Extracardiac minimal invasive implantation of cardioverter defibrillator in young children.

Implantable cardioverter defibrillator (ICD) placement in young children remains a challenge due to device-patient size mismatch and the important choice between an endovenous or an epicardial approach for lead implantation. We treated three children, with respectively Long QT-syndrome, Brugada syndrome and Brugada syndrome with sick sinus syndrome, ranging from 9 months to 7 years with a subxyphoidal ICD and extracardiac lead implantation by minimally invasive techniques. In all cases the thresholds were excellent. The devices could be properly placed in the preperitoneal space without discomfort to the patients. The clinical course was uneventful and results were excellent.

Does ranitidine provide protection against acid gastroesophageal reflux?

Continuous gastroesophageal pH monitoring was used to evaluate the effect of ranitidine on gastroesophageal reflux (GOR) in 60 patients scheduled for elective non-gastrointestinal abdominal or gynaecological surgery. The patients were randomly assigned to receive a single dose of ranitidine 50 mg either iv (RANIV group) or im (RANIM group) or a placebo iv (PLAC group) 90 min before surgery. The pH was measured continuously for six hours in the lower oesophagus using a flexible calibrated glass electrode. A pH < 4.0 was chosen as the boundary for defining occurrence of acid GOR. Both ranitidine treatments reduced the total number of acid reflux episodes and the global reflux index (P < 0.05). The duration of the acid reflux episodes (sum of refluxes) and the number of acid reflux episodes longer than five minutes were markedly decreased by ranitidine but the mean duration of the reflux episodes was unaffected. The pH values at induction, intubation, surgical incision and extubation were similar in the PLAC and RANIV groups but more acid than in the RANIM group. The mean pH of reflux episodes was less acid in both ranitidine groups than in the PLAC group (P < 0.05). Also the number of very acid refluxes (pH < 2.5) decreased with ranitidine (P < 0.05). Intramuscular and intravenous administration of ranitidine provide protection against gastroesophageal reflux, with shorter duration of reflux episodes occurring in the intramuscular group. Regardless of the administration of ranitidine, protection against gastroesophageal reflux is incomplete; the frequency of reflux episodes is reduced but not eliminated.

Incidence and aetiology of postoperative nausea and vomiting.

The reported incidence of emetic symptoms in surgical patients varies from 8-92%. Intractable postoperative nausea and vomiting remains one of the most unpleasant side-effects experienced by patients postoperatively, both in ambulatory and non-ambulatory care, and has potential risks for severe postoperative complications. Multiple factors are associated with an increased risk of developing postoperative nausea and vomiting: age, gender, pre-existing disease, premedication, operative procedure, anaesthetic and analgesic drugs, anaesthetic procedure, and postoperative symptoms. Prophylactic use of anti-emetic premedication is not currently routine practice because not all patients are at serious risk of postoperative nausea and vomiting, and currently available anti-emetics carry undesirable side-effects. However, anti-emetic prophylaxis is very valuable for patients at increased risk. If symptoms do develop in the recovery room, several factors need to be considered in order for anti-emetic treatment to be successful. Adequate hydration and pain control should be ensured, tight-fitting oxygen masks avoided, and patients should be encouraged to take slow, deep breaths to decrease the sensation of nausea. To avoid side-effects, anti-emetics should be administered in minimally effective doses. If the administration of anti-emetics is initially unsuccessful, it may be useful to try a combination of anti-emetic drugs with different mechanisms of action.

Haemodynamic effects of isoflurane during propofol anaesthesia.

We have studied haemodynamic responses to 0, 0.25, 0.5, 0.75 and 1 MAC isoflurane administration in 10 patients during a zero-order propofol infusion and normocapnia. Isoflurane reduced mean arterial pressure (MAP), systemic vascular resistance and left ventricular stroke work in a dose-dependent manner (29%, 38% and 33%, respectively, at 1 MAC), while cardiac output (CO), stroke volume (SV) and heart rate were not affected significantly. Mean pulmonary artery pressure, pulmonary vascular resistance and right ventricular stroke work decreased by 13%, 10% and 17%, respectively (not significant). Pulmonary capillary wedge pressure and central venous pressure were affected minimally, while intrapulmonary shunting and PaO2 remained constant. It is concluded that administration of isoflurane during infusion of propofol caused a dose-dependent decrease in MAP as a result of afterload reduction without modification in CO or SV.

Pneumoperitoneum induced pH changes in follicular and Douglas fluids during laparoscopic oocyte retrieval in humans.

The effects of different insufflation media gases for pneumoperitoneum on the acidity of follicular fluid and blood acid--base balance were studied in two groups of patients during laparoscopic oocyte retrieval. Insufflation with 100% CO2 was compared with insufflation with 5% CO2 in air. End-tidal CO2 and the acid-base status of arterial blood, follicular and Douglas fluids were evaluated. When using 5% CO2 in air as insufflation gas, pH values and pCO2 levels observed in the aspirated follicular (pH: 7.35 +/- 0.06, pCO2: 38.8 +/- 4.5 mmHg) and Douglas fluid (pH: 7.40 +/- 0.07, pCO2: 38.5 +/- 6.2 mmHg) remained normal. With 100% CO2 insufflation, the follicular fluid pH (7.22 +/- 0.07) and pCO2 (53.1 +/- 10.9 mmHg) and the Douglas fluid pH (6.99 +/- 0.12) and pCO2 (90.3 +/- 18.4 mmHg) were grossly disturbed and outside the physiological range. No differences occurred in pO2 or HCO3 levels. These data suggest that pneumoperitoneum with 5% CO2 in air provides more optimal environmental conditions for oocytes used for in-vitro fertilization. However, further investigations on large patient groups are required to demonstrate whether such environmental conditions influence the success rate of in-vitro fertilization in humans.