Biomedical subjects

L Wiklund

Publications and source records attributed to L Wiklund.

At least 91 records · Page 5Linked to original sources

PubMed1995

Systemic perfusion pressure and blood flow before and after administration of epinephrine during experimental cardiopulmonary resuscitation.

OBJECTIVES: To evaluate instantaneous blood flow variations in the compression and relaxation phases of cardiopulmonary resuscitation (CPR) and the effect of epinephrine administration. DESIGN: Prospective, randomized, controlled trial. SETTING: Experimental laboratory in a university hospital. SUBJECTS: Twenty-two anesthetized piglets. INTERVENTIONS: A tracheostomy was performed and arterial, central venous, and pulmonary arterial catheters were inserted, followed by thoracotomy with placement of pulmonary arterial, aortic, and left anterior descending coronary arterial (extended study group) flow probes and a left atrial catheter. Ventricular fibrillation for 2 mins was followed by 10 mins of either open-chest (n = 10) or closed-chest (n = 12) CPR. Seven minutes after the initiation of CPR, all piglets received 0.5 mg of epinephrine iv; at 12 mins, direct current shocks were applied. MEASUREMENTS AND MAIN RESULTS: Open-chest CPR generated greater systemic perfusion pressure than closed-chest CPR, especially during the relaxation phase, resulting in greater mean blood flow. With both open- and closed-chest CPR, antegrade pulmonary arterial and aortic blood flow occurred during compression, whereas antegrade left anterior descending coronary arterial blood flow occurred during relaxation. During relaxation, retrograde flow was found in the pulmonary artery and aorta. During compression, retrograde flow was found in the left anterior descending coronary artery. The administration of epinephrine had the following effects: a) increased the systemic perfusion pressure more during open- than closed-chest CPR; b) increased the systemic relaxation perfusion pressure more than the compression perfusion pressure; c) decreased mean pulmonary arterial and aortic blood flow, but substantially increased the mean left anterior descending coronary artery blood flow; and d) reduced the retrograde flow in the left anterior descending coronary artery. CONCLUSIONS: Open-chest CPR generated greater systemic perfusion pressure and blood flow than closed-chest CPR. Epinephrine increased left anterior descending coronary artery blood flow but decreased total cardiac output, such that cerebral perfusion might be endangered. This problem will be studied separately.

Animals↗

PubMed1995

Lactate metabolism and hypocarbic hyperventilation. An experimental study in piglets.

Hyperventilation has been reported to increase blood lactate levels. Uncertainty exists as to whether high lactate levels are caused by increased peripheral release or decreased hepatic uptake. Seven piglets were investigated during controlled normoventilation and 13 piglets during controlled hyperventilation. Blood was drawn from catheters in the femoral artery and vein and in the hepatic vein. Blood flow was measured in the femoral artery by an electromagnetic flow meter and in the splanchnic area by indocyanine green extraction. In addition, repeated muscle biopsies from the hind limb and back muscles were taken. The mean PaCo2 was 5.4 in the normoventilated and 3.5 kPa in the hyperventilated group. The average hind limb oxygen uptake was the same in both groups. The arterial blood lactate concentration was significantly higher (P = 0.03) in the hyperventilated group (2.6 mmol.l-1) as compared to the normoventilated group (1.5 mmol.l-1). However, the release of lactate from the hind limb, and the muscular content of lactate were the same in both groups. Similar and unchanged skeletal muscle contents of glucose-6-phosphate, fructose-1,6-diphosphate, alpha-glycerophosphate, pyruvate, citrate and ATP were recorded in both groups. The splanchnic region did not take up or release lactate at normal PaCO2, but released lactate after 120 minutes of hyperventilation. The results indicate that the increased concentration of lactate during hypocarbic hyperventilation was not caused by an increased peripheral release from the skeletal muscles of the pig but could be caused by an altered splanchnic turn-over of lactate.

Adenosine Triphosphate↗

PubMed1995

Improved long-term preservation of the coronary vasculature with University of Wisconsin solution.

Experiments were designed to investigate coronary vascular function after prolonged cold storage of isolated rat hearts, using University of Wisconsin (UW) solution. Hearts perfused with crystalloid cardioplegic solution (Plegisol) were used as controls. After perfusion with 10 ml at 4 degrees C, hearts were stored for 1 or 10 hours in the respective solutions at 4 degrees C. To evaluate coronary vascular function after perfusion and storage, endothelium-dependent vasodilation was induced with 5-hydroxytryptamine (5-HT) and smooth muscle-dependent dilation with nitroglycerin (GTN). After perfusion only, or perfusion plus 1-hour storage, there was no intergroup difference in response to 5-HT and GTN. After 10-hour storage the vasodilatory response to 5-HT was abolished in the Plegisol group and slight vaso-constriction was observed, whereas in the UW group the vasodilatory effect of 5-HT persisted. The findings suggest that UW solution may be more favorable for prolonged cardiac preservation, as the coronary vascular reactivity was less affected.

Adenosine↗

PubMed1994

Temperature-dependent coronary reactivity after perfusion with University of Wisconsin solution in the isolated rat heart.

The purpose of this study was to determine the effects of different temperatures of University of Wisconsin solution on the reactivity of the coronary vasculature in retrogradely perfused isolated rat hearts. Hearts were perfused for 30 min at 20 degrees C or single-flush perfused at 12 degrees C and 4 degrees C. To study both endothelium-dependent and direct effects on smooth muscle, vasodilation was induced with 5-hydroxytryptamine (5-HT) and nitroglycerin (GTN). The vasodilatory effects of 5-HT and GTN during basal conditions were completely lost and instead a vasoconstriction was observed after 30-min perfusion at 20 degrees C (5-HT: 23.7 +/- 5% before to -19.2 +/- 8% after perfusion; GTN: 33.7 +/- 5.5% before and -11.9 +/- 6% after perfusion). The same response was observed after single-flush perfusion at 12 degrees C (5-HT: 26.5 +/- 5% and -6.5 +/- 3% and GTN: 35.9 +/- 6% and -11.2 +/- 4% before and after perfusion, respectively). Single-flush perfusion at 4 degrees C did not alter the response to 5-HT and GTN (5-HT: 25.9 +/- 6% and 30.4 +/- 7% and GTN: 45 +/- 5% and 32.7 +/- 7% before and after perfusion, respectively). This study suggests that the coronary reactivity after perfusion with University of Wisconsin solution is dependent of the temperature of the solution and provides good preservation of the coronary vascular function at 4 degrees C, whereas temperatures above 12 degrees C might be detrimental.

Adenosine↗

PubMed1994

Conjunctival oxygen tension is influenced by plasma and blood volume, and flow through the external carotid artery.

An investigation of the feasibility and validity of measurement of the conjunctival oxygen tension as a monitor of peripheral circulation, blood and extracellular fluid volume and cerebral circulation was carried out in 7 healthy volunteers and 5 unconscious critical care patients with proven total cerebral infarction. The healthy volunteers were subjected to changes in hydration achieved by the administration of furosemide and subsequent rehydration by administration of normal saline. Conjunctival oxygen tension was found to be a sensitive indicator of changes in the degree of hydration presumably by its ability to detect changes in peripheral circulation depending upon circulating blood and extracellular fluid volume. A drawback is that other stimuli of the sympatho-adrenergic system such as temperature and pain, interfere with measurement in the conscious volunteer. In patients with presumed total brain infarction the conjunctival PO2 cannot be used as a reliable monitor of cerebral blood flow because of varying perfusion of the palpebral conjunctiva from the external carotid artery in the occasional patient.

Adult↗

PubMed1994

The effects of different intravenous feeding regimens on the rates of synthesis of alpha1-antitrypsin after surgery.

The effects of two nutritional regimens on the synthesis of alpha-1 antitrypsin were investigated postoperatively in gynaecological cancer patients. Total parenteral nutrition (TPN) or a hypocaloric amino acid mixture was administered on the day of surgery and continued for 3 days. The rate of synthesis of alpha-1 antitrypsin was estimated by a computer model from serial plasma concentrations of this protein and a reference protein, albumin. The hypocaloric amino acid mixture resulted in a more negative nitrogen balance than that produced during administration of TPN containing the same amount of nitrogen but more non-protein energy. Urinary excretion of 3-methylhistidine was significantly greater (p = 0.017) in the hypocaloric amino acid group (350 +/- 40 mumol/day; mean +/- SE) on the third postoperative day, as compared to the TPN group (240 +/- 20 mumol/day). In spite of this the synthesis of alpha-1 antitrypsin was apparently greater in the hypocaloric amino acid than in the TPN group. The accumulated plasma appearance rate of alpha-1 antitrypsin was significantly higher (p = 0.0465) in HAA group, at 70 h it was 490 +/- 40 compared to 400 +/- 20 times the pre-operative synthesis in the TPN group.

Journal Article↗

PubMed1994

Glucose-insulin-potassium (GIK) prevents derangement of myocardial metabolism in brain-dead pigs.

Brain death is associated with neuroendocrine changes resulting in reduced myocardial glycogen content. The purpose of this study was to investigate the effects of glucose-insulin-potassium (GIK), on myocardial metabolism in brain-dead pigs. Sixteen brain-dead pigs were given GIK infusion (n = 8), or Ringer solution (n = 8). At end-point (7 h post brain death) arterial concentrations and myocardial arteriovenous (a-v) concentration differences of glucose, lactate and free fatty acids (FFA) were assessed, and myocardial biopsy specimens were taken from the right atrium and left ventricle. Biopsies were also taken from five normal pigs. Myocardial glycogen content in the GIK group was significantly higher compared to the control group, but comparable to the non-brain-dead animals. There was a higher and significant myocardial uptake of glucose and lactate in the GIK group compared to the controls. Plasma levels of FFA were significantly lower in the GIK group, and the myocardial uptake of FFA was 5 times higher in the control group compared to the GIK group. There were no significant differences in hemodynamic variables among the groups. In conclusion, intravenous supply of GIK to brain-dead pigs results in increased myocardial glycogen content and seems to prevent abnormal myocardial metabolism, which may have clinical implications for the myocardial protection of donor hearts.

Animals↗

PubMed1994

A novel anti-oxidative agent improves recovery of the heart after cardiac arrest.

Experiments were designed to determine whether adding a synthetic anti-oxidative agent H 290/51 (cis-7methyl-9-methoxy-5,5 a,6,10 b-tetrahydroindeno [2,1-b] indole), to a crystalloid cardioplegic solution was beneficial for myocardial recovery and coronary reactivity in isolated rat hearts after six hours cold arrest. Two groups of hearts were single-flush perfused using the Langendorff technique (10 ml at 4 degrees C) with either Plegisol (St. Thomas' Hospital Solution) (n = 6) or Plegisol with H 290/51 (n = 6) added to a final concentration of 1 mummol/L. The heart were then stored for six hours in the respective solution at 4 degrees C. A third group of hearts (n = 6) were single-flush with Plegisol and reperfusion was immediately started (the 'non-stored' group). Before and after the arrest phase the hearts were perfused at constant pressure with Krebs-Henseleit bicarbonate buffer. To evaluate coronary vascular function, endothelium-dependent vasodilatation was induced with 5-hydroxy-tryptamine (5-HT) and smooth-muscle relaxation with nitroglycerin (GTN). Myocardial contractility after 30 min reperfusion, measured as left-ventricular developed pressure (LVDP), was significantly improved in hearts in the Plegisol+H 290/51 group compared to hearts in the Plegisol group (LVDP 89 +/- 8.5% vs 57.2 +/- 10.7% of prearrest values; p < 0.05). LVDP in hearts receiving Plegisol+H 290/51 was comparable to non-stored hearts (88.2 +/- 1.3%). The vasodilatory response to GTN was significantly reduced in hearts perfused with plain Plegisol (p < 0.05) but not in hearts receiving Plegisol+H 290/51 or in the non-stored hearts.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

Central and regional blood flow during hyperventilation. An experimental study in the pig.

Mechanical hyperventilation not only reduces brain oedema after neurotrauma but also affects the central and systemic circulation. We have, in pigs, measured blood flow in the pulmonary artery, the portal vein and in the femoral artery, as well as estimated the splanchnic blood flow and studied the relative perfusion using the microsphere technique in normo- and hypocarbia during intermittent positive pressure ventilation. A normoventilated control group did not change in cardiac output, portal vein blood flow, splanchnic blood flow and femoral arterial blood flow. Hyperventilation was performed to a PCO2 of 3.0 +/- 0.1 kPa. We found that in pigs ventilated with high tidal volume skeletal muscle blood flow did not change during the first 60 min of hyperventilation but gradually decreased thereafter. Blood flow to the cerebellum decreased soon after the induction of hyperventilation, whereas the cerebral blood flow did not decrease until the second hour of hyperventilation. Cardiac output, splanchnic perfusion and portal vein blood flow all decreased. Myocardial perfusion and arterial blood flow to spleen and kidney decreased while pancreatic and liver arterial blood flows were unaffected. It is concluded that mechanical hyperventilation with low frequency and large tidal volumes reduces the flow to most tissues, where the relative decrease according to microsphere measurements is most pronounced in skeletal muscles, heart muscle and cerebellum. However, the changes in cardiac output and splanchnic blood flow were not observed when hyperventilation was induced by increased frequency, keeping the tidal volume constant.

Animals↗

PubMed1994

Failure of adenine nucleotide and water content of cold-stored rat livers to serve as graft viability indices for transplantation.

A study was undertaken to determine whether the cellular viability of the liver graft and posttransplantation outcome could the assessed by the graft energy status or change in water content prior to the transplantation procedure. These measurements were performed in a rat liver transplantation model. In a first set of experiments, the time for 50% survival of grafts preserved with UW solution or saline solution was determined. Grafts preserved with UW solution could be cold-stored for 19.9 h and grafted with a 50% success rate. The corresponding figure for saline-preserved grafts was 6.2 h. The energy status and water content of liver grafts preserved with UW solution for 19.9 h and livers preserved with saline solution for 6.2 h were compared. There were significant differences between livers preserved with UW solution and saline solution for ATP (p < 0.01), total adenine nucleotides (p < 0.05), ATP/ADP (p < 0.05) and energy charge levels (p < 0.05). ATP concentrations in the donor livers did not decrease significantly during cold storage when the success rate decreased from 100 to 0% after liver transplantation. The livers preserved with NaCl solution took up water during preservation. In contrast, the water content was reduced slightly in the livers preserved with UW solution and the differences were significant at all times. During cold storage using either the UW solution or saline solution for preservation, there were no significant time-related changes in the water content of the liver graft when the posttransplantation success rate decreased from 100 to 0% after liver transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenine Nucleotides↗

PubMed1994

Oculomotor and nystagmus tests in subjects with strabismus.

Smooth pursuit (SP) and saccades (SC) as well as nystagmus were recorded with electro-oculography in 21 healthy subjects with manifest non-paralytic strabismus. A normal SP function under binocular conditions could be recorded in 67% of the subjects and complementary monocular recordings increased the figure to 81%. The corresponding figure for the SC test was 38 and 67%, respectively. However, a minority of the subjects presented a normal test result under both binocular and monocular conditions. Spontaneous nystagmus and/or nystagmus after headshaking was present in 67%. These findings may indicate that subjects with strabismus have a combination of a 'subclinical' vestibular and oculomotor dysfunction.

Ear Diseases↗

PubMed1994

Mononuclear cells from dogs with acute lung allograft rejection cause contraction of pulmonary arteries.

PURPOSE: Experiments were designed to determine whether or not leukocytes activated by acute pulmonary rejection cause contractions of isolated pulmonary arteries. METHODS AND RESULTS: Separate suspensions of (a) polymorphonuclear cells (> 95%) and (b) mononuclear cells (85% lymphocytes/10% monocytes/5% polymorphonuclear cells), respectively, were obtained from the arterial blood of four groups of adult male mongrel dogs: unoperated dogs (controls), dogs with single-lung autotransplants, dogs with rejecting single-lung allotransplants, and unoperated dogs treated with the same immunosuppressants as allotransplanted dogs. These suspensions were added to rings of control intralobar pulmonary arteries suspended in organ chambers for measurement of isometric force. The endothelium was removed mechanically from selected rings. No significant change in basal tension of pulmonary arterial rings occurred by adding suspensions of polymorphonuclear cells from any of the four groups of dogs. Significant cell-number-dependent increases in tension occurred with suspensions of mononuclear cells from unoperated dogs, autotransplanted dogs, and unoperated, medicated dogs. These increases in tension were less in rings with compared to those without endothelium. Addition of a synthetic analogue of L-arginine abolished this difference. Suspensions of mononuclear cells from rejecting allotransplanted dogs caused significantly greater contractions in rings with endothelium than those observed with suspended cells from either unoperated, autotransplanted dogs or unoperated, medicated dogs. Addition of superoxide dismutase plus catalase or an antagonist of endothelin-A receptors (BQ-123) reduced contractions in rings with endothelium but not in those without endothelium to suspensions of mononuclear cells from rejecting allotransplanted dogs. CONCLUSIONS: The results of this study suggest that mononuclear cells cause contraction of pulmonary arteries, which can be partially inhibited by endothelium-derived nitric oxide. However, if the mononuclear cells are activated by acute pulmonary rejection, contractions are no longer inhibited by the endothelium. Under conditions of rejection, contractions are mediated in part by oxygen radicals and endothelin(s).

Animals↗

PubMed1994

The efficacy of oxymetazoline administered with a nasal bellows container and combined with oral phenoxymethyl-penicillin in the treatment of acute maxillary sinusitis.

The efficacy of a new administration form of oxymetazoline, a nasal bellows container, was investigated in two separate studies by means of a combined treatment with phenoxymethyl-penicillin for acute maxillary sinusitis. In the first study (study 1), oxymetazoline administered with a bellows (OXBE) was compared both with a placebo belows (PLBE) as well as with oxymetazoline and placebo administered with a conventional nasal spray (OXSP respective PLSP) in 73 patients. In the second study (study 2), OXBE was compared only with PLBE in 48 patients. Objective evaluation was made by comparing the radiographical improvement in conventional plain sinus X-ray images. A scoring system corresponding to the outcome of antral irrigation was used for evaluating the X-ray pictures. Subjective symptoms; nasal stuffiness and pain, were assessed by registrations on visual analogue scales. Neither with regard to radiographical improvement nor to decrease in subjective symptoms could any significant differences be found between the different treatment modes. Oxymetazoline administered with a nasal bellows thus did not accelerate the rate of healing of acute maxillary sinusitis in these two studies. It is inferred from these results that decongestion of the sinus ostia is not of primary importance for the course of healing of a manifest acute sinusitis.

Acute Disease↗

PubMed1994

Chordal tissue in endomyocardial biopsies.

The incidence of chordal tissue in endomyocardial biopsies from heart transplant recipients and the possibility of an association between this incidence and tricuspid regurgitation or tricuspid valvular abnormalities were prospectively investigated. The biopsies were performed to detect rejection. Postoperative echocardiography and Doppler were done according to routine schedule and always when chordal tissue was found histologically, for specific evaluation of the tricuspid valve function. Chordal tissue was detected in 24 of 1,265 bites at 206 biopsies during the study period. Echocardiographically there was no significant increase in tricuspid regurgitation and no major valvular abnormality in any patient after biopsy showing chordal tissue. The presence of chordal tissue in biopsy specimens implies that the tricuspid valve is potentially at risk in biopsy. Our results, however, also showed that occasional capture of chordal tissue by the bioptome did not necessarily result in tricuspid valve dysfunction.

Adolescent↗

PubMed1994

Effects of alkaline buffers on cytoplasmic pH in lymphocytes.

OBJECTIVE: To study experimentally possible adverse effects of bicarbonate on cytoplasmic pH. DESIGN: Open, randomized control trial of white blood cells from human volunteers. SETTING: Experimental laboratory in a large university hospital. SUBJECTS: Lymphocytes prepared from human blood. INTERVENTIONS: The fluorescent intracellular probe 2',7'-bis-(carboxyethyl)-5,6-carboxyfluorescein acetoxymethyl ester (BCECF-AM) was used to study the influence on cytoplasmic pH after the addition of different alkaline buffers to lymphocytes with normal as well as decreased initial intracellular pH. MEASUREMENTS AND MAIN RESULTS: In normal lymphocytes, sodium bicarbonate caused a marked, dose-dependent acidification of the cytoplasm followed by a slow, often unpredictable increase. Ringer's acetate solution decreased the intracellular pH dose-dependently this acidification effect continued throughout the measurements. In contrast, trometamol (tris) and Carbicarb both caused a pronounced dose-dependent and lasting alkalinization of the cytoplasm. Tris buffer mixture (Tribonate) produced a slight initial dose-dependent acidification, followed by a slow increase in cytoplasmic pH to values above those recorded during control measurements. Lymphocytes that were preincubated in acetate showed similar results after addition of tris buffer mixture or sodium bicarbonate. Lymphocytes with intracellular acidosis due to preincubation in an acid buffer demonstrated a more pronounced and dose-dependent decrease of cytoplasmic pH immediately after addition of the bicarbonate-containing buffers (sodium bicarbonate and tris buffer mixture). The decrease was only partly compensated for over the next 10 mins. Only the buffers that were not producing CO2 could fully compensate for the severe extra- and intracellular acidosis imposed on the lymphocytes by preincubation in an acid medium. CONCLUSION: Use of bicarbonate-containing buffers often results in an initial decrease of cytoplasmic pH.

Buffers↗

PubMed1994

Education of specialists in anaesthesia and intensive care in Europe--A Swedish perspective.

Sweden as well as most other countries in western Europe are parts of a common labour market where free movement of the labour force is encouraged. As in all recognised specialties of medicine, most national Anaesthesia societies or colleges have joined the Specialist Committee of the Union Européenne des Médicins Spécialistes (UEMS) as well as the European Board of Anaesthesiology in a joint European effort intended to promote the highest possible standard in the practice of Anaesthesia and Intensive Care throughout the European Union and the European Economic Space. Education of specialists in our field of medicine is considered one of the top priorities in this process. The European Academy of Anaesthesiology is working together with these organisations and is offering the specialist organisations or colleges in Europe to take part in their specialist examination, hospital recognition programme and in-training examinations. Our country, among others, has adopted the European Diploma of Anaesthesiology and Intensive Care as the national examination for future specialists in our discipline.

Anesthesia Department, Hospital↗

PubMed1993

A new respiratory rate monitor: development and initial clinical experience.

The need for continuous, noninvasive, and reliable respiratory rate monitoring during recovery from general anesthesia has long been recognized. Alternative principles can be grouped into those detecting the respiratory effort, and those detecting the actual result, i.e. the respiratory gas flow. The second category is of greatest interest for patient monitoring. In this paper, we report the development and initial clinical experience with a new acoustic air-flow sensor. By differential, multipoint detection of the air-flow in the mouth and nose region, the sensor can easily discriminate against different kinds of interference, including motion artefacts. The sensor is nonexpensive, rugged, simple to apply and inherently safe. An instrument with continuous display of respiratory rate, and an audiovisual apnea alarm has been designed and built. The complete system has been tested on patients during recovery after general anesthesia. In 16 patients, the respiratory rate displayed by the instrument has been correlated against that visually observed. A good correlation was obtained. Minor discrepancies can be explained from the fact that visual observation corresponds to the respiratory effort, whereas the sensor detects the actual air flow. In 12 patients, 24 hour simultaneous recordings were made of respiratory rate with the new sensor, with simultaneous recording of the oxygen saturation and the heart rate with a pulse oximeter. It was found that the new sensor reliably recorded respiratory depression and apnea. Such events may in some patients be as frequent as one incident per hour. One case of 'Ondine's curse' provided clear evidence that pulse oximetry has a low sensitivity to respiratory disorders.

Adult↗

PubMed1993

Pathophysiologic and therapeutic implications of acid-base changes during CPR.

Acid-base changes occurring during cardiac arrest and subsequent CPR are related to a complex low-perfusion state characterized clinically by venous and tissue hypercarbic and metabolic (lactic) acidosis. This low-flow state is a dynamic process dependent on the time intervals between onset of arrest, initiation of CPR, and restoration of adequate spontaneous circulation. Increased release of CO2 from ischemic tissues and reduced CO2 transport from the tissues to the lungs result in profound tissue acidosis. However, recent experimental data suggest that even very low pH is compatible with neurologically intact survival. Thus, the clinical use of buffer agents, and especially of sodium bicarbonate, is currently controversial. Because results of controlled clinical studies are not available, a careful review of well-performed experimental studies is necessary. So far, the use of either CO2-generating or CO2-consuming buffers has not been proved conclusively to increase neurologically intact long-term survival after CPR. More importantly, adequate ventilation and effective chest compressions must be quickly established after cardiac arrest. This will counterbalance the hypercarbic and metabolic acidemia of cardiac arrest by creating concurrent hypocarbic arterial alkalemia during at least the early phase of CPR. Thus, the treatment of the complex acid-base changes associated with CPR is based primarily on the classical maneuvers of A and B (airway and breathing = adequate oxygenation and ventilation), C (chest compressions), and D (early defibrillation for rapid restoration of spontaneous circulation). In cases of prolonged cardiac arrest or preexisting metabolic acidemia, buffer therapy may be indicated.

Acid-Base Imbalance↗