[Influence of the agents which maintain the coordination between spontaneous breathing and mechanical ventilation on haemodynamics and respiration].

OBJECTIVE: To investigate the haemodynamic and respiratory changes following intravenous administration with midazolam, pavulon or both of them in the patients having incoordination between spontaneous breathing and mechanical ventilation. METHODS: Thirty patients having incoordination between spontaneous breathing and mechanical ventilation were randomly assigned to receiving intravenous injection of pavulon (group 1), midazolam (group 3), and both (group 2) respectively with 10 cases in each group. The degree of coordination between spontaneous breathing and mechanical ventilation, blood pressure (BP), heart rate (HR), respiration frequency (RF), oxygen saturation of pulse (SpO(2)) were observed before the medication and at 5, 15, 30 and 60 minutes following the administration of drugs in all the patients. RESULTS: Incoordination between spontaneous breathing and mechanical ventilation, fast RF, decreased SpO(2) were observed before the drug in all patients. Improvement of respiratory was significant in group 2. Patients in group 2 were in excellent coordination between spontaneous breathing and mechanical ventilation, reaching 100% within 30 minutes after administration, and lasting longer. The haemodynamics maintained stable and a significant improvement in respiration and SpO(2) were found. BP and HR were elevated significantly, and RF and hypoxemia were improved, and the degree of coordination between spontaneous breathing and mechanical ventilation reached 100% 5 minutes after the drug, but with shorter duration in group 1. There were no obvious changes in BP, HR, RF and hypoxemia, and the degree of coordination between spontaneous breathing and mechanical ventilation was lowest in group 3. CONCLUSION: The combined use of midazolam and pavulon has little influence on circulation, and it also can maintain the coordination between spontaneous breathing and mechanical ventilation. It is suggested that the combined use of midazolam and pavulon is an optimal way to improve the ventilatory function in mechanical ventilation.

Off-pump coronary artery bypass grafting: a case report.

It is easy to take for granted the seemingly effortless way cardiovascular surgeons are able to bypass atherosclerotic coronary arteries. The process used today was developed over many years of rigorous study, experimentation, success, and failure. Early cardiac surgery was performed blindly, through small incisions, on a beating heart. Advances in medicine allowed surgery to be performed on hearts stilled by cardioplegic arrest, while the circulation was continued through the use of a cardiopulmonary bypass (CPB) machine. The development of the CPB machine allowed surgeons to perform the delicate work of coronary artery bypass grafting (CABG), first attempted on dogs, and then humans. This article briefly outlines the historical evolution of cardiac surgery that led to the development of the technology necessary to perform off-pump coronary artery bypass grafting (OPCAB). A case report of a 72-year-old female who underwent OPCAB is outlined. Included is a discussion of some of the benefits and potential complications of CABG and OPCAB. Anesthetic considerations for OPCAB procedures also are presented.

[Italian guidelines and recommendations for prevention and treatment of pain in the newborn]. / Linee-guida e raccomandazioni per la prevenzione ed il trattamento del dolore nel neonato.

OBJECTIVE: Despite accumulating evidence that procedural pain experienced by preterm infants may have acute detrimental and even long-term effects on an infant's subsequent behavior and neurological outcome, neonates admitted to Neonatal Intensive Care Units still frequently experience acute and prolonged uncontrolled pain. Many invasive and surgical procedures are routinely performed at the bedside in the NICU without adequate pain management. AIM: To develop evidence-based guidelines and recommendations for pain control and prevention in Italian i.e. heel lancing, venipuncture and percutaneous venous line positioning, tracheal intubation, mechanical ventilation, lumbar puncture, chest tube positioning, for certain surgical procedures performed at the NICU, e.g. central venous cutdown, surgical PDA ligation, and cryotherapy, laser therapy for ROP, and for postoperative pain management. CONCLUSION: Adequate pain prevention and management should be an essential part of standard health care at the NICU, and recognizing and assessing sources of pain should be routine in the day-to-day practice of physicians and nurses taking care of the newborn. We hope these guidelines will contribute towards increasing the NICU caregiver's awareness and understanding of the importance of adequate pain control and prevention.

Measurement of mucociliary transport velocity in ventilated patients. Short-term effect of general anesthesia on mucociliary transport.

OBJECTIVES: The objectives of this study were to evaluate a method for measuring BTV in ventilated patients and to study the short-term effect of general anesthesia with midazolam, Fentanyl, pancuronium and O2:N2O on BTV. DESIGN: The study included phantom measurements on a bronchoscopy model and the determination of BTV in patients in a convenience sample trial. SETTING: The study took place in a university hospital. PATIENTS: Fourteen patients undergoing major abdominal surgery with planned postoperative mechanical ventilation were included in the study. All patients gave their written informed consent to participate in the study. INTERVENTIONS: Bronchial mucus transport velocity was measured with a small volume (0.05 to 0.08 ml) of technetium 99m-labeled albumin microspheres with an activity of 3 MBq. The radiolabeled bolus was deposited on the dorsal mucosal surface at the distal end of the right and left main bronchus via flexible bronchoscopy. The movement of the microspheres toward the trachea was visualized and recorded using a scintillation camera; quantitative evaluation utilized the condensed image. MAIN MEASUREMENTS AND RESULTS: The technique was validated in a bronchoscopy model and in an intubated patient by moving a radioactive drop in a catheter through the main bronchi at velocities from 0 to 20 mm/min. The velocities determined by the image processing technique correlated well with the data by the model and patient determination (right bronchus, r = 1.0; left bronchus, r = 1.0). In seven ventilated patients, mechanical irritation by the fiberscope produced no significant effect on BTV. The BTV was measured preoperatively in seven conscious patients one day before surgery while they received local anesthesia with 10 ml of 1 percent lidocaine and postoperatively while they received intubation anesthesia. The preoperative and postoperative BTV values showed no significant differences (10.5; 5.7 to 13.7 mm/min; vs 9.7 (3.7 to 15.3) (median with range). CONCLUSION: By this method, bronchial transport velocity can be determined in a relatively short time in ventilated patients. General anesthesia with midazolam, Fentanyl, pancuronium and O2:N2O does not influence BTV.

Detection of overdosage of sedation in a patient with renal failure by the absence of lower oesophageal motility.

We report an accidental overdosage of morphine and midazolam in a patient with renal failure receiving haemofiltration detected by the absence of oesophageal motility. This situation demonstrates the difficulties of assessing the level of sedation as well as the dosage requirements in this type of patient.

Midazolam does not antagonize fentanyl-mediated analgesia in surgical patients.

STUDY OBJECTIVE: To determine whether midazolam possesses a clinically significant antianalgesic action in surgical patients. DESIGN: Randomized, controlled study. SETTING: Inpatient anesthesia at a university department of neurosurgery. PATIENTS: 2 groups of 10 patients each who were scheduled for supratentorial brain surgery, did not have elevated intracranial pressure, and were free from systemic disease. INTERVENTIONS: Patients underwent anesthesia induction with hexobarbital, succinylcholine, and pancuronium; anesthesia was maintained with injections of droperidol-fentanyl (Group 1) or with midazolam-fentanyl (Group 2) following a predetermined repetitive dosing schedule, such that fentanyl 0.1 mg was injected upon predominant increases in heart rate, whereas droperidol 2.5 mg or midazolam 2.5 mg was injected upon increases in blood pressure. MEASUREMENTS AND MAIN RESULTS: Duration of anesthesia and invasiveness of surgery were similar in both groups. The amount of fentanyl required was 0.55 +/- 0.18 mg/hr (mean +/- SD) in Group 1 and 0.53 +/- 0.17 mg/hr in Group 2. Injections of droperidol 7.5 +/- 3.4 mg/hr (Group 1) and midazolam 5.9 +/- 2.3 mg/hr (Group 2) were administered intraoperatively. This redosing regimen was associated with uninterrupted hemodynamic stability, indicating comparable and adequate anesthetic depth. Plasma concentrations of metabolites and hormones indicative of humoral stress activation did not differ between groups. CONCLUSION: Under these clinical conditions, the administration of midazolam, when compared with droperidol, was not associated with signs of any antagonistic or antianalgesic action toward fentanyl-mediated analgesia.

[Low-dose midazolam. Effect on the induction doses of fentanyl and on hemodynamics in the coronary patient]. / Midazolam à faible dose. Effet sur les doses d'induction de fentanyl et sur l'hémodynamique chez le malade coronarien.

A study was carried out to see whether the administration of a small dose of midazolam determined a reduction of the dose of fentanyl necessary for induction of anaesthesia. Sixteen patients undergoing coronary artery bypass surgery were randomly allocated to either of two groups. Patients in group M received 0.075 mg.kg-1 midazolam intravenously 3 to 5 min prior to induction with fentanyl (5 micrograms.kg-1.min-1), whereas patients in group P only received placebo. The mean dose of fentanyl administered to obtain complete loss of reaction to a painful stimulus was 20 +/- 3 micrograms.kg-1 in group M and 21.5 +/- 2.5 micrograms.kg-1 in group P (NS). However the small dose of midazolam associated with fentanyl caused a significant drop in blood pressure by 20%. After the administration of pancuronium (0.15 mg.kg-1), the patients in group P showed a significant increase in heart rate (+ 14 b.min-1), accompanied by an increase in cardiac index (+0.45 l.min-1.m-2). Pretreatment with midazolam seemed to protect the patient from this undesirable reaction. It was concluded that induction with a combination of a small dose of midazolam and fentanyl did not lead to a reduction in the dose of fentanyl necessary to obtain profound analgesia. However, it gave rise to a haemodynamic pattern quite distinct from that seen during induction with fentanyl alone.

Failure of intravenous low dose midazolam to influence memory recall in drug paralysed post-operative patients sedated with papaveretum.

Sedation of ventilated patients in the Intensive Care Unit generates a tension between adequate sedation to maintain comfort and ease of ventilation and over sedation with undesirable prolongation of ventilation and delays in discharge. Studies in animals suggest very low dose midazolam, but not higher doses, potentiate the sedative effects of opiates. We undertook a trial of opiate sedation versus opiate sedation plus low dose midazolam (1 mg/hour) to determine whether a similar effect could be demonstrated in man. Although ventilator time and the duration of admission to Intensive Care was not prolonged by the addition of midazolam, we were unable to demonstrate any statistically significant benefit with regard to memory recall.

[A case of suicide by an intravenous injection of pancuronium].

A 25-year-old male anesthesiologist was found dead in his room with an intravenous drip line connected with his leg. There were several empty ampules of pancuronium, midazolam and buprenorphine around him. Pancuronium and midazolam in the blood and urine samples collected at postmortem examination were detected by spectrofluorometry and ECD-gas chromatography, respectively. The concentrations of pancuronium and midazolam were 0.3 micrograms/g and 0.12 micrograms/g in the blood, respectively; 0.9 micrograms/g and 0.05 micrograms/g in the urine, respectively. The cause of death was determined to be asphyxia due to respiratory muscle paralysis caused by pancuronium.

[Comparison of the effects of midazolam and thiopental on the neuromuscular response of vecuronium, atracurium, and pancuronium]. / Comparación de los efectos del midazolam y del tiopental en la respuesta neuromuscular del vecuronio, atracurio y pancuronio.

To assess the possible interactions of midazolam and thiopental with the muscular relaxants vecuronium (0.08 mg/kg), atracurium (0.5 mg/kg), and pancuronium (0.1 mg/kg), a comparative analysis was undertaken in two groups of 18 and 32 patients treated respectively with midazolam (0.3 mg/kg) and thiopental (5 mg/kg). The beginning of the effect, maximal blockade, duration of the clinical response, and the spontaneous recovery index were measured on electromyographic recordings of action potentials evoked by train of four supramaximal stimuli delivered every 20 sec on the ulnar nerve. Conditions for intubation were assessed 2 minutes after administration of muscular relaxant. There were no significant differences in neuromuscular parameters in either of the two groups of patients treated with midazolam or with thiopental independently of the relaxant drug administered.

[Anesthesia and intraoperative treatment in 2 cases of simultaneous liver, pancreas, and kidney transplantation]. / Anestesia y tratamiento intraoperatorio en dos casos de trasplante simultáneo triple de hígado, páncreas y riñón.

We report two cases of patients who underwent simultaneous triple transplants (liver-pancreas-kidney) using organs taken from a single donor in each case. The anesthetic technique and perioperative treatment of each patient is described. The favorable evolution in both cases seems to indicate that although this type of transplant may be more complex, it is nevertheless a good therapeutic option for patients suffering terminal liver failure, kidney failure or diabetes type I.

Effects of anesthetic induction in patients with diastolic dysfunction.

PURPOSE: To evaluate the effects of anesthetic induction on bi-ventricular function in patients with known preoperative left ventricular (LV) diastolic dysfunction undergoing coronary artery bypass grafting surgery (CABG). METHODS: Fifty patients with diastolic dysfunction undergoing CABG were studied. Preoperative transthoracic echocardiographic (TTE) examination was performed on the day before surgery and transesophageal echocardiography (TEE) assessment was undertaken after induction of anesthesia with sufentanil, midazolam, isoflurane, and pancuronium. Mean arterial pressure (MAP) and heart rate (HR) were recorded. The diameters of the left atrium (LA) and right atrium (RA) and right ventricular (RV) end-diastolic area (EDA), end-systolic area (ESA) and fractional area change (FAC) were obtained from the apical 4-chamber view. The LV EDA, LV ESA and LV FAC were measured from a transgastric midpapillary view. Pulsed wave Doppler of the transmitral flow (TMF) and transtricuspid flow (TTF), pulmonary venous flow (PVF) and hepatic venous flow (HVF) were measured. Mitral (Em, Am) and tricuspid (Et, At) annulus velocities were assessed by tissue Doppler imaging (TDI). Assessment of diastolic dysfunction was graded from normal to severe using a validated score. RESULTS: Following induction of anesthesia, HR decreased (66 +/- 12 vs 55 +/- 9 beats.min(-1), P < 0.0001) while MAP remained unchanged (86.1 +/- 9.0 vs 85.6 +/- 26.5 mmHg, P = 0.94). The diameters of the LA, RA and RV chambers increased, and these increases were associated with opposite changes in LV dimensions. The RV FAC decreased, but the LV FAC remained unchanged. While most Doppler velocities decreased (P < 0.05), a greater reduction in the atrial components of the TMF, TTF and TDI ratios was observed. The LV diastolic function score improved after induction of anesthesia (100% of patients with a score > or = = 3 pre-induction compared to 58% of patients with a score > or = 3 post-induction; P = 0.0004). CONCLUSION: In patients with left ventricular diastolic dysfunction, cardiac dimensions and bi-ventricular filling patterns are significantly altered after induction of general anesthesia. These changes can be explained to some extent by a reduction in venous return with general anesthesia, reduced atrial contractility, and the effect of positive pressure ventilation. Although the LV diastolic function score improved after induction of anesthesia, it is difficult to dissociate this effect from that of altered loading conditions.

Anesthetic management of bidirectional cavopulmonary shunt in a patient with pulmonary atresia with intact ventricular septum associated with sinusoidal communications.

Pulmonary atresia with intact ventricular septum (PAIVS) is sometimes associated with coronary artery anomalies, including right ventricle (RV)-to-coronary artery fistulas (sinusoidal communications), coronary artery stenoses, and coronary artery occlusions. In some cases, the coronary circulation depends entirely or partly on the desaturated systemic venous blood supply from the RV. Under these circumstances, decompression of the RV can result in fatal myocardial ischemia. A 6-month-old boy, diagnosed with PAIVS associated with sinusoidal communications, underwent a bidirectional cavopulmonary shunt procedure under venoarterial cardiopulmonary bypass (CPB). During CPB, to prevent RV decompression, we maintained right atrial pressure above 5 mmHg and used a pump perfusion rate of 30%-40% of the calculated value based on body surface area. Although electrocardiography showed slight ST depression and bradycardia, myocardial contractility after weaning from CPB was adequate to maintain the circulation with the administration of dobutamine and atrial pacing. In patients with PAIVS and RV-dependent coronary circulation, it is important to maintain coronary artery perfusion throughout the period of anesthesia.