The value of occlusive balloons in the management of abnormal placentation: A retrospective study.

Abnormal placentation is a potential cause of maternal morbidity and mortality from massive postpartum bleeding. The objective of this study was to investigate the efficacy of occlusive balloons when used as an adjunct to surgery in reducing blood loss and transfusion requirements. A retrospective study of 42 patients was performed involving consecutive cases of abnormal placentation who delivered with either conventional surgery with preoperatively placed occlusive balloons or conventional surgery alone. No differences were noted between the control group and the group of patients who had occlusive balloons with regard to estimated blood loss (P = 0.767), packed red blood cells transfused (P = 0.799), amount of crystalloids infused (P = 0.435), total procedure duration (P = 0.076), and length of ICU stay (P = 0.315) or total hospital stay (P = 0.254). Prophylactic intravascular balloon catheters did not benefit women with abnormal placentation when compared with conventional surgery alone.

Hypothermia attenuates NO production in anesthetized rats with endotoxemia.

Sepsis is often associated with upregulation of nitric oxide production and fever, and it is common to control an excessive febrile response with antipyretic therapy and external cooling. Our aim was to evaluate the effect of hypothermia on NO production in a model of septic shock. Rats were anesthetized, ventilated, and instrumented for hemodynamic monitoring and divided into four groups. Normothermic controls (NC) received saline intravenously and were maintained at 37 °C. Hypothermic controls (HC) received saline but were allowed to become hypothermic. Normothermic endotoxic (NE) received Escherichia Coli lipopolysaccharides (LPS) intravenously to induce endotoxic shock and was maintained at 37 °C. Hypothermic endotoxic (HE) received LPS intravenously and was allowed to become hypothermic. Exhaled NO (NOe) was measured from mixed expired gas at time zero and every 30 min, for 5 h. After injection of LPS, NOe increased substantially in the NE group (700 ± 24 ppb), but increased only to 25 ± 2 ppb in the HE group. NOe increased to 90 ± 3 ppb in the NC group, and to 17.6 ± 3.1 ppb in the HC group after 5 h (P < 0.05), whilst blood pressure remained stable. In the HE group, blood pressure fell immediately after injection of the LPS, but thereafter remained stable despite the rise in NOe. In the NE group, the blood pressure fell gradually, and the animals became hypotensive. During the natural course of endotoxemia in anesthetized rats, allowing severe hypothermia to ensue by not actively managing temperature and hemodynamics resulted in significantly reduced expired NO concentrations, lung injury, and prolonged survival. The clinical benefits of such a finding currently remain unclear and merit further investigation.

Cardiac manifestations of subarachnoid hemorrhage.

INTRODUCTION: Cardiac manifestations of intracranial subarachnoid hemorrhage patients include mild electrocardiogram variability, reversible left ventricular dysfunction (Takotsubo), non-ST elevation myocardial infarction, ST-elevation myocardial infarction and cardiac arrest, but their clinical relevance is unclear. The aim of the present study was to categorize the relative frequency of different cardiac abnormalities in patients with subarachnoid hemorrhage and determine the influence of each abnormality on outcome.  METHODS: A retrospective review of 617 consecutive patients who presented with non-traumatic aneurysmal subarachnoid hemorrhage at our institution was performed. A cohort of 87 (14.1%) patients who required concomitantly cardiological evaluation was selected for subgroup univariate and multi-variable analysis of radiographic, clinical and cardiac data.  RESULTS: Cardiac complications included myocardial infarction arrhythmia and congestive heart failure in 47%, 63% and 31% of the patients respectively. The overall mortality of our cohort (23%) was similar to that of national inpatient databases. In our cohort a high World Federation of Neurosurgical Surgeons grading scale and a troponin level >1.0 mcg/L were associated with a 33 times and 10 times higher risk of death respectively. CONCLUSIONS: Among patients suffering from cardiac events at the time of aneurysmal subarachnoid hemorrhage, those with myocardial infarction and in particular those with a troponin level greater than 1.0 mcg/L had a 10 times increased risk of death. 

Nitric oxide plays a minimal role in hypoxic pulmonary vasoconstriction in isolated rat lungs.

The goal of this study was to elucidate the importance of nitric oxide production during hypoxic pulmonary vasoconstriction (HPV). One group of Sprague Dawley rats received an ip injection of saline (controls), while a second group received an ip injection of Escherichia coli lipopolysacharides (LPS-treated) to render them septic. Three hours later, the animals were anesthetized and prepared for the isolated lung experiment. The lungs were ventilated and perfused with diluted autologous blood (Hct 23%) at constant flow rate while monitoring pulmonary arterial pressure (Pa). Nitric oxide production from the lungs was monitored by measuring its concentration in the mixed exhaled gas (NOe) offline. NOe in the isolated lungs was 2 ppb in controls and 90 ppb in the LPS treated lungs. Hypoxia caused Pa to rise from 10 to 17 mmHg in control lungs, and from 10 to 27 mmHg in the LPS treated lungs. NO production was then manipulated to determine if it affects HPV. NOe was increased by adding L-arginine to the blood, and was blocked by adding nitro-L-arginine (LNA). L-Arginine had minimal effect on NOe in control lungs, but increased NOe in LPS treated lungs, and yet HPV was similar in the 2 groups. Despite inhibition of NO synthesis with nitro-L-arginine (LNA), HPV was potentiated equally in control and in LPS treated lungs (Pa rose by 23 mmHg). Thus NO production did not affect the difference in HPV between control and LPS treated lungs. The results suggest that NO does not plays a primary role in HPV.

Evolution of segmental anesthesia for Laparo-Endoscopic Single Site (LESS) cholecystectomy.

AIM: Transumbilical Laparo-Endoscopic Single Site (LESS) surgery promises improved cosmesis, quick recovery, reduced postoperative pain and shorter length of hospital stay. Since only a simple umbilical incision is used, LESS surgery can be completed with segmental epidural anesthesia. This study describes the evolution of our technique of LESS cholecystectomy from a combination of spinal and epidural anesthesia to thoracic epidural alone and presents our experience with its safety, the observed morbidity, and the reported patient satisfaction. METHODS: In August 2009, a prospective evaluation of LESS cholecystectomy with regional anesthesia was undertaken. We recruited patients with chronic cholecystitis or symptomatic cholelithasis. Blood loss, operative time, complications, and length of hospital stay were measured. Preoperatively and 14 days postoperatively, outcome and symptom resolution were scored. RESULTS: Fifteen consecutive patients underwent LESS cholecystectomy; first with combined spinal-epidural (CSE), and then with thoracic epidural anesthesia alone. Immediate postoperative pain and discomfort were well tolerated. VAS scores upon admission to PACU were 0.4 (1.7±2.2). At postoperative day 14, the patients scored high values for "Satisfaction", 10 (10±1.0) and "Cosmesis", 10 (9.3±1.5). CONCLUSION: LESS cholecystectomy with epidural anesthesia can be undertaken safely. Patient satisfaction and cosmesis are particularly prominent amongst our patients. Our experience supports further utilization of epidural anesthesia for selected patients undergoing LESS cholecystectomy.

Effect of pre-breathing oxygen at different depth on oxidative status and calcium concentration in lymphocytes of scuba divers.

AIM: In-water pre-breathing oxygen at various depths reduces decompression-induced bubble formation and platelet activation, but it could induce side effects such as oxidative stress. The aim of this study was to investigate the effect of in-water pre-breathing oxygen, at different depths, on the oxidative status and intracellular calcium ([Ca(2+) ]i) of peripheral blood lymphocytes isolated from six divers. They participated in a 4-diving protocol. Two week recovery time was allowed between successive dives. Before diving, all divers, for 20 min, breathed normally at sea level (dive 1), 100% oxygen at sea level (dive 2), 100% oxygen at 6 msw (dive 3), 100% oxygen at 12 msw (dive 4). Then they dived to 30 msw for 20 min with air tank. METHODS: Blood samples were collected before and after each dive. Hydrogen peroxide (H(2) O(2) ) levels, catalase (CAT) activity, mRNA expression of CAT, glutathione peroxidase (GPx) and superoxide dismutase (SOD), and the [Ca(2+) ]i in lymphocytes were measured. RESULTS: The dives slightly decreased lymphocyte number and significantly reduced lymphocyte H(2) O(2) levels. CAT activity was higher after scuba diving and, dive 3 enhanced mRNA gene expression of CAT, GPx and SOD. The [Ca(2+) ]i was higher after dive 1 and 2 than pre-diving, while was maintained at pre-diving value after dive 3 and 4. CONCLUSION: Our results suggest that pre-breathing oxygen, in particular at 12 msw, may enhance lymphocyte antioxidant activity and reduce reactive oxygen species levels. Pre-breathing oxygen in water may also preserve calcium homeostasis, suggesting a protective role in the physiological lymphocyte cell functions.

Pulmonary gas exchange in diving.

Diving-related pulmonary effects are due mostly to increased gas density, immersion-related increase in pulmonary blood volume, and (usually) a higher inspired Po(2). Higher gas density produces an increase in airways resistance and work of breathing, and a reduced maximum breathing capacity. An additional mechanical load is due to immersion, which can impose a static transrespiratory pressure load as well as a decrease in pulmonary compliance. The combination of resistive and elastic loads is largely responsible for the reduction in ventilation during underwater exercise. Additionally, there is a density-related increase in dead space/tidal volume ratio (Vd/Vt), possibly due to impairment of intrapulmonary gas phase diffusion and distribution of ventilation. The net result of relative hypoventilation and increased Vd/Vt is hypercapnia. The effect of high inspired Po(2) and inert gas narcosis on respiratory drive appear to be minimal. Exchange of oxygen by the lung is not impaired, at least up to a gas density of 25 g/l. There are few effects of pressure per se, other than a reduction in the P50 of hemoglobin, probably due to either a conformational change or an effect of inert gas binding.

Patients selection for awake neurosurgery.

BACKGROUND: Based upon the surgical location and indication, including redundant regions, eloquent areas, deep brain stimulation, and epilepsy foci, some patients will benefit from an awake craniotomy, which allows completion of neurocognitive testing during the intra-operative period. This paper suggests patient selection criteria through a new decision algorithm. METHODS: We completed a retrospective chart review at Tampa General Hospital after IRB approval; data were obtained concerning total number of craniotomies, indications, and problems experienced for selection of awake vs. general anesthetic techniques. RESULTS: A total of 397 craniotomies were performed during the two years 2005 and 2006: among those 79 patients received an awake craniotomy (20%). We have utilized a sedation sequence which includes dexmedetomidine, propofol and LMA placement. A skull block is then performed to anesthetize pin placement, and desflurane and remifentanil are used for maintenance until the dural incision. At this time the inhalation agent is stopped and the LMA is removed while breathing spontaneously: the patient remains sedated on dexmedetomidine and remifentanil for the duration of the operation and can communicate effectively if closely coached. Analysis of all patient data led us to a decision tree to guide the surgeon and anesthesiologist in selecting the awake patients. DISCUSSION: We describe the sequence of steps and anesthetic agents which has proved successful for our group. Finally, the use of the proposed decision algorithm simplifies preoperative anesthetic selection and prevents erroneous assignment of inappropriate patients to an awake technique.

Hyperbaric oxygenation ameliorates indomethacin-induced enteropathy in rats by modulating TNF-alpha and IL-1beta production.

The effect of hyperbaric oxygenation (HBO2) was investigated in a rat model of indomethacin-induced enteropathy. Enteropathy was induced by two subcutaneous injections of indomethacin (7.5 mg/kg) 24 hr apart. Six groups of rats (n=8) were treated with and without HBO2 (100% oxygen at 2.3 atm absolute) for 1 hr once or twice a day for 2 or 5 days. Disease activity index (DAI) and total ulcer length were measured. Other rats were randomized into two groups (n=16) with and without HBO2 (1 hr once a day) and four rats were killed in each group at 12, 24, 48, and 72 hr after the final injection of indomethacin. Serum and intestinal mucosal TNF-alpha, IL-1beta, myeloperoxidase (MPO), and iNOS expression was measured. HBO2 treatment significantly attenuated indomethacin -induced intestinal ulceration and improved DAI. Indomethacin increased MPO activity and iNOS expression, and these were reduced by HBO2 treatment, with a concomitant reduction in TNF-alpha and IL-1beta. Our data suggest that HBO2 treatment has a beneficial effect on indomethacin-induced enteropathy and this effect is possibly mediated by decreased production of TNF-alpha and IL-1beta.

Hyponatremic seizures after suprapubic catheter placement in 7-year-old child.

We report a case of hyponatremic seizures in a 7-year old boy with spina bifida following cystoscopy and suprapubic catheter placement. Immediate postoperative cystogram and pelvic computed tomogram (CT) after the development of seizures demonstrated a fluid collection from the suprapubic catheter site into the anterior abdominal wall. The subsequent reabsorption of free water from the fluid collection, with the contribution of postoperative hypotonic intravenous fluid administration and possible transient inappropriate antidiuretic hormone (ADH) secretion resulted in acute dilutional hyponatremia and consequent seizures. Strategies to prevent hyponatremia in children during urological procedures, with emphasis on the importance of reserving free water as the irrigation fluid are discussed.

Emphysematous cystitis: rapid resolution of symptoms with hyperbaric treatment: a case report.

INTRODUCTION: Emphysematous cystitis is a rare disease that occurs most often in elderly diabetic patients characterized by gas formation in the bladder wall due to infection. The infecting organism is usually an aerobic bacterium, most commonly E. coli although anaerobic species have also been reported. We report the use of hyperbaric oxygen in a patient with emphysematous cystitis and air in the femoral vein in which the treatment rapidly resolved the symptoms and radiological abnormalities. METHODS: A 65-year-old female presented to the Emergency Department with altered mental status, weakness, dark urine, dysuria and fever. She was febrile and lethargic. Abdominal exam showed suprapubic tenderness. Urinalysis was positive for white blood cells and bacteria. A CT scan of the abdomen demonstrated extensive air in the bladder wall with an air bubble in the femoral vein. Presumptive diagnosis was urinary tract infection, emphysematous cystitis, and sepsis. A question of air embolism was raised due to the intravascular gas. The patient was treated with hyperbaric oxygen (2.85 atm abs, 90 minutes) on two separate occasions in the first 12 hours. Within 24 hours, the patient's condition rapidly improved. Repeat CT scan 48 hours after admission showed near complete resolution of the emphysematous cystitis. The patient grew Klebsiella pneumonia from her urine. CONCLUSIONS: Emphysematous cystitis is a rare condition caused by either aerobic or anaerobic bacteria and may be associated with both bladder wall and intravascular gas formation. Hyperbaric oxygen therapy has not been previously reported as a treatment modality. The rapid improvement in our patient may indicate a role for hyperbaric oxygen in addition to IV hydration and antibiotics in this disease.

Role of nitric oxide in acidosis-induced intestinal injury in anesthetized rats.

We investigated the pathogenic mechanism(s) of small intestinal injury during acidosis in relation to circulating nitric oxide (NO) in an experimental rat model. Rats were anesthetized, paralyzed, and mechanically ventilated with room air. Hydrochloric acid (0.16 mmol bolus followed by 0.132 mmol/kg/h) was infused through the jugular vein for 5 hours. Control rats received a saline infusion. Arterial blood gases, blood pressure, and blood pH were measured every 30 minutes. The involvement of NO in this acidosis model was assessed by measuring plasma concentration of nitrite/nitrate (NOx) and by evaluating inducible NO synthase (iNOS) expression in small intestinal mucosa. Intestinal injury was assessed by measuring myeloperoxidase (MPO) activity, thiobarbituric acid reactants (TBARS), and histologic scores. HCl infusion was associated with hypotension, decreased blood pH, increased plasma concentration of NOx, augmented intestinal mucosal iNOS expression, MPO activity, TBARS, and histopathologic injury scores. Pretreatment with an iNOS inhibitor, aminoguanidine (AG, 50 mg/kg), reversed HCl-induced hypotension without a change in blood pH. HCl-induced lesions, MPO activity, TBARS, and plasma NOx production were decreased by AG. Our data show that the pathogenic mechanisms of acidosis-induced small intestinal lesions involve up-regulation of NO production by increased expression of iNOS and augmentation of superoxide radicals and MPO activity.

Hyperbaric O2 reduces intestinal ischemia-reperfusion-induced TNF-alpha production and lung neutrophil sequestration.

Treatment with hyperbaric O2 (HBO) ameliorates ischemia-reperfusion (I/R) injury. Since tumor necrosis factor-alpha (TNF-alpha) plays an important role in I/R injury, we hypothesized that the effect of HBO in I/R injury may be due to its ability to inhibit TNF-alpha production. In this study, one group of rats received HBO during 60 min of ischemia (HBO group, n = 9), while control rats endured the same procedure but did not receive HBO (non-HBO, n = 9). A group of sham-operated control rats (SHAM, n = 6) underwent laparotomy without occlusion of the artery and HBO treatment. Intestinal I/R led to an increase in serum TNF-alpha concentration to [mean (SEM)] 165 (32) pg/ml (P < 0.01 vs SHAM rats). HBO attenuated this increase [34 (9) pg/ml; P<0.05 vs non-HBO group]. Intestinal I/R also resulted in a marked increase in lung myeloperoxidase content [0.62 (0.04) U/g vs 0.17 (0.02) U/g of SHAM rats, P<0.01]. HBO suppressed this increase [0.40 (0.04) U/g, P<0.05 vs non-HBO rats]. HBO ameliorated the injury to the intestine and lung. The number of neutrophils sequestered in the lung was reduced in HBO rats compared to non-HBO rats [6.4 (0.9) neutrophils/per oil field and 10.9 (2) neutrophils/per oil field, respectively; P < 0.05]. These findings demonstrate that HBO inhibits TNF-alpha production during intestinal I/R, and this reduced TNF-alpha production may be attributed to the beneficial effects of HBO.

Environmental stress on diving-induced platelet activation.

Platelet activation has been suggested to play an important role in the pathogenesis of prethrombotic states and thus may be responsible for decompression illness during compressed air (scuba) diving. To investigate the effect of physical, mental, and environmental stress on platelet activation during immersion in ice-cold water, we examined 10 male breath-hold divers (BHD), 10 elite BHD (eBHD), and 10 scuba divers during immersion in an ice-covered lake at moderate altitude. Platelet activation was examined by surface expression of activation-dependent glycoproteins CD62p, CD63, and CD42a with flow cytometry 10 min before and 1 min and again 24 h after diving. Plasma epinephrine level was also measured. In addition, the relationship between the activated platelets and the epinephrine level was evaluated. The percentage of platelet activation increased from 2.1 +/- 0.4 to 5.7 +/- 0.3, 1.8 +/- 0.3 to 12.9 +/- 0.8, and 3.7 +/- 0.9 to 31.2 +/- 0.8 in BHD, eBHD, and scuba divers, respectively. The percentage of platelet activation returned to pre-immersion levels in BHD and eBHD divers 24 h after diving, but was still higher in scuba divers. A positive relationship exists between the plasma epinephrine level and the percentage of the platelet activation. This study suggests that physical and mental stress enhance platelet activation during diving in ice-cold water.

A comparison of the cost-effectiveness of remifentanil versus fentanyl as an adjuvant to general anesthesia for outpatient gynecologic surgery.

The unique pharmacokinetic properties of remifentanil make it a potentially useful adjuvant during general anesthesia for ambulatory surgery. Fentanyl, inexpensive and easy to administer, is the most common opioid used for this purpose. As an adjuvant to general anesthesia for outpatient gynecologic surgery, we questioned if remifentanil was cost-effective as an alternative to fentanyl. Thirty-four patients undergoing gynecologic laparoscopy or hysteroscopy were prospectively and randomly assigned to a standard practice (n = 18) or a study (n = 16) group. Standard practice patients received fentanyl (3 microg/kg) before induction; study patients received remifentanil by continuous infusion (0.5 microg x kg. min(-1) at induction, then 0.2 microg x kg x min(-1)). Sevoflurane was titrated to a Bispectral index value of 40-55. We investigated recovery profiles, patient and health care professional satisfaction, and drug costs. The incidence of rescue antiemetic treatment (2 of 16 vs. 8 of 18; P = 0.013) and the nausea visual analog scale scores during second stage recovery (0.2 vs. 0.6; P = 0.044) were more frequent in the study group. However, the incidence of intraoperative adverse events and other postoperative sequelae, recovery times, pain and nausea visual analog scale scores, opioid analgesic dosage requirements in the postanesthetic care unit, and satisfaction survey responses were similar between groups. Perioperative drug costs per patient were $17.72 more in the remifentanil (vs. fentanyl) group.

Inducible nitric oxide synthase in the lung and exhaled nitric oxide after hyperoxia.

The effect of hyperoxia on nitric oxide (NO) production in intact animals is unknown. We described the effects of hyperoxia on inducible nitric oxide synthase (iNOS) expression and NO production in the lungs of rats exposed to high concentrations of oxygen. Animals were placed in sealed Plexiglas chambers and were exposed to either 85% oxygen (hyperoxic group) or 21% oxygen (negative control group). Animals were anesthetized after 24 and 72 h of exposure and were ventilated via a tracheotomy. We measured NO production in exhaled air (E(NO)) by chemiluminescence. The lungs were then harvested and processed for detection of iNOS by immunohistochemistry and Western blotting analysis. The same experiments were repeated in animals exposed to hyperoxia for 72 h after they were infused with L-arginine. We used rats that were injected intraperitoneally with Escherichia coli lipopolysaccharide to induce septic shock as a positive control group. Hyperoxia and septic shock induced expression of iNOS in the lung. However, E(NO) was elevated only in septic shock rats but was normal in the hyperoxic group. Exogenous infusion of L-arginine after hyperoxia did not increase E(NO). To exclude the possibility that in the hyperoxic group NO was scavenged by oxygen radicals to form peroxynitrite, lungs were studied by immunohistochemistry for the detection of nitrotyrosine. Nitrotyrosine was found in septic shock animals but not in the hyperoxic group, further suggesting that NO is not synthesized in rats exposed to hyperoxia. We conclude that hyperoxia induces iNOS expression in the lung without an increase in NO concentration in the exhaled air.