Georg Petroianu

Control of blood pressure, heart rate and haematocrit during high-dose intravenous paraoxon exposure in mini pigs

A therapeutic regimen was established to keep blood pressure, heart rate and haematocrit within the normal range during high‐dose paraoxon (PX) exposure (ca. 150 × ld50) in mini pigs in order to achieve survival. Previous experiments showed that mini pigs exposed to high‐dose PX died shortly after PX infusion due to hypertension, tachycardia and increased haematocrit if no antihypertensive and fluid therapy was initiated. Therefore, antihypertensive and fluid therapy with magnesium (MgSO4) and Ringers solution was established to keep the blood pressure, heart rate and haematocrit within a pre‐established normal range.

Idiopathic chronic hiccup: combination therapy with cisapride, omeprazole, and baclofen

Idiopathic chronic hiccup (ICH) is defined as recurring hiccup attacks that last for longer than an arbitrary time limit (eg, 1 month) and for which no organic cause can be found. In patients with ICH, therapy is largely empiric. For practical purposes, idiopathic hiccup can be assumed to have its origin either in the viscera (gastrointestinal tract) or in the central nervous system. Cisapride and omeprazole--through reduction of gastric acid production and facilitation of gastric emptying, respectively--are thought to reduce an assumed afferent input from the periphery to a putative supraspinal hiccup center. Baclofen is thought to reduce excitability and depress reflex hiccup activity. Fifteen male patients (mean [+/- SD] age, 68.2 +/- 11.6 years) who had recurring hiccup attacks for a mean duration of 100.8 +/- 134.1 months (range, 12 to 564 months) were treated for ICH with a combination of cisapride, omeprazole, and baclofen (COB). Therapy led to a total disappearance of hiccup in 40% (6 of 15) of the treated patients. An additional 20% (3 of 15) of patients experienced substantial relief. A Mann-Whitney rank order test showed a highly significant reduction in the severity of the hiccup attacks as reflected in the subjective assessment scale scores taken before therapy (8.6 +/- 1.3) compared with those taken after 20 weeks of therapy (4.1 +/- 3.8). Thus we concluded that COB is an effective empiric therapy in at least some patients with ICH.

Der Mallampati-ScoreVorhersage der schwierigen Intubation in der HNO-Laserchirurgie mittels Mallampati-Score

ZusammenfassungDer Mallampati-Score ist eine gebräuchliche Methode zur Vorhersage der schwierigen Intubation. Wir testeten seine Validität in der HNO-Laserchirurgie. Methoden: Bei 91 Patienten, die sich einem geplanten laserchirurgischen Eingriff in der HNO unterziehen mußten, wurde unmittelbar vor der Narkoseeinleitung der Mallampati-Score in der Modification nach Samsoon u. Young [18] ermittelt. Nach Narkoseeinleitung wurde die laryngoskopische Sicht nach Cormack u. Lehane [5] beurteilt. Es wurde untersucht, inwieweit ein Mallampati-Score ≥3 eine schwierige Intubation (d.h. einen Cormack u. Lehane-Grad ≥3) vorhersagt. Ergebnisse: 62 Patienten hatten einen Mallampati-Score ≤2. Von diesen hatten 4 (=6%) einen Cormack u. Lehane-Grad ≥3.29 Patienten hatten einen Mallampati-Score ≥3. Von diesen hatten 6 (=21%) einen Cormack u. Lehane-Grad ≥3. Schlußfolgerung: Dieser Unterschied war signifikant im χ2-Test (p<0,05). Patienten mit einem Mallampati-Score ≥3 waren also signifikant häufiger schwierig zu intubieren. Niedrige Sensitivität (60%) und Spezifität (72%) begrenzen jedoch den praktischen Wert des Tests.AbstractThe Mallampati score (MS), later modified by Samsoon and Young, is a common method used to predict difficult intubation. We tested its predictive value in otolaryngologic (ENT) laser surgery. Methods: Ninety-one patients scheduled for elective ENT laser surgery had the modified MS noted prior to induction in the supine position, with the tongue fully protruded and phonating ”ah”; 22 patients were female, 69 male. The mean age was 54±15 (6–84) years, height 171±9 (130–190) cm, and weight 72±21 (20–99) kg. After a standard induction, the laryngoscopic view was graded according to Cormack and Lehane (C&L). An intubation was considered difficult if the C&L score was ≥3, i.e., no part of the glottis seen during laryngoscopy. The hypothesis tested was that a MS ≥3 (i.e., only the base of the uvula or nine of the uvula was seen) is predictive of difficult intubation in this group of patients. This chi-square test was used for calculation of significance. Results: All intubations were performed in less than three attempts, and no C&L score of 4 (i.e., not even the epiglottis seen during laryngoscopy) was observed; 10 patients had a C & L score ≥3, i.e., a difficult intubation according to our definition. Sixty-two patients had a MS ≤2; of these, 4 (=6%) were difficult to intubate. Twenty-nine patients had MS ≥3; of these, 6 (=21%) were difficult to intubate. This difference was significant (chi-square=4.1, P<0,05). Conclusion: Difficult intubation was significantly more common in patients with MS ≥3. Low sensitivity (60%) and specificity (72%) limit the clinical value of this test, however.

Phospholipase A2-induced coagulation abnormalities after bee sting

We will examine the correlation between various bee venom phospholipase A2 (PLA2) concentrations and several parameters of coagulation in human plasma in order to offer a rationale for requesting a particular laboratory coagulation test after bee sting(s). We will also evaluate in vitro the influence of clinically available drugs with a noncompetitive inhibitory effect on PLA2 on the anticoagulant effect of bee venom PLA2. Prothrombin index (PTi), partial thromboplastin time (PTT), antithrombin III (AT III), soluble fibrin monomers (SFM), the activity of coagulation factors I, II, V, and VIII, and thrombelastography (TEG) parameters (split point [Sp], reaction time [R], kinetic time [K], coagulation time [R + K], maximal amplitude [MA], and the growth angle [alpha]) were determined before and after addition of 1.4, 2.7, and 4.1 units (1, 2, and 3 microg protein respectively) of bee venom PLA2. Linear regression was used to determine the significance of the relationship between these coagulation parameters and bee venom PLA2 concentrations used. To study the influence of ketamine, lidocaine, magnesium, furosemide, and cromolyn on the anticoagulant effect of bee venom PLA2, PTi and factor II- and V-activities were measured before and after addition of 2.7 units of PLA2 and PLA2 plus one of the tested substances. Determinations of F II, PTi, F V, and F VIII showed a negative correlation to bee venom PLA2 concentration (r = -0.88, -0.86, -0.81, and -0.79 respectively). A positive correlation was found for PTT (r = 0.69). FII- activity and PTi correlated better with bee venom PLA2 concentration than other parameters. F I, AT III, and SFM showed no changes. Whereas Sp, R, and K were prolonged by bee venom PLA2 and a was reduced, there was no correlation to the PLA2 concentration. Addition of none of the 5 substances could correct the effects of bee venom PLA2 on the coagulation. In a patient with toxic reaction or a severe anaphylactic reaction after bee sting(s) we suggest determinations of FII and/or PTi. This will allow a quick and economical assessment of coagulation abnormalities after bee sting(s). Noncompetitive PLA2-inhibitors (ketamine, lidocaine, magnesium, furosemide, and cromolyn) are unable to correct in vitro the anticoagulant effect of bee venom PLA2. They cannot be recommended at this stage for this purpose. Further investigations with competitive PLA2-inhibitors are warranted.

A randomized, controlled trial of the efficacy of closed chest compressions in ambulances

OBJECTIVE To examine the feasibility of closed chest compressions in ambulances. METHODS Ten male emergency medical technicians performed closed chest compressions on a Laerdal Skillmeter Resusci Anne placed 1) on the ground, 2) on the stretcher of an MB 510 ALS ambulance, 3) on the stretcher of an MB 310 ambulance, and 4) on the stretcher of a VW T4 BLS ambulance for 2 minutes each. The authors noted the percentage of correct compressions as shown by the mannequin and counted the heart rate of the participants before and after each session. The authors compared the percentage of correct compressions and the increase in heart rate during the three ambulance sessions with those of the session on the ground by rank order test for paired observations. A p < 0.05 after Bonferroni correction (factor 3) was considered significant. RESULTS The percentage of correct compressions was 90% +/- 7% on the ground, 77% +/- 19% in the MB 510, 60% +/- 31% in the MB 310, and 38% +/- 24% in the VW T4. Heart rate increase was 18 +/- 16 min-1 on the ground, 23 +/- 9 min-1 in the MB 510, 30 +/- 16 min-1 in the MB 310, and 32 +/- 13 min-1 in the VW T4. Only the difference in percentage of correct compressions between on the ground and the VW T4 was significant (p < 0.01 after Bonferroni correction). CONCLUSIONS The percentage of correct compressions in all the vehicles tested was lower when compared with the percentage on the ground, and the increase in heart rate was higher. Only one of these results was statistically significant. A further study with more participants seems warranted.

Präklinische Kontrolle von Tubuslage und Beatmung

ZusammenfassungDie ösophageale Tubusfehllage zählt zu den häufigen Ursachen schwerer Narkosezwischenfälle. Sie ist heute durch Kapnographie zuverlässig entdeckbar, Zwischenfälle sind daher prinzipiell vermeidbar. Da die quantitative Kapnometrie im Rettungsdienst (noch) nicht verfügbar ist, bleibt das Problem der Erkennung einer ösophagealen Tubuslage im präklinischen Bereich weiterhin akut. Im Tierversuch wurden 3 Geräte getestet, die zur präklinischen Überprüfung der Tubuslage eingesetzt werden: 1. CO2-unabhängiges „Öesophageal Detector Device“ nach Pollard und Wee, 2. Semi-quantitatives chemisches Einmalkapnometer EasyCAP (Nellcor, Idstein), 3. Nicht-quantitatives Miniaturinfrarotkapnometer MiniCAP III (MSA, Pittsburgh). Möglichkeiten und Grenzen der Geräte sowie Literatur hierzu werden diskutiert.AbstractOesophageal malposition of an endotracheal tube is among the leading causes of anaesthesia incidents. While clinical manoeuvres for detection of tube malposition are unreliable, monitoring (i.e. capnography) can prevent such incidents. The problem is particularly important in prehospital care, where capnography is not (yet) widely available. We tested three devices used for differentiating oesophageal from endotracheal intubation: 1. Non-CO2dependent Oesophageal Detector Device (ODD) as described by Pollard and Wee, 2. Semi-quantitative chemical disposable capnometer EasyCAP (Nellcor), 3. Non-quantitative infrared miniaturised capnometer MiniCAP (MSA). Methods. 50 anaesthetised minipigs were intubated with a Magill tube. An identical additional tube was placed in the oesophagus. The cuffs of both tubes were inflated. Unexperienced personel (students, laborary technicians) were asked to determine the position of one of the tubes by using one of the devices according to the randomisation plan. The decision had to be taken within 30 s. Using the ODD, the proband first injected 100 ml air into the lung (or stomach) and then tried to aspirate the same volume. EasyCAP and MiniCAP were used according to manuals. Results. Each device was used 25 times with a tracheal tube and 25 times with an oesophageal tube. All tube position identifications were correct. When ventilating the oesophagus/stomach for capnometric control, regurgitation into the tube occurred six times (five times with the EasyCAP and once with the MiniCAP). In these cases, the decision was based on this occurrence and not on the display of the device. While using the ODD no regurgitation occurred. Conclusion. These devices are useful for preclinical practice. According to the literature and our experience, the ODD is superior for the initial control of tube position, especially in cardiac arrest. Capnometry is needed, however, for continuous control of ventilation.

The Mallampati Score. Prediction of difficult intubation in otolaryngologic laser surgery by Mallampati Score

ZusammenfassungDer Mallampati-Score ist eine gebräuchliche Methode zur Vorhersage der schwierigen Intubation. Wir testeten seine Validität in der HNO-Laserchirurgie. Methoden: Bei 91 Patienten, die sich einem geplanten laserchirurgischen Eingriff in der HNO unterziehen mußten, wurde unmittelbar vor der Narkoseeinleitung der Mallampati-Score in der Modification nach Samsoon u. Young [18] ermittelt. Nach Narkoseeinleitung wurde die laryngoskopische Sicht nach Cormack u. Lehane [5] beurteilt. Es wurde untersucht, inwieweit ein Mallampati-Score ≥3 eine schwierige Intubation (d.h. einen Cormack u. Lehane-Grad ≥3) vorhersagt. Ergebnisse: 62 Patienten hatten einen Mallampati-Score ≤2. Von diesen hatten 4 (=6%) einen Cormack u. Lehane-Grad ≥3.29 Patienten hatten einen Mallampati-Score ≥3. Von diesen hatten 6 (=21%) einen Cormack u. Lehane-Grad ≥3. Schlußfolgerung: Dieser Unterschied war signifikant im χ2-Test (p<0,05). Patienten mit einem Mallampati-Score ≥3 waren also signifikant häufiger schwierig zu intubieren. Niedrige Sensitivität (60%) und Spezifität (72%) begrenzen jedoch den praktischen Wert des Tests.AbstractThe Mallampati score (MS), later modified by Samsoon and Young, is a common method used to predict difficult intubation. We tested its predictive value in otolaryngologic (ENT) laser surgery. Methods: Ninety-one patients scheduled for elective ENT laser surgery had the modified MS noted prior to induction in the supine position, with the tongue fully protruded and phonating ”ah”; 22 patients were female, 69 male. The mean age was 54±15 (6–84) years, height 171±9 (130–190) cm, and weight 72±21 (20–99) kg. After a standard induction, the laryngoscopic view was graded according to Cormack and Lehane (C&L). An intubation was considered difficult if the C&L score was ≥3, i.e., no part of the glottis seen during laryngoscopy. The hypothesis tested was that a MS ≥3 (i.e., only the base of the uvula or nine of the uvula was seen) is predictive of difficult intubation in this group of patients. This chi-square test was used for calculation of significance. Results: All intubations were performed in less than three attempts, and no C&L score of 4 (i.e., not even the epiglottis seen during laryngoscopy) was observed; 10 patients had a C & L score ≥3, i.e., a difficult intubation according to our definition. Sixty-two patients had a MS ≤2; of these, 4 (=6%) were difficult to intubate. Twenty-nine patients had MS ≥3; of these, 6 (=21%) were difficult to intubate. This difference was significant (chi-square=4.1, P<0,05). Conclusion: Difficult intubation was significantly more common in patients with MS ≥3. Low sensitivity (60%) and specificity (72%) limit the clinical value of this test, however.

L-lactate protects in vitro acetylcholinesterase (AChE) from inhibition by paraoxon (E 600).

Intoxication with the organophosphorus compound paraoxon (POX), an inhibitor of serine hydrolases, is frequent. Oximes are the only enzyme reactivators clinically available. Recent work has shown that lactate is able to reduce in vitro the POX effects on butyrylcholinesterase (BChE). Most of the acute clinical symptoms, however, are caused by inhibition of acetylcholinesterase (AChE). Effects of lactate on the inhibition of AChE by POX were assessed in vitro in plasma of 12 (six male, six female) healthy human volunteers. The determinations were repeated using different lactate and different POX concentrations.

L-lactate reduces in vitro the inhibition of butyrylcholinesterase (BChE) by paraoxon (E 600).

Intoxication with the organophosphorus compound paraoxon (POX), an inhibitor of serine hydrolases, is frequent. Oximes are the only enzyme reactivators clinically available. Serendipitous observation led us to the hypothesis that lactate might attenuate some of the POX effects. In vitro effects of lactate on the inhibition of butyrylcholinesterase (BChE) by POX were assessed in plasma of 12 healthy human volunteers. The determinations were repeated using different lactate and different POX concentrations. The BChE activity determinations were performed in the following settings:baseline untreated plasma (BL); ii after addition of POX to plasma (pl+POX); iii after POX and plasma were incubated and then lactate was added (pl+POX/lact); iv after addition of lactate to plasma (pl+lact); v after lactate and plasma were incubated and then POX was added (pl+lact/POX); vi after lactate and POX were incubated and then added to plasma (lact+POX/pl).In the micro‐ and millimolar ranges, lactate is able to abolish in vitro the inhibition of BChE by POX in human plasma when added to plasma prior to POX or when incubated with POX prior to addition to plasma. Lactate added to plasma after POX has no protective effect. In a second set of experiments, the effect of lactate on BChE activity was determined. At high millimolar concentrations, lactate itself inhibits BChE to an extent comparable to POX. Lactate is a mixed inhibitor of BChE, being able to interfere with the enzyme–substrate complex (inhibition constant for the enzyme–inhibitor–substrate complex K I (EIS)<<< WCODE [220] >>>rb<<< WCODE [220] >>>ee = 81 mM) and the enzyme (inhibition constant for the enzyme–inhibitor complex K I (EI) = 26 mM). Copyright

Intubation with transillumination: nasal or oral?

Transillumination-guided intubation is a useful back-up method when laryngoscopic intubation proves to be difficult or impossible. The Trachlight (Laerdal, N-4001 Stavanger, Norway) is suited for both nasal and oral use. Intubation times (IT) and success rates (SR) for nasal and oral intubation with the Trachlight were compared. Twenty-four medical students, inexperienced in intubation were instructed in the use of the Trachlight. A demonstration also was performed. Subsequently, they were asked to intubate a Laerdal Airway Management Trainer (Laerdal, Stavanger, Norway) using the Trachlight. Each student intubated 10 times orally and 10 times nasally (five times through the right and five times through the left nostril). The succession of the students was randomized. The intubation times were measured and the position of the tube noted. Nasal and oral intubation times for the tenth trial (steady state conditions) were compared using the rank-order test for paired observations. Oral and nasal success rates were compared using the sign test for paired observations. The differences between nasal and oral intubation concerning intubation time and the success rates were not significant. Nasal intubation with the Trachlight seems to be more difficult than the oral intubation.