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Biomedical subjects

Y Arabi

Publications and source records attributed to Y Arabi.

At least 19 recordsLinked to original sources
PubMed2006

Association of obesity with increased mortality in the critically ill patient.

The impact of obesity on critical care outcomes has been an issue for debate in the literature. Variable data and conflicting results have been reported. The purpose of our study is to examine the impact of obesity on the outcome of patients admitted to a tertiary closed Intensive Care Unit (ICU) in Saudi Arabia. Data was obtained from a prospectively collected database from September 2001 to May 2004. Patients younger than 18, those with burns, brain death and readmissions were excluded. The study population was stratified into six groups according to their Body Mass Index (BMI). Primary endpoints were ICU and hospital mortality, duration of mechanical ventilation and ICU length of stay. A total of 1835 patients were included in the analysis. Baseline characteristics were similar among the six groups including severity of illness scores, reflected by Acute Physiology and Chronic Health Evaluation II (APACHE II) scores. The ICU mortality was not statistically different among the groups. Hospital mortality was lower in patients with BMI 35-39.9 kg/m2 and BMI >40 kg/m2 compared to those with BMI 18.5-24.9 kg/m2. Multivariate analysis showed that a BMI >40 kg/m2 was an independent predictor of lower hospital mortality (odds ratio 0.51, 95% confidence interval 0.28-0.92, P 0.025) after adjustment for other confounding factors. In conclusion, mortality of obese critically ill patients was not higher than patients with normal weight. In fact, the hospital mortality was lower for patients with BMI >40 kg/m2 compared to the normal BMI group despite similar severity of illness. Obesity might have a protective effect, although further studies are needed to substantiate this finding.

APACHE↗
PubMed2002

Effect of surfactant on pharyngeal mechanics in sleeping humans: implications for sleep apnoea.

Instillation of surfactant into the pharyngeal lumen reduces the pressure required to reopen an occluded airway, and decreases the apnoea/hypopnoea index (AHI). The authors hypothesised that surfactant also reduces the sleep-related increase in pharyngeal resistance. To test this hypothesis two single blind, crossover, placebo-controlled studies were performed. In protocol A seven male, asymptomatic snoring subjects were studied during sleep. Inspiratory pharyngeal resistance was calculated from plots of airflow versus supraglottic pressure (seven breaths) before and after surfactant or saline instillation. In protocol B, in a different group of seven male subjects with sleep apnoea (AHI 15.2 (12) events x h(-1)) the effect of surfactant or saline on sleep disordered breathing was measured, for 1 h immediately before and after surfactant or saline instillation. Surfactant decreased pharyngeal resistance calculated at peak pressure (group mean (SD): pre versus post 83.7 (76.4) versus 49.4 (71.1) cmH2O x L(-1) x s(-1)) and significantly reduced the respiratory disturbance index (RDI pre versus post 79.7 (58.7) versus 59.6 (56.9) events x h(-1)). Saline did not decrease resistance (pre versus post 58.6 (31.1) versus 72.5 (73.4) cmH2O x L(-1) x s(-1)) or RDI (pre versus post 75.3 (42.4) versus 79.9 (46.1) events x h(-1)). Surfactant reduced the collapsibility of the pharynx and led to a modest reduction in respiratory disturbance index. The authors speculate that surfactant may delay occlusion by reducing the liquid "bridging" within the folded pharyngeal lining.

Biological Products↗
PubMed1999

Daytime blood pressure elevation after nocturnal hypoxia.

The purpose of this study was to investigate whether nocturnal hypoxia causes daytime blood pressure (BP) elevation. We hypothesized that overnight exposure to hypoxia leads the next morning to elevation in BP that outlasts the hypoxia stimulus. We studied the effect on BP of two consecutive night exposures to hypobaric hypoxia in 10 healthy normotensive subjects. During the hypoxia nights, subjects slept for 8 h in a hypobaric chamber at a simulated altitude of 4,000 m (barometric pressure = 462 mmHg). Arterial O(2) saturation and electrocardiogram were monitored throughout the night. For 30 min before the nocturnal simulated ascent and for 4 h after return to baseline altitude the next morning, BP was measured every 5 min while the subject was awake. The same measurements were made before and after 2 normoxic nights of sleep in the hypobaric chamber at ambient barometric pressure (745 mmHg). Principal components analysis was applied to evaluate patterns of BP response after the second night of hypoxia and normoxia. A distinct pattern of diastolic BP (DBP) elevation was observed after the hypoxia night in 9 of the 10 subjects but in none after the normoxia night. This pattern showed a mean increase of 4 mmHg in DBP compared with the presleep-awake baseline in the first 60 min and a return to baseline by 90 min. We conclude that nocturnal hypoxia leads to a carryover elevation of daytime DBP.

Adolescent↗
PubMed1998

Progressive retropalatal narrowing preceding obstructive apnea.

Pharyngeal occlusion during obstructive apnea is thought to be an inspiratory-related event; however, occlusion also occurs in the absence of negative intrathoracic pressure. We hypothesized that inspiratory-related pharyngeal occlusion would be preceded by significant expiratory narrowing. Eight sleeping patients with obstructive apnea were studied. Pharyngeal caliber, airflow, and esophageal pressure (Pes) were simultaneously monitored during three to four consecutive breaths preceding occlusion (between 3 and 22 events were studied per subject). Relative changes in retropalatal airway cross-sectional area (CSA) were determined from fiberoptic images (five frames per second) normalized to the maximum CSA. During inspiration, CSA was significantly reduced only during the breath immediately preceding the apnea (Group mean CSA +/- SEM: 51 +/- 8% at the start of inspiration compared with 37 +/- 8% at midinspiration). During expiration, for all breaths there was an initial significant increase in CSA compared with the nadir CSA during the preceding inspiration (CSA: breath-3, 57 +/- 10% to 79 +/- 3%; breath-2, 59 +/- 8% to 76 +/- 4%; breath-1, 37 +/- 8% to 64 +/- 8%), followed by a significant narrowing at end-expiration compared with the peak CSA during that expiration (CSA: breath-3, 79 +/- 3% to 62 +/- 6%; breath-2, 76 +/- 4% to 50 +/- 10%; breath-1, 64 +/- 8% to 36 +/- 10%). Occlusion occurred at a pressure significantly less than that generated during the previous unoccluded breath (Pes: breath-1, -10.8 +/- 2.9 cm H2O; occlusion, -8.2 +/- 1.9 cm H2O). These results show that expiratory narrowing produced a significant reduction of CSA at end-expiration prior to obstructive apnea.

Adult↗
PubMed1996

Adrenal insufficiency, recurrent bacteremia, and disseminated abscesses caused by Nocardia asteroides in a patient with acquired immunodeficiency syndrome.

Nocardia asteroides is an opportunistic pathogen of increasing incidence in human immunodeficiency virus (HIV)-infected persons. The lungs are the most common site of infection, followed by the brain; involvement of other extrapulmonary sites is less common. We describe a patient with acquired immunodeficiency syndrome who presented with a number of unique manifestations of nocardial infection: the first reported case of bilateral adrenal abscesses with adrenal insufficiency, the first case of a renal abscess due to N. asteroides alone, and the first case of recurrent, symptomatic bacteremia. A review of the literature on nocardial infections in HIV-positive individuals is presented.

AIDS-Related Opportunistic Infections↗
PubMed1981

Influence of oral mannitol bowel preparation on colonic microflora and the risk of explosion during endoscopic diathermy.

Oral mannitol has been widely accepted as the bowel preparation of choice for colonoscopy and elective colorectal operation because it is well tolerated by patients. Recent concern has been expressed regarding the risk of explosion and sepsis using oral mannitol because it may provide a nutrient for certain gas-producing bacteria in the colon. Samples of colonic contents aspirated at operation were compared in patients prepared by oral mannitol, by whole bowel irrigation, mannitol preceded by 48 h of oral antibiotics (neomycin with metronidazole) and in patients who did not undergo any preparation. Significantly higher counts of gas-producing Escherichia coli were recovered from patients prepared with mannitol alone compared with whole bowel irrigation or mannitol preceded by oral antimicrobials. These data are consistent with the hypothesis that fermentation of mannitol by Escherichia coli is responsible for the production of potentially explosive gas mixtures after oral mannitol preparation and may also explain the increased incidence of sepsis when oral mannitol is used for bowel preparation.

Bacteria↗
PubMed1981

Faecal toxin and severity of antibiotic-associated pseudomembranous colitis.

The relationship between faecal toxin titre, histological evidence of pseudomembrane in the rectum, and severity of antibiotic-associated colitis has been analysed from data on 62 patients whose faeces contained Clostridium difficile toxin. There was a significant correlation between a toxin titre of 6400 or more and the presence of pseudomembrane (p less than 005). There was no correlation between toxin titre, duration of diarrhoea, total white cell count, temperature, serum albumin or serum orosomucoid concentrations. There was, however, a significant correlation between the presence of rectal pseudomembrane and duration of diarrhoea (p less than 0.005). Exposure to clindamycin or lincomycin was also associated with a significantly higher toxin titre than that seen in patients who were given other antibiotics. The duration of diarrhoea of diarrhoea was not longer and rectal pseudomembrane did not occur more often in the patients who had received clindamycin or lincomycin.

Anti-Bacterial Agents↗
PubMed1980

Clinical and manometric evaluation of rectal prolapse and incontinence.

The clinical presentation and manometric findings in 46 patients with rectal prolapse and/or incontinence are reported. Basal and maximal squeeze pressures in the anal canal of patients with prolapse alone did not differ from the pressures in age and sex-matched controls whereas anal pressures in both groups of patients with incontinence were significantly lower than in controls. Physiotherapy and faradism had no therapeutic value in rectal prolapse but gave improvement in 30 per cent of patients with incontinence. Rectopexy gave satisfactory results in all the patients with prolapse and improved incontinence in 70 per cent. Post-anal repair cured 87 per cent of patients with idiopathic anorectal incontinence or with persistent incontinence after rectopexy. No form of treatment was associated with any significant elevation of anal pressures.

Adolescent↗
PubMed1980

Modification of the physiological disturbances produced by whole gut irrigation by preliminary mannitol administration.

In a prospective non-randomized study of 42 patients it was found that the oral administration of 50 g of mannitol 2 h before whole bowel irrigation (WBI) improved the success rate of the bowel preparation and reduced the time required for the WBI. Mannitol is an osmotic cathartic, and it reduced fluid absorption from a mean value of 2.7 l in patients who had WBI alone to a mean of 1.2 l in those who received mannitol beforehand. Sodium absorption was also significantly reduced.

Administration, Oral↗
PubMed1980

Sepsis following operation for inflammatory intestinal disease.

The incidence and pathogenesis of sepsis following 107 elective operations in 87 patients with inflammatory bowel disease has been studied. Eighteen per cent developed wound sepsis and 13 per cent developed intra-abdominal abscess postoperatively. The prophylactic antimicrobial regimens used did not reduce the overall postoperative sepsis rates. The risk of developing postoperative sepsis was increased in patients with preoperative enterocutaneous or entero-enteric fistulas, pre-existing abscess and those with evidence of active disease (serum albumin less than 3.0 g/dl and serum seromucoids greater than 400 mg/gl). The incidence of postoperative sepsis was not affected by corticosteroid therapy at the time of surgery.

Abscess↗
PubMed1980

Importance of adding neomycin to metronidazole for bowel preparation.

A prospective randomized trial has investigated whether it is necessary to add oral neomycin to oral metronidazole as a means of preventing sepsis in elective colonic resection. Seventy-three patients completed the study; 41 received metronidazole and placebo neomycin and 32 received metronidazole and active neomycin. There was a significant reduction in the incidence of wound infection in patients receiving neomycin and metronidazole (22%) compared with metronidazole alone (51%, P<0.02). There was also a significant reduction in anaerobic infections in the group receiving metronidazole and neomycin compared with metronidazole alone (P<0.05). These results indicate that oral metronidazole alone is of no benefit for patients requiring elective colonic operations and that if oral metronidazole is advised it should always be given in combination with oral neomycin.

Administration, Oral↗
PubMed1980

Therapeutic trials of antibiotic associated colitis.

Since September 1977 we have seen 63 patients with Clostridium difficile and a faecal toxin, but only 33 had histological evidence of pseudomembranous colitis. We have conducted separate double blind trials of an antibiotic, vancomycin and an anion-exchange resin, colestipol, in patients with post-operative diarrhoea. Vancomycin was extremely effective at eradicating the organism and its faecal toxin. These changes were associated with a marked symptomatic improvement. Colestipol proved ineffective in absorbing the faecal toxin and caused no change in numbers of Clostridial difficile. There was no associated symptomatic response. Neither drug had any effect on diarrhoea not related to Clostridium difficile. A carrier state was created by those patients who continued to excrete the organism after Colestipol or placebo treatment. This was eradicated by subsequent treatment with vancomycin. Our brief experience with metronidazole is discussed and a rational basis for treatment advocated.

Anti-Bacterial Agents↗
PubMed1979

Prospective trials of minor surgical procedures and high-fibre diet for haemorrhoids.

Two hundred and sixteen consecutive patients seen for the first time with symptomatic haemorrhoids entered trials of conservative and minor surgical treatment. They were divided into two groups according to their pretreatment maximal anal pressure. Patients with pressures of 100 cm H2O (73.7 mm Hg) or more (108 patients) were treated by anal dilatation (37), sphincterotomy (34), or high-fibre diet (37). Four and 12 months later anal dilatation had produced significantly better results than sphincterotomy or diet. Furthermore, anal dilatation was the only treatment associated with a significant reduction in anal pressure at four and 12 months. Patients with pressures under 100 cm H2O (108 patients) were treated by rubber-band ligation (35), cryosurgery (36), or diet (37). Four and 12 months later significantly more patients were improved by rubber-band ligation than by cryosurgery or diet. These results suggest that haemorrhoids in patients with excessive activity of the internal anal sphincter are best treated by anal dilatation and that in all other patients rubber-band ligation is the treatment of choice.

Adult↗
PubMed1979

Comparison between systemic and oral antimicrobial prophylaxis in colorectal surgery.

In a prospective randomised trial in which 93 patients undergoing elective colorectal operations were given a short prophylactic course of metronidazole and kanamycin orally or systemically, postoperative sepsis occurred in only 3 (6.5%) of those given antimicrobials systemically, compared with 17 (36%) of those given oral prophylaxis (P less than 0.01). 15 of the 17 infections in patients who received antimicrobials orally were due to kanamycin-resistant bacteria present in the colon at operation. Bacterial overgrowth of Staphylococcus aureus was recorded in 6 of the patients who received oral therapy. Antibiotic-associated pseudomembranous colitis occurred in 7 patients, 6 of whom had received prophylaxis orally. These results indicate that oral administration of prophylactic antimicrobials in colon surgery should be avoided because of the risks of bacterial resistance, superinfection, and antibiotic-associated pseudomembranous colitis. Systemic per-operative antimicrobial prophylaxis is safer and more effective.

Administration, Oral↗