[Nocturnal hypoxemia after abdominal surgery: associated factors and usefulness of oxygen therapy]. / Hipoxemia nocturna después de cirugía abdominal: factores asociados y rol de la oxigenoterapia.

BACKGROUND: Postoperative nocturnal hypoxemia (PONH) is a main factor in the genesis of respiratory, cardiac and neurologic complications after surgery. AIM: To describe the phenomenon of PONH after elective laparoscopy and laparotomy, and to evaluate the usefulness of oxygen therapy in its prevention. PATIENTS AND METHODS: Fifteen elective patients (6 M, 9 F, 51 +/- 8 years old) scheduled for laparotomy (n = 8) or laparoscopy (n = 7) were studied. Ventilatory parameters and pulse oximetry were measured pre and postoperatively. Patients were randomly assigned to receive oxygen by nasal cannula either during the first or the second postoperative night. RESULTS: PONH (SatO2 < 85) developed in seven patients (47%), of which four had undergone laparoscopic surgery. PONH was more frequent in mildly obese patients and those presenting preoperative hypoxemia (p = 0.03). Peak Flow was lower in patients presenting PONH (p = 0.04). In five patients, PONH was associated with significant tachycardia. Oxygen administration was associated with a higher SatO2 and prevented PONH in 6/7 patients. CONCLUSIONS: PONH is a common event in patients older than 40 years scheduled for open or laparoscopic abdominal surgery, and develops more frequently in those with preoperative nocturnal hypoxemia and greater ventilatory impairment. PONH can be prevented, most of the time, with oxygen administration.

[Intraoperative monitoring of gastric intramucosal pH]. / Monitorización intraoperatoria del pH intramucoso gástrico.

BACKGROUND: Gastric mucosal pH may be a good indicator of splanchnic tissue oxygenation. AIM: To study the effects of abdominal surgical procedures on gastric mucosal pH. PATIENTS AND METHODS: Eighteen patients subjected to abdominal surgery were studied. All patients received general anesthesia and hemodynamic parameters were maintained within 20% of basal values. A tonometer was placed in the stomach after induction of anesthesia. Arterial blood gases and samples from the tonometer were obtained 30 minutes after induction and at 2 hours of surgery. Intramucosal pH was calculated using Henderson-Haselbach equations. RESULTS: Basal gastric mucosal pH was 7.4 +/- 0.1 and did not change during surgery. Two patients had a pH persistently below 7.35 without hemodynamic alterations or systemic acidosis. CONCLUSIONS: Gastric mucosal pH is not modified by abdominal surgery and some patients have low values despite the absence of hemodynamic derangement.

[Bacterial translocation in a model of small intestine autotransplant in dogs]. / Traslocación bacteriana en un modelo de autotrasplante de intestino delgado en perros.

BACKGROUND: Sepsis is the commonest complication of small bowel transplantation. These infections are presumably caused by bacterial translocation, due to splanchnic ischemia. AIM: To study bacterial translocation in the immediate postoperative period after a small bowel transplantation in dogs and to relate it to splanchnic ischemia. METHODS: Three groups of dogs were studied. In group A (n = 6) spontaneous episodes of splanchnic ischemia were monitored in the first 18 h of the postoperative period. In group B (n = 5), a 60 min ischemia was induced by superior mesenteric artery occlusion, two hours after small bowel transplantation. In group C (n = 5) a 60 min ischemia was induced by occlusion of mesenteric vein, two hours after transplantation. Bacterial translocation was assessed through bacterial cultures from the mesenteric vein and splanchnic ischemia with intramucosal pH measurement (a pH < 7.2 was considered indicative of ischemia). RESULTS: Twenty eight of 83 cultures were positive, specially for Gram negative bacilli. The incidence of positive cultures was 14% for group A, 17% for group B and 79% for group C (p < 0.01 compared to groups A and B). The higher incidence of bacterial translocation occurred during the first two hours after transplantation, when the lower intramucosal pH recordings were obtained. The percentage of positive cultures was 39% during periods of ischemia, compared to 24% during periods without ischemia (p = NS). CONCLUSIONS: Bacterial translocation occurs during the first two hours after intestinal transplantation, in concomitance with the lower intramucosal pH readings.

[Trichomonas vaginalis infection in pregnant women and newborn infants]. / Trichomonas vaginalis en embarazadas y en recién nacidos.

We studied 149 pregnant women at delivery and 113 newborns in order to determine the frequency of T vaginalis infection. Neutral red stain, dark field microscopy and culture methods were used with comparable yields. The age of women ranged from 12 to 43 years. A 27.5% infection rate was detected in mothers but all newborns were free from infection. Infection rates in relation to age among mothers confirmed previously reports.