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Biomedical subjects

Hinnerk Wulf

Publications and source records attributed to Hinnerk Wulf.

At least 19 recordsLinked to original sources
PubMed2006

Systematic review on the recurrence of postoperative nausea and vomiting after a first episode in the recovery room - implications for the treatment of PONV and related clinical trials.

BACKGROUND: Despite the presence of a plethora of publications on the prevention of postoperative nausea and vomiting (PONV) only little is known how to treat established symptoms. Besides the high effort of performing these efficacy trials (much more patients must give their consent than are actually included in a study) and ethical concerns, little is known about the rate of re-occurring PONV/vomiting after placebo. As a consequence investigators will have difficulties defining a clinically relevant effect for the new treatment which is crucial for any planning. A quantitative systematic review was performed in order to provide more reliable estimates of the incidence of re-occurring PONV/vomiting after placebo and to help investigators defining a clinically relevant treatment effect. METHODS: A systematic search of the literature was performed using an extended search strategy of a previous review. Data on the recurrence of PONV (any nausea or emetic symptom) and vomiting (retching or vomiting) was extracted from published reports treating PONV with placebo and unpublished results from two observational trials where no treatment was given. A nonlinear random effects model was used to calculate estimates of the recurrence of symptoms and their 95%-confidence intervals (95%-CI). RESULTS: A total of 29 trials (including the unpublished data) were eligible for the calculations. Depending on the length of observation after administering placebo or no treatment the recurrence rate of PONV was between 65% (95%-CI: 53%...75%) and 84% (95%-CI: 73%...91%) and that of vomiting was between 65% (95%-CI: 44%...81%) and 78% (95%-CI: 59%...90%). CONCLUSION: Almost all trials showed a considerable and consistently high rate of recurrence of emetic symptoms after placebo highlighting the need for a consequent antiemetic treatment. Future (placebo) controlled efficacy trials may use the presented empirical estimates for defining clinically relevant effects and for statistical power considerations.

Journal Article↗
PubMed2006

Physical therapy and active exercises--an adequate treatment for prevention of late whiplash syndrome? Randomized controlled trial in 200 patients.

The aim of this study was to compare the effect of a physical therapy regimen including active exercises with the current standard treatment on reduction of pain 6 weeks and 6 months after whiplash injury caused by motor vehicle collision. Two hundred patients were enrolled in a prospective randomized controlled trial. In the standard group, treatment consisted of immobilization with a soft collar over 7 days. In the physical therapy group, patients were scheduled for 10 physical therapy appointments including active exercises within 14 days after enrollment. Pain intensity was rated by all patients daily during the first week, the sixth week, and 6 months after recruitment, using a numeric rating scale (0-10). Data analyses were performed by comparing the mean (over 1 week) pain scores between the two different treatment groups. Ninety-seven patients were randomly assigned to the standard treatment group and 103 to the physical therapy group. During the first week, there was no significant difference in mean pain intensity between the standard treatment group (4.76+/-2.15) and the physical therapy group (4.36+/-2.14). However, after 6 weeks, mean pain intensity was significantly (p=0.002) lower in the physical therapy group (1.49+/-2.26 versus 2.7+/-2.78). Similarly, after 6 months, significantly (p<0.001) less pain was reported in the physical therapy group (1.17+/-2.13) than the standard treatment group (2.33+/-2.56). We conclude that a physical therapy regimen which includes active exercises is superior in reducing pain 6 weeks and 6 months after whiplash injury compared to the current standard treatment with a soft collar.

Accidents, Traffic↗
PubMed2006

Evaluation of the McPeek postoperative outcome score in three trials.

BACKGROUND: Postoperative outcome of patients is determined by recovery characteristics and self-reported quality of life. The first can be assessed with the McPeek score which values three aspects of recovery: mortality, postoperative critical care and duration of hospitalization. MATERIALS AND METHODS: We calculated the McPeek score of 669 patients in three trials: (1) colorectal cancer surgery, (2) antihistamine/volume loading in various operations, and (3) cholecystectomy. Beforehand, the average of intensive care unit treatment and duration of hospitalization were determined for the different operations to define McPeek score points. The score was tested on reliability, validity, and sensitivity. In addition, clinical applicability was assessed in a survey. RESULTS: The score was reliable with similarly distributed score points in the three trials at different institutions. Inter-rater reliability was high (97% overlap). Validity was proven by moderate high correlation to convergent criteria such as complications (trial I to III r=0.43, r=0.38, r=0.60), preoperative American Society of Anesthesiologists class (ASA) (r=0.24, r=0.28, r=0.57), and age (r=0.23, r=0.32, r=0.31). The score was different between patients with and without neoplasms (P<0.001, trial II) and between elective or emergency patients (P<0.001, trial III). In a survey, investigators reported that the score was easy to assess and more comprehensive than four other scores. CONCLUSIONS: The McPeek score values the postoperative outcome on a nonlinear scale. A priori, the average duration of hospitalization and critical care for a specific operation has to be defined. Our validation suggests that it is a reliable, valid, sensitive, and practical instrument for outcome analysis after anesthesia and surgery.

Adult↗
PubMed2006

Blood volume regulation in donors undergoing intermittent-flow plasmapheresis involving a high extracorporeal blood volume.

BACKGROUND: Intermittent-flow plasmapheresis (IFP) often involves a large extracorporeal blood volume (ECV) of donors during donation. Depending on equipment and donor characteristics, ECV can exceed 20 percent of a donor's blood volume (BV). It was the aim of this study to delineate mechanisms of BV regulation associated with these volume shifts. STUDY DESIGN AND METHODS: Parameters of BV regulation were recorded in 60 donors (30 men, 30 women) undergoing IFP, who were randomly selected after stratification for sex and BV. Shock index (SI), stroke volume (SV), cardiac index (CI), and thoracic fluid content (TFC) were determined at the beginning of the procedure and when maximum ECV (ECV(max)) was reached with noninvasive techniques. In a control investigation, donors were kept in reclined position for the duration of an IFP session without actually donating. RESULTS: SI increased significantly during IFP (+0.18; p < 0.0001). SV decreased significantly (-14.3 mL/stroke; p < 0.0001). CI did not decrease significantly (-0.07 L/min/m(2) body surface area; p = 0.33). Preservation of CI was due to a significant rise in heart rate (+13.4 beats/min; p < 0.0001). TFC decreased significantly during IFP (-0.77 kOmega(-1); p < 0.0001), indicating the development of an intravascular volume deficit. The changes of SI, heart rate, and TFC weakly correlated with ECV(max). CONCLUSION: The hemodynamic response during IFP is consistent with a hypovolemic challenge of the donors and is sufficient to maintain cardiac function. ECV(max) during donation does not reliably predict the degree of hypovolemic stress, as long as it remains below 20 percent. This might warrant reevaluation of collection limits based on ECV(max).

Adult↗
PubMed2006

The size 1(1/2) ProSeal laryngeal mask airway in infants: a randomized, crossover investigation with the Classic laryngeal mask airway.

Many problems with the Classic laryngeal mask airway (CLMA) in infants are believed to be related to its inadequate cuff design. One of the main limitations of the CLMA is that the resulting low-pressure seal can be inadequate for positive pressure ventilation (PPV). The ProSeal LMA (PLMA), a new laryngeal mask airway with a modified cuff, has been shown to form a more effective seal than the CLMA in children. The first infant size PLMA, size 1(1/2), became available recently. We studied 30 anesthetized, nonparalyzed infants aged 15 mo (2-30 mo) and weighing 9 kg (5-12 kg). The CLMA and PLMA were inserted in random order into each patient. Airway leak pressure and maximum tidal volume were measured. Ease of insertion, quality of initial airway, and fiberoptic position were also determined. Gastric tube placement was assessed for the PLMA. The mean airway leak pressure in neutral head position (26.7 versus 18.9 cm H2O), maximum flexion (35.6 versus 28.2 cm H2O), and the mean maximum tidal volume (312 versus 260 mL) were significantly higher for the PLMA (P < 0.01). Air entered the stomach in eight patients with the CLMA but did not with the PLMA. Gastric tube placement was possible in all but one patient. In three patients, the use of the PLMA led to some degree of clinically relevant compression of the larynx. The size 1(1/2) PLMA seems to be a more suitable device for airway maintenance in infants than the same size CLMA. The ability to insert a gastric tube at the same time, and a significantly higher airway leak pressure than with the CLMA, may have important implications for its use for PPV in infants.

Anesthesia↗
PubMed2005

Risk factors for bacterial catheter colonization in regional anaesthesia.

BACKGROUND: Although several potential risk factors have been discussed, risk factors associated with bacterial colonization or even infection of catheters used for regional anaesthesia are not very well investigated. METHODS: In this prospective observational trial, 198 catheters at several anatomical sites where placed using a standardized technique. The site of insertion was then monitored daily for signs of infection (secretion at the insertion site, redness, swelling, or local pain). The catheters were removed when clinically indicated (no or moderate postoperative pain) or when signs of potential infection occurred. After sterile removal they were prospectively analyzed for colonization, defined as > 15 colony forming units. RESULTS: 33 (16.7%) of all catheters were colonized, and 18 (9.1%) of these with additional signs of local inflammation. Two of these patients required antibiotic treatment due to superficial infections. Stepwise logistic regression analysis was used to identify factors associated with catheter colonization. Out of 26 potential factors, three came out as statistically significant. Catheter placement in the groin (odds-ratio and 95%-confidence interval: 3.4; 1.5-7.8), and repeated changing of the catheter dressing (odds-ratio: 2.1; 1.4-3.3 per removal) increased the risk for colonization, whereas systemic antibiotics administered postoperatively decreased it (odds ratio: 0.41; 0.12-1.0). CONCLUSION: Colonization of peripheral and epidural nerve catheter can only in part be predicted at the time of catheter insertion since two out of three relevant variables that significantly influence the risk can only be recorded postoperatively. Catheter localisation in the groin, removal of the dressing and omission of postoperative antibiotics were associated with, but were not necessarily causal for bacterial colonization. These factors might help to identify patients who are at increased risk for catheter colonization.

Journal Article↗
PubMed2005

Differences in time to defibrillation and intubation between two different ventilation/compression ratios in simulated cardiac arrest.

OBJECTIVE: During basic life support (BLS) by a two-rescuer-team early defibrillation and ALS procedures should be performed without interruptions of the BLS-ventilation/compression sequence. The objective of this study was to determine the impact of a ventilation/compression ratio of 5:50 versus 2:15 on the time intervals "Start BLS to first shock" and "Start BLS to intubation". METHODS: Using a random cross over design 40 experienced paramedics performed a standard BLS/ALS-algorithm according to ILCOR guidelines in a manikin model with ventricular fibrillation (resusci skillreporter anne, Laerdal, Norway) performing both the 2:15 and the 5:50 ventilation/compression ratio. BLS was started with bag/valve/mask ventilation, a semi-automatic defibrillator (corpuls 08/16S) was connected with the manikin, ECG-analysis and three shocks were performed and the tracheal intubation was prepared. Ventilation/compression sequence was only interrupted during ECG-analysis and defibrillation. Expiratory volumes and number of compressions were measured. Variables were compared using paired Students t-test. In addition paramedics were interviewed about work-flow and emotional stress during the tests. RESULTS: The time interval "Start BLS to first shock" was 78 s (2:15-group) versus 63 s (5:50-group), p<0.0001, the time interval "Start BLS to intubation" was 183 s (2:15-group) versus 150 s (5:50-group), p<0.0001, mean ventilation volumes per minute were 4490 ml (2:15-group) versus 4370 ml (5:50-group), p>0.1, mean number of compressions were 65 min-1. (2:15-group) versus 68 min-1 (5:50-group), p>0.1. The work-flow and emotional stress was appraised by the paramedics to be significantly superior in the 5:50 ratio (p<0.0001). CONCLUSIONS: The ventilation/compression ratio of 5:50 compared with 2:15 during BLS with an unsecured airway reduces the time until the first defibrillation and tracheal intubation was performed without changes in ventilation volume and compressions per minute. The Paramedics stated that the 5:50 ratio improved the work-flow and reduced the emotional stress.

Allied Health Personnel↗
PubMed2005

[Is ginger a clinically relevant antiemetic? A systematic review of randomized controlled trials].

BACKGROUND AND OBJECTIVE: The aim of this systematic review was to evaluate the clinical impact of ginger (Zingiber officinale) as an antiemetic. METHODS: A systematic search of the literature was performed using the databases of MEDLINE, EMBASE, and the Cochrane-Library. RESULTS: Of 100 published reports discerned as potentially relevant, 24 randomized controlled trials were evaluated, covering 1073 patients which had received ginger. Of these reports, 16 contained information regarding the antiemetic activity of the phytotherapeutic agent against kinetosis, postoperative nausea and vomiting (PONV), and morning sickness and hyperemesis gravidarum, respectively. Only a few studies were eligible for a quantitative analysis (meta-analysis). Thus, the majority of the reports were analyzed descriptively. To analyze the potential side effects of the drug, 15 reports with 777 patients were eligible. Of these, 3.3% suffered from slight side effects, mainly mild gastrointestinal symptoms and sleepiness, both not requiring specific treatments. One severe adverse event was reported in a study: an abortion occurred in the 12th week of gestation. However, a total of 136 patients were treated with ginger within the first trimenon of pregnancy without complications. CONCLUSION: There is no clear evidence for the efficacy of ginger in the treatment of PONV and of kinetosis. The results for the treatment of nausea and vomiting in pregnancy are encouraging, however, ginger should be applied for the time being only in controlled clinical studies. Applied in daily doses up to 6 g ginger seems to be a drug with few side effects.

Antiemetics↗
PubMed2005

Does femoral nerve catheter placement with stimulating catheters improve effective placement? A randomized, controlled, and observer-blinded trial.

Continuous peripheral nerve blocks offer the benefit of extended postoperative analgesia and accelerated functional recovery after major knee surgery. Conventional nerve localization is performed over a stimulating needle followed by blind insertion of the peripheral catheter. Correct catheter placement is confirmed by testing for satisfactory analgesia. Stimulating catheters offer the advantage of verifying correct placement close to the nerve during catheter placement. The aim of this randomized trial was to determine whether accurate catheter positioning under continuous stimulation accelerates the onset of sensory and motor block, improves the quality of postoperative analgesia, and enhances functional recovery. We compared femoral nerve catheters inserted under continuous stimulation with catheters that were placed using the conventional technique of blind advancement in 81 patients undergoing major knee surgery. Time of catheter placement was similar in both groups with 4 min (3/7.3; median, 25th/75th percentile) in the conventional group and 5 min (4/8.8) in the stimulating catheter group. In both groups, 42% of the catheters could be correctly placed (motor response of the patella with a current < or =0.5 mA) at first attempt. In 22 patients (58%) of the stimulating catheter group, the catheter had to be redirected 1-20 times, including 2 that could not be correctly placed within 20 min. The onset time of sensory and motor block was almost similar in both groups. There were no differences in the postoperative IV opioid consumption, and visual analog scale pain scores at rest and movement, or maximal bending and stretching of the knee joint during the 5 days after surgery. We conclude that with continuous femoral nerve blocks, blind catheter advancement is as effective as the stimulating catheter technique with respect to onset time of sensory and motor block as well as for postoperative pain reduction and functional outcome.

Aged↗
PubMed2005

The reliability and validity of the upper lip bite test compared with the Mallampati classification to predict difficult laryngoscopy: an external prospective evaluation.

Recently, a new bedside screening test to predict the occurrence of a difficult laryngoscopy has been developed as a substitute for the Mallampati classification. The Upper-Lip-Bite test (ULBT) evaluated the patient's ability to reach or completely cover the upper lip with the lower incisors. It is often accepted that new predictive tools should undergo an external evaluation before the tool is used in clinical practice. Thus, we evaluated this test with respect to applicability, interobserver reliability, and discriminating power and compared it with the Mallampati-score (using Samsoon and Young's modification). The ULBT could not be applied in 12% of all patients (Mallampati score, <1%). However, the interobserver reliability was better for the ULBT (kappa = 0.79 versus kappa = 0.59). The discriminating power to predict a patient with difficult laryngoscopy was evaluated in 1425 consecutive patients. Both tests were assessed simultaneously in these patients by two specially trained independent observers. After the induction of anesthesia, the laryngoscopic view was assessed by the attending anesthesiologist using the classification of Cormack and Lehane. A grade I or II was called easy laryngoscopy and grade III and IV difficult laryngoscopy. The discriminating power for both tests was low (0.60 for the ULBT [95% confidence interval, 0.57-0.63] and 0.66 [0.63-0.69]) for the Mallampati score), indicating that both tests are poor predictors as single screening tests.

Aged↗
PubMed2005

Independent risk factors for postoperative shivering.

Postoperative shivering (PAS) is uncomfortable for patients and potentially risky. In this observational trial we sought to identify independent risk factors for PAS after general anesthesia. Potential risk factors for PAS were recorded in 1340 consecutive patients. Signs of shivering, peripheral and core temperature, and thermal comfort were recorded in the postanesthetic care unit. The data were split into an evaluation data set (n = 1000) and a validation data set (n = 340). The first was used to identify independent risk factors for PAS and to formulate a risk score using backward-elimination logistic regression analysis. The proposed model was subsequently tested for its discrimination and calibration properties using receiver operating characteristic (ROC)-curve analysis and linear correlation between the predicted and the actual incidences of PAS in the validation group. The incidence of PAS was 11.6%. There were three major risk factors: young age, endoprosthetic surgery, and core hypothermia, with age being the most important. The risk score derived from this analysis had a reasonable discriminating power, with an area under the ROC-curve of 0.69 (95% confidence interval, 0.60-0.78; P < 0.0001). Furthermore the equation of the calibration curve (y = 0.69x + 6; R2= 0.82; P < 0.05) indicated a good and statistically significant agreement between predicted and actual PAS incidence. Postoperative shivering can be predicted with acceptable accuracy using the four risk factors identified in the present study. The presented model may serve as a clinical tool to help clinicians to rationally administer prophylactic antishivering drugs.

Adult↗
PubMed2004

Factors influencing preoperative stress response in coronary artery bypass graft patients.

BACKGROUND: In many studies investigating measures to attenuate the hemodynamic and humoral stress response during induction of anaesthesia, primary attention was paid to the period of endotracheal intubation since it has been shown that even short-lasting sympathetic cardiovascular stimulation may have detrimental effects on patients with coronary artery disease. The aim of this analysis was, however, to identify the influencing factors on high catecholamine levels before induction of anaesthesia. METHODS: Various potential risk factors that could impact the humoral stress response before induction of anaesthesia were recorded in 84 males undergoing coronary aortic bypass surgery, and were entered into a stepwise linear regression analysis. The plasma level of norepinephrine measured immediately after radial artery canulation was chosen as a surrogate marker for the humoral stress response, and it was used as the dependent variable in the regression model. Accordingly, the mean arterial blood pressure, heart rate and the calculated pressure-rate product were taken as parameters of the hemodynamic situation. RESULTS: Stepwise regression analysis revealed that the oral administration of low-dose clonidine (mean dose 1.75 μg.kg-1) on the morning of surgery was the only significant predictor (p = 0.004) of the high variation in preoperative norepinephrine plasma levels. This intervention decreased norepinephrine levels by more than 40% compared to no clonidine administration, from 1.26 to 0.75 nmol.l-1. There was no evidence for dose-responsiveness of clonidine. All other potential predictors were removed from the model as insignificant (p > 0.05). The use of beta-blocker, ace-inhibitors, ejection fraction, and body mass index were significant determinants for the hemodynamic situation (heart rate, mean arterial pressure, pressure rate product) of the patient during the pre-induction period. CONCLUSION: The oral administration of clonidine is the only significant predictor for the observed variation of norepinephrine levels during the preoperative period. Lack of significant dose responsiveness suggests that even a low dose of the drug can attenuate the preoperative stress response and thus is recommended in cardiovascular high risk patients.

Journal Article↗
PubMed2004

Successful treatment of severe anaphylactic shock with vasopressin. Two case reports.

Severe anaphylactic shock is a life-threatening situation that needs immediate treatment of progressive hemodynamic failure. We report two cases of severe anaphylactic shock treated with arginine-vasopressin (AVP): In a 42-year-old male patient anaphylactic shock was caused by the sting of a hornet. At the scene, he was found unconscious, cyanotic, with a heart rate of 130/min without measurable blood pressure. The patient was intubated and ventilated with 100% oxygen, intravenous epinephrine (1 mg over 2 min) had no effect on blood pressure. After injection of 10 IU vasopressin, followed by infusion of 40 IU vasopressin, hemodynamics could be stabilized at once. In the second case, a 47-year-old male patient was stung by a wasp. At the scene he was unconscious, blood pressure was not measurable, heart rate was 140/min. The patient was treated with 40 IU vasopressin followed by rapid infusion of 500 ml NaCl 0.9%. After injection of vasopressin, blood pressure raised to 80/50 mm Hg and heart rate decreased to 90/min. Both patients needed ventilator therapy for several days and recovered fully.

Adult↗
PubMed2004

Droperidol and dolasetron alone or in combination for prevention of postoperative nausea and vomiting after vitrectomy.

PURPOSE: Droperidol and the new serotonin-3 antagonists are effective drugs for the prophylaxis of postoperative nausea and vomiting (PONV). The aim of this trial was to evaluate whether dolasetron could be a substitute for droperidol, because the Food and Drug Administration has required a Black Box warning on the droperidol package insert. DESIGN: Randomized, placebo-controlled, double-blinded trial. PARTICIPANTS: Inpatients undergoing vitreoretinal surgery (standard 3-port pars plana vitrectomy for proliferative diabetic vitreoretinopathy, complicated retinal detachment, or macular disease, such as macular pucker, macular hole, or choroidal neovascularization). INTERVENTION: Two hundred forty patients (3x80) receiving droperidol (10 microg. kg(-1)), dolasetron (12.5 mg), or the combination of both drugs administered 5 to 10 minutes before the end of surgery. CONTROL: Eighty patients received saline placebos as controls. METHODS: Standardized general anesthesia was performed, including benzodiazepine premedication, propofol, atracurium or vecuronium, desflurane in N(2)O/O(2), and a continuous infusion of remifentanil. Postoperative analgesia and antiemetic rescue medication were standardized. Episodes of vomiting, retching, nausea, and the need for additional antiemetics were recorded for 24 hours. MAIN OUTCOME MEASURES: Severity of PONV (rated by a standardized scoring algorithm) was analyzed as the main end point of the study using the Kruskal-Wallis test. RESULTS: Data of 304 patients could be analyzed. Mean severity scores in the placebo, dolasetron, droperidol, and combination groups were 1.21, 0.76, 0.47, and 0.30. Incidences of PONV of any severity were 56%, 40%, 28%, and 18%, respectively. The reduction of the incidence of PONV and its severity was statistically significant in the droperidol group and in the combination group relative to the placebo. Dolasetron alone failed to reduce the incidence of PONV. The combination of dolasetron and droperidol showed an additive antiemetic efficacy. CONCLUSION: Low-dose droperidol (10 microg. kg(-1)) but not dolasetron (12.5 mg) reduced postoperative nausea and vomiting after vitreoretinal surgery. Dolasetron (12.5 mg) is not an equivalent substitute for droperidol.

Aged↗
PubMed2004

Stress response to tracheal intubation in patients undergoing coronary artery surgery: direct laryngoscopy versus an intubating laryngeal mask airway.

OBJECTIVE: Stress response caused by endotracheal intubation may be harmful for the coronary or cerebral circulation of high-risk patients. This study evaluated the hypothesis that tracheal intubation via an intubating laryngeal mask airway is associated with less cardiovascular and endocrine stress response than the conventional technique using direct laryngoscopy. DESIGN: Randomized, patient-blinded trial. SETTING: University department (single center). PARTICIPANTS: Eighty-six patients undergoing elective coronary artery surgery. INTERVENTION: Tracheal intubation was performed via an intubating laryngeal mask or by conventional direct laryngoscopy after standardized induction of anesthesia. MEASUREMENTS AND MAIN RESULTS: Electrocardiogram with automatic ST-segment analysis and invasive measured blood pressure were recorded continuously and blood samples to analyze norepinephrine plasma levels were taken at 4 times. Catecholamine concentrations and the pressure-rate product were analyzed by using an analysis of variance for repeated measures. In both groups, the pressure-rate product (p = 0.003) and norepinephrine concentrations (p < 0.0001) significantly decreased after induction of anesthesia. However, the fall was more marked in the patients intubated via the laryngeal mask (p = 0.031) than in patients receiving direct laryngoscopy. There were neither signs of cardiac ischemia nor major adverse events during induction of anesthesia. CONCLUSIONS: Reduction of cardiovascular and endocrine stress response associated with endotracheal intubation is more pronounced when performed via the intubating laryngeal mask. Thus, this technique can be helpful in high-risk cardiac patients.

Aged↗
PubMed2004

S-ketamine and s-norketamine plasma concentrations after nasal and i.v. administration in anesthetized children.

BACKGROUND: It has been suggested that nasal administration of s-ketamine may be used to improve sedation or premedication in combination with nasal midazolam in pediatric patients. In this study we measured and compared plasma concentrations of s-ketamine and its main metabolite s-norketamine after nasal and i.v. administration in preschool children. METHODS: During sevoflurane anaesthesia, 20 children, aged 1-7 years, weight 11-25 kg, received s-ketamine 2 mg x kg(-1) either intranasally (Group IN, n = 10), or i.v. (Group IV, n = 10). Six venous blood samples were obtained up to 60 min after drug administration for measurement of s-ketamine and s-norketamine plasma concentrations. RESULTS: Plasma concentrations [mean +/- sd] of s-ketamine in group IN peaked at 355 +/- 172 ng x ml(-1) within 18 +/- 13 min vs. 1860 +/- 883 ng x ml(-1) within 3 +/- 1 min in group IV (P < 0.01). Plasma concentrations of s-norketamine in group IN peaked at 90 +/- 128 ng x ml(-1) within 50 +/- 11 min vs. 429 +/- 277 ng x ml(-1) within 40 +/- 16 min in group IV (P < 0.01). One child in group IN experienced rapid and high level s-ketamine absorption with a peak plasma concentration of 732 ng x ml(-1) after 2 min, which decreased to 274 ng x ml(-1) after 60 min. Systolic blood pressure and heart rate remained unaltered in both study groups after s-ketamine administration. CONCLUSIONS: Nasal administration of s-ketamine 2 mg x kg(-1) results in a wide spread of plasma concentrations and absorption times. Rapid and high level drug absorption after nasal drug administration is possible. The use of a pulse oximeter and continuous observation after nasal administration of s-ketamine for pediatric premedication is recommended.

Administration, Intranasal↗
PubMed2003

Premedication with nasal s-ketamine and midazolam provides good conditions for induction of anesthesia in preschool children.

PURPOSE: To evaluate the efficacy and safety of intranasally administered s-ketamine and midazolam for premedication in pediatric patients. METHODS: Ninety children were randomly allocated to receive intranasally administered s-ketamine 1 mg.kg(-1) and midazolam 0.2 mg.kg(-1) (Group K1, n = 30), s-ketamine 2 mg.kg(-1) and midazolam 0.2 mg.kg(-1) (Group K2, n = 30), or midazolam 0.2 mg.kg(-1) (Group M, n = 30) as premedicants, using a double-blind study design. Sedation and anxiolysis were evaluated using a sedation and cooperation scale and recorded at several time points. RESULTS: Acceptable conditions (K1: 23; K2: 26, M: 19) for parental separation were not different between groups. Induction conditions were acceptable in 26 patients in K2 (P < 0.05 vs M) (K1: 23; M: 19). Compared to baseline values individual conditions significantly improved in groups K1 and K2 from 2.5 min after premedication until induction of anesthesia (P < 0.003), in group M conditions improved only five minutes after premedication (P < 0.05). Adverse effects observed in this series were within an acceptable range and similar for the three groups. CONCLUSION: Intranasal administration of s-ketamine and midazolam is an appropriate premedication in preschool children.

Adjuvants, Anesthesia↗