prevention of T3 reduction during the postoperative period of valvular cardiac surgery in adults. Eighteen patients who underwent cardiac surgery for valvular disease with invasive hemodynamic monitoring were randomly assigned to 2 groups: the T group received oral T3 (N = 8), 25 µg three times/day, initiated 24 h before surgery and maintained for 48 h and the NT group (N = 10) received placebo. Serum T3, thyroxine and thyrotropin were determined at baseline, 1 h before surgery, within 30 min of cardiopulmonary bypass and 6, 12, 24, and 48 h after removal of the aortic cross-clamp. Baseline T3 was similar in both groups (T: 119 ± 13; NT: 131 ± 9 ng/dL). Serum T3 increased during the first 24 h in the T group compared to the NT group (232 ± 18 vs 151 ± 13 ng/dL; P < 0.001). In the NT group, T3 was reduced by 24% (P = 0.007) 6 h after removal of the aortic cross-clamp, confirming the non-thyroidal illness syndrome. There were no differences in clinical or hemodynamic parameters between groups. Administration of oral T3 prevented its serum reduction after valvular cardiac surgery in adults, with normal serum levels for 48 h without disproportional elevations.

Efficacy and safety of combined piroxicam, dexamethasone, orphenadrine, and cyanocobalamin treatment in mandibular molar surgery

Third molar extraction is a common procedure frequently accompanied by moderate or severe pain, and involves sufficient numbers of patients to make studies relatively easy to perform. The aim of the present study was to determine the efficacy and safety of the therapeutic combination of 10 mg piroxicam, 1 mg dexamethasone, 35 mg orphenadrine citrate, and 2.5 mg cyanocobalamin (Rheumazin®) when compared with 20 mg piroxicam alone (Feldene®) in mandibular third molar surgery. Eighty patients scheduled for removal of the third molar were included in this randomized and double-blind study. They received (vo) Rheumazin or Feldene 30 min after tooth extraction and once daily for 4 consecutive days. Pain was determined by a visual analogue scale and by the need for escape analgesia (paracetamol). Facial swelling was evaluated with a measuring tape and adverse effects and patient satisfaction were recorded. There was no statistically significant difference in facial swelling between Rheumazin and Feldene (control group). Both drugs were equally effective in the control of pain, with Rheumazin displaying less adverse effects than Feldene. Therefore, Rheumazin appears to provide a better risk/benefit ratio in the mandibular molar surgery. Since the side effects resulting from nonsteroidal anti-inflammatory drug administration are a severe limitation to the routine use of these drugs in clinical practice, our results suggest that Rheumazin can be a good choice for third molar removal treatment.

Impact of marked weight loss induced by bariatric surgery on bone mineral density and remodeling

Data about the impact of bariatric surgery (BS) and subsequent weight loss on bone are limited. The objective of the present study was to determine bone mineral density (BMD), bone remodeling metabolites and hormones that influence bone trophism in premenopausal women submitted to BS 9.8 months, on average, before the study (OGg, N = 16). The data were compared to those obtained for women of normal weight (CG, N = 11) and for obese women (OG, N = 12). Eight patients in each group were monitored for one year, with the determination of BMD, of serum calcium, phosphorus, magnesium, parathyroid hormone, 25-hydroxyvitamin D, insulin-like growth factor-I (IGF-I) and osteocalcin, and of urinary calcium and deoxypyridinoline. The biochemical determinations were repeated every three months in the longitudinal study and BMD was measured at the end of the study. Parathyroid hormone levels were similar in the three groups. IGF-I levels (CG = 332 ± 62 vs OG = 230 ± 37 vs OGg = 128 ± 19 ng/mL) were significantly lower in the operated patients compared to the non-operated obese women. Only OGg patients presented a significant fall in BMD of 6.2% at L1-L4, of 10.2% in the femoral neck, and of 5.1% in the forearm. These results suggest that the weight loss induced by BS is associated with a significant loss of bone mass even at sites that are not influenced by weight overload, with hormonal factors such as IGF-I being associated with this process.

EEG spike source localization before and after surgery for temporal lobe epilepsy: a BOLD EEG-fMRI and independent component analysis study

Simultaneous measurements of EEG-functional magnetic resonance imaging (fMRI) combine the high temporal resolution of EEG with the distinctive spatial resolution of fMRI. The purpose of this EEG-fMRI study was to search for hemodynamic responses (blood oxygen level-dependent - BOLD responses) associated with interictal activity in a case of right mesial temporal lobe epilepsy before and after a successful selective amygdalohippocampectomy. Therefore, the study found the epileptogenic source by this noninvasive imaging technique and compared the results after removing the atrophied hippocampus. Additionally, the present study investigated the effectiveness of two different ways of localizing epileptiform spike sources, i.e., BOLD contrast and independent component analysis dipole model, by comparing their respective outcomes to the resected epileptogenic region. Our findings suggested a right hippocampus induction of the large interictal activity in the left hemisphere. Although almost a quarter of the dipoles were found near the right hippocampus region, dipole modeling resulted in a widespread distribution, making EEG analysis too weak to precisely determine by itself the source localization even by a sophisticated method of analysis such as independent component analysis. On the other hand, the combined EEG-fMRI technique made it possible to highlight the epileptogenic foci quite efficiently.

Evaluation of piroxicam-β-cyclodextrin as a preemptive analgesic in functional endoscopic sinus surgery

The preemptive analgesic efficacy and adverse effects of preoperatively administered piroxicam-β-cyclodextrin for post-endoscopic sinus surgery pain was determined in a prospective, double-blind, randomized, clinical study. Seventy-five American Society of Anesthesiologists status I-II patients, aged 18-65 years, were divided into three groups with similar demographic characteristics: group 1 received 20 mg piroxicam-β-cyclodextrin, group 2 received 40 mg piroxicam-β-cyclodextrin and group 3 received placebo orally before induction of general anesthesia. A blinded observer recorded the incidence and severity of pain at admission to the post-anesthesia care unit (PACU), at 15, 30, and 45 min in the PACU, and 1, 2, 4, 6, and 24 h postoperatively. All patients received patient-controlled morphine analgesia during the postoperative period and consumption was recorded for 24 h. During the PACU period, mean visual analogue scale values were significantly lower in groups 1 and 2 compared to group 3 (P < 0.05). During the postoperative period, morphine consumption was 3.03 ± 2.54, 2.7 ± 2.8, and 5.56 ± 3.12 mg for each group, respectively (P < 0.05). As a side effect, bleeding was observed in groups 1 and 3, nausea and vomiting in all groups, and edema only in group 3. However, no significant differences were detected in any of the parameters analyzed, which also included epigastric pain, constipation/diarrhea and headache. Similar hematological test results were obtained for all groups. Preemptive administration of piroxicam-β-cyclodextrin effectively reduced analgesic consumption, and 40 mg of the drug was more effective than 20 mg piroxicam-β-cyclodextrin without side effects during the postoperative period.

Effects of different levels of positive airway pressure on breathing pattern and heart rate variability after coronary artery bypass grafting surgery

The application of continuous positive airway pressure (CPAP) produces important hemodynamic alterations, which can influence breathing pattern (BP) and heart rate variability (HRV). The aim of this study was to evaluate the effects of different levels of CPAP on postoperative BP and HRV after coronary artery bypass grafting (CABG) surgery and the impact of CABG surgery on these variables. Eighteen patients undergoing CABG were evaluated postoperatively during spontaneous breathing (SB) and application of four levels of CPAP applied in random order: sham (3 cmH2O), 5 cmH2O, 8 cmH2O, and 12 cmH2O. HRV was analyzed in time and frequency domains and by nonlinear methods and BP was analyzed in different variables (breathing frequency, inspiratory tidal volume, inspiratory and expiratory time, total breath time, fractional inspiratory time, percent rib cage inspiratory contribution to tidal volume, phase relation during inspiration, phase relation during expiration). There was significant postoperative impairment in HRV and BP after CABG surgery compared to the preoperative period and improvement of DFAα1, DFAα2 and SD2 indexes, and ventilatory variables during postoperative CPAP application, with a greater effect when 8 and 12 cmH2O were applied. A positive correlation (P < 0.05 and r = 0.64; Spearman) was found between DFAα1 and inspiratory time to the delta of 12 cmH2O and SB of HRV and respiratory values. Acute application of CPAP was able to alter cardiac autonomic nervous system control and BP of patients undergoing CABG surgery and 8 and 12 cmH2O of CPAP provided the best performance of pulmonary and cardiac autonomic functions.