Jan Bonde

Lung recruitment manoeuvres are effective in regaining lung volume and oxygenation after open endotracheal suctioning in acute respiratory distress syndrome

IntroductionLung collapse is a contributory factor in the hypoxaemia that is observed after open endotracheal suctioning (ETS) in patients with acute lung injury and acute respiratory distress syndrome. Lung recruitment (LR) manoeuvres may be effective in rapidly regaining lung volume and improving oxygenation after ETS.Materials and methodA prospective, randomized, controlled study was conducted in a 15-bed general intensive care unit at a university hospital. Eight consecutive mechanically ventilated patients with acute lung injury or acute respiratory distress syndrome were included. One of two suctioning procedures was performed in each patient. In the first procedure, ETS was performed followed by LR manoeuvre and reconnection to the ventilator with positive end-expiratory pressure set at 1 cmH2O above the lower inflexion point, and after 60 min another ETS (but without LR manoeuvre) was performed followed by reconnection to the ventilator with similar positive end-expiratory pressure; the second procedure was the same as the first but conducted in reverse order. Before (baseline) and over 25 min following each ETS procedure, partial arterial oxygen tension (PaO2) and end-expiratory lung volume were measured.ResultsAfter ETS, PaO2 decreased by 4.3(0.9–9.7)kPa (median and range; P < 0.005). After LR manoeuvre, PaO2 recovered to baseline. Without LR manoeuvre, PaO2 was reduced (P = 0.05) until 7 min after ETS. With LR manoeuvre end-expiratory lung volume was unchanged after ETS, whereas without LR manoeuvre end-expiratory lung volume was still reduced (approximately 10%) at 5 and 15 min after ETS (P = 0.01).DiscussionA LR manoeuvre immediately following ETS was, as an adjunct to positive end-expiratory pressure, effective in rapidly counteracting the deterioration in PaO2 and lung volume caused by open ETS in ventilator-treated patients with acute lung injury or acute respiratory distress syndrome.

Offset of pharmacodynamic effects and safety of remifentanil in intensive care unit patients with various degrees of renal impairment

IntroductionThis open label, multicentre study was conducted to assess the times to offset of the pharmacodynamic effects and the safety of remifentanil in patients with varying degrees of renal impairment requiring intensive care.MethodsA total of 40 patients, who were aged 18 years or older and had normal/mildly impaired renal function (estimated creatinine clearance ≥ 50 ml/min; n = 10) or moderate/severe renal impairment (estimated creatinine clearance <50 ml/min; n = 30), were entered into the study. Remifentanil was infused for up to 72 hours (initial rate 6–9 μg/kg per hour), with propofol administered if required, to achieve a target Sedation–Agitation Scale score of 2–4, with no or mild pain.ResultsThere was no evidence of increased offset time with increased duration of exposure to remifentanil in either group. The time to offset of the effects of remifentanil (at 8, 24, 48 and 72 hours during scheduled down-titrations of the infusion) were more variable and were statistically significantly longer in the moderate/severe group than in the normal/mild group at 24 hours and 72 hours. These observed differences were not clinically significant (the difference in mean offset at 72 hours was only 16.5 min). Propofol consumption was lower with the remifentanil based technique than with hypnotic based sedative techniques. There were no statistically significant differences between the renal function groups in the incidence of adverse events, and no deaths were attributable to remifentanil use.ConclusionRemifentanil was well tolerated, and the offset of pharmacodynamic effects was not prolonged either as a result of renal dysfunction or prolonged infusion up to 72 hours.

Gentamicin dosing in critically ill patients.

Gentamicin is used worldwide in the treatment of serious infections in critically ill patients. The therapeutic efficacy of gentamicin is correlated to the peak serum concentration and the adverse effects to the trough concentrations. Information concerning the pharmacodynamics in critically ill patients is scarce, but pharmacokinetic data are available. A once‐daily dosage regimen has replaced multiple dosing of gentamicin in most intensive care units. No studies evaluating the superiority of either of these dosage recommendations in critically ill patients have ever been conducted. Based on 8 meta‐analyses performed addressing this issue on a wide range of patients and theoretical considerations, we consider a once‐daily dosage regimen feasible in critically ill patients. In septic patients the volume of distribution is significantly increased compared to normal patients, implying that the initial dose should be increased in this patient population. Additionally a general trend towards using higher loading doses (5–7 mg/kg) has been observed in USA, and the appropriateness of this dosing strategy is based on a large descriptive American study. We recommend that the initial dosage of gentamicin in critically ill hyperdynamic septic patients should be 7 mg/kg. Optimal and appropriate monitoring of the treatment with gentamicin in the critically ill patient is still an issue for further investigation. The treatment period with gentamicin should be short (3–5 days), bearing the pharmacological properties of aminoglycosides (small volume of distribution and poor tissue penetration) in mind. In patients with reduced renal function the initial dose of gentamicin should also be increased and maintenance dose reduced preferentially by prolonging the dosing intervals. However, the use of aminoglycosides in a high dose regimen in oliguric or anuric patients or patients who present with a rapidly decreasing renal function needs further consideration.

Implementation of percutaneous dilation tracheotomy – value of preincisional ultrasonic examination?

Background: In this observational study we have evaluated the implementation of percutaneous dilation tracheotomy (PDT), using the foreceps dilation technique (Portex) in a multidicsiplinary ICU.

Anesthesia and Complications of Extracorporeal Shock Wave Lithotripsy of Urinary Calculi

The techniques of anesthesia for extracorporeal shock wave lithotripsy of urinary calculi and the associated complications in 600 treatments with the second generation lithotriptor Siemens Lithostar were studied. General anesthesia was used in 17 treatments (2.8%) and epidural anesthesia was applied in 73 (12%), primarily in children and patients in need of simultaneous surgical auxiliary procedures. A total of 510 treatments (85%) was performed with a combination of local infiltration anesthesia and supplementary intravenous opiates. In 65% of the cases only 2 injections of opiates were sufficient for pain relief. There were no complications in 394 treatments (77%) and minor complications, such as arrhythmia (9.2%) and nausea/vomiting (7.6%), were easily treated. Respiratory depression was observed in 10 cases (2%) and this potentially dangerous complication was associated with simultaneous administration of opiates and midazolam. Only 9 treatments (1.8%) had to be terminated due to complications. It is concluded that most treatments of urinary calculi with this second generation extracorporeal shock wave lithotriptor can be performed with local infiltration anesthesia combined with supplementary short-acting opiates intravenously for pain relief and sedation. When administering supplementary midazolam for sedation the risk of respiratory depression should be considered.

Plasma YKL-40 and CHI3L1 in systemic inflammation and sepsis—Experience from two prospective cohorts

YKL-40, derived from the CHI3L1 gene, has been associated with outcome of infectious and inflammatory diseases. We hypothesized that plasma YKL-40 concentrations and CHI3L1 genotype could be used as prognostic biomarkers in the assessment of systemic inflammatory response syndrome (SIRS) and sepsis. The objective of the study was to assess the prognostic value of plasma YKL-40 and CHI3L1 genotype in patients with SIRS and sepsis. Plasma YKL-40 and CHI3L1 genotype (rs4950928) were analyzed at time of admission to intensive care units (ICU), in two prospective cohorts of consecutive SIRS patients (cohort 1, n=272; cohort 2, n=502). The plasma YKL-40 cut-off for predicting survival was determined in cohort 1 by receiver operator characteristic analyses and validated in cohort 2. In cohort 1 patients with plasma YKL-40 ≤505ng/ml (area under the curve 0.64 (95% confidence interval (CI) 0.57-0.70), p<0.001, sensitivity 53%, specificity 76%) had superior day 90 survival (81% vs. 55%, p<0.001, hazard ratio (HR) 2.29 (95% CI 1.29-4.07)). In the second cohort plasma YKL-40 ≤505ng/ml was also associated with superior survival (61% vs. 38%, p<0.001, HR 1.43 (1.03-1.99)). CHI3L1 minor allele homozygosity was associated with low plasma YKL-40 at time of admission (p=0.002) and no variation (p=0.462) in concentrations throughout the first 14 days in the ICU, but this was not associated with better survival. In conclusion patients with SIRS and sepsis, plasma YKL-40 ≤505ng/ml at time of ICU admission was associated with better survival. However, this association was not observed for patients homozygous for the low expressing YKL-40 CHI3L1 allele.

Accuracy of Cryptorchidism Diagnoses and Corrective Surgical Treatment Registration in the Danish National Patient Registry

PURPOSE In recent years several Danish studies of the etiology, time trends and long-term health consequences of cryptorchidism have relied on diagnoses and surgical treatments registered in the National Patient Registry. We evaluated the diagnostic accuracy of these registry data. MATERIALS AND METHODS According to the Danish National Patient Registry, 16,168 males were diagnosed with cryptorchidism and 9,244 surgical treatments for cryptorchidism were performed between January 1, 1995 and October 10, 2009. We randomly selected 500 diagnosed cases, of which 284 had been managed surgically. We requested the medical records from the departments making the diagnoses and performing the surgery. RESULTS We successfully retrieved medical records for 452 diagnosed cases (90%) and 249 operations (88%). Overall positive predictive value of a registry diagnosis of cryptorchidism was 80% (95% CI 77-84) using the testicular position described by the physician performing the clinical examination as the gold standard. Similarly the positive predictive value of the surgical treatment registration was 99% (95% CI 98-100) using the type of procedure performed. CONCLUSIONS The data on cryptorchidism in the Danish National Patient Registry are quite accurate. In etiological research the limited misclassification will in most cases only slightly attenuate estimates of the true relative association. Thus, the registry has the potential to serve as a valuable research tool, although caution should be exercised when studying time trends or geographical differences.

Assessment of the respiratory exchange ratio in mechanically ventilated patients by a standard anaesthetic gas analyser

Background: The respiratory exchange ratio (R) is the CO2 production divided with O2 consumption. R is an essential factor included in several formulas during routine blood gas analysis. Instant and individual measurement of R may be of particular interest to improve the evaluation of each single patient. A standard anaesthetic gas analyser has been recommended for measurement of R among spontaneously breathing healthy subjects, but there is no experience using this method among mechanically ventilated critically ill patients. This study validates the assessment of R by a Brüel & Kjær gas analyser (B & K) during positive pressure ventilation of intensive care patients.